| Abstract: | As a part of a general programme at the University of California, Berkeley, in the study of the seismic behaviour of reinforced concrete members, several of the severely cracked test specimens were repaired. The repair was made using either epoxy resin or concrete. In this paper a comparison of the performance of the original specimens with their performance after the repair is given. The repaired specimens were found to behave in a very satisfactory manner except where the injected epoxy had to restore a large region of destroyed bond between the concrete and the reinforcing steel. This condition was found to be particularly prevalent at the interior beam-column joints of moment-resisting frames. In such joints the bottom reinforcing steel of a beam tends to slip through a column due to the gradual bond degradation under cyclic loading. This is mainly caused by the formation of plastic hinges at the column faces. In order to avoid this condition, special details of reinforcement are suggested for controlling the location of plastic hinge formation. |
