TEST TO FAILURE OF A PRESTRESSED CONCRETE BRIDGE

The test to failure of two spans of a simple span, prestressed concrete highway bridge is described, and the measured and computed load-deflection curves for the bridge are presented and compared. The calculated load-deflection curve, based on strain compatibility relationships, compares reasonably well with the curve obtained experimentally. Severe dishing of the deck slab led to a separation between the bridge deck and the girders; the result was a loss of composite action and subsequent shear failure of the girders. Questions are raised regarding the state of existing knowledge of the behavior of composite, prestressed concrete, multi-beam bridges.