The effect of traffic vibration on adhesive curing during installation of bonded external reinforcement

Abstract

This paper describes a programme of research which was conducted to examine the effect of traffic vibration on adhesive curing during the installation of bonded external reinforcement. Steel and carbon fibre reinforced plastic (CFRP) plates were used in conjunction with four epoxy adhesives. A literature review was undertaken in order to select appropriate magnitudes for the strains and frequency of vibration to be used during an experimental programme involving the vibration during cure of lap joints, steel and reinforced concrete beams. The lap joint results show that vibration during cure causes a progressive reduction in strength with increasing strain level. The tests involving strengthened steel beam specimens suggest that use of simple lap joints will give a safe prediction of the effect of vibration during cure. In the reinforced concrete beams there were noticeable differences in failure mechanism between those strengthened with steel as opposed to CFRP plates. However, in both cases failure modes in the concrete masked any effect arising from vibration during cure. Recommendations for the design of externally reinforced concrete elements have been proposed which involve increasing the partial safety factor on the ultimate shear strength of the bonded joint if the joint is to be subject to traffic vibration during cure.