System Approach to 3DCP: Profitability through Process Optimization


A severe labor shortage and rapid urbanization have created a growing need for construction automation. Various tools and methods such as Digital construction, prefab, and 3DCP (3D Concrete Printing) are available for automating construction activities. These tools were invented decades ago, but 3D-Printed homes have become popular in recent years. Around the world, few builders are implementing 3DCP for the construction of houses and small buildings. Due to the cost of material and production issues, 3D printing houses is still not profitable. The public excitement has facilitated initial sales, but the early adopters are struggling to make an ROI (Return on Investment). This lack of profitability force prospective construction companies to turn away from the technology. A new technology to become mainstream, a critical adoption rate must be reached. If not, investments will dry out and the technology may get phased out. Construction automation is a pioneering field, there is no clear path to profitability. Most, if not all, early adopters of 3DCP are not making an ROI. The current automation practice is inefficient, process optimization could be a way to make 3DCP cost-competitive.

Automation was first introduced by the manufacturing sector, over the years various methodologies were used to improving the efficiency of automation. According to a 2020 McKinsey & company report, manufacturing productivity increased by 60% in last 25 years. It was the result of various improvements made in the process design (eg: Lean, SCM etc.) – robots are used for automating a process. As productivity increased, manufactured goods became cheaper. In contrast, construction productivity grew by 1% year over year for last two decades. The cost of construction is also going up. The current construction process is not compatible with automation. Since construction requires the coordination of different activities, automating it becomes complex. The construction automation companies often overlook the complex nature of the construction process. This is a reason for the high cost of 3D printed construction. Construction 3D printers are expensive, to make the initial investment worthwhile, utilization of the machines should be maximized. For this, the construction process should be optimized. There are various engineering methodologies available for optimizing processes. Systems engineering is a field of engineering that deals with the management of complex processes. System Approach is a methodology in systems engineering that can be applied to manage complex processes like construction.

System Approach to Automated construction

Systems engineering is an interdisciplinary field of engineering and engineering management that focuses on how to design, integrate, and manage complex systems over their life cycle. Some terminologies are;

System: A system is the set of principles or procedures according to which a process is done – the construction process is a system.

Sub-system: Individual elements of a system that work together to create the system

System Approach addresses one problem by considering the whole picture; the problem will be analyzed in its environment. The construction process (system) includes various activities (sub-systems) such as site work, foundation, MEP, and all other related jobs. Applying automation without considering the interfaces between these sub-systems makes the process more complex and costly. This is a major reason for the production issues faced by the early adopters of 3DCP. This article discusses the application of system approach for the development of a new construction procedure that leverages multiple automation techniques. 3DCP and prefab are two construction automation methods with complementing characteristics. A process that integrates the elements of both methods could be an optimized construction process. The management and control of such a process can be handled by leveraging digital construction tools. Integration of 3DCP, Prefab and digital construction into a single construction project will be a complex endeavor. Systems approach can be apt for developing this kind of complex process. Figure 1 illustrate the different phases of System Approach to 3DCP, in the following sections, the various phases are discussed in detail.

Figure 1: System Approach Phases

Analyze: Know your problem inside out

System Approach to automated construction is an orderly process that starts with an analysis phase. The main activity during this phase is conducting a comprehensive study on the construction process and automation techniques. The objective is to identify the opportunities for automation and predict its effects on the overall productivity of construction.  

Implementation of new technology is challenging. To develop an automated construction process, the capabilities and limitations of the technology should be understood. The objective of the analysis phase is to collect as much information as possible. It will require deep and exhaustive research into problems and solutions. Some outcomes of analysis into 3DCP would be.

  • Different 3DCP machines and printing mixes will be compared on price and properties. This will help to identify the most economical and robust system that can be implemented.
  • Printing strategies like in-situ and print to assemble will be analyzed on their practical and economic benefits. The strategy with the best economics will be selected.
  • The effects of 3D- Printed wall systems on other related works such as MEP or Finishing will be studied, all possible challenges and available options will be listed out.

The above list is not comprehensive, the analysis will cover all topics related to the construction process. This comprehensive study will help to identify the complementarity of various practices and technologies. Building a house or other structures involves 3rd party inspections and permits. The data collected for the analysis phase will help educate the 3rd parties and authorities about the viability and security of the automation processes. More data will help to substantiate the claims in front of permitting/licensing authorities. By the end of the first phase, all stakeholders in a construction project and their interests will be identified. To improve productivity a collective effort of all stakeholders is necessary. System approach to construction automation is an attempt to bring process improvement by creating harmony between various activities on and off the construction field.

Design Phase: An overview of the solution

The analysis phase will be followed by a Design phase. During this phase, a construction process that utilizing automation will start to take shape. The specifications and scope of the process will be decided in this phase of system approach. The design of the system will contain the following elements.

  • The Objectives: Based on the information gathered during the analysis phase, the goals of the new system will be decided. It will be a high-level description, for example, the objective of the system can be constructing a custom-designed house in 6 weeks and at a cost 30% cheaper than to traditional process.
  • The process diagram: A high-level diagram showing major subsystems and the process flow. Process diagram will provide a system-level understanding of various interfaces in the system.
  • A brief description of the process: The design should contain a high-level description of the process and the inter-relations between various sub-systems. This description will be the written form of the process diagram. It should also mention the method of implementation.
  • Success factors: A criteria for evaluation of the process should be decided at this phase. The system must satisfy a set of minimum requirements to be considered viable. Success factors can be revisited at any point to evaluate the progression of the system approach.

By the end of the design phase, a rough picture of the final system will be generated. In the next phase, this high-level design will turn into a detailed construction procedure.

Develop: How to achieve the objectives?

In the development phase, a detailed construction process will be created; detailed procedure describing the start to finish of the construction process. The skeleton from the design phase will provide the guideline for this phase. Developing the system requires a wide range of expertise in various construction activities. The systems engineer should know about construction 3D printing, conventional construction, structural and architectural design, and all other activities. During this phase, all the details of the automated construction process will be finalized. The development process involves the following.

  • Selection of the technologies and machines required for the construction job.
  • Necessary licenses and contracts will also be secured.
  • Development of new construction practices – if required
  • Creation of the procedure for the construction process.
  • Identification of the risk factors in the process and risk mitigation measures.
  • Calculating all required resources and planning their allocation.
  • Creation of required standards and performance measuring criteria.
  • Creation of training for all the stakeholders.

People involved in the development process should have a broad knowledge of various construction automation techniques. The development team should be both optimistic and skeptical during the development process. The team should include a skeptic of construction automation. This will help to identify the risk factors in the process. As the development progress, the original design may get changed. The initial understanding of the technologies may change and goals will have to be adjusted. Developing a system consist of various technologies is demanding. The efficiency of workflow in such a system will depend on the smoothness of the interfaces between various subsystems. Achieving this smoothness is the primary function of system approach. A construction project can be finished in multiple ways, but to create profitability the process should be as efficient as possible. Things may not go as planned when implementing new technology, multiple iterations may be required to find the right way of doing things. Multiple validations and revisions should be carried out during the development phase; correcting a mistake during development is easier than doing it during implementation.

Implement: time to break the ground

 In this phase, the plans created in the development phase will be excicuted. Even though this article is mainly discussing 3DCP, the scope of systems approach to automated construction includes everything from architectural design to completing the house. The first step in the implementation is implementing the required training. All the stakeholders should be capable to perform the respective duties at the efficiency required by the system design.  

Innovative design is often overrated and the difficulties of producing the design are overlooked. Production phase is the most demanding phase of innovation. Similarly in the system approach, previous phases were just conducting research and making calculations. But during implementation, the plans should be executed according to the calculations. Even in conventional construction, it is hard to execute every aspect of the project according to the plan. Most construction projects will burn more cash than the initial budget. Unexpected delays and problems are the nature of building construction, during the implementation of new technology these problems can get worse. The efficiency of the system approach will be decided by the performance of the designed system during the implementation phase. The different automation tools such as 3DCP and Digital construction must perform in real-world conditions. One important thing is to make records of the actual performance of the construction process. The records are made for each activity and technology used in the process. This documentation is important for improving the System Approach. Even after extensive research and planning there is a good chance for the process to be flawed. The initial projects will testify for the efficacy of the system approach, failure to achieve the objectives are indication of mistakes in the previous phases. Since it is the early days of construction automation, the projects can be plagued with unplanned problems. If a building project cannot be finished as per the plan, the plans may have to be changed in the middle of the implementation phase. Finishing each project and handing over them to the customers should be the primary focus during the implementation phase. Corrections to the system will be made in the next cycle. Customer satisfaction is important for the proliferation of 3D-Printed houses.

Evaluate and improve

Systems approach to automated construction is a continuous process, with each project the construction process will get better. Evaluation of the process occurs at every point of the system approach. Before moving from one phase to the next, the performance and direction of the methodology will be evaluated. It helps to keep the focus of the system development process. By the end of the implementation phase, all the performance data of the system will be available.  After the conclusion of the Implementation phase, a comprehensive evaluation of the system will be conducted to identify the root causes for the problems. Even if the system performance is satisfactory, an evaluation will search for improvement opportunities.

The last phase in the system approach is to adjust the construction process for improvements. Like evaluation, improvements can be made at every point of the system approach. There is a lack of examples for automated construction projects, only a few automated building projects have been completed. Each project is a learning opportunity, improvements will be made to the process each time a house is built. Initially, the improvements will be of noticeable magnitude but after dozens of projects, the process will get perfected. Eventually, standards and benchmarks will be created for construction automation. There is a huge gap between the effectiveness of automation in manufacturing and construction. For comparison, an average car can be built in 30 hours, but automated construction projects still take months to finish. If construction can reach vehicle manufacturing productivity, an average home be finished in few weeks. By using a system approach, the effectiveness of automation can be improved.

System approach can be applied to the whole construction industry, it will create new practices and tools by considering the whole picture. Implementing a system approach in the designing and manufacturing of 3D printers and related systems will create machines that can perform better in real-world applications.

More lessons from Manufacturing

Automation was created to improve the productivity of manufacturing plants. Today most of the manufacturing plants are fully automated. Industrial automation is a billion-dollar industry. When applying automation to the construction sector, the process improvement philosophies of manufacturing should not be neglected. Manufacturing processes are being improved continuously for increasing efficiency. Factories have come a long way from the automated spinning mills of the eighteenth century. Automated manufacturing has made products cheaper and factory floors safer. Over the years, various production philosophies such as Lean, Six-sigma, Toyota Production System, Kaizen, etc. were developed for optimizing the processes. On seeing the process efficiency in manufacturing, other industries adopted some of these methodologies for designing better processes.

The initial investment for automation is huge, to make ROI the machines should be in production mode as much as possible. At present, the construction automation machines are in a state of storage or idle for most of the time. Machines are made for operation, whenever a machine is not working it is not returning the investment. Construction is an old trade, the processes were designed for human labor. To construction automation profitable, the process must be made compatible for automating. A construction process that utilizes the 3D printers to the maximum extend has to be developed. The operation of such a process may require an entirely new supply chain. By utilizing the process optimization methodology the automated construction can be made more cost-competitive.

[NK #004] 3DCP link roundup (week-end edition!)

Special (selected) homework study material for All of us 🙂

ARelated current scientific literature collection:

  1. Carbonaceous admixtures in cementitious building materials: Effect of particle size blending on rheology, packing, early age properties and processing energy demand
    • Souradeep Gupta, Jean-Marc Tulliani, Harn WeiKua – link
  2. Computational Frameworks for Multi-Robot Cooperative 3D Printing and Planning” (PhD Thesis)
    • Laxmi Prasad Poudel – link
  3. 3D Concrete Printing: A Road Map for future of Automated Construction in India
    • Raman Shaw, Kundan K. MauryaandProf. Damodar Maity – link
  4. Working with Randomness: A Perspective on Using Spatial Statistics to Engineer the Mechanics of Heterogenous Materials
    • Mija H. Hubler, Zahraa H. Alquraini – link
  5. Advanced Design for Manufacturing Processes
    • Special issue – link
  6. A Study on the Analysis of the Trend of installations Using 3D Printing Technique
    • Kim, Ji Min, Lee, Tae Hee – link
  7. A state of the art on the future of 3D printing Smart technology and its impact on the infrastructure industry
    • Avinash Varma K – link

Wishes for a pleasant weekend to All.

Stay 3Dposted 🙂

[NK #003] 3DCP link roundup

Dear All Brave who come forth and enter the abaton (for now) of what is … Construction Automation applied 🙂

This is the 3rd installment of our current journey; let’s see where it leads…

ARelated/selected news clippings collection:

  1. Construction begins on CYBE’s first 3D-printed homes in the Carribean” – link
  2. A scaled down medieval irrigation system 3D printed in concrete” – link
  3. The world’s first 3D-printed parkour park is unveiled in Prague” – link
  4. Concrete industry Brievengat ‘prints’ homes with 3D concrete printer” – link
  5. Basingstoke start-up proposes tunnel-spraying bots” – link
  6. Could Future Offices be 3D Printed by Robots?” – link
  7. Biggest 3D-Printing Home Opportunity I’v ever seen…” – link
  8. The ‘World’s Longest’ 3D-Printed Concrete Bridge Erected in The Netherlands” – link
  9. Retrotechtacular: 3D-printed buildings, 1930s style” – link
  10. Australia’s first ‘digital’ construction management degree to commence in 2022” – link
  11. How a new construction technology could save two thirds of concrete” – link

BRelated current scientific literature collection:

