COMPUTATION OF TENSILE STRESS IN PRESTRESSED MEMBERS DUE TO CABLE RESTRAINT DURING DETENSIONING

The report supplements a previous study (Project ERSD-110-75-6, Highway Research Program, N.C. State University) concerned with end cracking of prestressed concrete girders during cable release. A computer program is developed that will assist in the computation of tension stress due to cable restraint during detensioning, the primary cause of the end cracks. In addition when high tensile stress is unavoidable rational procedures for sheathing some of the cables to reduce tension are described. A parametric study indicates that this tensile stress is of permissible magnitude when the ratio of the length of the cable at each end to the casting bed length is 5% or higher.