Performance of Bulb-Tee Girders Made with Self-Consolidating

Self-consolidating concretes (SCCs) have been developed to improve quality and increase pro-duction rates in the concrete construction indus-try. These materials exhibit a low viscosity such that mechanical vibration is not required after SCC placement. SCC has been used for a number of years in the architectural and structural precast concrete industry; however, it has not been used significantly in pretensioned concrete bridge members due to stringent material quality control standards speci-fied by state departments of transportation (DOTs). To facilitate DOT acceptance of this material for use in concrete bridge members, the performance of full-scale SCC girders was studied. Four 35-ft-long (10 m) bulb-tee girders were produced. Two girders were produced using a conventional high-early strength concrete (HESC) and two with an SCC. All girders were tested to failure twice, once at each end. The performances of the SCC girders was compared with those of the HESC girders and with code requirements. Responses of the HESC and SCC girders were comparable. The slip of the strand did not initiate failure of the girder in any tests. Both HESC and SCC girders exceeded the flex-ure and shear capacities predicted by the ACI code. In addition, the transfer lengths and in-place creep and shrinkage effects of the SCC girders were lower than expected