Shear capacity of dry-cast extruded precast/prestressed hollow-core slabs

Abstract

Based on previous testing and analysis, it is believed that North American concrete design codes yield conservative shear designs for precast/prestressed hollow-core slabs in the 203 to 305 mm depth range. The objective of this research program is to calibrate the Canadian code shear equations to precast/prestressed hollow-core slabs, through testing a series of full-scale slabs to failure in shear. A total of twelve hollow-core slabs from one slab producer, using two types of extruders were tested in shear. Test variables include the bearing length and the prestressing level. Results are presented in terms of experimental to predicted capacity using the Canadian and American concrete design codes, the failure mode, crack profiles, and the critical section location for shear. It was concluded that the Canadian code shear equations are inappropriate for use with hollow-core slabs with low prestressing levels in the 203 to 305 mm depth range.