Evaluation of The Effect of Micro-Silica and Nano-Silica Pozzolan on Mechanical Properties of Fiber Reinforced Porous Concrete pavement

If concrete pavements are designed and constructed with durable and sustainable materials, can pass a long time without any or slight repair. Concrete generally has high initial costs compared to asphalt but has longer life and lower repair costs but given the problems of asphalt pavements in high-traffic roads which often have failures such as uneven, cracks, the use of concrete pavements brings fixes to mentioned problems and reduces repair period. Therefore, in this vitro study the effect of micro-silica and Nano-silica pozzolan as an alternative to a percentage of the weight of cement in the concrete mix was reviewed. In addition, the steel fibers (0.2 and 0.3 and 0.5 volume percent) and PPS (0.1 and 0.15 and 0.2 volume percent) were used to improve the mechanical properties of porous concrete. The test results of mechanical properties of concrete containing micro and Nano silica and fibers shows a significant increase in compressive, tensile and flexural strength. Also in all mixes compressive, tensile and flexural strength were same in concrete containing fibers and pozzolan. In all schemes with the increasing of Nano-silica optimum percentage of 4 percent and micro-silica to 8 percent in concrete containing fibers, compressive strength of samples containing fibers improved. Fiber has not have much impact on porosity and permeability compared to micro and Nano silica while, by increasing the amount of micro and Nano silica permeability and porosity rapidly decrease.