High-toughness concrete composite fiber mesh combined with embedded brick masonry walls and construction method thereof

Abstract

The application discloses a high-toughness concrete composite fiber mesh combined embedded brick masonry wall and a construction method thereof, and belongs to the technical field of civil engineering. A plurality of horizontal FRP (Fiber Reinforced Polymer) bars are arranged on the two side walls of a pre-reinforced brick masonry wall at intervals, and a plurality of FRP structural columns are arranged on the two side walls of the pre-reinforced brick masonry wall at intervals. For the pre-reinforced brick masonry wall with a reinforced concrete structural column at the starting end, the FRP structural column is arranged at a position less than 4 m away from the reinforced concrete structural column. For the pre-reinforced brick masonry wall without a reinforced concrete structural column at the starting end, the FRP structural column is arranged starting from the starting end. After the FRP structural column is arranged, a high-toughness concrete surface layer is coated on the two side walls, and a fiber mesh is laid on the wall, and then the high-toughness concrete surface layer is coated. Thus, the problems of the brick masonry wall in the prior art, such as brittleness, shear failure, poor seismic performance and poor integrity, are solved. The constraint and overall performance of the wall body are strengthened, the wall body has stable vertical load bearing capacity, part of the seismic energy is consumed, and the damage to the wall body caused by the earthquake is reduced.

Description

Technical Field

[0001] This invention relates to the field of civil engineering technology, specifically to a high-toughness concrete composite fiber mesh combined rebar brick masonry wall and its construction method. Background Technology

[0002] Brick masonry walls are mainly constructed from bricks and mortar. Compared to reinforced concrete structures, brick masonry structures have lower strength, poorer overall integrity, lower tensile and shear strength, and are inherently brittle. Under horizontal seismic action, masonry walls are prone to cracking, reduced stiffness, and eventually brittle failure, resulting in severe damage to masonry structures during earthquakes and posing a serious threat to people's lives and property. Therefore, research on brick masonry structures is particularly important.

[0003] With the continuous updating of seismic design codes and the damage to walls during use, some walls no longer meet the requirements of current codes. Demolishing and rebuilding buildings that do not meet the codes would inevitably lead to a huge waste of existing building resources. Therefore, reinforcing brick masonry buildings that do not meet seismic requirements and improving the seismic performance of the walls to meet the requirements of current codes has become an important research topic in the construction industry.

[0004] In recent years, with the continuous development of fiber materials, FRP has been widely used in the field of masonry structure reinforcement and repair. FRP reinforcement has advantages such as high strength, lightweight, corrosion resistance, and convenient construction. However, FRP uses an organic matrix as a binder, which has certain shortcomings such as poor high-temperature resistance and difficulty in construction in low-temperature and humid environments. The emergence of inorganic cement-based composite materials can, to some extent, make up for the limitations of FRP reinforcement using an organic matrix. TRC is a new type of fiber-reinforced cement-based composite material composed of bidirectional fiber woven mesh and high-performance concrete. The high-performance concrete used has good bonding performance with the wall, and the force transmission direction of the bidirectional fiber mesh is clear. However, the high-performance concrete used in TRC matrix does not contain fibers, resulting in poor crack limiting ability and weak tensile strength of the matrix. Cracking of the matrix leads to low utilization of the fiber mesh and large crack width in the wall, which is not conducive to the aesthetics and long-term use of the structure. Summary of the Invention

[0005] Technical problem: The purpose of this invention is to overcome the shortcomings of the seismic performance of masonry structures and to provide a high-toughness concrete composite fiber mesh combined rebar brick masonry wall and its construction method, which is not prone to brittle failure, has good integrity and shear and seismic performance, and strong crack limiting ability.

[0006] Technical Solution: This invention provides a high-toughness concrete composite fiber mesh combined rebar brick masonry wall, comprising a pre-reinforced brick masonry wall with or without reinforced concrete structural columns. Multiple horizontal FRP bars are spaced apart on both sides of the pre-reinforced brick masonry wall, and multiple FRP structural columns are spaced apart on both sides of the pre-reinforced brick masonry wall. Specifically: for pre-reinforced brick masonry walls with reinforced concrete structural columns at the beginning, FRP structural columns are installed starting less than 4m from the reinforced concrete structural columns; for pre-reinforced brick masonry walls without reinforced concrete structural columns at the beginning, FRP structural columns are installed starting from the beginning. P-shaped structural column; the FRP structural column includes multiple longitudinal FRP bars press-fitted onto horizontal FRP bars at intervals, and FRP stirrups that pass through the wall and bind the multiple longitudinal FRP bars attached to the two side walls at intervals. The multiple horizontal FRP bars arranged at intervals on the two side walls are held together by tie bolts passing through the wall. The top of the multiple longitudinal FRP bars extends to the upper ring beam, and the bottom of the bars extends to the lower ring beam. After the FRP structural column is installed, a layer of high-toughness concrete surface layer is coated on the two side walls, and fiber mesh is laid on the entire wall on the coated tough concrete surface layer, and then another layer of high-toughness concrete surface layer is coated.