  1. Modelling the interlayer bond strength of 3D printed concrete with surface moisture
    • Gerrit Marius Moelich, Jacques Kruger, Riaan Combrinck – link
  2. Incremental viscoelasticity at finite strains for the modelling of 3D concrete printing
    • Boumediene Nedjar – link
  3. Developing Mix Proportions for Class C Fly Ash-Based Alkali-Activated 3D-Printed Concrete Mixtures
    • Fareh Abudawaba, Eslam Gomaa, Ahmed Gheni, Mohamed ElGawady – link
  4. Effect of autogenous shrinkage on microcracking and mass transport properties of concrete containing supplementary cementitious materials
    • M.H.N. Yio, M.J. Mac, Y.X. Yeow, H.S. Wong, N.R. Buenfeld- link
  5. Industry 4.0 in a project context: Introducing 3D printing in construction projects
    • Nils O.E. Olsson, Emrah Arica, Ruth Woods, Javier Alonso Madrid – link
  6. Synergies on rheology and structural build-up of fresh cement pastes with nanoclays, nanosilica and viscosity modifying admixtures
    • Hugo Varela, Gonzalo Barluenga, Irene Palomar, Alberto Sepulcre – link
  7. Evaluation of zeta potential of calcined clays and time-dependent flowability of blended cements with customized polycarboxylate-based superplasticizers
    • Ricarda Sposito, Matthias Maier, Nancy Beuntner, Karl-Christian Thienel- link
  8. Bottom-up approaches to engineered living materials: Challenges and future directions
    • Sara Molinari, Robert F. Tesoriero Jr., Caroline M. Ajo-Franklin- link
  9. 3D Printing Mudrocks: Experiments in Validating Clay as a Build Material for 3D Printing Porous Micromodels
    • Franciszek Hasiuk, Chris Harding- link
  10. The Algorithm and Application of Fast Surface Slice and Color Acquisition for Color 3D Printing
    • Yang Xiao, Yi Yang, Yi Wang- link
  11. A Drone-Assisted 3D Printing by Crane Structures in Construction Industry
    • Fabio Parisi, Agostino Marcello Mangini, Maria Pia Fanti; Nicola Parisi- link
  12. Short-duration near-nozzle mixing for 3D concrete printing
    • Nan Zhang, Ming Xia, Jay Sanjayan – link
  13. Rheology and shrinkage of concrete using polypropylene fiber for 3D concrete printing
    • Mien V. Tran, Yen T.H. Cua, Chau V.H. Le – link
  14. Numerical simulation of multi‐layer 3D concrete printing
    • Jon Spangenberg, Wilson Ricardo Leal da Silva, Raphaël Comminal, Md. Tusher Mollah, Thomas Juul Andersen, Henrik Stang – link
  15. The effect of using polypropylene fibers on the durability and fire resistance of concrete
    • Hassan Suiffi, Anas El Maliki, Fatima Majid, Omar Cherkaoui – link
  16. Pumping of Flowable Concrete: Analytical Prediction and Experimental Validation
    • Rami Khatib and Kamal H. Khayat – link
  17. Cost–Benefit Analysis and Environmental Impact Assessment of 3D Printing Applications in Building Construction in Oman
    • Vineet Tirth, Syed Waheedullah Ghori – link
  18. Influence of supplementary cementitious materials, curing conditions and mixing ratios on fresh and mechanical properties of engineered cementitious composites – A review
    • N.Shanmugasundaram, S.Praveenkumar- link
  19. What Did You Add to My Additive Manufacturing Data? Steganographic Attacks on 3D Printing Files
    • Mark Yampolskiy, Lynne Graves, Jacob Gatlin – link
  20. Evaluation of interlayer bonding in layered composites based on non-destructive measurements and machine learning: Comparative analysis of selected learning algorithms
    • Sławomir Czarnecki, Łukasz Sadowski, Jerzy Hoła – link
  21. Digital fabrication of eco-friendly ultra-high performance fiber-reinforced concrete
    • Arun R. Arunothayan, Behzad Nematollahi, Ravi Ranade, Kamal H. Khayat, Jay G. Sanjayan – link
  22. Experimental study on large-scale 3D printed concrete walls under axial compression
    • Xiaoyu Han, Jiachuan Yan, Mingjian Liu, Liang Huo, Junlin Li- link
  23. Flexural Behavior of 3D Printed High-Strength Ductile Concrete Beams with Optimized Topology” (Thesis)
    • Amadeu Malats Domenech – link
  24. 3D-Printed Biodigital Clay Bricks
    • Yomna K. Abdallah, Alberto T. Estévez- link
  25. Cost–Benefit Analysis and Environmental Impact Assessment of 3D Printing Applications in Building Construction in Oman
    • Vineet Tirth, Syed Waheedullah Ghori – link
  26. Investigation for Developing 3D Concrete Printing Apparatus for Underwater Application
    • Jun Pil Hwang, Hojae Lee, Hong-Kyu Kwon – link
  27. Digital Fabrication Techniques for 3D Printing with Everyday Materials” (PhD Thesis)
    • Michael L. Rivera – link
  28. Numerical simulation of multi‐layer 3D concrete printing
    • Jon Spangenberg, Wilson Ricardo Leal da Silva, Raphaël Comminal, Md. Tusher Mollah, Thomas Juul Andersen, Henrik Stang – link

CExtra points [for those that reached the post’s End!], some Conferences/Seminars to keep a (keen) eye out 🙂

  1. “European Military Additive Manufacturing Symposium” (link)
  2. “3D Printing for Production -AM 2021” (link)
  3. “Advanced Manufacturing Technology Conference 2021” (link)
  4. “Inside 3D Printing Seoul” (link)
  5. “Health and Safety in Additive Manufacturing” by TÜV SÜD (link)

As the (net savvy) Youth likes to say: “sharing is caring“!

Stay 3Dposted 🙂

[NK #002] 3DCP link roundup

Dear Viewer,

Please find below the 2nd installment of the (Industry & Market!) data gathering; all for your perusal 🙂

A. Related/selected news clippings collection:

  1. Tiny house, fine print” – link
  2. The New York Times, “3D Printing Homes” – link
  3. Stratasys introduces Protectam Data Security Platform for US Government and Defense 3D Printing” – link

B. Related current scientific literature collection:

  1. Examining layer height effects on the flexural and fracture response of plain and fiber-reinforced 3D-printed beams
    • Authors: Sooraj A.O. Nair, Avinaya Tripathi, Narayanan, Neithalath – link
  2. A new mortise and tenon timber structure and its automatic construction system
    • Authors: Wentao Qiao, Zexiong Wang, Dong Wang, Long Zhang – link
  3. Extrusion and rheological characterization of cement-based materials containing different types of clays” (MSc Thesis)
    • Authors: Aydın, Eylül Mina – link
  4. Applying 3D Printing as a New Building Technology: Potentials and Challenges in the Egyptian Context
    • Authors: Amr Alaa El-din, Mohamed Ibrahim, Zeyad El-Sayed – link
  5. Developing Mix Proportions for Class C Fly Ash-Based Alkali-Activated 3D-Printed Concrete Mixtures
    • Authors: Fareh Abudawaba, Eslam Gomaa, Ahmed Gheni, Mohamed ElGawady- link
  6. Waste management and possible directions of utilising digital technologies in the construction context
    • Authors: Samad Sepasgozar, Deirdre Frances Mair, Faham Tahmasebinia, Sara Shirowzhan, Heng Li, Amy Richter, Liming Yang, Shixiong Xu – link
  7. Case studies of AI in architecture – Combining Al and BIM in the design and construction of a Mars habitat
    • Authors: Naveen K. Muthumanickam, Jose P. Duarte, Shadi Nazarian, AH Memari, and Sven G. Bilen – link
  8. 3D Printed Formwork for Concrete: State-of-the-Art, Opportunities, Challenges, and Applications
    • Authors: Andrei Jipa and Benjamin Dillenburger – link
  9. 3D-printing of architectured short carbon fiber-geopolymer composite
    • Authors: Siqi Ma, Hualong Yang, Shenjian Zhao, Peigang He, Zuhua Zhang, Xiaoming Duan, Zhihua Yang, Dechang Jia, Yu Zhou – link
  10. Energy Performance of 3D-Printed Concrete Walls: A Numerical Study
    • Authors: Thadshajini Suntharalingam, Irindu Upasiri, Perampalam Gatheeshgar, Keerthan Poologanathan, Brabha Nagaratnam, Paulo Santos and Heshachanaa Rajanayagam – link
  11. Design and Evaluation of Asphalt Concrete Incorporating Plastic Aggregates Fabricated Using 3D Printing Technology
    • Authors: Aamer Nazir, Min-Chih Liao, Yan-Wei Zhu, and Usman Nazir – link
  12. Milling a cement-based 3D printable mortar in its green state using a ball-nosed cutter
    • Authors: James Dobrzanski, Richard Buswell, Sergio Cavalaro, Peter Kinnell, Weiqiang Wang, Jie Xu, John Kolawole – link
  13. Tailoring rheological–strength–ductility properties of self-cleaning geopolymer composites with asphalt emulsion
    • Authors: Yafeng Pang, Xingyi Zhu, Ming Yang, Jiangtao Yu – link
  14. Operational Technology on Construction Sites: A Review from the Cybersecurity Perspective
    • Authors: Muammer Semih Sonkor, Borja García de Soto – link
  15. Reliability and effectiveness of laser scanners in future construction efforts on the Moon and Mars
    • Authors: Jacek Katzer, Czesław Suchocki, Wioleta Błaszczak-Bąk, Paweł K. Zarzycki, Marzena Damięcka-Suchocka- link
  16. Filament geometry control in extrusion-based additive manufacturing of concrete: The good, the bad and the ugly
    • Authors: R.J.M. Wolfs, T.A.M. Salet, N. Roussel- link
  17. Mechanical characterization of 3D printed concrete subjected to dynamic loading
    • Authors: Rosanna Napolitano, Costantino Menna, Daniele Forni, Domenico Asprone, Ezio Cadoni- link
  18. A scientometric review of waste material utilization in concrete for sustainable construction
    • Authors: Waqas Ahmad, Ayaz Ahmad, Krzysztof Adam Ostrowski, Fahid Aslam, Panuwat Joyklad- link
  19. Investigations of the Mechanical Properties of DLP 3D Printed Graphene/Resin Composites
    • Authors: Muammel M. Hanon, Arsany Ghaly, László Zsidai, Zoltán Szakál, István Szabó, László Kátai- link
  20. Machine Sensing for Mineral Foam 3D Printing
    • Authors: Bedarf, Patrick; Szabo, Anna; Zanini, Michele; Dillenburger, Benjamin – link
  21. A 3D-Printing Centered Approach to Mars Habitat Architecture and Fabrication
    • Authors: Matthew Troemner, Elham Ramyar, Jonathan Meehan; Benton Johnson, Nima Goudarzi, Gianluca Cusatis – link
  22. Non-linear rheological behavior of superplasticized cementitious suspensions at high shear rates
    • Authors: Ángel De La Rosa, Lucía Garijo, Gonzalo Ruiz, Rodrigo Moreno- link
  23. Correlation of interlayer properties and rheological behaviors of 3DPC with various printing time intervals
    • Authors: Yanqun Xu, Qiang Yuan, Zemin Li, Caijun Shi, Qihong Wu, Yanlin Huang- link
  24. Shrinkage behavior of cementitious 3D printing materials: Effect of temperature and relative humidity
    • Authors: Mohsen Rezaei Shahmirzadi, Aliakbar Gholampour, Alireza Kashanic, Tuan D. Ngo- link
  25. Set-on-demand approaches for geopolymers in concrete 3D printing
    • Authors: Shravan Muthukrishnan, Sayanthan Ramakrishnan, Jay Sanjayan- link
  26. Life cycle assessment of a low-height noise barrier for railway traffic noise
    • Authors: Mariam Abdulkareem, Jouni Havukainen, Jutta Nuortila-Jokinen, Mika Horttanainen- link
  27. Examining layer height effects on the flexural and fracture response of plain and fiber-reinforced 3D-printed beams
    • Authors: Sooraj A.O. Nair, Avinaya Tripathi, Narayanan Neithalath- link
  28. Comparison between Methods for Indirect Assessment of Buildability in Fresh 3D Printed Mortar and Concrete
    • Authors: Irina Ivanova, Egor Ivaniuk, Sameercharan Bisetti, Venkatesh N. Nerella, Viktor Mechtcherine- link
  29. Development of Photocatalytic 3D-Printed Cementitious Mortars: Influence of the Curing, Spraying Time Gaps and TiO2 Coating Rates
    • Authors: Behzad Zahabizadeh, Iran Rocha Segundo, João Pereira, Elisabete Freitas, Aires Camões, Carlos J. Tavares, Vasco Teixeira, Vítor M. C. F. Cunha, Manuel F. M. Costa, Joaquim O. Carneiro- link

Hope the above Knowledge links will be useful and become fruitul input for the Next steps, evolutions, escalations, bigger, faster & (even more) automated 🙂

Stay 3D posted 😉

[NK #001] 3DCP link roundup

Hello there & “welcome aboard!” our Dear 3D Construction Printing co-enthusiast!

Please find below the first batch of news-clippings as well as selected published research papers/works are for your (3DCP) interest & viewing pleasure (sorted in no particular order; for now).

Tea & study time it is then!

  1. US army to 3D print concrete buildings and bridges in disaster areas” – link, 2nd link
  2. “Futuristic houses are being 3D printed by robots — and could go on sale for £360,000”link
  3. Live talk with Zaha Hadid Architects, ETH Zurich and Holcim on their 3D-printed concrete bridge Striatus” – link
  4. 3D printing could help build homes with unique designs more cheaply, advocates say” – link
  5. Humans and Robots, Co-existing Peacefullylink
    • Article by Zack Mannheimer (founder/CEO of Alquist)
  6. Training the key to future success of 3D printing in construction” – link
  7. A 3D Printed Book Cabin Has Been Placed in a Shanghai Park” – link
  8. 2021 3D Printing Industry Awards – Vote now” – link
  9. “New Era of 3D-Printing” – link
  10. Restoring coral reefs with 3D-printed skeletons” – link
  11. Are you ready for a 3D-printed house? They’re cheaper, stronger and long-lasting, developers say” – link
  12. Are you ready for a 3D-printed house?” – link
  13. A cure for construction” – link
  14. 3d Printed Homes: A Fix for Global Housing Problems?” (link)
  15. 3D printing clean(er) and more sustainable energy and parts” (link)
  16. World’s first 3D-printed steel bridge completed in Amsterdam” (link)
  17. 3D Printing making headway”link
    • The longest bridge ever built using 3D printing is located in Nijmegen, Netherlands, at the Saint-Gobain Weber Beamix factory

Related current scientific literature collection:

