323 / 2023-10-14 21:05:22

Mechanical properties of hybrid fiber reinforced rubber concrete under the coupling of sulfate and freeze-thaw cycles

Concrete; Rubber; Microstructure; Polymer fiber

Rubber Concrete (RC), an innovative concrete type, is gaining significant attention for addressing serious pollution issues by incorporating granulated waste tire particles. Notwithstanding its ecological benefits, the mechanical and durability shortcomings of rubber concrete typically demand reinforcement through fiber addition. This research meticulously examined the mechanical and durability characteristics of rubber concrete fortified with polypropylene and basalt fibers (PBRC) through a comprehensive series of experiments. These include evaluations of apparent morphology, mass, static compressive and tensile testing, ultrasonic nondestructive testing, and scanning electron microscope (SEM) examinations under concurrent sulfate attack and freeze-thaw conditions. The results indicated a gradual increase in the mass loss rate of both RC and PBRC, concurrent with an increase in the number of freeze-thaw cycles, and accompanied by additional pits and peeling of the cement paste from the specimen surface. The compressive and splitting tensile strengths of the RC and PBRC groups exhibited distinct patterns, with the RC group manifesting lower residual strength relative to the PBRC group. However, it is crucial to acknowledge that excessive fiber addition also detrimentally impacted the rubber concrete's strength, and SEM results revealed that the fibers restricted microcrack development in the microstructure, thereby reducing the concrete's brittleness. This study may serve as a pivotal reference for employing environmentally friendly material fibers in recycled aggregate concrete.