Numerical Simulation on PPFRC with Different Contents

Abstract

Polypropylene fiber reinforced concrete (PPFRC) is such a composite material that can enhance and improve the mechanical property of the concrete with small mixing amount of polypropylene fiber. By taking into consideration the heterogeneous characteristics of materials at meso-scopic level, the initiation of micro cracks, the propagation and the coalescence between cracks have been simulated in PPFRC specimens with different amount of addition under three point bending load. The numerical analysis shows that there is only little difference on failure pattern and path between PPFRC and plain concrete. However, polypropylene fiber can reduce or even eliminate plastic cracking and can help to control crack expansion and it could be identified that most fibers in PPFRC are broken under tensile stress. Furthermore, polypropylene fiber plays different roles during the substrate plastic shrinkage and hardening stages. The toughness and deformability have been significantly improved with mixing of polypropylene fibers but the rupture strength is almost the same. Meanwhile, it also could be found that, with the increasing amount of polypropylene fiber, the deformation ability and the toughness have been increased, but the strength is kept almost the same, while the elastic modulus is actually decreased.