Uniaxial tensile test of multi-scale polypropylene fiber reinforced concrete

Based on uniaxial tensile test on 21 plain and polypropylene fiber concrete specimens with the dimensions of 100 mm × 100 mm × 250 mm with epoxy paste method,the influence of the different scales of polypropylene fiber and hybrid fiber on concrete uniaxial tensile strength is investigated,and the uniaxial tensile stress-strain whole curves of the different scale polypropylene fiber reinforced concrete is analyzed.Single-doped and blended polypropylene fiber can improve the tensile strength of concrete by 11% to 27%、 The strain hardening of low-stress occurs during the uniaxial tensile for the single-doped crude polypropylene fiber and blended polypropylene fiber concrete,and the surrounding area of the descent stage of single-doped and blended polypropylene fiber concrete stress-strain curves is larger than the plain concrete stress-strain curve of the package area.The tensile toughness enhancement effect of different scales of polypropylene fiber concrete is illustrated as blended fiber concrete single-doped coarse fiber concrete single-doped fine fiber concrete plain concrete.