Accurate Prediction of Shear Strength of Deep Hollow Core Slabs

Abstract

The weight of concrete could be reduced by using hollow core slabs instead of heavy solid slabs, leading to cost reduction. The long span be also achieved by introducing prestress in hollow core slabs. but the evaluation of shear strength of precast-prestressed hollow core slabs are needed because the cross section is reduced in web and arranging shear reinforcement is not possible. The current code ACI318-11 specified that the web shear strength of hollow core slabs with a thickness greater than 315mm without shear reinforcement shall be one half of the calculation value. In this study, the web shear capacity of precast-prestressed hollow core slabs were evaluated based on experimental tests. For this purpose, nine full scale specimens were made and tested. Using the slab shear strength obtained from test result, the accuracy of shear strength equations specified in ACI318-05,11, AASHTO(2012), EC2(2002), and EN1168(2011) were evaluated. This study also proposed a proper factor limiting the shear strength specified in ACI318-05 for deep precast-prestressed hollow core slabs.