Experimental bond behaviour of welded mesh reinforcement at elevated temperatures

The bond characteristics between steel reinforcement and concrete are important when modelling global behaviour and predicting reinforcement fracture at ultimate failure. The current paper presents the measured bond stress-slip relationship for welded ribbed and smooth mesh reinforcement at ambient and elevated temperatures, which is commonly used in composite floor slabs. The tests incorporated the bond stress of the mesh resulting from the longitudinal and transverse bar together with the strength of the connecting weld. It was found that the 6, 7 and 8 mm diameter ribbed mesh fractured at all temperatures and the 10 mm diameter ribbed mesh failed by splitting owing to the low cover/bar diameter ratio. All mesh reinforcement with plain bars (6, 7, 8 and 10 mm diameter) failed by fracture of the weld followed by pull-out of the longitudinal bar. The results presented in this paper can be used in current structural models and will aid in defining the ultimate failure criteria of slabs with welded mesh reinforcement. © 2008 Thomas Telford Ltd.