Bond strength and reliability analysis of stainless steel rebar embedded in fiber reinforced coral aggregate concrete

Abstract

• The failure pattern of all specimens was that rebars were pull out from concrete. • The content of CFs for optimum bond strength is about 0.6%. • The modified thick-walled cylinder theory can accurately predict the bond strength. • The bond lengths were suggested based on the reliability analysis. In order to take full advantage of local material sources in marine environments, dead coral debris is used as a new type of aggregate to manufactured concrete. Due to that coral aggregate concrete (CAC) presents greater brittleness and the abundant existence of Cl - in CAC, carbon fibers (CFs) and stainless steel rebar (SSR) are adopted to reinforce CAC, so as to improve the mechanics of CAC and the durability of CAC structure. Therefore, it is essential to study the bond performance between CFs reinforced CAC and SSR. In this study, 63 CFs reinforced CAC specimens embedded with SSR were submitted for pull-out tests. All specimens showed a pull-out pattern, and further analysis showed that CAC strength, c / d ( c is the thickness of CAC cover, and d is the SSR diameter), and d / l a ( l a is the bond length) presented an approximately linear relationship with bond strength, while CFs content presented an approximate parabolic relationship with bond strength. Based on the above-mentioned results, a bond strength formula was obtained from regression statistics. Also, suggested bond lengths are given through reliability analysis based on the bond strength formula. Furthermore, corrections concerning the properties of CAC and SSR were made to the thick-walled cylinder model to derive the bond strength theoretically, with results showed that the theoretical value fits well with the experimental value.