In areas likely to have expansive soil or fill, the registered geotechnical engineer shall perform soil tests to determine where such soils or fills do exist.
Soils or fills meeting all four of the following provisions shall be considered to be expansive, except that tests to show compliance with Items 1, 2 and 3 shall not be required if the test prescribed in Item 4 is conducted:
- Plasticity index (PI) of 15 or greater, determined in accordance with ASTM D4318.
- More than 10 percent of the soil particles pass a No. 200 sieve (75 µm), determined in accordance with ASTM D422.
- More than 10 percent of the soil particles are less than 5 micrometers in size, determined in accordance with ASTM D422.
- Expansion index greater than 20, determined in accordance with ASTM D4829.
Steel slag shall be tested for expansive properties in accordance with ASTM D4792 prior to use as a fill material.