Assessing the zeolite’s effectiveness on the mechanical performance of cement-stabilised sand through triaxial test and microstructure analysis

In this research, a series of consolidated drained compression triaxial tests were carried out to investigate the mechanical performance of Babolsar sand. Next, the parameters such as cement zeolite substitution percentage, cement content, and curing time were determined. The results revealed significant mechanical strength of specimens by replacing zeolite up to 35% compared with cemented sand mixtures for all ranges of cement percentages. Also, the samples showed more ductile behaviour due to increasing strains at failure. Increasing the zeolite substitution by up to 35% generated shearing band failure. However, exceeding the 35% substitution, the barrelling shear mode was predominant. All samples were compressed initially until reaching a point of instant zero dilation and then dilated until the end of the tests. The dilation tendency was higher in zeolite percentages up to 35%. Moreover, increasing the cement content enhanced the dilation of specimens due to hardening and interlocking cement and sand with zeolite. Finally, microstructure analysis results showed the Si/Ca ratio as a key index to approximate triaxial shear strength development.