Laboratory Soil Testing
ABTS maintains in-house laboratory soil testing services for testing all of our soil samples. Through this soil testing we determine and evaluate the physical properties of soils including primarily the Plasticity Index using the Liquid and Plastic Limit test to help determine the amount of clay in a sample as well as the natural moisture content of soil using the moisture content determination. Additional soil testing can be performed as needed that might include grain-size distribution and percent fine materials. All laboratory soil testing is performed in accordance with the American Society for Testing Materials (ASTM) Standards.
Field Soil Testing
In the field, ABTS typically augments soil borings and collection of soils samples during field investigations with in-situ soil testing strength determinations. This is achieved using the Dual Mass Hammer, Dynamic Cone Penetrometer (DCP) soil test. The DCP test measures the materials' in-situ resistance to penetration. The soil testing is performed by driving a metal cone into the ground by repeated striking it with a 17.6 lb hammer dropped from a distance of 2.26 feet. The penetration of the cone is measured after each blow and is recorded to provide a continuous measure of shearing resistance. The test can be performed up to about 6 to 8 feet below the ground surface. Soil testing results can be correlated to California Bearing
Ratios (CBR), in-situ density, resilient modulus, and soil bearing capacity.
Soil Compaction Testing
Soil compaction testing is a key part in the home construction process to ensure a new building pad is constructed properly. Compaction testing ensures that the soil matrix is consolidated and potential settlement of the fill soil is all but eliminated prior to any slab construction. The compaction test uses a nuclear density gauge in the field to measure the dry density and moisture content of the soil. The test results are compared to an optimum moisture content and maximum dry density performed in the lab on a sample of the fill soil to be used. The correlation yields a percent of compaction, with 100% being the maximum value, and 95% generally being the industry accepted minimum for newly placed structural fill soils.