Forming the Foundation of Our WorId...
Source: a circular put out by
the National Aggregates Association...
Aggregates consist of sand, gravel, or rock fragments that are used in their natural state or are utilized after mechanical processing. Quarried stone is crushed and processed to produce crushed stone aggregates.
Between 1970 and 1990, U S. sand, gravel and crushed stone use averaged 1.84 billion tons per year, reaching a maximum of 2.17 billion tons in 1988. In 1998, a total of 2.8 billion tons were used in the U.S.
California leads the United States in the production of sand and gravel. New York leads the nation in the production of crushed stone. Delaware is the only state in the Union that does not produce crushed stone.
In 1992, construction sand and gravel valued at $2.9 billion was produced by 4,100 companies from 5,600 operations in 50 states. Leading states in order of volume were California, Colorado, Ohio Michigan, Texas, Washington, Minnesota, Illinois, and Arizona. If taken together, this accounted for about 50% of this total
Crushed stone valued at $5.6 billion was produced by 1,600 companies operating 4,000 active quarries in 49 states. Leading states in order of production were New York, Pennsylvania, Texas, Illinois, Florida, Kentucky, Missouri, North Carolina, Tennessee, and Virginia which together accounted for about half of the total in 1992
Though sources of potential aggregates are widely distributed throughout the United States in a variety of geologic environments, they are not evenly distributed geographically.
Aggregates are most commonly used within 30 to 50 miles of their place of extraction.
Efficient transportation of aggregates to the user is an important factor in providing lower costs in construction projects.
The cost of transporting aggregates by truck increases substantially in direct ratio to the number of miles the material must be hauled.
In the early years of the 21st Century, the restoration of an aging infrastructure will require the mining of substantial amounts of aggregates.
Aggregates are used in nearly all residential, commercial and industrial building construction and in most public works projects, such as roads and highways, bridges; railroad beds; dams; airports; water and sewer systems; and tunnels.
Individual crushed stone quarries range in size from small operations reporting production of less than 50,000 tons annually to those with production of more than 10 million tons. Individual sand and gravel operations range in size from those reporting production of less than 25,000 tons annually, to those which produce more than 2 5 million tons.
Potential sources of crushed stone and sand and gravel may be widespread, but specific land use considerations, socioeconomic reasons, or the physical and chemical properties of the materials may limit the utility of these sources.
AIthough nature dictates the location of aggregates, sources can be lost if houses or other developments are constructed over the resou rces.
56% of imported sand and gravel comes from Canada, 21% from the Bahamas, 8% from Antigua and the remaining 15% from other countries.
Out of the crushed stone imported into the United States, 55% comes from Canada, 27% from Mexico, 14% from the Bahamas, and 4% from other nations.
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