An experimental investigation of high strength concrete bridge girders was conducted. The investigation included fabrication and testing of 70 ft (21.3 m) long, 54 in. (1372 mm) deep, pretensioned, prestressed high strength concrete bulb-tee girders. The design concrete compressive strength for the girders was 10,000 psi (69 MPa). Two girders were used to evaluate long-term static load and fatigue performance. Results from the girder used to determine long-term static load behavior indicated prestress losses that were significantly less than those predicted by the AASHTQ Standard. The girder used to determine fatigue performance withstood more than 5 million cycles of fatigue loading and satisfied all serviceability requirements. Upon completion of the long-term static load and fatigue test, measured flexural properties for both girders were adequate with respect to both design and specification requirements. Based on results from this investigation, high strength concrete bridge girders can be expected to perform adequately over the long term when designed and fabricated in accordance with current AASHTQ provisions.
