The transfer of stress through a steel to concrete adhesive bond

This paper describes part of a programme of research aimed at investigating the potential for strengthening reinforced concrete beams in shear by means of externally bonded steel plates. This may be a useful strengthening technique following the assessment of older bridge and building structures designed to outdated codes of practice. In order to produce a design guide for such shear plate bonding, a method for determining the anchorage length needs to be devised. By measuring the strain distribution in a steel plate adhesively bonded to a concrete block, the shear stress distribution within the adhesive and the effective anchorage length can be determined. A series of 15 experimental tests have been conducted to investigate the transfer of stress through a steel-concrete adhesive bond. The experimental programme was supported by theoretical and finite element analysis. The shear stress in a steel-concrete adhesive bond was found to be distributed exponentially, peaking at the loaded end of the specimen. For the specimens used, the stress distribution was distributed over a length of up to 155 mm for serviceability loads.