The Center for Regenerative Design and Collaboration, a Costa Rica venture, has figured out a way to grind up junk plastic and mix it with concrete to make bricks, cinder blocks, and similar building materials.
The waste plastic doesn’t have to be sorted by type. The conglomeration is mixed with minerals to create a plastic-limestone concoction that’s then ground into a coarse sand. This “plastic sand,” which weighs only a quarter as much as the usual sand for building, is then blended with regular concrete, making up as much as 10 percent of the total volume.
The hybrid concrete can be used to make cinder blocks, patio bricks, and other building elements. The blocks meet or exceed all strength and fire-resistance standards set by the American Society for Testing and Materials and are marketed as a “green” building material.
The center has a pilot project in Cape Town, South Africa, which has both a major plastic waste problem and a crucial housing shortage. The plant there is being expanded to turn out 100 tons of the plastic aggregate daily, enough to make about 200,000 building blocks.
Pilot projects also are under way in Costa Rica and New Jersey and the company now is using its ground-up plastic to develop a hybrid asphalt.
TRENDPOST: The global revolt against plastic waste is leading innovators to move beyond recycling to find ways to reprocess used plastic into durable products from fenceposts to houses. The reprocessed plastic industry will grow rapidly through the 2020s as the world turns more sharply away from virgin plastics.
