Cyclic behavior of RC beam-column joints with epoxy resin and ground tire rubber as partial cement replacement

Abstract

Abstract The introduction of polymers in ordinary cement concrete in order to reduce the Portland cement consumption is gaining more attraction in the field of civil engineering. However, in order to promote the use of Polymer-Modified Concrete (PMC) in real works, in addition to the mechanical characterization of the material, the study of its structural behavior is necessary. Two Polymer Cement Concrete (PCC) with 5% and 15% of cement replacement (expressed in terms of polymer/cement mass ratio (p/c)) by Ground Tire Rubber and epoxy, respectively, have been considered. The above replacements of cement were considered as optimum in a previous research carried out by the authors. This paper reports the experimental behavior of Reinforced Concrete (RC) beam-column joints made with conventional and PCC subjected to quasi-static reversed cyclic loading. The specimens included a control, one reference specimen made of a traditional concrete, and another two ones in which the joint zone was casted with epoxy resin and ground rubber respectively as partial cement replacement. The influence of the two polymer-cement concretes on the overall structural behavior of the RC joints was studied in terms of load-carrying capacity, strength degradation, ductility, stiffness degradation, energy dissipation capacity, equivalent viscous damping ratio, joint damage level and pinching width ratio. The results revealed that the epoxy resin concrete exhibited a good structural behaviour. On the contrary, the results corresponding to ground tire rubber concrete discourage its use in structures.