There’s an interesting article in today’s New York Times about a movement towards mixing concrete to be environmentally friendly (though not “green,” which means freshly poured).

Concrete is one of the oldest manufactured building materials, having been used in ancient Rome, and that kind of provenance tends to discourage significant expeimentation. So it’s good to see people working to take a process that is probably not severely polluting, as industrial processes go, and actively make it cleaner. It’s particularly encouraging that a technique is being developed with a negative carbon footprint—a rare example of industry having a net positive effect on the environment without necessarily going for the hippie dollar.