DETERMINATION OF FIBER CONTRIBUTION IN COMPOSITES EMPLOYING TENSION SOFTENING PROPERTIES

摘要

Tension softening (TS) properties are essential for composing a constitutive model for cracked members, but even more critical for the investigation of the nature of ductile cementitious composites. In this study, the authors propose a new way for determining the fiber contribution in fiber reinforced cementitious composites. The specimens were made of 11 types of cementitious composites that were reinforced by polypropylene (PP) fibers, alkaline-resistant glass (ARG) fibers or the hybrid use of them. The authors analyzed TS properties of them, and contribution of fiber in the TS stress was obtained by subtracting the TS stress of the plain matrix from the ones of reinforced composites. The subtracted stress indicated the contribution which corresponded to the volume fraction of PP or ARG fiber. The proposed way of achieving fiber bridging stress diagram is a precise in-situ evaluation method.