Study on the mechanical performance of alkali residue-based light-weighted soil

In this study, a novel approach for reusing alkali residue is presented, whereby a lightweight soil is developed through a process of drying alkali residue. The mechanical properties of the alkali residue-based lightweight soil were investigated using compression, shear, and California bearing ratio tests. The results reveal that the compressive strength of the soil increases with the addition of ground granulated blast furnace slag, higher wet density, and increased curing time. Among these factors, the wet density exerts the greatest influence on compressive strength, followed by ground granulated blast furnace slag content and water–solid ratio. The secant modulus, cohesion, internal fraction, and California bearing ratio were found to be dependent on the mix proportion and curing time. A high-precision predictive model was developed for compressive strength, and the functional relationships between compressive strength and other mechanical properties were established, enabling accurate predictions of secant modulus, cohesion, internal friction angle, and California bearing ratio based on compressive strength.