Experimental and Theoretical Investigation of Precast Concrete Hollow-Cored Slabs used as Horizontal Floor Diaphragms
Full-scale precast prestressed hollow-cored flooring slabs have been tested under fully reversible horizontal shear loading to determine their suitability as horizontal diaphragms in multistorey buildings. No structural topping screed was used, but in situ reinforced end beams were used to reproduce the presence of beams in a frame environment. A hypothesis is presented which describes the shear transfer mechanism between two adjacent slabs. This is based on the shear friction mechanism appropriate to this type of construction. The critical plane is the longitudinal joint between the slabs. An analytical model is derived to predict the shear failure load. The results are within 10 % of the experimental values. The results show that, under working load conditions, the deformation at the interface between the slabs is fully recoverable. Under ultimate load conditions, although some permanent damage occurs by abrasion of the asperities of the cracked matrix, the shear resistance of the joint is in excess of BS 8110 design values by between 1O % and 63 %. Design guidance for the use of hollow-cored slabs as horizontal floor diaphragms is offered.
K.S. Elliott, G. Davies and W. Omar
Author(s): Elliott, K S;Davies, G;Omar, W
Keywords: load tests;floors;beams;reinforced concrete;precast;end beams;hollow slabs;joints;shear strength;diaphragms;multistorey buildings;cracks;cyclic loads;dowel action;modelling;stiffness;design