The U.S. is the third largest consumer of concrete in the world, behind India and China. It's a simple mix of water, sand, aggregate, sometimes small amounts of additives or air, and typically 10 to 15% cement. One of the waste streams that results from this production is empty cement bags. In the U.S., that waste amounts to 39 million empty bags per year. Concrete Mode is a small craft company that has found a way to repurpose some of those bags.