Behavior of slender RC columns strengthened with partial and full wrapping of BFRP sheet, subjected to variable eccentric loading

This paper conducts an evaluation into the behavior of slender square reinforced concrete columns specimens strengthening with unidirectional basalt fiber reinforced polymer (BFRP) sheets which is a new environmentally friendly class of composite materials prepared from basalt rock as wrapping. axial concentric and eccentric compression loading tests were performed on these columns. This study intends to examine experimentally the efficiency of these strengthened column specimens by using a new interesting FRP composite material under variable eccentricity. Also, it aims to study the partial and full wrapping configuration of the BFRP sheet parameter. Hence, nine square slender reinforced concrete columns with 29 slenderness ratios were subjected to concentric and eccentric loading of each simply supported column specimen, and variable end eccentricity to width ratios of (0, 0.25, and 0.75) were utilized at both column ends. Modes of failure, ultimate Load capacity, flexural moment capacity, and lateral displacement at mid-high columns were presented and discussed for this purpose. From this research, it can be established that, in spite of that, the BFRP wrapping restriction efficacy declined with eccentricity an incline, using BFRP sheets as partial or full wrapping for strengthening reinforced concrete columns improved the performance of columns generally. As well as, increases the load and moment carrying capacity. Moreover, at the same load, lateral displacement for the columns strengthening by wrapping BFRP is lower than non-strengthening columns under variable eccentricities, especially for full wrapping.