Investigating flexural performance of waste tires steel fibers-reinforced cement-treated mixtures for sustainable composite pavements

Abstract

In many parts of the world, the cement-treated base course material has been extensively used within composite pavements for enhancing the load-carrying capacity of pavements. However, its vulnerability to cracking under repetitive traffic loading, due to its brittle nature, significantly cuts off its lifespan and hence reducing the sustainability of composite pavements. To provide a solution to this problem, this study is aimed to investigate the flexural performance of cement-treated base (CTB) mixtures reinforced with the Waste Steel Fibers (WSF) extracted as a residual product from the scrap tires. The flexural performance is evaluated in terms of flexural fatigue and flexural strength. Moreover, the effect of steel fiber reinforcement on the dynamic modulus of the cement-treated base mixtures was also studied. The specimens for dynamic modulus were prepared by using a gyratory compactor to better simulate the traffic loading. Furthermore, the basic split tensile strength and unconfined compressive strength of WSF reinforced CTB mixtures were also studied. Lastly, important correlations were derived based on the results obtained in this study, to predict the flexural performance of CTB mixtures in terms of dynamic modulus and fatigue life by conducting basic split tensile strength tests and flexural strength tests. Based on the results, WSF reinforcement has noticeably enhanced tensile strength, dynamic modulus, flexural strength, and fatigue life of CTB mixtures. On the other hand, the variations in the compressive strength due to WSF reinforcement were trivial. Based on the results, the steel fibers content of 0.3% by volume of the wet compacted blend has shown more promising results than lower and higher WSF contents.