Experimental study on the influence of water/cement ratio and polypropylene fiber on the mechanical properties of nano-silica concretes

摘要

The purpose of this study was to investigate the effects of polypropylene fiber and water/cement ratio on the compressive, tensile, flexural and abrasion strength, porosity and hydraulic conductivity of nano-silica concrete. Other properties of all specimens displayed extensive mutual similarity.The experimental findings show that, with decreasing water/cement ratio from 0.5 to 0.3, all mechanical properties of the concrete improved, while any further decrease in the water/cement ratio caused deterioration of the flow properties and performance of the concrete, i.e., a reverse effect on its mechanical properties. The highest compressive strength was achieved by introducing 0.1 % fiber together with nano-silica. The highest tensile and flexural strength levels, in turn, were obtained for 0.25% fiber, while 0.15% fiber yielded the highest and lowest coefficients of hydraulic conductivity and porosity, respectively, in the concrete samples.