ABSTRACT

The design of rectangular concrete deck slabs of bridges has traditionally been based on methods developed by Westergaard1 in which it is assumed that a wheel load is distributed over a prescribed effective width.2,3 The slab is designed for bending effects only, the assumption being that the resulting shear capacity is adequate. The effects of any in-plane forces are thus neglected; however, it has been known for some time that these in-plane forces can have considerable effects on slab behaviour. In particular, when these forces are compressive, they have been shown to give much enhancement to slab strength.