  1. “A 3D-Printing Centered Approach to Mars Habitat Architecture and Fabrication”
    • Authors: Matthew Troemner, Elham Ramyar, Jonathan Meehan, Benton Johnson – link
  2. “3D printing lunar architecture with a novel cable-driven printer”
    • Authors: Dianjin Zhang, Dekai Zhou, Guangyu, Zhang, Guangbin, Shao, Longqiu Li
    • Published online on the 24th of September 2021 – link
  3. “Industrialised Mass Housing in Saudi Arabia: A Qualitative and Technological Study”, PhD Thesis – link
    • Author: Alshabib, Abdulaziz Dakhel M.
  4. “Non-linear rheological behavior of superplasticized cementitious suspensions at high shear rates”
    • Authors: Ángel De La Rosa, Lucía Garijo, Gonzalo Ruiz, Rodrigo Moreno
    • Published online on the 20th of September 2021 – link
  5. “Set-on-demand approaches for geopolymers in concrete 3D printing”
    • Authors: Shravan Muthukrishnan, Sayanthan Ramakrishnan, Jay Sanjayan
    • Concrete 2021 Conference – link
  6. “Correlation of interlayer properties and rheological behaviors of 3DPC with various printing time intervals”
    • Authors: Qiang Yuan, Yanqun Xu, Zemin Li, Caijun Shi, Qihong Wu, Yanlin Huang
    • Published online on the 13th of September 2021 – link
  7. “Shrinkage behavior of cementitious 3D printing materials: Effect of temperature and relative humidity”
    • Authors: Mohsen Rezaei Shahmirzadi, Aliakbar Gholampour, Alireza Kashani, Tuan D. Ngo
    • Published online on the 20th of September 2021 – link
  8. “Examining layer height effects on the flexural and fracture response of plain and fiber-reinforced 3D-printed beams”
    • Authors: Sooraj A.O. Nair, Avinaya Tripathi, Narayanan Neithalath
    • Published online on the 16th of September 2021 – link
  9. “Machine Sensing for Mineral Foam 3D Printing”
    • Authors: Bedarf, Patrick; Szabo, Anna; Zanini, Michele; Dillenburger, Benjamin
    • International Conference on Intelligent Robots and Systems 2021- link
  10. “Characterization of Fresh and Hardened Properties of 3D Printable Cementitious Materials Produced with Ground-Granulated Blast-Furnace Slag”, MSc Thesis – link
    • Author: Shoueb, Mohamad Basel
  11. “A scientometric review of waste material utilization in concrete for sustainable construction”
    • Authors: Waqas Ahmad, Ayaz Ahmad, Krzysztof Adam Ostrowski, Fahid Aslam, Panuwat Joyklad
    • Published online on the 4rd of September 2021 – link
  12. “Investigations of the Mechanical Properties of DLP 3D Printed Graphene/Resin Composites”
    • Authors: Muammel M. Hanon, Arsany Ghaly, László Zsidai, Zoltán Szakál, István Szabó, László Kátai
    • Published online on the 16th of September 2021 – link
  13. “Acoustic performance optimization of a cementitious composite with a porous medium”
    • Authors: Sen Lin, Genbao Zhang, Junbo Sun, Shilin He, Changfu Chen, Amr M. Morsy, Xiangyu Wang
    • Published online on the 23rd of September 2021 – link
  14. Additive Fabrication of Large-Scale Customizable Formwork Using Robotic Fiber-Reinforced Polymer Winding
    • Authors: Ya Ou, Ding-Wen Bao, Guan-Qi Zhu, and Dan Luo
    • Published online on the 17th of September 2021 – link
  15. Flexure resistant 3D printed zeolite-inspired structures
    • Authors: Rushikesh S. Ambekar, Eliezer F. Oliveira, Brijesh Kushwaha, Varinder Pal, Pulickel M. Ajayan, Ajit K. Roy, Douglas S. Galvao, Chandra S. Tiwary
    • Published online on the 17th of September 2021 – link
  16. 3D printing in tourism: an answer to sustainability challenges?
    • Authors: Galina Berjozkina , Rasoul Karami
    • Published online on the 20th of September 2021 – link
  17. Incremental viscoelasticity at finite strains for the modelling of 3D concrete printing
    • Author: B. Nedjar –link
  18. Examining layer height effects on the flexural and fracture response of plain and fiber-reinforced 3D-printed beams
    • Authors: Sooraj A.O. Nair, Avinaya Tripati, Narayanan Neithalath
    • Published online on the 16th of September 2021 –link
  19. Conceptual design of a concrete staircase based on topology optimization“, MSc Thesis,
    • Authors: BjØrnar Sandvik, Ehsan Qaraee, Ramesh Kumar – link
  20. Influence of bottom ash and polypropylene fibers on the physico-mechanical, durability and thermal performance of foam concrete: An experimental investigation
    • Authors: Osman Gencel, Syed Minhaj Saleem Kazmi, Muhammad Junaid Munir, Gokhan Kaplan, Oguzhan Yavuz Bayraktar, Duygu Ozturk Yarar, Arash Karimipour, Muhammad Riaz Ahmad
    • Published online on the 17th of September 2021- link
  21. Development of Photocatalytic 3D-Printed Cementitious Mortars: Influence of the Curing, Spraying Time Gaps and TiO2 Coating Rates
    • Authors: Behzad Zahabizadeh, Iran Rocha Segundo, João Pereira, Elisabete Freitas, Aires Camões, Carlos J. Tavares, Vasco Teixeira, Vítor M.C.F. Cunha, Manuel F.M. Costa, Joaquim O. Carneiro
    • Published online on the 27th of August 2021 – link
  22. “Design and Evaluation of Asphalt Concrete Incorporating Plastic Aggregates Fabricated Using 3D Printing Technology”
    • Authors: Aamer Nazir, Min-Chih Liao, Yan-Wei Zhu, and Usman Nazir
    • Published online on the 22nd of September 2021 – link
  23. A qualitative conceptual framework to tackle skill shortages in offsite construction industry: a scientometric approach
    • Authors: Syed Saad , Wesam Salah Alaloul , Syed Ammad , Abdul Hannan Qureshi
    • Published online on the 20th of September 2021 – link

With kind regards,

Dr. N.S. Katsiotis

Mining & Metallurgical Engineer

PhD in Chemical Engineering


extra points for those of us who made it here (not_2LDR :P):

European Military Additive
Manufacturing Symposium

12th and 13th October 2021 | Maritim Hotel | Bonn | Germany


3D Printed Homes: Current Technology & The Future

Automated construction methods such as prefabs and 3D printing are gaining popularity, mainly because of high home prices. Concrete 3D printing has proved its feasibility through various projects around the globe. However, 3D printing is still in a pioneering stage, many iterations and experiments are needed for perfecting this technique. The results of the 3D printing construction projects are promising a solution for the labor shortage in the construction industry. Today, industrial 3D printing is a common practice in prototyping, but construction 3D printing is still evolving as a viable technique for construction. Around the world startup companies are working to bring the technology to the mainstream. Because of the popularity for 3D printing in recent years, the companies overwhelmed with orders and inquiries. Many people are in line for a 3D printed construction project; at present the lead time on a project can even be over a year. 

3D printing companies keep their numbers secret and sometimes make claims that are not even close to the actual numbers. In 2019 Business Insider published an article with a misleading headline “These 3D-printed homes can be built for less than $4,000 in just 24 hours” and many other media outlets echoed this unverified claim. The misleading news reports has helped to create public interest in the technology, but the true numbers can be demoralizing to many prospective adopters. At present, a 3D printed house will cost more to construct, and the process will take months to complete. This article discuss about different aspects of the construction 3D printing, to provide an insight into the capabilities and prospects of this technology. 

The 4000 Dollar home?

Home prices in the US have reached the highest point in history, partially due to the increased cost of the material and labor. While labor is the biggest cost in construction, the industry is also facing a shortage of skilled labor. 3D printing can offset a portion of this labor shortage thus reducing the cost. But at present 3D printing construction can be significantly costlier than conventional construction techniques. A few 3D printed houses have been built around the country, and the actual cost of these projects is rumored to be anywhere from 140 percent to 300 percent of conventional construction. The cost can vary depending on the type of system and material being used. There are many factors contributing to this high price, the main components of a 3D printing cost are discussed below.

  • Material: 3D printing machines use engineered concrete mixes (ink) to create the desired structures. For a concrete mix to be a 3D printing ink the formability, consistency and curing properties should be within a defined range. Different companies like ICON, Apis-Cor, Mighty Buildings, etc. have developed their own proprietary inks for their own 3D printing machines. At present there is no fixed standard for these concrete mixes and companies are producing the material in batches for each project. There are no published numbers on the price or properties of these proprietary mixes, yet by analyzing the reported expense of 3D printing projects it is evident that the material can cost four times or more compared to regular concrete. This price of the material is the main reason behind the high price point of the 3D printing construction projects. Since the 3D printing concrete is a highly engineered concrete mix the price will never be lower than regular concrete, but in the future mass production can bring the cost down from the current point.  If the price of ink falls to a comparable level to regular concrete, 3D printing construction can become cheaper than conventional construction. 
  • Machines:  Construction 3D printers are a system of computer-controlled machines used for placing the ink layer by layer. Currently there are only a few companies manufacturing 3D printers large enough to build houses; the price of these machines can run anywhere from hundreds of thousands to millions of dollars. Apart from the gantry, or robotic actuator, there are other supporting systems such as material mixers, pumps, hoppers, nozzle assemblies, etc. needed for the printing operation. Some of these machines are more complex and sensitive than the gantry or the robot. The construction jobs may require additional machines like cranes, tractors etc. The total cost of all the machines needed for 3D printing a home can run into the millions. Because of the high demand and lack of competition, the price for these 3D printers remains high. Just like any machine, these early models are yet to prove their reliability and durability. A portion of the total price of machine and maintenance will be added to the total price of each project, but in the future more reliable and efficient models will bring this cost down.
  • Transportation: Transportation cost is the cost associated with moving the machines, materials and people involved in the construction process. Due to the shortage of printers, the machines need to be transported long distances. The transportation of the entire 3D printing system and materials can take many truck loads and larger printers will need cranes to move its massive parts around the work site. Sometimes the printing will require a tent, and in that case the tent will also need to be transported.  This will increase the cost of construction, but as more printers and subsystems become available in the market the cost of transportation will be lowered.
  • Wastage: This factor is often overlooked. Getting a consistent 3D printing mix is still an art rather than science. A lot of factors can affect the consistency of the mix, and this consistency is important in making a high-quality wall. Before each project the team must do a lot of test prints to create the perfect mix for that specific job. The projects are not printed in one stretch either; all projects are printed in sections. Each time the machine starts, a lot of material is wasted in the process of setting the mix consistency for the actual printing. This wastage adds up to the tons by the end of the project. Due to the quick setting nature of the mix sometimes the material line can clog, and in that case the entire line needs to be flushed. Due to the high cost of materials, the cost of wasted mix will be significant, but as companies perfect their mixes and printing practices, the wastage in the process can be minimized.
  • Operational cost: Operational cost is the expense of running an operation. The operational cost for 3D printing construction comes from wages, energy bills, set up cost and other miscellaneous expenses. Human operators are required to ensure the accuracy and precision of the printing operation, as any unnoticed changes in any stage of the operation may have serious consequences. Today, most 3D printing jobs need more than one person to operate and monitor the entire system. Setting up is the process of getting the printer and other machines ready for the actual printing of the house. This process may require cranes, tractors, generators, waterlines, etc. Today, the operations in a 3D printing construction site are far from optimized and it will take many years of experience to achieve. As time progresses, more trained professionals and optimized operational procedures will bring higher efficiency.

Build a House in 24 hours?

Home construction is a long process; a lot of money and labor is involved in it for many months. Shortening the construction timeline will obviously reduce the total cost of construction. The ability to build a house in 24 hours would be momentous but that is not a practical goal. Some companies may have claimed to build a house in 24 or 48 hours, but they are talking about the actual print time of the wall’s construction. A project is more than just walls, and even the wall printing is parted into sections. The total printing process taking one or two weeks to finish, and many test prints need to be completed before that. Because each layer of material will require a curing time to achieve the strength to carry the weight of the layers on top of it. After the walls are cured, other works need to be carried out to finish the project. Therefore, no 3D printed construction project can be or was finished in 24 hours. 

3D printing has the potential to reduce the time for constructing the walls of the home. After the walls are installed, conventional roofing, electrical, plumbing and finishing processes need to be done. By 3D printing the walls the total time of the project can be reduced, but the total time will still be over a month. Reducing the time to build a home will increase the availability of homes, thus reducing the price. 

The 3D printing operation is sensitive to environmental conditions, therefore variations in temperature and humidity will impact the timeline of the project. The printing mixes are optimized for a specific temperature and humidity level. A change in the specified climate conditions will negatively impact the quality of the print. For this reason, in most cases the actual printing had to be limited to a certain time of the day. And printing is impossible during a raining if it is not done inside a tent. Printing inside a tent can produce better quality walls, but it is obviously much more expensive.

What will happen to construction workers? 

Labor is the biggest expense in construction. The labor shortage is increasing the cost of labor year by year. In this situation automating the construction processes is important to make affordable housing a reality. Construction is the only main industry that hasn’t seen any significant automation, and 3D printing is one way to automate to construction. 3D printing is not capable of offsetting all the manual labor, people are required for different procedures before during and after the 3D printing process. During the printing operation, people are required for inserting reinforcement, insulation, rough wiring, and plumbing, etc. After finishing the walls, roofing, flooring, and other finishes are to be done conventional contractors. 

For every replaced job, automation will create more sophisticated jobs in the technology sector. Development of automated construction will create jobs for printer operators and robotic manufacturers. It will also open more research and development jobs in material science, software development etc. 3D printing construction is in a state like the industrial robots of the 1980s; today all factories are automated to different degrees, and the conditions are prefect for construction industry to adopt automated construction techniques. 

A Dream come true for Architects

High cost of construction was always a limiting factor in architectural innovations in building designs. Architects usually come up with innovative shapes in their designs, but the cost of making the curved structures make the designs financially impossible. The advent of 3D printing is promising a new future for architectural design. 3D printing can make curved walls as easy as straight walls. Due to structural issues and code restrictions, 3D printing companies are taking baby steps in bringing this change into new construction. However, curved rooms will soon be a norm in the 3D printed homes. This architectural freedom can easily bring more innovative designs to no-permit required structures such as planters, firepits etc.

At present, the print mixes have similar properties to concrete; they are good with compression and poor with tensile loads. Therefore, rebar is inserted into the concrete. Developing new materials can change this, if a company come up with a 3D printing ink that can perform under tensile load it can ultimately accelerate the construction 3D printing technology.  

The permit and code rules have some restrictions in place to protect the aesthetics of a neighborhood. But these restrictions were formalized before the advent of 3D printing technology as the technique mature the governing authorities will eventually adopt the new rules and standards. This is a field that need some focus from the companies involved in this industry. Engineering and architectural standards needs to be developed for 3D printing construction.


Construction is an essential process, with significant ecological effects. Sustainable housing is a long-sought achievement and 3D printing may be capable of making it a reality. Material scientists around the globe are working to develop an eco-friendly 3D printing mix. Construction is one of the largest CO2 producers, making the construction more sustainable will solve a lot of environmental issues. 

