The glorious Pantheon Dome in Rome, Italy, was built out of concrete over 2,000 years ago. Today, concrete is the most widely used building material in the world.
Concrete is a mixture of sand, gravel, and cement, which is made by heating crushed limestone – sedimentary rock formed from the skeletal remains of countless sea creatures buried on sea floors over millions of years.
Easton: “Cement is really bad for the planet for 2 reasons. The first is the emissions from the fossil fuel needed to bake all that limestone. And the second is that baking the limestone actually releases all the CO2 that those dead sea creatures sequestered millions of years ago. So cement’s a double whammy of a carbon footprint.”
That’s David Easton of Watershed Materials. Globally, cement and concrete are now responsible for six percent of all carbon pollution.
Easton’s company has created a formula that can make strong concrete blocks with just half the cement and using local sand and gravel, reducing the energy required to make it by more than 50 percent. Easton hopes this new concrete building block will provide the foundation for a more sustainable future.
Reporting credit: ChavoBart Digital Media.
Photo: Concrete blocks being made at the Watershed Materials factory (source: Watershed Materials website).