Measured effects on engineering properties of clayey subgrade using lime–Homra stabiliser

Abstract

The engineering properties of clayey subgrade soils may need to be improved for suitability in construction using appropriate stabilisation methods. Stabilisation of pavement subgrade soils has traditionally relied on treatment with lime, cement and sometimes special additives, which are regarded as waste materials. Alternatively, the Egyptian bricks/ceramic industry generates large amount of calcined-clay waste or crushed clay bricks (known as Homra). In this study, standard laboratory soil tests were conducted to measure changes in the engineering properties of clayey soils when treated with a lime+Homra (L+H) blend. Tests were conducted on untreated control soil samples and on varieties of treated samples with L+H ranging from 1% to 11% for lime and 5% to 15% for Homra. The results showed that the L+H clay samples exhibit low plasticity, swelling, maximum dry density and consolidation settlement. On the other hand, results showed a significant increase in California Bearing Ration, soil cohesion and soil strength. The internal friction angle concerning shear strength parameters is also enhanced. It can be summarised that engineering properties of clayey soils can be enhanced using lime and Homra. This is advantageous for work construction in the civil engineering field.