At present most of the 3D printing mixes are cement-based. Cement is not an eco-friendly substance. Nevertheless, 3D printing is better for the environment because of the decreased waste of the raw materials. Good amount of research is dedicated towards creating alternative materials for construction. Recently, Omlab a Netherland based startup was successful in developing a bio-degradable 3D printing ink for construction. Wasp, an Italian startup has 3D printed a structure using soil and straw. If the researchers can produce an eco-friendly ink with similar properties of cement-based mixes, it can create a huge impact in the industry’s sustainability goals. 3D printing can also eliminate many intermediate steps in the construction process that will also reduce emissions and pollution. 

All structures around us are overbuild, most of the material being used is for ease of construction rather than for structural integrity. 3D printing can reduce material usage by creating complex shapes for perfect load transfer. Today most structures are made as filled blocks, and most of the material in the structure is not required for its designed structural properties. By using 3D printing the required amount of material can be placed where it is required. This way, some structures can save up to 70% of material; it will have a positive effect on the price and sustainability of the buildings.

Concrete is fire-resistant in nature and using concrete instead of wood can reduce the risk of fire. This can result in lowered insurance cost. Concrete is also not susceptible to termites and other insects, resulting in lowered maintenance cost. Concrete, compared to wood, also has superior strength. Because of the strength the damages caused by natural disasters or adverse climate phenomenon will be minimal, saving a lot of money in damage repairs. 


3D printing construction is here, and the technology has proven its ability to revolutionize the construction industry for the better. Despite some claims about the price of 3D printed homes being clickbait, the claims were generated popularity for the technology. By nature, 3D printed homes are better in many ways to conventional houses, but a lot of research and development must be done to unveil its full potential. The technology is growing at a fast pace, trying new techniques and materials. Soon, 3D printers will be a regular sight on construction sites. Innovative startups are racing to capture the once in a century opportunity. There are dozens of companies coming up with different types of materials and techniques to improve the quality and sustainability of concrete 3D printing. Despite the present cost of materials and machines being very high, the tipping point is not far away. By the end of this decade, fully automated 3D printing could be a common practice.

Omlab is Replacing Cement with Toilet Paper and Calcium

Everyone always asks how can 3D printed concrete be better for the environment? Here is a potential solution! Traditional 3D printed concrete (can I say that yet?) uses a very high portion of cement in the mix compared to regular concrete that would get poured in a formwork. Omlab asks the question, How can we get all the benefits of 3d printed construction (Labor reduction, form freedom, speed) without harming the environment?

This startup in the Netherlands is changing the way concrete impacts the environment. By developing a new mixture that has similar structural properties to concrete without the harmful environmental side effects, Omlab wants to change the long term implications of construction for good. 

I got to meet with founders Margreet Van Uffelen & Huub Looze to get a tour around their facility seeing their printer and past prints. They shared the origin story of Omlab along with their vision for where the company will go in the future. Right now they are very much in the research and startup phase perfecting their mix, print methods, and curing strategy.

The material is 90% calcium removed from drinking water. A small portion is cellulose taken from sanitized toilet paper from the sewage processing plant and they also use a bio polymer binder kamera rich in proteins.

This mixture is completely biodegradable and actually promotes many types of life because of the high calcium concentration. One may ask how can a biodegradable material be used in construction outdoors? The solution is a weatherproof coating. The best part is once it cures it resembles concrete very closely not only in looks but also strength. Omlab is now undergoing strength testing to evaluate the real world potential of this product. 

The biggest upcoming project for Omlab is a public toilet 3d printed with their material that they have already developed a 1:10 scale model of. If the project is successful it will be the first 3d printed building made in a sustainable environmentally friendly way. That is a big achievement and a nice step in the right direction, the next step will need to be scaling it up in a cost effective way. Regardless of the current costs, it is so important that people keep experimenting with the materials used in construction particularly for construction automation. Material science is more advanced than it had ever been in the past. 

Materials at the moment has the potential to be the holy grail of 3d printing because if someone developed a printable concrete at the same cost as regular concrete, all the sudden all these companies with construction 3d printers would be able to complete their construction projects at a lower price than traditional construction. There are many other ways the cost benefits can be achieved but it seems to me a materials development would be the fastest way. 

Omlab is quite open and they are great people, you should reach out to them and learn more about their materials. 3D printed construction companies should work with Omlab to figure out what it takes to extrude their solution from gantry and robotic arm systems. 

My Construction Printer Operator Test with CyBe

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While in the Netherlands, I visited CyBe construction. With their robotic arm mortar printing system, CyBe has completed projects around the world with many more underway from their various clients/partners. 

The training was a 2 week event starting with just learning the basics and watching the very experienced CyBe team operate the robotic arm they have in the facility. By the end of the first week I was beginning to assist with prints lead by my trainer Marc. The second week we went to France Sunday-Thursday to visit Lille University and a 3D printed guardhouse in La Havre which I filmed a tour of with CyBe CEO Berry Hendriks while we were there. 

After the France excursion there were 2 days left of training before my final exam to earn the Basic Operator Certificate. On Friday of the first week I was feeling pretty confident with the system but after spending 4 days away from the machine I certainly felt a bit rusty coming back. I had gained some confidence with the equipment after the first week but hadn’t yet built nearly the true muscle memory level of operation exhibited by Marc, Yop, Alwin, and Jeremy. 

I decided that I would live stream my Basic Operator Final Exam on YouTube to give my subscribers an insight to the 3D printed construction world that they otherwise may not have been able to access. In the month since I filmed that live stream it has already accumulated over 50,000 views with an average watch time of 20 minutes so relative to my small channel it was a big success and something I will try to do again in the future. 

The test was going to be a wall element from a building that was designed by a company in Japan. 5 of these identical wall units are organized in a circle which makes up the small round building. The curvature of the walls mean the base is significantly smaller in surface area than a slice of the middle segment meaning there will be overhang in the layers and considerations of balance are critical to keeping the printed concrete upright while it prints and cures. 

There are some things that need to happen pre print to ensure a safe and productive environment. Ideally you don’t want to print concrete directly on concrete because removing it afterwards could pose a challenge that could damage the print. A couple simple sheets of cellophane can prevent the concrete material from sticking to the slab. Another strategy often employed by CyBe is constructing a small platform out of pallets to print on. Once you have your print area set up you can start your first layer test. During the first layer test make sure the extruder remains in the print area. After the first layer move on to the rest of the print in auto mode so that you don’t need to keep your hand on the controller. It’s generally recommended to keep people out of the print area but for some prints it’s critical to remove portions of the material which requires humans being near the print. By running a full dry test you can be confident there are no rogue points on the print path that would send the printer in a random, potentially dangerous direction. 

The mortar material used by CyBe is a differentiating factor of this company because instead of using accelerator additives they use retarder to actually slow the hardening rate of their material. The dry mix has so much accelerant in it that this retarder is required to prevent the material from hardening to quickly. At ideal levels, the material is nearly completely solid after the 5th or 6th printed layer. This adjustment is done at the mixer which is one of the most critical components of the print process. The mixer is where the dry mix, water and additive come together and get combined thoroughly in the rotor-stator before entering the hose which leads directly to the extruder head of the printer. Adjusting the retarder levels is critical because depending on factors like the length of the hose, time between layers, ambient temperature, humidity ect… you may want to raise or lower the levels to accommodate the circumstances you are printing in. 

Starting the mixer flow is somewhat of an art if you just turn it on and leave it then you are bound to cause a clog. The key is to start the water flow and the additive at an even higher level than final print values and slowly start introducing the material which only mixes at one constant speed (for my purposes). You start in 10 second intervals leaving the dry mix pump on for 1 second and off for 9 then on for 2 and off for 8 and so on until you are on for 9 seconds off for 1 at which point you can just leave it on completely. After the material is fully flowing you can reduce the water levels and the additive levels until the mix is satisfactory for printing. You know the material is dialed in right when it begins stacking slightly from the extruder head. Another great test is to use a spatula to get one small length of printed material. When it is ready, the material will stick to the spatula even upside-down, you will also feel a slightly firm ‘core’ if you poke the material with your finger. 

When the concrete slabs that make up the floor of the CyBe facility were built, they didn’t have robotic arms precisely extruding concrete so the slab that we were printing on was slightly uneven maybe by +-1cm initially this gave me some concern but the CyBe team assured me it would not cause a print failure. The trick on the first layer is to slow down the machine a bit. The material is always extruded at a constant pace so if you slow down the robotic arm you end up with a thicker line of more material, this thicker layer allows for more margin of error on the print bed and gives a nice base to print the next layer on. The ABB robotic arm is of course extremely precise so after that thicker first layer compensates for any irregularity in the print area every layer after that will be precisely the height it was programmed to be (Usually 12.5cm)

Printing is actually the easy part. If everything was done properly for the setup and material qualities the only thing left is cutting away any sections of the print you wish to leave open and keeping the mixer full of dry material. In the CyBe facility they were using 25kg bags of concrete but with a large silo jumbo bags (1.2T) of concrete can be loaded in to further reduce the human labor input required. During the print someone should water down the 

After the print comes the cleaning process. This is a critical step of anything involving concrete especially when it is so fast to harden. Cleaning off the wet material is much easier than trying to pry off the rock chucks of concrete after it becomes solid so you want to do this part quickly and CyBe does. Their system mixes the additive in at the mixer rather than the extruder head so 90% of the cleaning process is done at the mixer which simply involves flushing out the hose with tiny sponge balls then replacing the mixing iron with the cleaning iron and running water through the mixer until all of the sediment from the concrete mix leaves the machine. Overall the cleaning process takes about 10-15 minutes which is notably shorter than the competitors that I’ve seen granted it is a smaller machine. 

I have to say I was very impressed by the lack of cracking in the CyBe prints, Nearly every 3d printed building I’ve seen in the world has some aesthetic non structural cracks but I didn’t see these in the CyBe prints. Being able to hose down the material so quickly after the print goes a long way in controlling the temperature of the concrete as it cures. Keeping the temperature under control significantly reduces the risk of cracking. Another unique factor of CyBe is the sponging process they use to smooth their prints. As mentioned earlier, the material cures within 5-6 layers but within that range the layers are still somewhat wet and malleable so manually brushing over them with a sponge can fill in the layer pattern resulting in a completely smooth wall. 

I was the first person to receive training as an individual rather than a team but I did have 2 CyBe employees assisting me with parts of the print because it generally requires a team of 3 to operate the printer. When everything is going well it’s mostly just standing around, after a year or two of experience it’s even possible to operate the printer solo but with so much going on and little margin for error it’s much safer to use a team. I certainly made a few mistakes, most notably in the beginning I didn’t turn on the water flow on the mixer and while we were calibrating the material component values I let the mixer run empty forgetting to add more material. Luckily this all happened prior to the print. I also left the water heater off but that didn’t cause any issues although it would have gone better at the right heated values, that may be why dialing in the material in the beginning was a bit tricky. You can watch the whole thing with all raw footage from the live feed on my YouTube channel. I managed to get through printing the entire 2.5m wall unit without anything coming up that would detriment the print. At the end of the print I was awarded my Basic Operator Certification. 

Learning to operate a concrete printer felt like a bit step on my journey around the world researching construction automation technology. I had spent over a year researching everything I could find publicly available on the internet but the knowledge acquired from actually making a print happen from start to finish is a completely new level for me. I hope to continue to expand my skillset and learn the operation of other printers. I have learned so much from this experience I think it will be even easier for me to learn how to operate the next one because so many factors are similar especially when it comes to the mixer and the controller which have been very similar with some unique differences at each site I’ve visited. Most of these differences in the mixer are due to the lack of functionality in the off the shelf mixer pump systems currently available on the market. The available equipment is designed for different use cases that are less precise so the units require after market modifications by the companies operating the printer yielding differences between competitors. 

The debate between robotic arms and gantry systems for 3d printing on the construction site rages on. I can say without a doubt both have their own set of advantages and disadvantages. You can’t truly identify one as superior unless you clearly define a particular project. Robotic arms can’t make monolithic structures larger than their print area but for many applications you don’t wan’t a monolithic structure anyway.  When you have to move the printer that is certainly much easier with a robotic arm rather than a gantry system that must be assembled every time. This is something we discussed on an episode on the Automated Construction podcast below.

I certainly expect great things from CyBe in both the near and extended future. They are a nimble and efficient organization considering many verticals trying to make 3D printing mainstream on the construction site. For more information on their technology check out you can also schedule a call with me to discuss which printer would best suit your project via make sure to subscribe to my YouTube channel and consider leaving your email here on my website so that on the rare occasion (so rare it’s never happened yet) that I send something out to my email list you don’t get left out.

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Vertico Pushes Parametric Design in Printed Concrete

While in Europe I had the pleasure of visiting Vertico 3D and their founder Volker Ruitinga. Volker was my first podcast guest via zoom so it was particularly special to visit his facility and record a second podcast in person while visiting Eindhoven, the Netherlands. Those who listened to the first podcast episode remember Volker came from the automobile industry which helped him procure a robotic arm from his old company.

Vertico specializes in parametric design, you’ll see how many different textures they have explored with let me know in the comments if one sticks out as your favorite in particular, I’m sure Vertico would like the feedback as well. They have come a long way since then, currently using no parts from the original system. They’ve upgraded the robot, the pumps, mixing system and even added a silo. In the early days Vertico was hand mixing their concrete in buckets now they load in 1.2 ton concrete bags at a time!

At the Vertico facility they’ve kept many of their old and early prints which gives an excellent timeline of their progress featured in the video below. Volker was kind enough to openly discuss some of the early failures and issues they ran into providing some insight to the daily challenges of a tech startup.

While visiting, I also got the chance to play with some of the parametric design tools vertico has built in the Grasshopper plugin of Rhino. In about 10 minutes I was able to create a printable design and I filmed the process along with the print to be released on youtube later this week. (see below)

Not only did they print my design but also the inverted version of my design, a 2.5m tall column(with a way cooler design than mine) and then the same column but inverted. There was also a 5th print in the same row but that one is confidential, details will be released when the project is ready. The second print had some slight slump causing some inconsistency in the print but Volker was able to very carefully adjust the speed of the printer to compensate for the area which had suffered from the slump to recover the print in about 5 layers. The print was able to reach the last layer without a stoppage.

For those wondering why the lighting is so unique, Vertico shares a warehouse (protected by the historical society) with another startup growing produce/vegtables in tandem with fish in a hydroponic ecosystem.

If you like the designs by Vertico go on their website and make an inquiry, they may even be willing to help bring your idea to reality. Keep in mind they are located in Europe, specifically Eindhoven, the Netherlands so shipping may be a significant expense if you aren’t located nearby.

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Visiting Cobod in Copenhagen and Their Prints in Belgium / Germany!

