An Experimental Study on Reentrant Corner Crack Reinforcement for Pretensioned, Prestressed Concrete Slabs

Reentrant corner cracks have been observed in pre¬tensioned concrete slabs, but the phenomenon has not been explained in relation to the introduction of prestressing. In this study, a strand pullout experiment was conducted to confirm the occurrence of reentrant corner cracks and investigate the effect of reinforce¬ment on these cracks. The specimens were made in the shape of a unit rib of an inverted ribbed precast concrete slab, and three types of reinforcing elements were placed across the predicted surfaces of the cracks. The results showed that the maximum applied tensile load increased by up to 10.2% with reinforcement. In the specimen with mesh reinforcement, when the slip increased to 2 mm (0.079 in.), the load reduction ratio was limited to 52.2% of that of the unreinforced speci¬men. These findings provide practical insights into the behavior of reentrant corner cracks, enhancing under¬standing of how reinforcement can effectively maintain structural integrity.