Experimental Study on Axial Tensile Strength of Low Volume Fraction of Ternary Hybrid Fiber Reinforced Concrete

In this paper, according to the national standard and testing methods,the direct tension strength,splitting tensile strength and cubic compressive strength test were carried out for 8 different groups of hybrid fiber (containing steel fiber, macro-polypropylene fiber and dura fiber) reinforced HPC specimens.The results showed that when the volume proportion of ternary hybrid fiber was less than 1%, there was not obvious influence for the concrete compressive strength, but the splitting tensile strength increased by 26% ~ 69%; the ratio between splitting tensile strength and compressive strength for HFRC increased to 1/12~1/9. When added 0.7% steel fiber, 0.19% macro-polypropylene fiber and 0.11% dura fiber, the confounding effect was the best. Based on the advantages and disadvantages of tensile splitting strength and direct tensile strength test and the results of tests, the concept of equivalent tensile strength and calculative formula was put forward .