A Comparison of CFRP Retrofitted Columns Under Lateral Impact Loads with Different Boundary Conditions

Abstract

AbstractThe effectiveness of CFRP-retrofit of circular reinforced concrete (RC) columns under vehicular lateral impact is experimentally investigated. Eight 1/3 scale RC columns with two different configurations of FRP-wrapping (0 layer and 2 layers) were tested, with cantilever and propped cantilever conditions, under two different impact velocities. The impact load was applied at the typical vehicular impact location. Transient dynamic responses, damage evolution and post-impact damage are investigated by comparing the results obtained with different configurations and loading conditions. It is shown that the dynamic response and post-damage of RC columns are significantly affected by the CFRP-retrofit configurations, the impact velocity, and the boundary conditions. CFRP-wrapping can effectively reduce the vulnerability under lateral impact loading, converting the failure mode from shear- to flexural-dominated. Generally, brittle shear failure mode was observed for plain columns. Larger damage was obtained by increasing the impact velocity. Moreover, the influence of boundary conditions on the dynamic behavior of RC columns has been studied. The results indicate that the propped cantilever RC column experienced much more considerable damage than the cantilever one.KeywordsImpact loadsCFRP retrofitBoundary conditionsRC columnsFailure modes