Stabilizing a silt using waste limestone powder

Limestone powder produced by mechanical crushing of quarried rocks to usable sizes is a by-product, which has been studied as an alternative additive material for stabilising mechanical behaviour of a low plastic silt. Use of such application can reduce the amount of waste limestone powder, thereby reducing the environmental impact from disposal into landfills. The low plastic silt mixed by adding 0%, 5%, 10%, 20%, 30%, 40%, and 50% of dry limestone powder has been characterized by means of various laboratory tests, including fall cone, unconfined compressive strength (UCS), California Bearing Ratio, and one-dimensional consolidation test. The testing results indicated a substantial decrease in Atterberg’s limits, increment in strength, and a decrease of its deformability with limestone powder addition in the silt. The specimens tested in UCS were cured for 0, 7, 14, and 28 days. This results in a reduction of about 25% in thickness of flexible pavement with limestone powder treated subbase layers. Evidently, the optimum content of limestone powder used appears to be about 30% of the total powder content in mixtures tested.