The effect of polypropylene fiber addition to mechanical properties of concrete

Abstract

Concrete is the one of the building construction materials that has a high compressive strength, but it has lower tensile strength. The addition of fibers to concrete is expected to improve its mechanical properties. In this study, the concrete was added with Polypropylene (PP) fiber with a length of 12 mm. The compressive strength of concrete specimens was 20 MPa with the variety of fiber used was 0.5 kg/m3; 1 kg/m3; and 1.5 kg/m3. The test were conducted on 36 specimens in the form of cylinders and cubes. The tests were compressive strength, split tensile strength and water absorption at the age of 28 days. The highest value of the compressive strength of the fiber concrete was the amount of Polypropylene fiber 1 kg/m3, namely 2.92 MPa, increase of 6.92% of the compressive strength of concrete without additional fiber. The highest value for the split tensile strength in the amount of Polypropylene fiber 1 kg/m3 was 2.34 MPa or an increase of 21% from the tensile strength value of concrete without additional fiber. Meanwhile, the lowest water absorption capacity of concrete is the addition of 1.5 kg/m3 of fiber, which is 2.366% or has decreased by 64% from the concrete without fiber.