چكيده انگليسي :
The use of masonry bricks to build structures has been of interest to humans for a long time. In our country, structural walls are an important part of engineering and non-engineering buildings. Based on this, strengthening and improving the performance of walls, especially walls made with masonry materials, has been the focus of researchers. For a long time, various methods, such as strengthening with FRP, concrete, or steel jacket, have been considered for strengthening masonry walls, each of which has its drawbacks. Therefore, it can be a good idea to replace resin with mortar as the main difference between strengthening with FRP and using woven fabric or TRM.
The experiments performed in this thesis are divided into three groups. In the first group, preliminary tests were done on the masonry wall components. Also, with 45 direct shear tests, the optimal length and thickness of the TRM composite were obtained as 50 and 5 mm, respectively. By comparing 16 different mixing designs, the optimal mixing design of mortar with adhesion and resistance properties was determined. In the second group, nine brick walls include 1 non-reinforced base specimen and 8 specimens strengthened by textile reinforced mortar (TRM) and Parallel wires steel-reinforce mortar (PW-SRM) methods, which were subjected to out-of-plane loading. The results showed that the specimen reinforced with high-resistance parallel wires could increase the load and out-of-plane ductility by 2303 and 10.4, respectively. Also, in one specimen, the grooving method was used to improve the out-of-plane performance, which increased the maximum load by 88% compared to the control specimen without grooves. The third group consisting of 11 masonry walls, including one control specimen, nine reinforced samples, or one repaired, was subjected to in-plane reciprocating loading according to the recommendations of ACI code. Out of 9 reinforced walls, 4 samples were reinforced with TRM composite, which is a combination of 120 gram glass textile with 10 x 10 mm meshes with innovative mortar. The composite made of the combination of parallel steel wires with high strength with mortar (PW-SRG) reinforced the two walls. Then, the cyclic diagrams of load-lateral displacement, bearing capacity and ductility, the amount of cumulative consumed energy, stiffness, and also cyclic damping were investigated in different specimens. The results in this section proved the effectiveness of the PW-SRM strengthening method. The specimen reinforced with parallel cross bars with mortar method strengthen with high tensile steel wires had the best performance. The maximum load in compression and tension was 171.8 and 159.7 kN, respectively, and 30 mm in some places. The load increase in this specimen compared to the control specimen in compression and tension has increased by 114.8% and 100.0%, respectively, and compared to the CS strengthened by the TRM method, it has grown by 34.1% and 26.7%, respectively.
Finally, the relationships and mathematical parameters governing the numerical modeling of masonry walls and their reinforcement components were investigated in ABAQUS software. Numerical models of seven laboratory specimen with various strengthening methods were presented. In order to validate the numerical models, the value of bearing capacity and deformation corresponding to the numerical models of this research were compared with the results obtained from the numerical models in the laboratory specimens.
