simulation of reinforced concrete columns strengthened with cfrp wraps

The stability and integrity of the structure mainly depend on the response of columns supporting the loading. it, therefore, becomes important that columns provide adequate resistance under applied loadings throughout their design and operational life. however, due to poor design, changes in usage of structures, and material deterioration the columns may need retrofitting and strengthening. out of several strengthening and retrofitting techniques available, carbon fiber reinforced polymer (cfrp) wrapping has been widely used in confining reinforced concrete (rc) columns resulting in a significant increase in their load-carrying capacity. therefore, in this study, the cfrp-wrapped rc columns have been assessed by conducting detailed experimental and numerical investigations. for this purpose, ten rectangular rc columns with an aspect ratio of 1:2 were studied experimentally under uniaxial compression. out of ten specimens, two plain and rc columns each, without cfrp wraps, were used as control specimens. for the remaining six rc columns, three different cfrp wrapping techniques (fully wrapped, wrapped up to a two-third height of the column, and wrapped with cfrp strips at 51 mm spacing) were used to investigate the effect of confinement. furthermore, finite element analyses were initially carried out using atena to simulate the response of columns tested during the study and reported by other researchers which were then followed by the parametric investigation in which the effect of concrete compressive strength and ratio of longitudinal steel on the behavior of cfrp-wrapped rc columns was studied. based on the detailed investigations, it was found that the use of cfrp wraps to confine columns not only proved to be effective in the enhancement of load-carrying capacity (64.75 and 19.55% compared to control plain and rc columns, respectively) but also resulted in avoiding the yielding of steel reinforcement as well as the crushing of the concrete in the steel core region. furthermore, most of the equations available in the literature for predicting the failure load of the fully wrapped rc columns were found to be overly conservative (with a difference of 28% lower load prediction) when the peak loads were compared with the experimentally exhibited and numerically predicted peak loads. © 2022, iran university of science and technology.