Seismic enhancement of reinforced concrete columns with lap splices using external steel collars

Abstract

This research investigated the behavior of reinforced concrete (RC) columns with lap splices and mechanical splices. The study conducted the full-scale test and predicted a lateral load capacity using the proposed numerical model. The test configuration was a cantilever column subjected to a cyclic lateral loading and a constant gravity load. The tested specimens consisted of the RC column without lap splices, RC columns with spliced reinforcement including lap splices and mechanical splices, and RC column with lap splices strengthened by external steel collars. The experimental result indicated that the lateral load capacity of the RC column with mechanical splices was closed to that of the control specimen (column without lap splices). The numerical model using the fiber section analysis was used to predict the lateral load vs displacement relation of the columns with mechanical splices. The numerical model could provide the lateral load capacity in a good agreement with the tested specimens. The strengthening technique by using external steel collars can enhance the ductility and lateral load capacity of RC columns with lap splices significantly.