The question is whether the aggregate industry depends on, reflects or drives the U.S. economy. Rather than look at the chicken, consider the egg. The major component is the aggregate, and synthetic lightweights are of prime interest to the construction industry. Some synthetics are lightweight substitutes for mineral aggregate, and can be made from recycled materials, such as a mixture of plastic, fly ash or bottom ash (a waste product of coal-fired electric plants). Concrete made from synthetics can have a rough texture or be made as smooth as glass, while at the same time being cutable, nailable and screwable. Estimates are that only about 25 to 30 percent of these recyclable materials are being utilized, with the rest dumped in landfills. Imagine the growth potential if most ash is used to make economically beneficial products. Currently, lightweight mineral aggregate is more than a
展开▼
