The influence of the mode II fracture energy on the behaviour of composite plate reinforced concrete

Abstract

In this paper, the finite element method is used to analyse the behaviour of concrete externally strengthened by sheets of carbon fibre reinforced polymer (CFRP). The bond between concrete and CFRP is modelled by a discrete approach using interface elements. The mechanisms involved in the behaviour of externally reinforced concrete specimens are complex, the global strength of the specimen being governed by the strength of each individual material as well as by the adhesion properties conferred by the epoxy. It is observed in experiments that, in most cases, failure occurs due to the loss of cohesion of a portion or lamina of concrete attached to the epoxy-fibres layers, the latter remaining intact. In this paper, the results of numerical simulations of bond tests are presented, aiming to contribute for a better understanding, in qualitative and quantitative terms, of mode II fracture energy in concrete and its influence on the behaviour of the interface concrete-FRP.