Flexural destructive field testing of a prestressed concrete wide hollow slab girder

Abstract

A flexural destructive field test was conducted on a girder of decommissioned prestressed concrete hollow slab girder bridge. This girder had undergone serious deterioration before testing, which was reflected particularly by the longitudinal cracks in its bottom flange and diagonal cracks in the webs near its ends. During the test the girder was loaded with hydraulic jacks to its ultimate bearing capacity based on the current design code. The test results indicate that the cracks and deflections developed continuously with increment of loading and failure of the slab girder occurred due to crushing of concrete at a load of 274 kN rather than its theoretical value of 376kN, which means that the girder still has a flexural bearing capacity as high as 1618kNm. Analysis of the curves of load-deflection, load-crack width and degradation of rigidity shows that though existing cracks have certain effect on the initial loading performance of the girder, they seem to have no effect on its ultimate flexural capacity. The existing cracks, however, are bound to be detrimental to the durability of the bridge.