Drexel University materials scientists Alexander Moseson and Michel Barsoum have created a low-tech, low-energy cement they hope will reduce carbon output as developing countries build more sidewalks, roads and housing.
Potential demand for lower-carbon building materials has sparked a race to replace Portland cement featuring a handful of manufacturers and scientists. Some claim to sequester carbon within the cement itself. Others use alternative fuels. Still others tap unconventional feedstocks, such as magnesium silicate, that require lower kiln temperatures.
Moseson and Barsoum are trying the latter, mixing recycled iron slag or fly ash with readily available limestone. "We literally used a bag of garden lime from Home Depot," Moseson said. Instead of a coal-fired kiln, they use a bucket with a spoon at room temperature.
: Daily Climate
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