Axial compressive performance of masonry columns strengthened with ECC jacket and FRP strips

Fiber Reinforced Polymer (FRP) and Engineered Cementitious Composites (ECC) have been widely used to strengthen masonry columns due to their superior mechanical performance. Compression tests of masonry columns strengthened with ECC-jacket, FRP-strips, and ECC-jacket-FRP-strips were conducted in this study. The influence of the ultimate tensile strain of ECC and the number of FRP strip layers was investigated. The failure modes, load-displacement curves, strength, deformation, lateral strain, and energy absorption were analyzed and discussed. The results indicate that, compared with unconfined columns, the load-bearing capacity of columns strengthened by ECC jacket and two layers of FRP strips was significantly improved; 119% and 90.2% increases were achieved, respectively. There was a 242.4% and 119.4% increase in the corresponding ultimate deformation, respectively. In addition, the columns combine strengthened with ECC jacket and two layers of FRP strips exhibited excellent compression behavior, and their compressive strength was 274.5% higher than that of unconfined columns. The compressive strengths predicted by the available analytical models were adopted to evaluate the predictive ability of different models. The prediction model of the code CNR-DT 200/2013 exhibited better agreement with the experimental results in this study.