Assessing the Strength of Lime-treated Clayey Soil Combined With Natural Pozzolana

Author : Abdelmoumen Aala Eddine DRISS

Abstract :Enhancing the mechanical strength of cohesive soils by adding chemical stabilisers such as cement, lime, and fly ash has been a longstanding method in soil stabilisation. This study is part of a research effort designed to evaluate the effect of integrating natural pozzolana to improve the efficacy of lime treatment on local clayey soil. This study demonstrates the effects of lime, natural pozzolana, and their combination on the soil’s shear strength and parameters, categorised as fat clay (CH). To achieve this purpose, several tests, including pH testing, compaction, undrained unconsolidated triaxial testing, and microstructural examination by scanning electron microscopy (SEM), have been performed on the different combinations under investigation. The analysed soil was mixed with natural pozzolana and lime, with concentrations varying from 0% to 20% and 0% to 6%, respectively. The treated samples underwent curing for 1, 7, and 28 days. The results indicated that the properties of clay soil may be markedly enhanced with lime treatment. The combination of lime and pozzolana yields superior shear strength values compared to either lime or pozzolana alone. Integrating natural pozzolana into lime treated clay soil induces an additional chemical reaction, particularly over time (pozzolanic reactions), enhancing flocculation and generating supplementary cementitious materials that significantly enhance soil shear strength, cohesiveness, and friction angle.

Keywords :Clay soil, Lime, Natural pozzolana, Compaction, Shear strength.

Conference Name :International Conference on Advances in Sustainable Civil Engineering Applications (ICASCEA-25)

Conference Place Istanbul, Turkey

Conference Date 14th Oct 2025