Bond behaviour of welded mesh reinforcement at elevated temperatures

摘要

This paper presents experimental studies of the bond strength at elevated temperatures between welded mesh reinforcement and concrete used in composite slabs. Unlike previous work, which concentrated on the bond of single bars, the current work investigates the contribution of the bond provided by welded transverse bars placed at defined spacing within a welded mesh reinforcement mat. The bond strength-slip-temperature relationship, for various sized ribbed and smooth bars, was obtained for temperatures from 20°C to 1000°C. Results showed that for smooth bars the weld fractured followed by pull-out of the longitudinal bar. For ribbed bars, the longitudinal bar normally fractured except the 10mm bar, which failed by concrete splitting. The results allow a better prediction of the reinforcement fracture failure mode observed in numerous fire tests on floor plates.