A recent study in Construction and Building Materials introduces EarthWorks, a method for 3D-printing recyclable earthen formworks using waste soil from construction sites. These shape-optimized, code-compliant structures offer an efficient and sustainable approach to reinforced concrete construction while supporting zero-waste and circular economy principles.
Study: EarthWorks: Zero waste 3D printed earthen formwork for shape-optimized, reinforced concrete construction. Image Credit: creator12/Shutterstock.com
The Challenge of Sustainable Concrete Construction
With urbanization accelerating and environmental concerns growing, reducing concrete use and improving sustainability in construction have become priorities. One solution is to optimize the shape of concrete structures to minimize material consumption. However, implementing these optimized designs requires custom formwork and skilled labor, presenting logistical and financial challenges.
Improving the efficiency of formwork production can enhance resource use and lower construction costs. Using a low-cost material like mud further reduces expenses. This study explores how locally sourced materials and additive manufacturing (AM), a flexible 3D-printing method, can address these challenges, making 3D-printed earthen formworks both practical and scalable.
Study Outline
For the study, the researchers tested various techniques for designing and printing formworks that accommodate conventional reinforcement, hydrostatic pressure, and precise connections. Instead of focusing solely on finished building elements, they developed temporary formworks for reinforced concrete, allowing for the creation of complex 3D geometries through continuous extrusion.
For the formworks, they used minimally treated mud, primarily sourced from construction sites. The mechanical properties of the soil were analyzed to optimize its suitability for AM technology. Large-scale 3D printing allowed for precise, custom-shaped formworks.
To improve performance, the EarthWorks method incorporated additives such as straw and a wax-like coating to limit water absorption from the concrete. Cylindrical samples with varying water content (5 %–20 %) were tested under hydrostatic pressure to assess the durability of the formworks. These tests, conducted by researchers at MIT, helped determine the most effective conditions for successful implementation.
Results and Discussion
The cylindrical formworks were tested under wet concrete at 0.11 MPa pressure, demonstrating good structural integrity. Failures occurred only in samples with 15 %–20 % water content. Cylinders with less than 10 % water content maintained their shape, while those with higher moisture levels showed stress-related buckling and splitting approximately 5 cm from the base.
These findings suggest that EarthWorks can support the construction of complex, optimized structures using a cost-effective and low-carbon formwork method. Unlike traditional wooden formworks, which require a two-step construction process—building the form first and then pouring the concrete—EarthWorks allows for the direct use of on-site waste soil to create precise, flexible molds, improving efficiency.
Beyond cost savings, this method offers significant environmental benefits. It reduces emissions associated with traditional formwork materials and ensures that concrete is used only where structurally necessary. According to the study, incorporating shape optimization through EarthWorks could lower the carbon footprint of reinforced concrete frames by over 50 %.
Future Applications
The study confirms that additive manufacturing can efficiently produce shape-optimized concrete structures using low-carbon, fully recyclable formworks. The EarthWorks method is already being considered for real-world construction applications.
To help transition this innovation into industry practice, the research team has established FORMA Systems. While adopting EarthWorks requires access to a large-scale 3D printer, the long-term material savings may justify the investment.
Beyond formworks, this approach could be expanded to other applications. Future possibilities include constructing templates for multi-story residential buildings using earth-based materials. However, refining and standardizing adobe construction techniques will be necessary to ensure cost efficiency. EarthWorks presents a promising pathway for building stronger, more cost-effective, and environmentally sustainable structures.
Journal Reference
Curth, A. et al. (2024). EarthWorks: Zero waste 3D printed earthen formwork for shape-optimized, reinforced concrete construction. Construction and Building Materials, 449, 138387. DOI: 10.1016/j.conbuildmat.2024.138387, https://www.sciencedirect.com/science/article/abs/pii/S0950061824035293
Disclaimer: The views expressed here are those of the author expressed in their private capacity and do not necessarily represent the views of AZoM.com Limited T/A AZoNetwork the owner and operator of this website. This disclaimer forms part of the Terms and conditions of use of this website.