In May I had the incredible opportunity to visit with Cobod in Copenhagen Denmark at their headquarters and manufacturing facility. Regular viewers of my platform will be familiar with Cobod from my videos with Printed Farms in Florida where they built Floridas first 3D printed building, a 30×30 garage. 

Cobod has sold many printers globally and their current system, the BOD 2 offers many improvements and upgrades from their previous BOD 1 system. Notable clients of Cobod include GE, L&T construction, Kamp C Peri,  Printed Farms, and many more. Peri is not just a client but also an early investor of Cobod and a licensed distributor of the printing system. Of all the users of the Bod 2 system Peri has completed the most prints, the largest prints, and the most innovative prints including a 5 bedroom building in Beckum, Germany and a 5 unit apartment building in Wallhausen, Germany both of which I had the chance to visit during my time in Europe and I was quite impressed. Not only did I get to visit these projects but I also was able to tour them with the head architect from Mense-Korte who designed the 5 bedroom house and a co-owner of Rupp construction, the owner/developer of the 5 unit apartment building. These videos can be seen below along with my visit to Kamp C in Belgium where they printed the first 2 story building in Europe with a team of students. I also did a video of the Bod building near the Cobod facility showcasing the design with architect Alma Bangsgaard Svendsen.

The BOD 2 is a modular gantry system that can get quite large. This system allows for onsite or offsite printing. Depending on location and size the printer takes about 4 hours to set up and take down requiring a crane or all terrain forklift to lift each module into place. Operating the system is quite similar to a typical 3D printer and the team at Printed Farms was able to learn enough to complete their 30×30 garage through only virtual training. 

The Cobod team was quite welcoming, all the employees seem very excited to be working on such revolutionary technology and are quite passionate about their work. While staying with Cobod they also had a materials PHD named Nikolaos Katsiotis visiting from Greece, it was great getting his perspective on the materials side of the concrete printing world as well. 

I was interested to hear from Fabian Meyer-Brötz that the printed apartment building in Wallhausen was very well received by the community. I have had a lingering fear that some people would not appreciate the modern design or printed layers simply because it is different, historically people have been afraid of change but in the case of these 3D printed houses that does not seem to be the case. Most marvel at the exciting prospects the technology offers in the form of automation. Even the contractors working for Rupp seemed very excited to be working on such an innovative project despite most of their construction activities being similar to a typical job site. In the 5 unit apartment building people were so excited to work on the project that subcontractors and furnishing companies offered their services and products without cost just for the sake of having their work showcased in a futuristic project. Neither Bekum nor Wallhausen was particularly known for being futuristic so if the projects were so well received in those cities then I would imagine there will be similar reactions all over the world.  

The excitement over these projects can’t last forever but it doesn’t appear to be slowing down any time soon. There is still so much discovery to do in terms of what construction automation technology is capable of and every project yields new opportunities and learning experiences that will contribute to the improvement of buildings to come. Everyone I’ve talked to who contributed to building a 3D printed concrete structure always has the perspective that future projects will be substantially more efficient both in terms of time, material usage, and cost. The first projects have a learning curve, both Mense-Korte and Peri had the impression that if the same buildings were to be printed again they would be somewhere between 10% and 20% more efficient than the first try. That margin of improvement will continue to get better as everyone involved advances on the learning curve. Stay posted because there are some super impressive Cobod projects underway that I will be visiting once I return back to the United States!

The Most Innovative 3D Printed House in the World

I’ve recently put out a video on my YouTube channel about the most innovative 3D printed house in the world. Of course every 3D printed house at this stage of the industry is innovative but the consideration in design and architecture that went into this project demonstrates a new level for digital fabrication of shelter. 

Mense-Korte is the architecture firm behind this project and COBOD manufactured the 3D printer that was used by the general contractor PERI. There was certainly an extensive education process to clearly illustrate the capabilities of the concrete printer to the architects. Mense-Korte brought outside the box thinking and detail oriented German engineering to the table. The longstanding debate of offsite vs onsite printing has been answered on this project that marries the benefits of both to compensate for some of the limitations of 3D printing concrete, mostly the fact that it can’t print in mid air. By printing certain components off site they were able to add overhangs and other features that couldn’t be printed in mid air on site. 

Other features of the building like a bath and a fireplace were also 3D printed into the building. There is a vast universe of unexplored potential implementing this technology and this project goes further than any other into new territories. As architects and construction firms figure out what should and should not be printed the efficiency of this technology is increasing even if we ignore improvements to the hardware or software itself. 

The on site portion of this project was done with a protective tent like structure around the building. A protective layer around the printer can make it much easier to maintain consistent temperature and humidity parameters, also mitigating any wind. Creating an environment in homeostasis makes the print process much smoother in terms of printed line aesthetics and the concrete cures stronger under optimal conditions which can be achieved in a closed environment. The real question is whether or not the benefits of the tent are worth the added expense. For this project it was because it is meant to showcase the state of the art in its best form. Other outdoors projects can have post processing like manually applied stucco or even alternative print heads COBOD has developed to give a smooth finish to the concrete. 

I believe architecture and design is one of the biggest missing links when it comes to implementing this technology on a massive scale and Mense-Korte is off to a great start. As more firms educate themselves on the possibilities of 3D printed construction we will only see better and better designs at increasing levels of efficiency. One of the most important areas this is happening is within the MEP (Mechanical Electrical Plumbing) systems. Making considerations for these things in advance means the printer can intentionally leave spacing where need be as opposed to cutting holes in drywall later on in the process. 

As this technology becomes more advanced ancillary products will emerge that take advantage of the layer by layer strategy 3D printers use. Every aspect of the home must be rethought and optimized for printing, things like electrical and plumbing should simply be placed where they belong at the proper stage of the print along with and reinforcement. This method could eliminate almost all the heavy lifting on the construction project besides the roof. 

For the latest updates on the best 3D printed construction projects happening around the world make sure to subscribe to my youtube channel at the link below

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Relativity Space 3D Prints Rocket Engines for Space ($500M Funded)

Relativity space is a 5 year old startup that just closed a $500 million dollar D round of funding. We are going to take a look at their 3D printed rocket engines and hear from CEO Tim Ellis along with critical employees Karin Kuo, David Lemier, Ryan Quinn, and Drew Hess. 

3D printing offers a familiar yet unique set of benefits in engine manufacturing. Most notably interior features can be highly customized in comparison to the limited capabilities of CNC. Intricate AI generated interior structures can even reduce the weight of the engine which increase fuel efficiency.

Relativity Space has been scaling up quickly and now aims to produce 1 engine per week. They have come a long way still pursuing their initial vision. I suspect it will not be long before shares of Relativity hit the public markets.

Some say simplicity is the penultimate goal of good engineering. Any software engineer will tell you more code doesn’t equal good code. The best can achieve more with less. Relativity space brings this principal into the hardware sector seeking to drastically reduce parts required for rockets built to reach outer space. 

The traditional model of building rockets involves high precision CNC subtractive manufacturing. Imagine an enormous block of metal chiseled into a desired rocket form, the biggest flaw in this method is inability to control interior features of the unit without post production processing and welding. Founder Tim Ellis realized in 2016 that 3D printing could eliminate the many flaws of CNC in rocket manufacturing, reducing waste and speeding up launch dates. Most importantly he realized nobody else was doing it!

With a cold call to Mark Cuban, Relativity raised an initial $500k seed round.

Through 2017 an additional $9.5M was raised in the A round.

March 27th, 2018 closed $35M B round.

October 1st, 2019 closed a $140M C round.

As of November 23rd, 2020 they have closed a 500M D round of funding led by Tiger Global Management with participation from new investors Fidelity Management & Research Company LLC, Baillie Gifford, ICONIQ Capital, General Catalyst, XN, Senator Investment Group, and Elad Gil. Existing investors participating in the round include BOND, Tribe Capital, K5 Global, 3L, Playground Global, Mark Cuban, Spencer Rascoff, and Allen & Company LLC, among others.

Part of the company vision is people beginning to occupy space with their technology. According to CEO Tim Ellis everything in space will need to be 3D printed. 

The Terran 1 is the payload rocket being developed by Relativity Space. A dedicated mission can be purchased for a cool $12M which can accommodate 1,250kg payload to Low Earth Orbit (LEO) or 950kg to Sun Synchronous Orbit (SSO). The rocket is 115.4 ft tall with a 7.5 ft diameter. The first stage occupies 55.7 of the vertical ft with 9 Aeon 1 engines for a total of 228,600 lbf-vac fueled by liquid natural gas and liquid oxygen. The second stage is smaller, only 37.4ft tall with a single Aeon Vac Engine.

As mentioned earlier the Aeon engines are 3D printed reducing the total parts required for a spacecraft engine to under 1,000 as opposed to the 100,000+ part engines used in the past. Any time you can reduce parts required by magnitudes the savings are immense. This strategy is similar to an approach Tesla has been claiming to aim towards for a long time. Currently cars are made of a ton of different parts, Tesla aims to use injection molding to build an entire car chassis in one shot. The cyber truck utilizes steel origami for its structural one piece internal/external frame. Relativity space uses 3D printing because it allows customizability between engines. They can easily make slight modifications which will maximize efficiency for any particular mission. Further missions with heavier payload have different demands than small low earth orbit satellites. 

The 3D printer they developed for rocket printing purposes is called Stargate. It is a robotic arm that 3D prints a custom metal alloy. 

At this exciting stage of the technology it is certain many efficiencies and new strategies are being realized on a regular basis. With their recent $500M round of funding they will certainly accelerate space travel. Having already partnered with NASA, who knows which space spheroid they’ll be printing on next. 

Ali Mustapha on the Biggest 3D Printed Building in the World with Apis Cor Printer

Recently I had the pleasure of having Ali Mustafa on the automated construction podcast to talk about his involvement as project manager on the Biggest 3D printed building in the world which was built in Dubai. This Large 10,000 sqft building set the Guinness world record for the biggest 3d printed building back in 2017, a record which has not been beaten since. 

The project was completed using an apis cor printer operated by 3 people on site. 

Many people are aware that Dubai has outwardly spoken about an initiative to increase the use of 3D printing in construction. Because of this expressed interest, there are now a handful of buildings in Dubai constructed using 3d printing. 

Dubai has so much innovative construction pushing the limits of engineering. The well known Burj kalifa is the tallest building in the world. The speed at which the city of Dubai rose from the desert shows the speed at which they build and Ali believes that 3D printing will accelerate the building process further. 

You may be wondering how such a small printer can build such a large building. The key lies in its manageable size. It is a small unit that does not require tedious assembly on site unlike the larger gantry style printers. This unit functions like a robotic arm extending its nozzle from a central point. Need to build bigger than its radius? No problem. Simply move the printer to the next point on the build and resume printing. 

Apis Cor is currently working on a project in Louisiana where they are hoping to complete 2 big firsts. If successful, their project will be the first regularly permitted building in America and also the first 2 story 3D printed house in America. All the other 3D printed houses currently completed in America have had special circumstances around them making their construction possible. Once there is a precedent in the permitting system it will become significantly easier to win permits in the future. Many potential buyers are dissuaded by the concept of 3D printing a building because they fear the permitting issue, once more projects have been completed that fear will dwindle down and the industry will move into a more mature stage. 

During the construction process Apis Cor will be doing an instructional workshop on printer operation for companies that have put a $3000 down payment on the Apis Cor printer. The potential for an event like this is exponential because the number of people with a deep understanding of the tech will drastically increase. At this point, education is one of the most critical aspects of growing the automated construction space. The most fun part of my job is being surrounded by brilliant forward thinking risk takers. Everyone involved in the construction innovation revolution shares a common willingness to challenge the status quo and tackle the most critical issues head on. 

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Reflection on discussion with Henrik Lund-Nielsen CEO of COBOD

I finally got the chance to talk with Henrik Lund Neilsen the CEO and Founder of COBOD. After automation caught his interest, Henrik personally went on a world tour of 35 3D printing companies that he was able to compare and contrast in his pursuit of bringing this technology to a bigger scale in the construction industry. After this grant funded journey, COBOD emerged with the BOD and eventually BOD 2 concrete 3D printer. 

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COBOD has a unique value proposition for their customers seeking to gain a competitive edge in the construction industry. 3D printing addresses the labor shortage in the construction industry that makes some regions very expensive to build in. On top of that, speed and reliability are two major advantages 3D printing can offer as well. Construction is multifaceted with each facet behaving slightly differently depending on location. In some regions of the world labor is cheap but the people may be unreliable, other areas the labor can be 10x more expensive and even more unreliable! Long term automation and technology offer a solution to the reliability problem. Construction automation seeks to mend the reputation of over budget over schedule construction projects that the world has become so used to. If you’ve got a contractor that always sticks to the schedule don’t loose their number any time soon there is still a ways to go before 3D printing is ubiquitous.

Henrik ensures that any modifications to the printer will be made retroactively available for existing customers. This is a strategy shared by another 3D printing company ‘Prusa’. It is a relief to see some construction 3D printing companies taking notes from the forward thinking printing companies rather than the traditional printer models where the profit is all in the ink. Unlike many other companies COBOD chooses to be material agnostic without a restrictive warrantee. 

Without going into too much detail, Henrik told me they have developed a ‘magic’ material that can make regular concrete buildable. This method requires 1% additional material added to the regular mix. Unlocking the solution to a more affordable buildable concrete will have an enormous impact on the economic feasibility of 3D printed concrete. 

Henrik wanted to stress the importance of scale when printing concrete. There is benefit to allowing more time between layers so when you are using a tiny 3’x 3’x 3’ concrete printer then you may only have 30 seconds between each layer. Scaling up to 40’x 50’ + yields significantly more space to print thus increasing time to complete each layer ultimately makes the entire process more efficient. Some projects take longer than others, we briefly discussed how some projects aimed for a 24 hr print time whereas others choose to spend months on a print in order to academically dissect and observe the process. Like every person I’ve spoken to pioneering this novel industry, Henrik is not shy to admit progress and improvements are being made with every build. Very soon larger multifamily developments will test the potential of automation and if they demonstrate favorable economic viability we’ll start to see similar projects pop up all over the world. 

First Ever 3D Printed House for Sale Listed on Zillow for $299,000 USD

SQ4D has developed their own concrete 3D printer. As you can see from my first video below at one of their builds, their printer is a collapsible gantry system on rails. It is very unique because of its ability to mechanically collapse itself for ease of transport and disassembly. They do not publicly disclose whether or not this printer is for sale but they have boldly become the first company to publicly list a 3D printed house for sale. They were able to do so because the permits for the building have been granted by the local municipality. The biggest accomplishment will be an Occupancy Certificate that will be granted after all of the inspections have been passed during the construction process. There are a few companies actively pursing the first Occupancy Certificate for a 3D printed house so the race is on to see who is able to complete construction with a passing grade first.

