Composite toughened cement stabilized macadam with rubber/PVA fiber: Deformation, durability and stress evacuation effect

To enhance the toughness of cement-stabilized macadam (CSM) base and improve its resistance to cracking and durability, rubber/ Polyvinyl Alcohol (PVA) fiber CSM was prepared. Techniques for the pre-treatment of rubber particles and PVA fibers were proposed. The deformation characteristics of rubber/PVA fiber CSM were systematically studied. The heat transfer rules under different conditions were revealed. The fatigue performance and frost resistance of rubber/PVA fiber CSM were clarified. The flexural performance and stress evacuation effect of rubber/PVA fiber CSM were elucidated. The results indicate that, compared to CSM, PVA fiber CSM, and rubber CSM, the dry shrinkage strain of rubber/PVA fiber CSM can be reduced by 14.1–38.9 %. The average temperature shrinkage coefficient can be reduced by 21.5–58.3 %. In comparison to CSM, rubber/PVA fiber CSM exhibits a 16.6 % reduction in temperature difference during heating and a 23.0 % reduction during cooling. The mass loss rate and unconfined compressive strength (UCS) loss rate after freeze-thaw cycles of rubber/PVA fiber CSM are effectively mitigated. The fatigue life at different stress levels can be increased by 30.8–80.4 %, and the critical flexural strain energy density can be improved by 18.8–63.6 %. After complete cracking, the strain can be reduced by 42.8–54.3 %, resulting in the smallest crack propagation area, which effectively evacuates the internal stress of the base and delays crack development.