A UHP-ECC surface layer combined with a wire mesh strengthening method for brick masonry walls: Experimental investigation on seismic behavior

Many existing brick masonry structures require strengthening due to low mortar strength and inadequate seismic detailing. Considering their cost-effectiveness and ease of construction, a UHP-ECC surface layer combined with a wire mesh is proposed for strengthening brick masonry walls. The tests employed wall thicknesses of 180 mm and 240 mm and strengthening forms of single- and double-sided as parameters. Six specimens, including four strengthened walls and two unstrengthened walls, were tested under low-cycle reversed loading. A validated finite element model was further employed to analyze the effects of vertical compressive stress, aspect ratio, and mortar strength. The strengthened walls exhibited significant increases in peak and ultimate loads, stiffness, ductility, and energy dissipation, with double-sided strengthening performing the best. Thicker walls showed greater cumulative energy dissipation, whereas unstrengthened walls experienced early cracking and rapid damage progression. Parameter analysis showed that higher vertical compressive stress and mortar strength, as well as a lower aspect ratio, significantly increased load-bearing capacity. A shear capacity formula for UHP-ECC strengthened brick masonry walls is proposed, providing an experimental and theoretical basis for seismic strengthening design. • The UHP-ECC surface layer strengthening method is proposed for brick masonry walls. • The UHP-ECC surface layer effectively restrains wall deformation and enhances shear capacity. • Double-sided strengthening significantly improves ductility and energy dissipation capacity. • The effects of vertical compressive stress, aspect ratio, and mortar strength on seismic behavior are investigated. • A shear capacity calculation formula is proposed and validated against experimental results.