Experimental Study On Shear Wall Strengthened With Prestressed Wire And Polymer Mortar

In recent years, the performance and service requirements of construction has changed quickly along with the rapid development of the national economy and the diversification in various industries across the country. Therefore, the strengthening industry has become more and more important in civil engineering, and played an increasingly significant role in the local economic development and social progress. Up to now, the strengthening technology applied to existing engineering structures has become a hot topic in the research and development of the engineering field.Traditional strengthening methods such as increasing section, pasting carbon fiber cloth and steel bonded reinforcement have different limitations when applied to shear walls.The contents of this paper are as follow: 1. Put forward the reinforcement scheme of shear wall strengthened with the prestressed steel wire mesh-polymer mortar, and strengthen the shear wall. 2. 12 shear wall specimens were made with four of them were single-sided reinforced, six of them were double-sided reinforced. 3. Low reversed cyclic test were executed to the 2 unstrengthened specimens, 4 single-sided reinforcement specimens and 6 double-sided reinforcement specimens. 4. On the basis of the tests, analyses of cracking morphology, skeleton curve, stiffness curve, ductility and energy dissipation capacity of the shear walls were discussed in this paper. The main conclusions: 1.In order to study the characteristics of prestressed steel wire mesh-polymer mortar reinfocement technology and research the reinforcement scheme of shear wall. According to the tests, the strengthened technology is reliable and feasible in engineering. 2.Unreinforcement specimens’ hysteresis curve is close to Z mode which means that the slip has a great influence. Single-side reinforced specimens’ hysteretic curve become plump gradually, reflecting the deformation ability of specimens is good, and the strengthened technology ccould significantly improve the shear wall specimens of energy dissipation and seismic capacity. Double-sided reinforced specimens’ hysteretic curve is more plump, and show “pinch approach”effect. That is because the cracks between the base and the bottom of shear wall limited the development of the cracks, and the shear walls destroyed at the position between the base and the bottum of the walls. The specimens has a little slip, forming a "pinch approach" effect. 3. The strengthening technology significantly increase the cracking load,and yield load was increased 83.3%, the peak load was increased 9.5%. 4. Strengthening technology with prestressed steel wire mesh-polymer mortar can improve the ductility of test specimen, single-sided reinforcement can be increased by 21.5% to 31.1%, double-sided can be increased by 4.2% to 64.0%. 5. Unreinforced specimens’ stiffness degradation is quicker than single reinforced specimens, unreinforced specimens’ stiffness degradation is more quicker than the double-sided reinforced specimens. Compared with no prestressed horizontal specimens, the 0.2 prestressed horizontal specimens’ stiffness degradation speed is lowest,and the 0.3 prestressed horizontal specimens’ is slightly slower. Axial compression ratio of 0.2 compared with the axial compression ratio of 0.4, the specimens stiffness degradation is faster. 6. The strengthening technology could improve the final energy consumption by 8.5% to 96.6%; the final energy consumption increased by the increase of the number of the r einforcement and axial compression ratio. The final energy consumption with the prestress of 0.2 is greater than no prestress and with the prestress of 0.3.