Experimental Research Of The Properties Of Polypropylene Fibers Reinforced Concrete Structure

Polypropylene fibers reinforced concrete is applied quite often nowadays overseas. It starts to gain popularly in China recently as well. Obviously, the addition of polypropylene fibers is significant in controlling plastic shrinkage cracks in the early stage and improving ductility for concrete at low fiber volume fraction. Mechanical properties of polypropylene fibers reinforced concrete and the properties of reinforced concrete flexural members are studied by means of several experiments.1 Concrete containing polypropylene fibers at the same weight fraction (0.9kg/m~3) is investigated in terms of compressive, axial compressive , and splitting tensile strength properties. The strength of polypropylene fibers reinforced concrete and the grade of concrete strength are positively correlated. Test results show that the fibers, when used in lower grade of concrete strength, could result in lower strength compared to the plain concrete; while it could result in close to, or even higher strength compared to the plain counterpart when used in much higher grade of concrete strength.2 In this paper, the influence of polypropylene fibers on flexural properties of reinforced concrete beams is studied through the tests of six beams. The results show that the addition of polypropylene fibers can increase cracking load of flexural members. In certain range of load, fibers have impact on reducing crack width, while it almost has no impact on flexural stiffness of reinforced concrete members.