Shear strengthening of existing reinforced concrete beams with embedded bars – an overview

This paper presents an overview of the deep embedment (DE) method – also referred to as the embedded through-section method – a promising technique for concrete shear strengthening. The aim of this work was to collate pull-out and beam test results with a view to identifying existing gaps in knowledge. A careful evaluation of pull-out test results showed that, except for the effect of embedded length, the bond performance of DE bars epoxy-bonded into concrete is not fully understood. Analysis of beam test results identified significant gaps in knowledge, particularly with regard to the effect of concrete strength, loading type, shear span-to-effective depth ratio, size effect and DE bar surface coating. Moreover, the analysis of beam test results revealed a novel interaction between steel tension and DE shear reinforcement. Finally, yet importantly, the paper summarises the research required for robust implementation of the DE technique.