Ultimate Load Test of Slab‐on‐Girder Bridge

Abstract

An ultimate load test on a short‐span simply supported bridge having six rolled‐steel girders and a noncomposite deck slab is described. The main conclusions drawn from the test are as follows: (1) The bearing restraint forces reduced the bending moment at midspan by a minimum of 11%; (2) the transverse load distribution pattern of the bridge improves by a relatively small margin as the ultimate limit state is approached; (3) any composite action between the deck slab and a girder that may exist at service loads, and is due only to bond or friction between steel and concrete, completely breaks down as the load approaches the failure load for the girder; and (4) a girder continues to carry loads long after the formation of first yield.