Effect of eccentricity on strengthening efficiency of bar mesh high ductile concrete (BMHDC) on slender masonry columns

Abstract There is a lack of studies available in the literature focusing on the reinforcement of slender masonry columns commonly observed in the practice. This work presents the results of an experimental investigation on the effect of bar mesh high ductile concrete (BMHDC) on the mechanical behavior of slender masonry columns subjected to different eccentric axial loading. Eighteen full-scale rectangular specimens with a length of 2400 mm (aspect ratio of 10) were prepared and tested under three different eccentricity-to-section height (e/h) ratios (0, 0.15 and 0.3). For each loading eccentricity, three unreinforced columns as control specimens and three columns strengthened with two-sided BMHDC system were tested. The behavior of slender columns was presented and discussed based on failure mode, axial load-displacement relationships, peak load and axial deformation. The results showed that the peak load gain caused by BMHDC system increased as e/h increased. Besides, the stiffness, deformability, energy dissipation and flexural capacity were also improved by BMHDC system. Considering the additional eccentricity caused by lateral deflection mostly observed in the slender columns, a second-order analysis was carried out to predict the axial load bearing capacity of tested columns. A comparison between predicted values and results obtained from current study validated the accuracy and effectiveness of the analysis.