Research On Seismic Performance Of Brick Masonry Walls Reinforced With TRC

Brick masonry structure still has a large stock in China,and is one of the main structural forms of old residential quarters in cities and towns.Due to the low seismic fortification level of such buildings during construction and the aging of masonry materials due to long-term load and environmental effects,which makes them more vulnerable to earthquakes and other disasters.Reinforcement can effectively improve the reliability of masonry structures and extend their service life.Textile-Reinforced Concrete(TRC)is a fiber reinforced material composed of textile and cement-based materials,which has good crack limiting ability and corrosion resistance.TRC uses cement-based materials as the matrix,so it has good bonding ability and cooperative stress performance with brick masonry walls,especially suitable for the reinforcement of masonry structures.In this thesis,the seismic performance of brick masonry walls strengthened with TRC is studied,mainly considering four factors: TRC reinforcement method,textile type,wall damage degree and wall type.Through the analysis of the failure modes of each wall and the seismic indicators such as stiffness degradation,ductility and energy consumption,the following conclusions are drawn:(1)Through studying the seismic performance of the undamaged ordinary brick masonry wall reinforced with TRC,the following conclusions are drawn: the unreinforced wall has obvious brittle failure characteristics when it is damaged,and the TRC reinforcement can make the wall damage process have a certain ductility,and the strengthened wall is less damaged when it is damaged;TRC reinforcement can improve the rigidity and peak bearing capacity of the wall;TRC reinforcement can improve the ultimate displacement,ductility and energy consumption capacity of the wall.Compared with the unreinforced wall,the ultimate displacement,ductility and energy consumption capacity of the carbon fiber TRC double-sided reinforced wall have increased by 57.01%,50.60% and 211.95% respectively;the seismic performance of walls strengthened with single-sided and double-sided carbon fiber TRC is better than that of double-sided basalt fiber TRC.(2)Through studying the seismic performance of damaged ordinary brick masonry walls reinforced with TRC,the following conclusions are drawn: TRC reinforcement can restore and improve the stiffness and peak bearing capacity of damaged walls;with the increase of damage degree,the ductility and energy consumption capacity of the damaged wall strengthened by TRC decreased,but both were higher than unreinforced wall;the failure mode of the damaged brick masonry wall strengthened by TRC is related to the failure mode of the original wall after the completion of the damage.(3)Through studying the seismic performance of windowed brick masonry wall reinforced with TRC,the following conclusions are drawn: the rigidity and peak bearing capacity of the wall directly strengthened by TRC are improved to different degrees compared with the unreinforced wall;TRC reinforcement can improve the ductility of the wall.The load of the unreinforced wall decreases rapidly after reaching the peak value and has a significant brittle failure feature.The wall strengthened by TRC enters a period of stability after the load reaches the peak value,and the failure has a certain ductility;TRC reinforcement can improve the energy consumption capacity of the wall.Compared with the unreinforced wall,the energy consumption of the wall directly strengthened by TRC increased by 73.3%,and the energy consumption of the wall strengthened by TRC can also basically recover to the level of the unreinforced wall after pre-damage.(4)By comparing and analyzing the seismic performance of different types of walls reinforced with TRC,the following conclusions are drawn: the seismic performance of the walls reinforced with TRC after moderate damage is basically the same as that of the undamaged brick walls reinforced with TRC;after severe damage,the seismic performance of walls reinforced with TRC has significantly decreased compared to undamaged brick walls reinforced with TRC;the window weakens the seismic performance of the wall obviously;in addition,the damage will increase the gap between the energy consumption capacity of the ordinary reinforced wall and the windowed reinforced wall.(5)Based on the data of this test,domestic and foreign codes are used to calculate the seismic shear bearing capacity of brick masonry walls reinforced with TRC.The results show that the seismic shear bearing capacity of walls calculated by domestic codes is conservative,so corresponding improvement suggestions are put forward for the formula given by domestic codes.In addition,based on the test fitting method,the restoring force model of TRC reinforced ordinary brick masonry wall is established.The model fits well with the skeleton curves obtained from the test,which can provide a reference for the seismic performance analysis of TRC reinforced ordinary brick masonry wall under earthquake action.