Almost a year ago I was able to find the location of an experimental 3D printed house that was under construction by SQ4D. That 1,900 sqft home evidently only cost them $6000 in materials   according to their website which seems incredibly affordable. It is very possible that they have gone back to the drawing board since that build to make improvements to the material which could potentially drive up the price by multiples. Overall 41% of the construction was done by the ARCS 3D Printer they developed which led to an overall savings of 30%. Generally speaking a new product should be at least 25% better than the incumbent solution so this 30% reduced cost prediction bodes very well for the future of the industry.

I’ve visited this project a few times as they made progress on the build. The concrete walls were done before I got there, it was the manual labor (Roof, Windows, Doors, Gutter, Siding) that took the longest. Last time I was inside I saw that some of the walls had been smoothed out with concrete to give the interior a flat finish. For many people, the ability to hide the fact that the home was printed makes it much more appealing although personally I appreciate the raw nature of the exposed concrete. 

Their newest project to be constructed is a 1,500 sqft 3 bedroom 2 bathroom house. SQ4D is offering a 50 year limited warrantee on the build which is incredible considering that it is the first time a 3D printed house has ever been listed for sale. It is certainly understandable for a buyer to be wary of a new technology so this warrantee is a very important demonstration of SQ4D taking accountability for their work which helps the pioneering buyer be more confident in their decision. The home will also feature a 750 sqft 3D printed garage to match. 

List price has been set to $299,000. According to zillow the average home in this neighborhood is worth $394,000 so it is very likely the house will sell over list price especially in the current housing market where the supply has been low and prices have been increasing. 

It will be very interesting to follow along this project as SQ4D makes history. 0 to 1 is the hardest step in an emerging industry, it is a sure sign of some very exciting builds to come. It is very challenging for people to get out there and be the first in anything but after the first bushwhacking pioneers make it through the rough patches early adopters start to pour in. As exposure and footprint of this technology increases so will its capabilities. Economies of scale will make this already cost saving technique vastly more efficient as competition increases on all fronts, hardware, software and material. If you’d like to stay up to date on what I learn about this industry, subscribe on YouTube or the email list on

Zillow Listing:,-NY,-11901_rb/2075583035_zpid/

SQ4D Website:

3D Printed Building in Florida by Printed Farms using a COBOD BOD 2 Printer

Printed farms is a construction start up that has recently purchased the first COBOD BOD 2 printer in America. This gantry style system has been seen in Europe and was used by Kamp C to build a 2 story demo house there. The same system is also being used to build another 2 story home and also a 5 unit apartment complex. 

I got the unique opportunity to be on site as Printed Farms began construction of their first building. The financier of the project decided their first build would be a 30×30 tractor shed. In Florida the hurricanes can have extremely high wind speeds. Fortunately the printed concrete is very sturdy with a strength over 5000 psi. 

Although Printed Farms is a relatively new start up their founders Jim Ritter and Fredrik Wannius are not new to construction. They have financed construction projects across a range of uses and realized in that process how inefficient traditional construction models can be. Many of these struggles relate to organizing the large team of people that it takes to construct a building especially with the ongoing shortage of manual labor in many regions. Reducing manpower needed for the job is only a small part of the benefits realized with 3D printed construction technology. Data is everything and when you have a BOD 2 system plugged into a laptop onsite you have full control of the project at your fingertips. 

The printer is equipped with various sensors to improve ease of use but it still requires some training to operate. If the ground or slab that you’re printing on is uneven, the BOD 2 is able to compensate for those irregularities, there is also a sensor in the extruder portion of the printer that alerts the concrete pump to send more through the hose. Generally the COBOD team would come out to train the print operator in person but due to typical 2020 complications the training process was completed online. Fredrik has become very competent with the massive 3D printer and feels like the online training was very good although he still collaborates with the COBOD team if he has any questions. 

Printing outside exposed to the elements was a substantial feat achieved in this build. Many projects have needed protective tents surrounding them in order to maintain specific temperatures and humidity. When you need to build a temporary structure around an entire construction site things start to get expensive with the current solutions. Floridas natural climate allowed for this project to be completed outside. 

Printed Farms has many fascinating projects in the pipeline that Fredrik discusses in the video. Although most of the printing is currently experimental, 3D printing in construction is at a transformative stage and soon its products will become consumer facing. 

12 Steps to Operate a Concrete 3D Printer

Recently I had the incredible opportunity to be one of the first Americans to see the 3D printed Fibonacci house under construction by Twente Additive Manufacturing. Maybe you saw it in the video I posted last week.

I also got to explore their facility and watch a few prints. I took the opportunity to ask pointed questions about the process so that I could compile the golden nuggets of knowledge directly from the experts during a print to share with you. For this weeks video, I have made an instructional introduction to operating a concrete 3D printer. There is a lot going on and so this short video barely scratches the surface of the various challenges one can face with different prints. Like Jim Ziemlanski says every print is different and with those differences come different challenges. At this point Jim has racked up many hours on the machine and is highly knowledgeable.

To understand what is involved on a basic level, here are the steps I’ve contrived from my observations during my time in the Twente Additive Manufacturing facility. 

  1. Design
  2. Test Run of first layer
  3. Choosing 1K vs 2K material
  4. Filling the mixer
  5. Dialing in the details
  6. Material consistency testing 
  7. Water Content Testing
  8. Backpressure
  9. Print 
  10. Watch for problems
  11. Analyze water content
  12. Insert rebar & lifting hold
  13. End the print gracefully

Designing the file is usually done in Rhino with the Grasshopper plugin. This is the industry standard software for parametric design in 3D printed construction. The file is then converted into a print path for the specific printer and its parameters can be updated in real time during a print if any changes need to be made thus eliminating the need to start over. 

Next you test the first layer path of the printer to ensure that you are printing on a uniform high from the print surface. If you print surface is uneven it may be possible to compensate for that with your printer assuming it is a correctable margin (< 2cm). It is best to start on a perfectly flat surface because that will ultimately be the plane of your objects first layer. 

Twente prints in two different material types, 1K and 2K. 1K is a simpler concrete mix developed by Laticrete. I’ve had Matthew Carli, the Director of Innovation at Laticrete on my podcast (Episode 3) to talk about the 3D printed construction space. The 2K material is developed by Baumit and requires a unique Baumit extruder along with an accelerant additive that is plugged into the nozzle and extruded with the proprietary material that it reacts with to allow the concrete to be printed on steeper angles, even permitting bridging and overhangs that would not be possible with regular concrete. As one may expect this more complicated material is much more expensive. 

Loading the concrete mixer is the next step. The mixer used at TAM is loaded by hand but long term as the demand increases for 3D printed concrete parts it is likely they will use larger hoppers so they need to fill them less often. 

Before printing, the concrete mix has to be dialed in properly. The settings need adjusting based off environmental factors like humidity and temperature. The hose from the mixer is nearly 20 ft long so it takes a while for the changes made to show in the end of the extruder. As the concrete drips from the extruder it is collected in 5G buckets and used for something that doesn’t need as particular parameters that way it doesn’t go to waste. 

To verify the water content wt% a 50 gram sample of the wet extruded concrete is taken and microwaved to remove the water. It is then weighed again to determine how many grams of water were in it. This difference in weight allows you to find the wt%. 

Before you start printing, back pressure must be applied to the extruder that way the concrete hose from the mixer stays full and doesn’t get any air pockets. This is done by hand with a spatula until the printer hits the print bed and starts on the first layer. This is similar to my Prusa MK3 desktop 3D printer that will extrude excess plastic which needs to be removed immediately before the print starts. 

Printing is actually the easy part. If everything is going smoothly all you have to do is watch but at this scale, issues can be costly and time consuming to clean up so its best to keep an eye on it. Concrete has a tendency to clog so if the print shows signs of looking sloppy it may be best to pause the print, clear the clog, and resume from where you left off. Other issues can arise if the design doesn’t allow the concrete enough strength to support itself. Making a 3D model is easy but without an understanding for the limitations of a printer/material a novice could easily design something impossible to print. While printing, it would be wise to do more water wt% calculations as you go. 

During the print it can be opportune to add supports in the form of rebar or supports for a hold that the piece can be lifted from in the future. This can be done by hand as long as it is placed evenly to allow the next concrete layer to print over top of it. 

Ending the print is similar to starting it because once again you must apply back-pressure to the printer that way it doesn’t drip all over the freshly done print. This is once again done with a spatula by hand. 

Just because the object is done, doesn’t mean you are. Next every part of the system that touched wet concrete has to be cleaned rigorously otherwise it could easily ruin the equipment. This paragraph is short but that process is long. 

Next week we will take a look at the things TAM has printed around the grounds of their facility. There are all kinds of prints they have achieved that range from practical to creative. We will also take a look at how the offsite prints are transported to their final locations. 

Icon 3D Prints Tiny Homes and Military Defense Structures

Recently I got the chance to speak with Dmitri Julius and Alexander Le Roux from Icon. If you haven’t heard, Icon is a startup that raise $35 Million A round led by Moderne Ventures to continue their progress developing the equipment and methodology for 3D printing buildings at scale. 

Our initial scheduling got rained out.  According to the head of communications at Icon, Brooke Baguess (who was instrumental in organizing our interview) filming after the rain is somewhat of an unintentional tradition for Icon. Also unintentionally, the day we had to reschedule for was 9/11. Coincidentally, Dmitri Julius had served in the US Marine Corps for 8 years earning the rank of sergeant starting in Feb 2003 only a year after the attack on the twin towers. I felt compelled to thank him and the rest of the troops/first responders for their service. 

Dmitri still has the chance to interact with the US Marine Corps in his role as Vice President of Operations at Icon. In California, a project was completed to 3D print a ‘Vehicle Hide Structure’ that could serve to conceal a cargo or weaponized vehicle. Icon has an ongoing relationship with the military that should prove mutually beneficial for years to come. 

Mobile Loaves and Fishes is the non-profit organization that Icon 3D printed these homes in Austin, TX. They’ve built a growing community of tiny homes that features an ICON made building as the welcome center. Homelessness is a rising issue in Austin, America, and around the world. ICON is poised to combat that with their technology. Dmitri mentioned that as Mobile Loaves and Fishes expands, ICON has stepped up to the plate and hopes to print many more homes for them in the future. 

I asked Dmitri how his role at ICON changed pre and post funding. Dmitri expressed that at their startup no task is ‘beneath’ them and the team is willing to get their hands dirty on the job site when it’s needed.

Icon is on a bit of a hiring spree post funding and as they begin to fill those positions and the company expands the real changes will start to manifest. A big fundraise is huge for a startup but the effects are not fully realized until the money gets spent. 

Next I spoke with Alexander Le Roux, a Co-Founder of Icon and also the CTO. Alex started his first 3D printed construction company in college called Vesta printers. He achieved a rudimentary design that demonstrated the ability to print concrete vertically high enough for a wall of a home. 

After college he met Jason Ballard and Evan Loomis. Together the three of them founded Icon to take the technology to the next level. 

Icon has developed a signature formula to print with that they call Lavacrete. It has a strength of 6000psi and as you can see in the building behind me (not even the latest version) it prints very smoothly. We constantly use the term ‘print’ to describe the automated pouring of concrete without any formwork, I can’t help but consider that in the mature stage of this presently niche industry companies may emulate the business model of paper printing companies and sell the printer at a loss to profit long term on the ink. 

Alex and I talked a bit about the future of this technology. He mentioned how people tend to overestimate what can be done in a day but underestimate what can be done in 10 years. I wanted to know about projects on the horizon for Icon especially now that they have the funding to pursue bigger things and Alex said he can’t talk about it but I could tell he is very excited for what’s to come. If you have a project in mind that you’d like to do with Icon, Alex says to go to their website and use their contact form. They won’t accept just any project but if it is a good fit they may be willing to work with you.

After our discussions I checked out one of the homes they built, I could only go in the living room at the time but it was very nice. It certainly had a tiny home vibe, the room actually featured a full kitchen as well. The space is well utilized and it doesn’t feel cheap like it would if it had been built with cinderblocks. 

Check it out yourself at the link below. 

Reflection on discussion with Max Trommer, CEO of Rebartek

I recently had the opportunity to speak with the CEO of Rebartek AS Max(imillian) Trommer. His startup has developed an autonomous system of building rebar cages offsite that can latter be connected on site. 

large projects take thousands of man-hours assembling rebar cages. This time consuming process can hold up the schedule especially in places where labor is hard to come by like Norway where Rebartek is headquartered. Currently Rebartek does their fabrication in their facility, but there are many exciting developments ahead for their tech. One concept being tested is a semi mobile gantry system that could be brought to a construction site to decrease the shipping expenses of the assembled cages. This makes a lot of sense if you consider the volume of an assembled rebar form vs the the volume the rebar would take up if it were unassembled and parallel. 

Max started this company a couple years ago after working on a large bridge project and seeing firsthand how costly and time consuming it was to assemble the rebar. Initially he had a partner that helped him get the concept off the ground which was a key component for the concept because Max had no prior experience with automation robotics. Fast forward to now and his perspective on the complications of automation has changed drastically. 

Their initial concept has been realized but with more experience, Rebartek is now fine tuning the system and using machine learning to achieve a variety of efficiencies. 

Norway like many other countries faces a serious labor shortage that if left unsolved will lead to serious bottlenecks in the construction industry. Long term, a weak labor force means less buildings will be built and affordable housing access will decrease. Rebartek offers a solution to lighten a slice of this shortage and offer benefit to the construction schedule. 

Max would like future engineers to consider how to pursue parametric design and code based solutions and recommends pythons as a very versatile useful tool for aspiring engineers looking to automate tasks. 

As Rebartek continues to develop their technology and increase the efficiency of their product offering they will build a very compelling backlog of projects. It will take more projects to accurately depict the true time/cost savings because every project is so different but as always with technology over time there is no doubt we will see significant developments. 

Check out the Rebartek Youtube channel to get an idea of how their tech works.

Can You Buy a 3D Printed House?

This is the most common question I receive from both the YouTube comments and my website

If you’re watching this video maybe you’ve seen some of my other videos where I tour 3D printed buildings and make content around the automated construction industry. Thanks to viewers like yourself, I now am getting access to opportunities and companies that previously had no interest in responding to me and because of you I’ll be able to make some really awesome videos coming up with some really awesome cutting edge companies. 

