A new masonry building material developed by California-based startup Watershed Materials is twice as strong as concrete, offers a low carbon footprint and is based on the mineral geopolymers found in the world’s plentiful source of natural clay.
Funded by the National Science Foundation, Watershed Materials’ new masonry bricks have demonstrated a compressive strength of 7,000 psi. That’s twice the strength of concrete! Additionally, material tests have shown that the bricks offer superior weather and chemical resistance.
The bricks are also impressive from an ecological perspective. Currently, traditional concrete building materials result in about 6% of the planet’s C02 emission due their inclusion Portland cement, fly ash (a byproduct of coal burning) or blast furnace slag (a byproduct of iron and steel products). By contrast, Watershed Materials’ technology utilizes more ecologically friendly and globally available natural clay-based minerals to form strong geopolymer reactions.
Although natural clays have been used in building for centuries, their potential strength has to date been largely overlooked due to their lack of immediate binding capabilities. Watershed Materials addressed this by changing the clay’s chemical structure.
“These minerals were overlooked by others because they are not immediately reactive as a geopolymer,” explains Watershed Materials’ director of technology Dr. Jose Muñoz. “We’ve solved the puzzle to allow natural clays to form geopolymer bonds for the production of high strength building materials.”
As locally sourced clays all have their own specific makeup, the colour and look the materials vary depending on their local origin, introducing an element of diversity into the material designs.
Article by Els Zijlstra