Investigation of silica fume influence on the compaction and strength properties of cement-stabilized fine to medium sand

Abstract

Stabilization of marginal desert soils while enhancing sustainability through reduced CO₂ emissions and the use of industrial by-products, remains a challenging task. Cement-stabilized soil can be improved by adding silica fume (SF), leading to enhanced physical and mechanical properties. Moreover, SF is both economically viable and environmentally friendly. This study investigates the effect of SF on the compaction and strength properties of cement-stabilized fine to medium sand. Laboratory tests included the modified Proctor test, unconfined compressive strength test (UCS), ultrasonic pulse velocity (UPV), California bearing ratio test (CBR) and microstructure tests comprising of scanning electron microscope (SEM), and Energy-Dispersive X-ray Spectroscopy (EDS) and Fourier Transform Infrared Spectroscopy (FTIR) to examine and quantify changes responsible for variations in mechanical behavior. Three cement contents (8%, 12%, and 16%) and varying SF contents were used for compaction and strength evaluation, with curing periods of 3, 7, and 28 days. Results show that silica fume positively influences the engineering properties of cement-stabilized sand, increasing dry unit weight, compressive strength, and stiffness with increasing SF content. From both efficiency and economic perspectives, 12% silica fume is identified as the optimum ratio.