Performance evaluation of dry and epoxy jointed segmental prestressed box girders under monotonic and cyclic loading

A large number of post-tensioned prestressed concrete segmental bridges are being constructed worldwide. Use of different materials and shear keys will have varying effects on the performance of segmental girders even during the service load. The type of joints, quality of joint, degree of mechanical actions and the joint materials will contribute to the variation in the behaviour of the segmental girders. Hence, the need for investigation on the epoxy jointed segmental box girder and dry jointed segmental box girder becomes necessary. This paper presents the experimental investigations carried out in laboratory environment on a scaled model of a simply supported precast post-tensioned box-girder bridge deck that is cast using segmental construction method. Performance of box-girders with dry and epoxy joints is evaluated under static and cyclic loading. It is observed from the results that the flexural strength of dry jointed specimen is less than the epoxy joint due to high concentration of rotation and deflection at individual joints of segmental girder. Upto design load, segmental box girder specimen with dry and epoxy joints behaved like monolithic beam. However, it is found from the study that first joint opening load of the dry jointed specimen is 27% less than the epoxy jointed specimen due to lack of resistance to tension between the joints. Due to high concentration of rotation and deflection at individual joints in the dry jointed specimen, the maximum load and failure load are 8.6% and 16.7% less than that of the epoxy jointed specimen. The study will help in understanding the role of type of joint and the material used on the performance of the segmental bridges.