Abstract
This paper presents the results of the second phase of a comprehensive research program at California State University at Fullerton on the applications of polymeric composite materials and adhesives in developing repair and retrofit systems for reinforced concrete beam-column joint subassemblages. Primary focus is on the low reversal cyclic fatigue behavior of interior beam-column reinforced concrete joints. A description of this phase of the ongoing research program is presented. In this program, a total of twelve full-scale reinforced concrete connection tests were performed. Results obtained from the latest six specimens repaired and rehabilitated using REPLARK composite system are presented. Two connection specimens were used as control specimens and were tested to failure under inelastic reversal cyclic loading regime. The two 'repairable' damaged specimens were re-tested under a similar loading regime after being repaired with both epoxy injection and carbon/epoxy laminates. To investigate the performance of the composite systems as retrofit systems, two other full-scale tests were conducted on undamaged specimens strengthened with specially designed carbon/epoxy laminates. P/ delta and M/ Theta hysteresis curve for each connection and the associated mode of failure are presented. Discussion on the advantages of using carbon epoxy laminates and recommendations for future research are presented. The results from a simple analytical model describing the behavior of connections retrofitted with composites is presented. The results of the analytical model were in a good agreement with the experimental results.