Study on the shear performance of prestressed concrete hollow slab bridges considering the effect of beam‐end cracks during service

Abstract This study investigates the impact of initial beam‐end cracks on the shear performance of pretensioned concrete hollow slabs (PCHSs). Static loading tests with varying shear span‐to‐depth ratios were conducted on PCHSs with different pre‐existing crack levels. Results showed that the length of tendon isolation segments at beam ends significantly influenced shear failure modes. Inclined cracks intersecting with insufficiently anchored tendons caused tendon slippage and debonding, reducing crack restraint and further deteriorating shear capacity. As the shear span‐to‐depth ratio increased, failure modes progressed from bond‐diagonal compression to bond‐shear and finally flexure/shear‐bond. Compared to uncracked specimens, PCHSs with initial cracks exhibited a 25.0% reduction in initial stiffness, a 41.3% decrease in cracking load, a 34.8% lower tendon slippage load, and a 10.6% lower ultimate load, though ultimate deflection remained similar. An improved analytical model based on the Naji model was developed, showing a mean prediction‐to‐test ratio of 1.21 with a standard deviation of 0.10, demonstrating its effectiveness in predicting shear capacity of damaged PCHSs.