Shear performance of polypropylene fiber reinforced high-strength self-compacting concrete beams

Abstract

This paper consists of two parts. The first one looks for producing self-compacting polypropylene fibrous concrete (PFSCC) with reasonable passing, filling, and flow abilities and segregation resistance. Limestone powder with a particle size less than 75 μm was used to increase the fines fraction in the mix. The second part of this study deals with the effect of adding polypropylene fibers on the shear strength of self-compacted reinforced concrete beams. Eighteen beams were cast, each 1.8 m long, 150 mm wide, and with an overall depth of 200 mm. Four volume percentages of polypropylene fibers were used: 0, 0.1, 0.2, and 0.3 percent of the cementitious materials' weight. The test results showed that the polypropylene fibers have no serious adverse effect on the fresh properties, and this effect was reduced by using a plasticizer. Moreover, although the polypropylene fibers improved the tension properties of the hardened concrete, they don't have an impact on compression properties. The test results showed that the presence of polypropylene fibers increased the cracking shear stress and the shear strength, and this increase depends on the volume fraction of the fibers.