Interfacial fracture toughness of composite concrete beams

Abstract

A test for measuring the interfacial fracture toughness of a bi-material interface, essentially for concrete overlaid pavements was developed. The measured interfacial fracture toughness of steel fibre-reinforced, roller-compacted, polymer modified concrete (SFR-RC-PMC) onto ordinary Portland cement concrete (OPCC) was found to be 52.0 J/m 2 and 22.6 J/m 2 for rough and smooth interfaces respectively. The experimental interfacial fracture toughness results can be suitable for the design of overlays on worn concrete pavements. In addition, the measured interfacial fracture toughness was used to predict the cracking trajectory of the composite beams under four-point bending (4 PB) tests. It was concluded that a single interfacial fracture parameter, the ERR (energy release rate) at interface, is an appropriate and sufficient parameter to assess the interfacial delamination performance of a composite beam under 4 PB flexure.