The Effect of Polypropylene Fiber on the properties of fresh and hardened self-compacting concrete (SCC)

Abstract

The Self-compacting concrete (SCC) defines as a highly flowable, non-segregating concrete that fills uniformly and completely every corner of formwork by its own weight and encapsulate reinforcement without any vibration, whilst maintaining homogeneity. This research conducted to evaluate the effects of polypropylene fiber addition on characteristics and properties of SCC mixes in fresh and hardened state of SCC. In this study, the concrete mixes were added with polypropylene fiber of 0.0 %, 0.05%, 0.1 %, and 0.15 % Of volume fraction, mineral admixture i.e., silica fume 10% of weight of cement and chemical admixture i.e., Super Plasticizer 1.2% of cement and silica fume is used with constant w/(c+s) ratios which equal 0.49. For determining the self-compact ability properties like passing ability, flowability, viscosity, and segregation resistance the following tests such J-ring, Slump flow, V-Funnel and L-Box tests were performed. After 7 and 28 days of curing, cubes, cylinders, prisms, compressive, splitting and flexural strengths were tested. Tests results indicate that polypropylene fibers tend to reduce the flowability and passing ability but will increase viscosity and segregation resistance of SCC.  Furthermore, it can be concluded that polypropylene fiber reduces deformability of SCC in the fresh state. After7and 28 days of curing, concrete specimens’ tests indicate that polypropylene fiber addition up to 0.15% of volume fraction tend to improve the compressive strength, tensile strength, and flexural strength of hardened SCC.  It also can be suggested that polypropylene fibers allowed to be added into SCC mixes up to 0.15% by volume of concrete.