Concrete construction typically relies on temporary wooden moulds, known as formworks, into which concrete is poured. These moulds are costly, labour-intensive to produce, and often discarded after use. Researchers at MIT have devised an innovative alternative using mud, a widely available material that can often be sourced directly from construction sites, offering a sustainable and cost-effective solution.

This new method uses lightly treated soil, strengthened with additives such as straw and coated with a wax-like layer to prevent water seepage from the concrete. Through the use of large-scale 3D printing, the soil is transformed into accurate moulds that are both reusable and fully recyclable. This eliminates the reliance on timber, significantly cutting costs and reducing waste.

Environmental and Structural Benefits
The environmental benefits of this method are noteworthy. Concrete production accounts for approximately 8% of global carbon emissions, but the MIT team’s approach allows for the creation of shape-optimised concrete structures that use significantly less material. This technique has the potential to reduce carbon emissions from reinforced concrete by over 50%. Additionally, the reusable mud moulds avoid the waste associated with traditional wooden formworks, further enhancing the environmental advantages.

The method also supports complex architectural designs. The flexibility of 3D printed soil moulds allows architects and engineers to create intricate or unconventional shapes more easily and affordably than is possible with wooden moulds. Using computational techniques called “shape optimisation,” the system ensures that concrete is applied only where structurally necessary, enabling the production of lightweight yet strong elements that minimise material usage and carbon output.

Collaboration Driving Innovation
The EarthWorks method, as it is called, is the result of a collaborative effort led by MIT PhD student Sandy Curth, who heads the Programmable Mud initiative. The project brought together architects and engineers, including Caitlin Mueller, an associate professor at MIT, who highlighted how this approach bridges the gap between innovative design and sustainability. “Concrete is a wonderful material when used thoughtfully and efficiently,” Mueller explains. “This technique enables performance-driven complexity with low carbon emissions and low cost.”

The research team has demonstrated that the system can be deployed without disrupting existing construction processes. By incorporating 3D printing technology directly on-site, this innovation offers a practical and scalable solution to reduce costs and emissions in construction.

A Vision for the Future of Construction
While the primary focus of this innovation is on replacing formworks for concrete, its potential extends much further. Curth envisions a future where entire structures, such as residential buildings, could be constructed using mud. In regions where adobe-style architecture is already prevalent, this method could modernise and systematise the construction process, providing affordable and durable housing solutions on a large scale.

A Step Towards Sustainable Building
This approach presents a transformative way to combine sustainability with advanced technology in the construction industry. By turning something as simple as soil into a reusable and environmentally friendly material, the EarthWorks project offers a compelling vision for the future of sustainable construction.

Source: MIT
Photos: MIT