3 times a week someone will call me asking if a 3D printed house can be built their neighborhood so I figured it would be helpful to make a video answering this simple question. 

The short answer is yes but if you are looking to find the cheapest option, the tech is so new that it will be challenging to find someone that has a printer and the skills to use it who is willing to do a project with just one home. If you need a regular house built, the construction equipment for that project is available at every construction equipment rental outlet in the nation.  By my estimations there currently under 100 large scale concrete 3D printers capable of printing a tall enough wall for a house. 

To buy a 3D printed house, you will either have to make a deal directly with a company and pay them enough to convince them to use their very busy printer to make one house for you or buy the entire printer yourself which could cost more than the house. 

Ultimately the dream of automation and technology is to decrease the price of work therefore allowing more people and organizations access to building tech that would have otherwise been out of reach. Unfortunately in order for this goal to be realized the industry needs to get bigger in order to realize efficiencies of scale. Think of the way Tesla first sold their expensive roadster car back in 2010, it was nearly 10x more expensive than the Tesla model 3 that you can buy today. Teslas use of cutting edge automation in their manufacturing plants gave them an edge that has become impossible to ignore but for a very long time before the economies of scale were realized, many people thought the industry of electric cars would never be profitable and for a long time Tesla was the most shorted company on the US stock exchange.

It’s no secret there is a serious labor shortage in construction here in America and many other countries around the globe. Some are concerned automation will replace jobs but think of it this way, there are so many different types of architecture and there is room for all of them. No matter what there will always be people that appreciate a handmade building over one built by machines. 

The labor shortage is causing less new construction projects to be started. This is a major problem because according to there is a shortage of 2.5million houses that need to be built in America. 

I’ve been in Austin for the past few months and in the short time I’ve been here I’ve seen the number of tents on highway medians and under bridges double and housing is only getting more expensive. 

The reality is unless more people start picking trade school over college homelessness and shelter insecurity will become an increasingly pressing matter. 

If you do still want to buy a 3D printed house the first big question is will it be permitted in your local municipalities zoning laws and construction code. The construction technique is so new that it can be tricky to figure out the permitting situation. 

If you want to make the process go smoothly then you can replicate traditional construction methods like CMU concrete blocks and fill columns of your printed concrete with rebar and traditional poured concrete. This is great for helping your municipality understand your project and getting though the paperwork quicker but because you will need to rely on traditional construction methods for all the structural elements of the building you will not realize the labor efficiencies. 

To print the house using the printed concrete as a structural element of the building, you force your architect or engineer to venture into unknown territory. For a professional engineer to sign off on your plan, you will need to test the structure to failure. Yes, this means that if you want to build a 3D printed house that is structurally dependent on printed elements then you must build not one but two houses because one of them will need to be destroyed in order to be sure it is strong enough. This is an irritating barrier to entry that is not cost effective at all but it is absolutely critical to ensure the safety of every house built with this technology. 

Thinking about the big picture this isn’t important, it’s only a temporary setback before enough data is collected for engineers to be able to accurately predict the strength of printed concrete elements every time, but for now every new structure must be proven to failure. 

Short term, a clever way around this is to use repeating modular segments that are identical. If you can build a house out of 3 or 4 different modular segments for example, one for a wall, one for a corner, one for a window and one for a door, then you only need to test each of those segments once and they can be printed and repeated into infinity as long as you continue testing the concrete parameters. 

If you wanted to build multiple similar units then this starts to make a lot more sense from a financial perspective because you always have the fixed cost of testing the new design so the more you build the more cost effective it gets. 

One of the major benefits of 3D printing as opposed to prefab is that your machine is capable of infinite designs as opposed to prefab units that are identical. If you want to build 1000s of units of the same building for the lowest price and fastest time then prefab is your best bet. If you want units that look unique, 3D printing concrete becomes a much more interesting option but the current environment of regulation is holding the tech back from its full potential and rightfully so until the safety standards have been proven to a sufficient redundancy. 

If you watched this entire video and you are still interested in getting a 3D printed house built for yourself knowing that being the first in your area to do so could be an expensive challenge then feel free to send an email to and I can try to help. 

If you have any questions don’t hesitate to let me know in the comments, I will try to answer them as best I can. I am working on redeveloping my website to include a job listings section as many companies competing in the race to automate construction are currently hiring especially Engineers and Architects with parametric design experience. If there is anything else in particular you think would be a good addition to the website let me know. I would like to provide a place where resources are available for people pursuing automated construction projects who need them.

If you’ve signed up for my mailing list already which includes 114 people at this point thank you, soon I will be sending the first one.  for many people, their email inbox is a sacred place not to be bogged down with constant spam. Because of this I will make sure to only send emails when it is really worth it, maybe once or twice a month. It’s really meant for the people who have a deep interest in the long term prospect of automated construction, so if you’re only interested in the surface level project videos, then there is really no need for you to be on the mailing list. 

I hope this video answers some of your questions and that you aren’t too disappointed you can’t just order a 3d printed house online and have it come in a week for under $100,000. In time all technology is improving incredibly fast and there is no reason to suspect that this technology won’t ultimately be the same.

If you want to learn more, check out my other videos where I cover 30 companies competing in 3D printing houses and tour various 3D printed buildings.

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Reflection on Conversation with the CFO of BEMORE3D, Jose Luis Puchades Valencia

Recently I got the opportunity to speak with a cofounder and the CFO of BeMore3D, Jose Luis Puchades Valencia. BeMore3D developed their own large scale concrete printer. They started as a 3D printing company with plastics but then developed a 2×2 meter printer as a proof of concept for printing concrete and from there they engineered the much larger printer that they use today. 

Their biggest accomplishments to date are printing the first houses in both Spain and Africa. A focus on materials is at the heart of BeMore3D, they are constantly working on developing solutions and have experience fine tuning their mix with local ingredients to achieve a cost effective material to print with.

Jose told me that soon they will be unveiling a brand new website that will be transformative for their online presence and allow potential clients a whole new suite of functions including the process of buying a large scale concrete printer from BeMore3D. If you don’t want to wait for their new website you can contact them directly and place an order. 

You can see in the house printed in Africa that the project goes through the whole day and as the sun moves there are drastic changes in the temperature and humidity. Concrete is sensitive to these factors so BeMore3D has included sensors in their printer that detect the ambient conditions for the project and adjust the parameters of the print like how much water is included in the mixture. 

By using polymeric fibers in their concrete mix they are able to avoid using traditional steel supports and rebar. Eliminating the need for these things down the line will really help in maximizing the autonomy of the project. BeMore3D has many exciting projects lined up, I will be sure to track their accomplishments as they grow and spread their tech around the world. 

Mighty Buildings Modular Prefab Houses Incorporate 3D Printed Synthetic Stone

There is a brand new company with 30 million in funding from silicon valley investors on the scene of Automated Construction that just came out of stealth mode in August 2020 and they’ve already delivered their first  2 units to customers.

Anyone who has done construction in California is familiar with the shortage of skilled laborers that is driving construction costs through the roof stick built housing in California costs $321. Mighty buildings has developed a solution decreasing this cost by 45%. Of course if the land has precarious circumstances the cost to build a secure foundation could be well over the expense for the home.

Mighty Buildings has been developing a solution for 3D printing unlike any I’ve seen on a large scale. With a custom printer and custom material, Mighty Buildings has differentiated their product significantly from materials based on Portland cement.

They call it synthetic stone. This material is lighter and supposedly stronger than concrete while also having an even higher thermal resistance which is an enormous benefit in the fiery land of California. Having a home that is fire resistant to this degree can be the difference between having a place to go back to after a natural disaster. Unlike concrete which cures over time, Mighty Buildings synthetic stone requires ultraviolet light to instantly harden which creates such a strong structure that they can 3D print a flat horizontal roof with a breadth up to 14ft.

All of their printing is done completely off site in one of their controlled facilities. After it is printed they use a crane to drop it into place. If it is a bigger home then it will be placed one section at a time but the smallest model is all in one. Down the line, they are looking towards solutions that will chemically seal the modular segments together so that the exterior shell can form a monolithic impenetrable structure. Achieving a monolithic structure offers many benefits like preventing water damage, and improving insulation which in turn can decrease your electric bill and improve the overall sustainability of your home. 

Mighty buildings first home has already achieved a Certificate of Occupancy  for their first residential homes and the occupant seems quite satisfied so far. This was made possible largely because they got the material they are using to be UL certified which goes a long way in cementing the legitimacy and trust in their product. 

Mighty buildings is much more a tech startup than a construction company and that is evident in their approach to the entire process. It will be very exciting to see this company grow as they reach their early adopter customer base and begin to receive feedback on a large scale on what it is actually like to live in one of these homes. As with any tech I am positive that Mighty Buildings will be constantly trying to improve their product. 

3D printing lends itself to intricacy because if you can make a really cool model or a unique parametric design then a 3D printer can achieve a level of detail that would be absolutely cost prohibitive otherwise. Designing models like that can take a long time but once they are made they can be printed over and over with the press of a button. Because of this there is no doubt that the Mighty Buildings catalog will be expanding drastically over time.

If they had no interest in offering a diverse lineup of products then they would have just build injection molds for their current product line but instead they opted for the infinitely more versatile option of 3D printing. 

In the near future I have some really awesome videos planned with some really awesome companies, I am really looking forward to stepping up my game as I continue to research automated construction sharing my findings.

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Reflection on Conversation with Peter-Paul Van Der Berg and Marijke Aerts

Today, over an hour into an episode of the Automate Construction Podcast with Peter-Paul Van Der Berg and Marijke Aerts I realized it was not recording because I was signed into the wrong email address when I sent out the invitation to the meeting. After noticing this I was able to turn on QuickTime screen capture which could only record my screens visuals not the audio, I used my phone to record the meetings audio from my laptop and tried to sync up the sound. I will try to recount the missing details from the first portion of our conversation because it was a terrific eye opening experience for me and I’d like to share it.

The Kamp C team and its critical partners have 3D printed the first multi story house in Europe, specifically in Antwerp, Belgium. This was a showcase project meant to demonstrate the possibilities and practicality of 3D printed construction techniques.  Peter-Paul said the printing of the house went off without a hitch and there were not big issues to be resolved which is incredible considering this house is the first of its kind in Europe.

The house printed in Belgium was done without any rebar or internal supports besides the printed concrete and the insulating foam. The interior wall and exterior wall of the building are completely separated with no bridging to maintain the best insulating properties. Many people have requested Kamp C build them a model of the house but Kamp C is not a typical construction company and they are primarily in the pursuit of exploring new technologies and strategies related to construction. 

There is a newer project in Belgium for a recreational space that will be 3D printed that Kamp C has been assisting with. The number of projects in this space will increase over the coming years, one group plans on printing 7 units in Belgium by 2023. 

Kamp C is not your typical construction company, they are funded in part by the local government in the pursuit of innovation and sustainability. They are working on building commercial buildings with ‘circular’ construction which means that over the course of multiple decades they will build 4 buildings, one at a time and after the life of the first one has expired it will be deconstructed and the materials from the first building will be used to rebuild the last, if the project is successful the parts from the other buildings will be reused many times over as well. 

They also gave a really interesting example of what differentiates their strategies from traditional construction companies. In the circular building project they want to lease out the products of certain construction trades like windows and lighting so that the contractor is responsible for the life of the project not just the deliverable on the last day the final punch list is closed out. This strategy is being implemented in order to change the way construction is perceived and keep investors from cutting corners in order to get the job done quickly or cheaply when there are better long term solutions available. 

It was very unique that an organization tied to the government was willing to hop on this podcast with me. One thing they mentioned is that when someone comes to them with an idea, first they say yes and then they figure out how to get it done. This open minded attitude and entrepreneurial spirit is what seems to drive Kamp C toward the unprecedented type projects they tend to work on. Governments can sometimes regulate and impede markets but by supporting Kamp C Belgium has made it clear they are dedicated to exploring cutting edge solutions. Belgium will see an advantage when these construction techniques catch on and they already have some experience. 

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Introduction to Material Science and Rheology of Extrudable Concrete for 3D Printing in Construction

3D printed construction might be the most promising way to automate construction so recently many people have been pursuing the perfect mix for printing. Rheology is the study of how materials flow so that is the science being applied to concrete made for printing.

My name is Jarett Gross and I’ve gathered this information mostly from research featured at Digital Concrete 2020 to simplify some of the material science behind forward thinking disruptive construction methods. 

These materials range from nearly free adobe mixtures of dirt and straw to ultra strong and highly engineered custom concrete hybrid mixtures that can be cost prohibitive in respect to affordable housing. 

Currently most groups automating large forms are using unique mixtures of concrete engineered to have properties conducive to a sturdy structure.

The material needs to hold immediately exiting the machine. Generally that is either achieved by a stiff mortar or a thinner mix with an accelerant added at the point of extrusion to cure the concrete faster and achieve angles gravity otherwise would not permit. (1)

Thixopotry is a property that allows a mixture to flow when it is being moved but remain firm after it has been placed so this is behind many of the developments in this space.

Some of these mixes include various forms of supports which I will cover in an upcoming video, others are strong enough to support themselves like the project in Brazil by InovaHouse3D. 

Many mixtures have been considered using Portland cement. Wollastonite micro fibers have been shown to enhance flexural strength without detriment to compressive strength. The same study shows printed concrete demonstrates anisotropic behavior, in other words like the grain of wood it fails easier parallel to the grain vs perpendicular to the grain (2)

Mixes can be thick or have more flow, these properties can be influenced by viscosity modifying admixtures’VMA’. NanoClay can improve the strength of the print but makes the mixture more susceptible to clogging to viscosity modifying admixtures can improve the flow. (3) 

Two minute delay time between layers has 25-86% higher strength than a 15 minute interval it is important to get a monolithic structure (4)

Fly ash silica fume metakaolin limestone powder and quartz powder have been identified as having useful properties for printed concrete. Plasticizers, accelerators, retarders, and viscosity modifying agents can be used but increase cost dramatically (5)

Limestone can be implemented with less cement to decrease cost to print and improve sustainability. 

