Experimental study on the flexural behaviour of lap-spliced rapid hardening concrete beams

Rapid-hardening concrete (RHC) has recently garnered significant attention because of its potential to expedite construction schedules and enhance structural performance. However, the flexural behaviour of lap-spliced RHC beams requires further investigation to provide valuable insights into the performance of this innovative construction material and splice technique. This study examined the flexural behavior of 22 lap-spliced RHC beams with varying lap splice lengths and compared them with four normal-strength concrete (NSC) beams. The key parameters investigated included lap splice length, concrete type, concrete cover, bar diameter, and splice end shape. The flexural performance of the beams was evaluated by analysing the load-deflection response, crack patterns, reinforcement strain distribution, and failure modes. Rapid-hardening concrete beams were tested three days after casting, whereas normal-strength concrete beams were tested 28 days later. The results of the study revealed that lap-spliced RHC beams exhibited increased ductility and load capacity by an average of 76 % and 32 %, respectively. In addition, the lap splice length in RHC beams could be reduced by up to 30 %.