ABSTRACT
Sand, gravel, crushed stone, natural aggregate, and construction materials, are but a few of the terms used to describe one important item in the physical environment of society. In concert with this observation of aggregate as a key element in transportation, we also recognize the need for aggregate resources in the construction of homes, buildings and other structures such as bridges. Available sources of aggregate are constantly under threat from competing landuse options, sterilization and simple over-exploitation. Aggregate resources rarely occur in convenient locations and the costs involved in locating and transporting aggregates from source area to use are constantly increasing. During the last few years several texts have appeared on the subject and as public and government awareness expands, more publications are likely to appear. The chapter also presents an overview of the key concepts discussed in this book.
