Bond behaviour of deformed bars embedded in RAC

Abstract

To investigate the bond behaviour between recycled aggregate concrete (RAC) and rebar, this paper considers recycled aggregates (RAs) (RG of grade I and III and RS of grade II), w/c ratios (40% and 50%), and replacement ratios of RAs (0%, 30%, 50% and 100%). The results were as follows: (a) bond stress–slip shows tendencies like those of normal concrete up to a replacement ratio of 50%; (b) shearing stress–strain is influenced by grade and the replacement ratio of RAs; (c) τb is influenced by grade and the replacement ratio of RAs, but at high w/c, τb is not influenced by the quality and the replacement ratio of RAs; (d) [Formula: see text] is influenced by the w/c ratio; and (e) τb between RAC and rebar is overestimated or underestimated by existing equations. As a result, a new equation (with modification of either the β value, invariable value or others), or modified development length or lap splice length must be considered.