[0007] The multiple horizontal FRP bars and multiple longitudinal FRP bars are located in the mortar joints. The groove depth of the mortar joints is 1.2 to 1.5 times the diameter of the FRP bars. The spacing between the multiple horizontal FRP bars is the distance of four brick courses, and the spacing between the multiple longitudinal FRP bars is the length of one brick.

[0008] The distance between multiple FRP structural columns spaced apart on both sides of the pre-reinforced brick masonry wall is less than 4m.

[0009] The diameter of the horizontal FRP reinforcement is 6-8 mm; the diameter of the longitudinal FRP reinforcement is 10-12 mm.

[0010] The spacing of the FRP stirrups along the height direction of the structural column is 150-300mm.

[0011] The thickness of the high-toughness concrete surface layer is 10-20 mm.

[0012] The number of layers of fiber mesh laid on the entire wall is 1 to 3, and each layer of fiber mesh is coated with 5mm thick high-toughness concrete.

[0013] The high-toughness concrete surface layer comprises the following components: 379 kg / m³ of ordinary Portland cement, 885 kg / m³ of fly ash, 455 kg / m³ of quartz sand, 379 kg / m³ of water, 17.4 kg / m³ of water-reducing agent, 1.26 kg / m³ of thickener, and 26 kg / m³ of polyvinyl alcohol fiber, wherein the volume ratio of chopped polyvinyl alcohol fiber is 2%.

[0014] The FRP reinforcement and stirrups are both fiber fabric reinforcements, composite materials formed with resin as the matrix. The fiber fabric includes one of glass fiber, carbon fiber, basalt fiber or aramid fiber; the fiber web is woven from one or two of carbon fiber, glass fiber, basalt fiber, aramid fiber and polyethylene fiber.

[0015] A construction method for a reinforced brick masonry wall using the above-mentioned high-toughness concrete composite fiber mesh includes the following steps: Step 1: Remove the loose layer on the surface of the pre-reinforced brick masonry wall with or without reinforced concrete structural columns. Groove the horizontal mortar joints of the pre-reinforced brick masonry wall every 4 courses of bricks. Groove longitudinally at the location of the pre-set longitudinal FRP reinforcement of the structural column. The depth and width of all grooves are 1.2 to 1.5 times the diameter of the FRP reinforcement. Step 2: Place the horizontal FRP bars into the groove of the horizontal mortar joint and fix them to the wall with tie bolts. Then, lay multiple longitudinal FRP bars at the location of the FRP structural column and arrange a ring of FRP stirrups every 150-300mm along the longitudinal FRP bars. Step 3: After the FRP structural column is installed, apply a layer of high-toughness concrete to both sides of the wall. Wet the fiber mesh used for reinforcement with cement slurry, lay it on the surface of the high-toughness concrete, and gently press the fiber mesh into the surface to ensure good adhesion between the fiber mesh and the substrate and enhance the synergistic stress. Then apply another layer of high-toughness concrete to the surface of the fiber mesh. Depending on the project requirements, one, two, or three layers of fiber mesh may be laid.

[0016] Beneficial Effects: This invention comprises a high-toughness concrete composite fiber mesh reinforced brick masonry wall, consisting of a high-toughness concrete surface layer, FRP reinforcement, fiber mesh, and brick masonry wall. The high-strength and tough concrete surface layer and the high-tensile-strength, clearly directional fiber mesh encase the masonry wall. FRP reinforcement is placed at pre-designed structural column locations within the wall and secured with stirrups. FRP reinforcement is implanted every four brick courses in the horizontal mortar joints of the wall, enhancing the wall's integrity and inducing shear slip failure. This improves the shear bearing capacity and ability to stably withstand vertical loads, and significantly enhances the masonry wall's seismic performance. This invention's masonry wall can be used for new masonry structures as well as for the repair and renovation of old brick masonry structures in residential areas, office buildings, etc. It features simple construction, minimal damage to the wall, and significantly improves the failure mode of the masonry wall, enhancing its integrity and seismic performance. Compared with existing brick masonry walls, this invention has the following characteristics: (1) In this invention, FRP bars are implanted in the longitudinal mortar joints of the brick masonry wall and stirrups are arranged, which is equivalent to adding additional structural columns to the wall, thereby improving the integrity and energy dissipation capacity of the wall. FRP bars are implanted in the horizontal mortar joints of the masonry wall, which not only enhances the overall performance of the wall, but also improves the shear bearing capacity of the masonry wall. The presence of tie bolts can ensure that the masonry wall and the horizontal FRP bars share the load, reduce the thickness of the external reinforcement layer, and increase the usable space area.

