Fracture Energy Optimization in Synthetic Fiber Reinforced Cementitious Composites

Abstract

AbstractA study has been carried out on cementitious composites reinforced with various synthetic fibers, focusing on their tensile behavior, toughness, and fracture mechanisms. A model is formulated to predict the tensile behavior and fracture energy of fiber reinforced cementitious composites (FRC) with short, randomly distributed fibers. The model accounts for the pull-out of fibers oblique to the fracture surfaces (including snubbing friction effect), and the variation of the fiber/matrix interfacial shear stress during pull-out. Experimental and analytical results are shown to be in close agreement for the one class of fiber reinforcement which best satisfies the assumptions of the model. Systems which violate the assumptions exhibited different failure mechanisms and were observed to show less satisfactory reinforcement performance, especially the composite fracture energy. The model is used to examine the effect of fiber properties on composite post-cracking behavior and is useful in design of such material systems with optimum performance and cost effectiveness.