INFLUENCE OF COMPOSITE MATERIALS AND PROPORTION ON THEIR FRESH PROPERTIES AND MECHANICAL ONES OF HYBRID FIBER REINFORCED CEMENTITIOUS COMPOSITES

Abstract

In this study, influence of composite materials and mix proportions on the fresh properties and the mechanical ones of Hybrid Fiber Reinforced Cementitious Composites ( HFRCC ) was experimentally investigated. Then, the influence was analyzed by applying the excess paste thickness theory proposed by Kennedy in 1940 and formulated as functions of dominant factors. Results of the experiment and the analysis revealed the following matters:1. The relative yield value and the relative plastic viscosity of HFRCC (yield value and plastic viscosity of HFRCC normalized by those of paste) decreased as the fiber volume content increased, and influenced by the geometry of contained steel fiber. Though it could not be quantified only by the excess paste thickness, the influence of sand-binder ratio, admixtures, volume content of each fiber and the geometry of the steel fiber on fresh properties and mechanical ones of HFRCC could be quantified by introducing modified excess paste thickness. However, it was not possible to apply it to express the influence of different water binder ratio.2. The value of ductility index obtained by three point bending test increased as the fiber volume content and the aspect ratio of the steel fiber increased. By introducing modified excess paste thickness, the influence of sand binder ratio, water binder ratio, fiber volume content and aspect ratio of the steel fiber on the value of ductility index of HFRCC could be quantified. However, it was not possible to apply it to express the influence of different admixtures.