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.