Research of Influence of Bed Joints Reinforcement On Strength of Masonry Shear Walls with Openings Made of Calcium Silicate Masonry Units

Abstract

This article describes results from testing reinforced and unreinforced walls made of calcium silicate units and having openings of different shapes. Conducted tests mainly focused on determining the effect of used reinforcement on the cracking morphology and values of cracking and failure forces. Every wall was made of calcium silicate units with vertical hollows (group I acc. to PN–EN 1996-1-1:2013). Tests covered 12 walls with the following external dimensions l = 4.45 m, h = 2.45 m, t = 180 mm, which varied in shape and dimensions of openings. Steel trusses of EFZ 140 / Z 140 type (Z1 type) and plastic meshes (Z2 type) were used as reinforcement. Models were divided into six series with a difference in the opening shape and the reinforcement type. Openings in walls were marked with letters A. B, and C. The opening of A type was a single window opening with a length of 1.50 m and a height of 1.12 m. That series included two models with truss type reinforcement (HA-Z1 (Z1 type of reinforcement) and two models with plastic mesh reinforcement (HA-Z2 (Z2 type of reinforcement). The opening of B type was also a window opening of 1.12 m in height, but longer - 2.50 m. That series included two models with truss type reinforcement (HB-Z1 (Z1 type of reinforcement) and two models with plastic mesh reinforcement (HB-Z2 (Z2 type of reinforcement). The opening of C type combined the window opening of 1.50 m in length and 1.12 in height and a door opening of 1.0 m in width and 1.90 in height. As in case of series of A and B type openings, tests were also performed on HC-Z1 series (Z1 type of reinforcement) and HC-Z2 series (Z2 type of reinforcement). The results were compared with test results for unreinforced walls with openings, tested under the same initial conditions. Reinforcement ratio in all reinforced models was ρ=0.07 (>ρmin=0.05). Walls were tested at different values of precompression stress σc = 0.1; 1.5 or 0.75 N/mm2. A mechanism of cracking and destruction, and values of cracking and failure stresses were analysed.