Wetting-drying durability performance of cement-stabilized recycled materials and lateritic soil using natural rubber latex

This research was conducted to assess the role of natural rubber latex (NRL) in improving the durability of cement stabilized lateritic soil and recycled materials blends against wetting–drying (w-d) cycles. 70% and 50% by weight of recycled materials, including steel slag (SS) and recycled concrete aggregate (RCA) were replaced for Lateritic soil (LS) and 5% cement by weight of dry aggregate was used in this research. The dry NRL to cement (r/c) ratios of 0%, 3%, 5%, and 10% were the influence factor that were investigated. The unconfined compressive strength (UCS), physical and weight loss, water absorption, and microstructural analysis were performed to evaluate the influence of NRL on the durability of cement-NRL stabilized SS:LS and RCA:LS by comparison with those of control cement-stabilized mixtures (without NRL). The results indicated that the UCS development of all mixtures was found to be similar in that the UCS value increased up to the third w-d cycle and gradually decreased thereafter. The microstructural analysis result indicated that the increase of UCS during the w-d cycles can be attributed to the high temperature, which promotes the moisture diffusivity of cementitious materials and thus increases chemical reaction and strength development. However, with further increase of w-d cycles, the strength reduction was attributed to the Ca2+ leaching from the cement-stabilized materials during the soaking stages and the dissolution of cementitious products. In addition, the crack propagation and extension gradually caused the crumbling of samples and microcracks, resulting in the deterioration and strength loss of samples. It was evident that the formation of the NRL films filled up the pore spaces and microcrack, acting as NRL film crack-bridging mechanism, resulting in the enhanced interparticle bonding strength and durability.