Tests of Partially Prestressed Concrete Girders

This paper reports a laboratory investigation of prestressed concrete bridge girders that duplicated designs used for the prestressed concrete bridges of the AASHO Road Test. Two pretensioned and two post-tensioned girders were subjected to repeated loads and were tested to failure. One girder of each type, designed for concrete tension of approximately 800 psi, was cracked under service loads throughout the test period. The other two girders, designed for a tension of approximately 300 psi, were subjected to repeated loads incremented beyond the service load level until cracks were formed. Only the post-tensioned girder designed for 800 psi tension suffered damage from the repeated loading. The results from the laboratory investigation of the full-size girders are in agreement with findings from the AASHO Road Test bridge research.