Griggs-Lang Consulting Geologists, Inc.
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G-L Engineering, P.C.
8 Brunswick Road
Troy, New York 12180
Aggregates are all around us. In the forms of crushed stone, sand and gravel, aggregates make up the foundation of our society: from driveways to highways, houses to hospitals, parking lots to airports, river embankments to dams.
Construction aggregates are used primarily in asphalt and concrete. A high percentage of blacktop and concrete is composed of aggregate: approximately 94 percent of asphalt pavement is aggregate and 80 percent of concrete is aggregate. Due to the high percentage of aggregates in asphalt and concrete every mile of interstate highway contains 38,000 tons of aggregates and about 400 tons of aggregates are used in construction of the average home1.
Because natural aggregate is a bulky, heavy material with no special or unique properties it is considered to have a low unit value. However, it has a high place value since a large part of its worth comes from its geographic location.
During the last 100 years, population in the United States increased about 370 percent. The unrelenting growth of our cities and highway systems during the 20th century created a continuous, ever-increasing demand for aggregate resources. In addition, the people demanded bigger and better houses and bigger and better roads. Those demands resulted in a 2,000-percent increase in the country's per capita consumption of aggregate2. Over the last 25 years the national average demand for crushed stone has increased by about 3.3 percent a year3.
The population of New York State reached 19,157,532 as of July 1, 20024. The New York State Department of Environmental Conservation Division of Mineral Resources website states that each person in New York consumes about 50 pounds of mineral products per day5. This amounts to approximately 175,000,000 tons of mineral products consumed per year in New York State.
Mines can only be operated where there is suitable material. It is important to note that a mine cannot be built just anywhere because not all stone or sand and gravel is suitable for aggregate for construction or road building. The rock may be too soft or have chemical properties that render it unsuitable for commercial use.
1National Stone, Sand and Gravel Association website: http://www.nssga.org/. 2Bill Langer, Carved in Stone, A Century of Keeping Up With Demand, Aggregates Manager, February 2003. 3Valentin V. Tepordei, Natural Aggregates-Foundation of America's Future, USGS Factsheet FS 144-97, Reprinted February 1999, U.S. Department of the Interior, U.S. Geological Survey. 4Census 2000 Data Engine, The United States Department of Commerce, Bureau of the Census, http://www.census.gov/main/www/cen2000.html. 5NYSDEC Division of Mineral Resources http://www.dec.state.ny.us/website/dmn/rocktalk.htm.