An Exploratory Investigation of Shear Fatigue Behavior of Prestressed Concrete Girders

This report presents the results of an exploratory investigation of shear fatigue behavior of precast prestressed girders with unshored cast-in-place slabs. It includes a literature survey of shear fatigue behavior and design specifications related to fatigue of structural concrete. Detailed summaries are given for the fatigue response and ultimate behavior of three full-scale prestressed girders including static and dynamic measurements of load, deflection, crack widths, strand stresses, and stirrup stresses. The controlled variable in this exploratory investigation was the maximum fatigue load. Other variables included in the investigation were concrete strength and prestressing losses. Fatigue data for stirrups in the girders were compared with data from fatigue tests of reinforcing bars in air. Shear fatigue data for the girders were compared and evaluated with results of previous studies and with present design code specifications.