Turning waste into building material

A US-based company has developed a new technology that repurposes excavated waste on building sites into building material, eliminating the problem of waste disposal. Watershed Materials’ onsite plant repurposes excavated material right at the job site to create concrete masonry units (CMUs) for use in the development.

The pop-up plant also helps the environment by eliminating truck traffic, reusing waste and reducing the need for imported materials.

The plant applies ultra-high compression to loose excavated material, transforming the waste into a sustainable CMU. The mineral grains turn into a sort of sedimentary rock under pressure, mimicking the natural geological process of lithification.

Watershed’s new technology is based on their compression technique developed earlier to reduce the amount of cement used in concrete blocks by 50%.

David Easton is the founder of the sustainable building materials start-up. Watershed Materials’ groundbreaking development happened in response to an enquiry from Naomi Porat, development manager of Alpha Group and part of the team working on the Kirkham Project, an urban infill redevelopment in San Francisco. The Kirkiham Project, which addressed the city’s need for additional housing, consisted of 445 new housing units, community plazas and gardens.

When neighbours began expressing concerns over construction traffic, the project site became the perfect place to assess the pop-up plant’s feasibility.  During the study, the Kirkham Project team identified compelling advantages of the onsite process, including reduced truck traffic, diesel emissions,  impact on neighbours as well as significant cost savings.