Development of stabilised soils for construction applications

Abstract

Lateritic soils from Papua New Guinea were stabilised with various percentages of rice husk ash (RHA), finely ground natural lime, cement and their combinations. The influence of stabilisers and their combinations was evaluated through Atterberg limits, standard Proctor compaction, unconfined compressive strength, splitting tensile strength, modulus of elasticity and California bearing ratio (CBR) tests. The durability of 38 stabilised soil mixtures was also investigated by studying the influence of water immersion on strength, water sorptivity and drying shrinkage. Correlations between compressive strength, modulus of elasticity and CBR were also established. Theoretical analysis of pavements incorporating subgrades improved by stabilised lateritic soils under traffic loads showed technical benefits in comparison with conventional flexible pavements without improved subgrades. Suitable stabilised soil mixtures using RHA, lime, cement and their combinations which can be used for the construction of road pavements, airfields, earth dams and low-cost housing are proposed. The use of locally available soils, RHA and lime in the production of stabilised soils for such applications can provide sustainability for the local construction industry.