Under a 25% replacement rate of limestone powder to cement, the impact on strength is within reasonable limits.  (6)

Metakaolin leads to a more dry mix that is stronger after extrusion but more difficult to extrude. Fly Ash can be included to improve the printability. Adding polypropylene fibers was shown to increase the yeild stress. (7)

Here are the details from a mix made in a region where dune sand is an abundant resource (8)

  • Cement was replaced by up to 10% silica fume and 30% fly ash
  • water-to-binder ratio used in the mix ranged between 0.35 and 0.40.
  • superplasticizer was added in the range of 1 to 3%, by binder mass.
  • compressive strength increased by 3% when 20% dune sand was utilized, but decreased by an average of 3% for every additional 10% subsequently.
  • superplasticizer and higher water- to-binder ratio exhibited improved workability
  • replacing cement with silica fume and fly ash, the slump flow and pumpability increased
  • Compressive strength increased by an average of 4% for every 10% fly ash replacement. The incorporation of 10% silica fume improved the strength by an additional 14%

Lightweight foam concrete is common but to use it for 3d printing it would need to be extrudable. Extrudable lightweight foam concrete could be great for 3d printing because of its thermal insulation and accoustic qualities in addition to fireproofing. 

The target dry density was 800kg/m^3 because that was figured to be the best balance between strength and staying lightweight. (9)

Structural fibers had a negligible effect on the mixes strength in tension, it is theorized that the fresh state properties of the material prevent the fibers to anchor in place which prevents tension strength (10)

As I mentioned, I will soon do a video on the support methods used for this type of construction. Another video on commercially available mixes for printed construction will probably be 3-6 months away as there are many solutions still in development that I would like to include. 

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(1) Enhancing Buildability of 3D Printable Concrete by Spraying of Accelerating Admixture on Surface 

Shantanu Bhattacherjee and Manu Santhanam Department of Civil Engineering, IIT Madras, Chennai 600036, India,

(2) Effect of Wollastonite Micro-Fiber Addition on Properties of 3D-Printable ‘Just-Add- Water’ Geopolymers 

Shin Hau Bong, Behzad Nematollahi, Arun R. Arunothayan, Ming Xia, and Jay Sanjayan 

Centre for Smart Infrastructure and Digital Construction, Faculty of Science, Engineering and Technology, Swinburne University of Technology, Melbourne, VIC, Australia 

(3) Use of the Chemical and Mineral Admixtures to Tailor the Rheology and the Green Strength of 3D Printing Cementitious Mixtures 

Mohammad Amin Moeini, Masoud Hosseinpoor, and Ammar Yahia 

Department of Civil and Building Engineering, 

Université de Sherbrooke, Sherbrooke, Canada Mohammad.Amin.Moeini@USherbrooke.Ca 

(4) Characterising Concrete Mixes for 3D Printing 

Atteyeh S. Natanzi and Ciaran McNally
School of Civil Engineering, University College Dublin (UCD), Dublin, Ireland 

(5) Rheology Evaluation of Cement Paste with Nanoclays, Nanosilica and Polymeric Admixtures for Digital Fabrication 

Hugo Varela, Gonzalo Barluenga, and Irene Palomar Department of Architecture, University of Alcala, Madrid, Spain

(6) Effect of Limestone Powder Substitution on Fresh and Hardened Properties of 3D Printable Mortar 

Yaxin Tao, Karel Lesage1, Kim Van Tittelboom1, Yong Yuan2, and Geert De Schutter1 

1 Ghent University, Ghent, Belgium 

2 Tongji University, Shanghai, China 

(7) Effect of Metakaolin, Fly Ash
and Polypropylene Fibres on Fresh and Rheological Properties of 3D Printing Based Cement Materials 

M. Dedenis1, M. Sonebi1, S. Amziane2, A. Perrot3, and G. Amato1 

1 School of Natural Build Environment, Queen’s University of Belfast, Belfast, UK 

Université Blaise Pascal, Polytech Clermont-Ferrand, 63174 Aubière, France 3 Univ. Bretagne-Sud, UMR CNRS 6027, IRDL, 56100 Lorient, France 

(8) Fresh and Hardened Properties of 3D-Printed Concrete Made with Dune Sand 

Hilal El-Hassan , Fady Alnajjar , Hamad Al Jassmi, and Waleed Ahmed 

United Arab Emirates University, Al Ain, UAE 

(9) Investigation on the Rheological Behavior of Lightweight Foamed Concrete for 3D Printing Applications 

Devid Falliano1, Giuseppe Crupi2, Dario De Domenico2, Giuseppe Ricciardi2, Luciana Restuccia1, Giuseppe Ferro1, and Ernesto Gugliandolo3 

1 Polytechnic of Turin, Turin, Italy   

2 University of Messina, Messina, Italy 3 G. Gugliandolo s.r.l., Messina, Italy 

(10) Experimental Investigation on the Early Age Tensile Strength of Fiber Reinforced Mortar Used in 3D Concrete Printing 

Marta Fioretti1, K. Sriram Kompella1, Francesco Lo Monte1, Laura Esposito2, Costantino Menna2, Sandro Moro3, Domenico Asprone2, and Liberato Ferrara1 

Department of Civil and Environmental Engineering, Politecnico di Milano, Milan, Italy 

2 Department of Structures for Engineering and Architecture, Università degli Studi di Napoli Federico II, Naples, Italy
3 BASF Construction Chemicals Italia, Treviso, Italy 

Juliana Martinelli and Andre Dantas, Founders of InovaHouse 3D + 3D Home Construction | Automated Construction Podcast Ep. 7

3D Home Construction and InovaHouse3D have partnered up to build Brazils first 3D printed house in early July 2020. At 66sqm or 710 sqft it has 2 bedrooms and is currently being tested for its viability. 

My name is Jarett Gross, I recently had the pleasure of speaking with Juliana Martinelli, founder of InovaHouse 3D and Andre Dantas, founder of 3D Home Construction. You can listen to the whole 100 minute conversation at the link above.

Printing the first house in Brazil was no easy feat but this team was able to achieve that lofty goal spending only $35,000 of their own money to develop the printer and print the house. This is a bootstrapped, grassroots startup driven by ambition and a dream.

The original printer developed by InovaHouse3D was given the friendly nickname ‘frankenstin’ because of the ‘use what you have’ nature of their project. With McGyver like resourcefulness they managed to demonstrate the viability of printed concrete on their custom machine.

Frankenstein helped push many of the early innovations and learning experiences for InovaHouse3D. Through their learning process they decided to build walls that are not connected by an interior support structure and don’t even use rebar. 

The local municipalities often deal with many non-compliant construction projects done by the Brazilian citizens so maybe that is why they are willing to work with this company. InovaHouse3D is keeping the municipalities involved every step of the way. Fortunately, there is a precedent set there for concrete forms without rebar and by adhering to those standards the process is more simple than other countries with more strict building codes. 

InovaHouse was built on the dream of affordable housing for the masses. This is a Brazilian company that is looking to make an impact in their home country and help their people improve living standards.

Now this company is raising money to print many more houses in a new location. The details of their next project have yet to be revealed but we can hope for as many as 10 houses on the next construction site near Brasilia, Brazil. The newest project will require around $250,000 in capital, interested investors should understand this is a long term investment in a new technology with a large reward potential when this tech becomes proven enough to be mainstream. 

Digital Concrete 2020 Highlights

Last week I had the unique opportunity of attending the Digital Concrete 2020 event sponsored by Sika, Twente Additive Manufacturing, Weber Beamix, BEKAERT, Rilem, O-BASF, and DOW chemical. Every 2 years this event is held to highlight innovations in the future of concrete, generally it is an in person event however obviously this year it was moved online. In total there was over 1200 pages of research papers, over 100 presentations exclusive to attendees and 12 hours public YouTube footage. 

From bridges to buildings construction techniques are evolving at a pace never seen before and considering construction is the biggest industry in the world, these changes will have significant effects related to efficiency, safety, sustainability, and affordable housing.

Engineering is complicated but anyone can understand the basics of printed concrete. All of these innovations fall into three important categories. Many topics discussed relate to the synergies between these categories but everything directly relates to at least one, Material, Printer, or Design. 

People are experimenting with all kind of materials like dune sand, aircrete, dirt, salt, fly ash, metakaolin, Fe rich slag, and fibers like wollastonite fiber or polypropylene fiber. 

There are many types of printers, most fall into the category of gantry style or robotic arm but many are a combination of both for maximum mobility. 

There is much debate over the best method of reinforcing these large structures especially when trying to make them larger scale. Some companies have a mix that does not require post processing and others use rebar wire or screws to attain more structural integrity. There is also debate in onsite vs offsite printing and whether or not to use accelerant.

Design is a critical part of the process, without quality design the potential of these technologies would be squandered. The beautiful part is these technologies permit existing software for parametric design to be used to its full potential. 

If you are interested in the future of construction then I would highly recommend attending the next Digital Concrete event in 2022 as I am sure there will be many significant developments in this field by then. I put together this video of highlights but it was very difficult to pick only 10 minutes from the 12 hours of event footage, you can watch the whole thing on the 3D Concrete Printing TUe YouTube page. 

3D Printed Hyper-Sustainable Shelter Emerging Object Mud Frontiers Project

This is the one of the most cost effective and affordable solution for autonomous construction. Mud and straw has been used as a construction material for thousands of years but never like this. Could this be an early iteration of affordable housing that has 0 emissions? Creators Ronald Real and Virginia San Fratello said ‘On the 40th anniversary of the Smithsonian Magazine, they announced the 40 things you need to know about the next 40 years. Number one on that list was: “Sophisticated buildings will be made of mud”. Emerging Objects explores these frontiers of technology and material using traditional materials (clay, water, and wheat straw), to push the boundaries of sustainable and ecological construction in a two phase project that explores traditional clay craft at the scale of architecture and pottery. The end goal of this endeavor is to demonstrate that low-cost and low-labor construction that is accessible, economical and safe is possible. The project began in the contemporary borderlands along the Rio Grande watershed beginning in El Paso and Juarez and ended near the headwaters of the Rio Grande in Colorado’s San Luis Valley, which was the edge of the historic border between the U.S. and Mexico prior to 1848. The entire region has employed traditional pottery and earthen construction traditions for centuries.’

Reflection on Conversation with Twente Additive Manufacturing

I had a great time speaking with Ian Comishin and Jonathan Ladouceur, the President and Head of Engineering from Twente Additive Manufacturing. In the very beginning of our discussion they even gave a quick virtual tour of their facility and showed a project that they were working on just minutes before our call. The tour uniquely includes a look at their 9-axis printer, many companies keep the details of their mechanical tech under wraps so it is great for people to be able to see what the large concrete printing apparatus looks like. We also get to see the beautiful surrounding Canadian landscapes and some other outdoor structures they have printed.

The project they are currently working on involves printing objects that have increasing vertical angles. They achieve this by increasing the height of the printed bead of concrete on the right side of the wall without increasing the width. Achieving a quality finish with so many variables at play is a challenge that they seem to have beaten. Twente additive manufacturing has consistently been pushing the limits of their print technology. They have even printed the formwork for the slab that they are now building a house on. 

When asked where Ian sees Twente fitting into the 3CDP industry he said that he wants to help other people that need 3DCP tech figure out how to make it work best for them. For example, he is sitting on a staircase that he printed but if there was a company that specializes in staircases, he would be happy to get them set up with the tech to print custom staircases. 

Ian and Jonathan were very transparent in discussing some of the challenges that they have faced in their projects. The two have been working on the same teams for many years at this point. They both seem to agree with me that 3D printed buildings should leave some of the exposed layers as a demonstration of the tech but there are many people that would prefer a smooth traditional looking finish. 

About halfway through we get to talking about permitting and regulations. Currently printed elements can be used as a facade but not as the structural support of a building. In order for structural engineers to recognize the structural properties of a printed element they need to basically build 2 houses any time they want to print 1 because one house needs to be destroyed to demonstrate that it is strong enough to be valid. Of course every place will have different details and specifics when it comes to municipalities and regulations. 

Down the line, Twente hopes to build the biggest printer in the world somewhere in Europe. Currently they are looking for partners or clients to help them achieve this goal over the next 18-24 months. Jonathan even specified that their printer will be able to print onsite and offsite. There are many was to segment companies in this sector and Twente does their best to fit into all of them, they use both gantry and robotic arm printers, single material and dual material printers, the list goes on. 

I am sure we will see many more exciting developments in the 3DCP space from Twente Additive Manufacturing if you are interested in the details you can listen to the zoom call with the virtual tour that we recorded and put on YouTube.

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Reflection on my conversation with Luai Kurdi, Tech Lead at Besix 3D

Many of you know Dubai is a hotspot for futuristic construction tech so it was great being able to speak to Luai Kurdi, the tech lead for printing concrete at Besix 3D. Besix 3D is a subsidiary of Besix which is quite an established construction company in Dubai. They have really demonstrated their dedication to automated construction technology by printing modular concrete pieces for the walls of an addition to their headquarters.

Luai was on the call with me from his apartment in Dubai where he had a beautiful view of the sea from his apartment in what seemed to be a skyscraper, you can see his view for yourself at 1:19:30 in the video. 

As an architecture student Luai was always looking for new innovations and techniques for architecture even though his school primarily wanted to focus on teaching the old ways. It was on his own initiative that he learned about parametric design. Being skilled in parametric design, 3DCP became appealing to him because of the way the two subjects excel in collaboration. 

A benefit of their technology is that it has the ability to operate while maintaining social distancing. This means that even in April and May of 2020 they were able to complete some prints without putting anyone in harms way. 

In our lengthy discussion we touched on many topics like how the recycle any excess concrete, construction software of the future, heat resistance of printed concrete, concrete pumps, and much more.

Luai speaks enough languages to be considered a polyglot which is quite a feat, this helps him operate in a global environment and communicate better with more people. It is important that people interested in doing a project with Besix 3D have clear goals for what they would like to accomplish and at 1:41:00 you can hear about the typical issues with customer requests so that you can make appropriate considerations. Luai would like more engineers to enter the 3DCP space, the technology still has much progress to be made so it will require brainpower from engineers that will shape the future of contech to push to the next level. 

Reflection on a conversation with Fernando De Los Rios, Founder of Hyperion Robotics

Fernando de los rios may be the only person who has already worked at not one but two 3DCP startups. Many people have heard of Cazza construction but their project never came to fruition. Now Fernando is one of the founders of a company called Hyperion Robotics and they have a fully functioning concrete 3D printer.

We spoke about the printing process, how they build a pop-up factory around the print site to build on site occasionally and the concrete pumps they use. Hyperion uses a Kuka robotics arm as the foundation of their machine. They are working on some really cool projects that include artificial reefs and some exciting future builds that are still under wraps. 

Fernandos startup experience extends beyond Hyperion Robotics and Cazza Construction, he also was a founder at a company called Prix (pronounced ‘pre’) that did grocery delivery. At Hyperion his primary responsibilities are on the business end rather than the hands on engineering but working in this high tech space he has certainly learned very much about the tech. 

Hyperion is a company from Finland where they have a great startup environment to promote innovation and entrepreneurship. If you are interested in getting something printed you can go to