Cracking and toughening of concrete and polymer-concrete dispersed with short steel wires

Abstract

A fibre-strengthened brittle solid can crack and fracture in a number of ways and simple models can be used to describe quantitatively the fracture processes. This paper discusses some of these models and compares experimental measurements of cracking stress and toughness for two brittle fibrous composites with the theoretical predictions. The two brittle matrices are concrete and concrete impregnated with polymethylmethacrylate reinforced by discontinuous (short) high strength steel wires. It involved extracting a single steel wire from each brittle matrix to evaluate the debonding stress and pull-out stress as a function of fibre embedded length. These key material parameters and the energetics of cracking determined in three-point flexural experiments, together with the cracking and toughening equations are then used to characterize the fracture behaviour of fibrestrengthened concrete and polymer-concrete composites.