Flexural behaviour of reinforced concrete beams under freeze-thaw cycles and sustained load

This paper presents an experimental investigation on the flexural behaviour of reinforced concrete beams under the combined effects of freeze-thaw cycling and sustained loading. Thirteen beams (2000 x 250 x 150mm) were fabricated and tested. Test parameters included four numbers of freeze-thaw cycles (20, 40, 60 and 80) and three levels of sustained load (0, 20 and 50% of the ultimate load of the control beam). After exposure, the beams were tested at room temperature under four point bending up to failure. The flexural behaviour was evaluated by studying the load-deflection curve, the ultimate load capacity, the ductility, the crack pattern and crack width and the evolution of the neutral axis depth. It was found that freeze-thaw cycles and sustained loading had significant effects on the flexural performance of reinforced concrete beams.