This paper deals with the problem of anchorage at the ends of steel plates glued to the tensile faces of rein forced concrete beams. A simple theoretid study of the force systems at the plate/glue and the glued concrete interfaces is presented. This suggests that high stress concentrations and peeling forces are present at the ends of the plates when the composite beam is loaded in flexure. Tests carried out to investigate the effectiveness of different anchorage arrangements are described in detail. The results from these tests confirm that, at the ends of the plates, interface stress concentrations exist, which have limiting peak values in the region of ã2 X tensile splitting strength of the concrete. Theoretical interface bond stresses, based on simple elastic behaviour, are found to have no consistent relationship to the measured peak values. However, if the maximum (unreduced) plate thickness is always used in these calculations, a simple method is proposed for obtaining a reasonable assessment of the peak stress. The efficiency of the different anchorage details is discussed, and it is shown that the use of additional glued anchor plates gives the best results. These plates overcome the problem of anchorage failure and enable the full theoretical flexural strength to be achieved, together with ductile behaviour.
R. Jones, R.N. Swamy and A. Charif