Experimental Study on Physical and Mechanical Indexes of Modified Silt

To solve the engineering problems existing in the filling of silt in the airport pavement subgrade effectively, the silt was modified with lime, mixed lime (strength grade 42.5 cement and lime), and cement (strength grade 42.5 and 52.5), the dosage to mass ratio of which was 4%, 6%, 8%, 10% and 12% respectively. Unconfined compressive strength tests, compression tests, compaction tests, and reaction modulus tests on different modified materials were conducted. The results show that the unconfined compressive strength and compression modulus of each sample increase with the increase of curing time and dosage ratio. The modified silt can effectively improve the compaction degree and subgrade reaction modulus of the original silt. The optimal content to mass ratio of silt was silt combined with 8% cement (strength grade 52.5). The modified silt can be used as a filler in the airfield subgrade directly.