Performance of Eccentrically Loaded Reinforced-Concrete Masonry Columns Strengthened Using FRP Wraps

This paper presents an experimental study that investigates the behavior of reinforced masonry (RM) columns strengthened using carbon fiber-reinforced polymer (CFRP) wraps under eccentric axial loading. Nine half-scale square RM columns with reinforced concrete (RC) end blocks were tested under three different eccentricity-to-section height ($e/h$) ratios (0.15, 0.25, and 0.50). For each load eccentricity, the columns were tested unwrapped, wrapped with one layer of CFRP, and wrapped with two layers. The effect of partially grouted masonry cells on column capacity was also evaluated. Existing analytical procedures for RC column sections were applied to the fully grouted RM columns. The experimental tests showed that CFRP wrapping increased the column’s axial capacity by up to 41% at a nominal $e/h$ ratio of 0.25, while an enhancement of 45% was achieved at a nominal $e/h$ ratio of 0.50. The analytical procedures were able to predict the failure mode and axial capacity of the tested columns. The columns’ axial capacities were estimated with a maximum error of 11%, which indicates the validity of the analytical procedures for eccentrically loaded RM columns.