Analytical study on creep shear failures of RC slender beams without web reinforcement

Abstract

Abstract. Sustained load problems, which can cause excessive deformation and severe damage to concrete structures, have been considered in current worldwide design codes by applying reduction factors on the compressive and tensile strength of concrete. A reduction factor in the shear design may also be required due to the decrease of shear-transfer action corresponding to the increases of the shear cracks opening. However, only a few studies are examining the effect of creep on shear performance of concrete structures, and the results are still inconclusive. As a complement to the previous experimental works, this study aims to investigate the effect of loading rate on the shear capacity of RC slender beams by non-linear finite element (FE) analysis. A spaceaveraged constitutive model with fixed multi-directional cracks was employed in the simulation of diagonal shear failure. The present study analytically examines the time-dependent effects on the beams under different loading rates until the delayed failure and compares the results with the previous experimental ones.

Influence of Longitudinal Reinforcement Ratio on Shear Strength of RC Slender Beam Under Different Loading Rates

“…The shear strength of the beams did not decrease owing to the application of slower loading rates. The increased shear strength due to the increase in fracture energy of concrete under much slower loading rates may relatively compensate for the adverse effect of creep [8]. An analytical study on shear-critical beams under sustained loading performed by Bugalia et al [9] also mentioned that RC slender beam was supposed to possess almost time-independent capacity within the service life.…”