Photo © Lawrence Okrent
A generation ago, concrete was thought of as a single substance; contractors would call up and order a truck full of “mud.” But now, just as bread comes in hundreds of varieties and flavors, thousands of concrete mixture are used for all sorts of purposes — for setting underwater, weather resistance in roads, high strength in skyscrapers. There are ductile concretes that bend and porous concretes that allow water to flow easily through.
“We really should give it a new name,” Baker said. “We call it concrete,’ but it’s the stuff you see on the sidewalk and the stuff you get delivered to the site — they’re both gray, but that’s about it.”