Crack Arrest Effect Of Polypropylene Fiber On Water Glass Acid-resistant Concrete

Acid-resistant concrete containing sodium silicate cracks easily, specially in the case of high temperature. This paper aimed to propose a method by adding polypropylene fiber into concrete to resolve the problem.On the basis of analysis of the cracking mechanism of fiber reinforced concrete, Comparative test have been done to investigate the crack arrest effect of concrete with or without polypropylene fiber at room and high temperature .Tensile strength, brittle coefficient, elastic modulus ratio, limit of tensile strain, toughness were chosen to indicate the crack resistance ability. The cracking performance of concrete containing fibers and shrinkage-reducing agent were also inverstigated. Scanning Electron Microscopy was used to analyze the mechanism of crack arrest..Results show that the polypropylene fiber greatly improves the post-cracking performance at both normal and high temperature. The early shrinkage of concrete could also be reduced, but not significantly. Adding polypropylene fibers and shrinkage-reducing agent simultaneously effectively improved the early shrinkage and cracking, showing a best way to crack arresting. The fiber improved the structure of concrete and bridged across the micro cracks in concrete attribute to the improvement of crack arrest ability of the concrete.