Structural retrofitting of impaired dapped-end beams: a review

Abstract

The ends of dapped-end concrete beams are introduced with reduced beam heights to facilitate connections, and consequently, the beam end is classified as a disturbed region. Due to these geometric/structural characteristics, the beams are subjected to numerous structural/durability issues. This paper reviews such critical distresses and into potential retrofitting options for dapped-end beams. It is found that the choice of the retrofitting configuration is governed considerably by the prevailing defect. The strength enhancement could be as high as 40% - 50% upon the choice of correct configuration whereas possibly be negligible upon inappropriate selection. Generally, the use of diagonal bars and plate jacketing are promising with steel applications. The bars can be prestressed to enhance the retrofitting efficiency. For fibre reinforced polymer applications, inclined/horizontal stripping and fabric wrapping are impressive approaches whilst combined systems show better results. The review also identifies required future research for formulating comprehensive retrofitting guidelines.