Mechanical properties of high performance concrete reinforced with basalt fiber and polypropylene fiber

Abstract

The mechanical properties of high performance concrete (HPC) reinforced with basalt fiber and polypropylene fibers were investigated in this study. The influence of single basalt fibers (BFs), single polypropylene fibers (PF) and hybrid fibers with different contents on the compressive strength, flexural strength, splitting tensile strength and stress-strain curve of HPC were investigated. A formula for calculating the flexural strength of hybrid fiber HPC was developed, and a conversion relationship between flexural strength and cube compressive strength was proposed. On the basis of experimental data analysis, the mathematical expression of the compressive stress-strain of hybrid fiber reinforced HPC was derived. Test results indicate that, the strength of HPC reinforced with single doped basalt fibers or polypropylene fibers increases with the increase of the fiber volume fraction. However, the compressive strength increases slightly, while the flexural strength and splitting tensile strength are improved significantly. When the two types of fibers are mixed into HPC simultaneously, there are two kinds of synergy effects (positive and negative synergy effects). When the basalt fiber content is 0.15% and polypropylene fiber content is 0.033%, the synergy effect of fiber mixing is the best. At this time, the compressive strength, flexural strength and splitting tensile strength increased by 14.1%, 22.8% and 48.6%, respectively, when compared with those of HPC without fibers.