Illustrations courtesy of the Portland Cement Association
Cement and concrete are key components of both commercial and residential construction in North America. The cement and concrete industries are huge. There are approximately 210 cement plants in the U.S. and 4,000 to 5,000 ready mix plants (where cement is mixed with aggregate and water to produce concrete). The Portland Cement Association estimates that U.S. cement consumption has averaged between 75 and 90 million tons per year during the last decade, and projects that consumption will exceed 100 million tons per year by 1997. Worldwide, cement production totaled 1.25 billion tons in 1991, according to the U.S. Bureau of Mines.
What does this mean in terms of the environment? Are these products good or bad? As builders and designers, should we be looking for alternatives or embracing concrete over competing materials? As with most building issues, the answers are not clear-cut. Concrete and other cementitious materials have both environmental advantages and disadvantages. This article takes a look at how these materials are made, then reviews a number of environmental considerations relating to their production, use, and eventual disposal.