Magnetic field effect on bond performance between reinforcement and concrete containing steel fibers

Magnetic fields influence microstructures of concrete with steel fibers differently, which has received less attention. Also, the structural behavior of scaled-down concrete specimens under magnetic field effect has rarely been assessed. Therefore, this study investigated the microstructural and mechanical performance of magnetic field on bond strength between reinforcement and concrete containing steel fibers using pre-magnetization and post-magnetization techniques. The results showed that pull-out failure occurred for all specimens. The fracture energy of SFRC specimens exposed to magnetic field increased by 82 and 53 % for No. 14 and No. 20 bars, respectively. The bond strength of SFRC exposed to the HMF, during the casting increased by 76 % and 63 % for No. 14 and No. 20 bars, compared to control specimen. Meanwhile, applying AEC to specimens marginally decreased their bond performance. Moreover, splitting tensile strength of SFRC specimens was closer to estimates of ACI 318-19 and CEB-FIP with a mean bound.