IMPROVEMENT OF THE CYCLIC LOADING RESPONSE OF STABILIZED EXPANSIVE SOILS

This research aims to investigate the active behavior of expansive soils stabilized with ground granular kiln slag (GGBS) and cement-activated slag (GGBS/C) subjected to cyclic loading. Key active parameters shear modulus, Young's modulus, damping ratio, and deviatoric stress are basically assessed, complemented by Fourier Transform Infrared Spectroscopy (FTIR) analysis to characterize the underlying chemical mechanisms. Untreated expansive soils exhibit very low stiffness and strength, making them highly susceptible to cyclic degradation. The results show that stabilization with GGBS and GGBS/C substantially improves the mechanical stability: Young 's modulus increases by 5200 % to 7200 %. And this is key: and shear modulus increases by 2000 % to 5700 %, while the damping ratio decreases by more than 90 %. Resistance to deviatoric stress also increases, increasing by 440% to 545% depending on the limiting stress. Also increasing the confining pressure from 100 to 300 kPa further strengthens the stiffness and cyclic resistance, resulting in more stable performance under repeated loading conditions