Bond Performance between Magnetized Rebar and Self-Compacting Steel Fiber Reinforced Concrete

Abstract

A new method aiming to improve bond performance between rebar and concrete is proposed in present paper. In this method, the rebar embedded in self-compacting steel fiber reinforced concrete (SSFRC) was magnetized to attract surrounding steel fibers. The special combination of rebar and the attracted steel fiber was expected to improve bond strength of rebar and concrete. Six groups of specimens were made to investigate the effect of rebar magnetization, steel fiber volume fraction and compacting method on bond strength between rebar and concrete. Results show that magnetization of rebar can greatly improve bond strength with the highest increase of 52%. The steel fiber volume fraction can be largely reduced under rebar magnetization condition and the highest bond strength 23.78 MPa was found on specimen with rebar magnetization of 30 mT and 0.25% steel fiber. Moreover, SSFRC was better than vibrated steel fiber reinforced concrete (VSFRC) when using this new method. A bond stress-slip model reflecting the effect of rebar magnetization and steel fiber volume fraction was also developed and verified by experimental results.