This specification covers quality-controlled graded aggregates that, when hauled to and properly spread and compacted on a prepared grade to appropriate density standards, may be expected to provide adequate stability and load support for use as highway or airport bases or subbases. Coarse aggregate retained on the sieve shall consist of durable particles of crushed stone, gravel, or slag capable of withstanding the effects of handling, spreading, and compacting without degradation productive of deleterious fines. Fine aggregate passing through the sieve shall normally consist of fines from the operation of crushing the coarse aggregate. Where available and suitable, addition of natural sand or finer mineral matter, or both, is not prohibited. The following tests shall be performed: grain-size test (dry and wet sieving), liquid limit test, plastic limit test, plasticity index test, sand equivalent value test, and expansion test.
