Strength Improvement of Clay Soil by Using Stone Powder

Abstract

Soil stabilization with stone powder is a good solution for the construction of subgrade for road way and railway lines, especially under the platforms and mostly in transition zones between embankments and rigid structures, where the mechanical properties of supporting soils are very influential. Stone powder often has a unique composition which justifies the need for research to study the feasibility of using this stone powder type for ground improvement applications. This paper presents results from a comprehensive laboratory study carried out to investigate the feasibility of using stone powder for improvement of engineering properties of clays.

The stone powder contains bassanite (CaSO₄. ½ H₂O), and Calcite (CaCO₃). Three percentages are used for stone powder (1%, 3% and 5%) by dry weight of clay. Several tests are made to investigate the soil behavior after adding the stone powder (Atterberg limits, Standard Proctor density, Grain size distribution, Specific gravity, Unconfined Compressive test, and California bearing ratio test). Unconfined Compressive tests conducted at different curing. The samples are tested under both soaked and unsoaked condition. Chemical tests and X-ray diffraction analyses are also carried out.

Stone powder reacts with clay producing decreasing in plasticity and The curves of grain size distribution are shifted to the coarse side as the stone powder percentage increase; the soil becomes more granular, and also with higher strength.