Behavior and Strength Predictions for CFRP Confined Rubberized Concrete under Axial Compression

This paper presents experimental versus theoretical comparison of carbon fiber reinforced polymer (CFRP) confined rubberized concrete (a new structural material). A total of sixty six rubberized concrete cylinders were tested in axial compression. The specimens were cast using 0 to 50% rubber replacement. Twenty seven cylinders were then confined with one, two and three layers of CFRP jackets. Axial compression results of the experimental study were compared with the North American and European design guidelines. The results indicate that the addition of rubber content in the concrete leads to premature micro cracking and lateral expansion in concrete. This increased lateral dilation exploited the potential of FRP jackets. The axial compressive strength and strain values for CFRP confined RuC cylinders reached up to unprecedented 600 and 330 percent of unconfined samples. Furthermore, the current international design guidelines developed for conventional concrete confinement failed to predict the compressive strength of rubberized concrete. There is a strong need to re-evaluate the current design codes and their applicability to investigate fiber reinforced confined rubberized concrete. Moreover, the proposed equations in this research can better predict the axial compressive strength of FRP confined RuC.