[0017] (2) The tensile strength of the fiber mesh used in this invention is 4660MPa. At the same time, the fiber mesh has good bonding performance with the high-toughness concrete surface layer after impregnation. The force transmission direction of the fiber mesh is clear and enhances the wrapping of the wall. The compressive strength of the high-toughness concrete used can reach more than 50MPa, and the ultimate tensile strain can reach more than 200 times that of ordinary concrete. At the same time, it has good bonding performance with the surface of the masonry wall. It is a reinforcement material with high strength, high ductility and good durability. It can effectively limit the development of the main crack in the wall and show the characteristics of multiple crack development, which significantly enhances the integrity and seismic performance of the masonry wall.

[0018] (3) The high-toughness concrete composite fiber mesh surface layer in this invention has the characteristics of multiple crack propagation, small crack width, good force transmission effect, and thin thickness. At the same time, the FRP reinforcement and high-toughness concrete composite fiber mesh reinforcement layer have good durability, which can extend the service life of the structure, significantly improve the integrity of the wall and its shear and seismic performance, and enhance the performance of masonry structures under seismic loading.

[0019] (4) The high-toughness concrete composite fiber mesh combined rebar brick masonry wall provided by this invention introduces high-strength FRP bars. By embedding FRP bars in the mortar joints, the requirements of enhancing the integrity of the original wall and delaying the degradation of wall stiffness can be met (based on the role of horizontal steel bars in the steel mesh cement mortar surface reinforcement method, which improves the shear bearing capacity of the wall and delays the degradation of wall stiffness). Figure 7 The bearing capacity of a wall with horizontal FRP reinforcement inserted in the middle decreases more slowly after the peak load compared to an unreinforced wall, and hardly changes the cross-sectional dimensions of the reinforced component. It also has the advantages of simple construction and minimal damage to the wall.

[0020] (5) The FRP reinforcement and fiber mesh used in this invention have corrosion resistance, which expands the application range of this reinforcement method; at the same time, the fiber mesh is very thin, which reduces the thickness of the reinforcement layer and hardly occupies the usable space of the structure.

[0021] (6) The high-toughness concrete used in this invention is an inorganic cement-based material with high strength, good tensile and compressive toughness and good durability. It forms a good constraint on the brick masonry wall, significantly enhances the integrity and shear bearing capacity of the brick masonry wall, and changes the brittle failure characteristics of the brick masonry wall.

[0022] (7) The inorganic cement-based material used in this invention as the matrix of the fiber mesh can make up for the poor high temperature resistance and unsuitability of the epoxy resin material used in the fiber cloth to the uneven surface of the brick masonry wall. The high toughness concrete has good bonding performance with the brick masonry wall and has the characteristics of multi-crack cracking and strain hardening, which can make the fiber mesh and the wall more uniformly stressed, delay the development of the main crack, and give full play to the mechanical properties of the two materials in the reinforcement layer.

[0023] (8) By planting steel bars in the wall and using a high-toughness concrete composite fiber mesh surface layer, the present invention significantly improves the integrity and rigidity of the wall, causes less damage to the wall, enhances the deformation capacity, and the specimen still has good load-bearing capacity under large displacement, reducing the risk of brick masonry structure collapse under earthquake action, reducing costs, and ensuring the safety of people's lives and property. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of the present invention.

[0025] Figure 2 This is a schematic diagram of the structure of Embodiment 2 of the present invention.

[0026] Figure 3 These are partial longitudinal cross-sectional views of embodiments 1 and 2 of the present invention.

[0027] Figure 4 These are partial horizontal cross-sectional views of Embodiments 1 and 2 of the present invention.

[0028] Figure 5 Hysteresis curves of simulated static tests for reinforced concrete structural column wall specimens.

[0029] Figure 6 Hysteresis curves for numerical simulation of reinforced concrete structural column wall specimens.

[0030] Figure 7 Hysteresis curves of a reinforced concrete structural column wall specimen after horizontal joint reinforcement is installed.

[0031] In the diagram: 1—reinforced concrete structural column, 2—brick masonry wall, 3—lower ring beam, 4—upper ring beam, 5—horizontal FRP reinforcement, 6—longitudinal FRP reinforcement, 7—FRP stirrups, 8—tie bolts, 9—high-toughness concrete surface layer, 10—fiber mesh, L—width of the pre-set structural column, h—thickness of the brick masonry wall. Detailed Implementation

[0032] The present invention will be further described below with reference to the embodiments shown in the accompanying drawings: This invention discloses a high-toughness concrete composite fiber mesh combined rebar brick masonry wall, comprising a pre-reinforced brick masonry wall with or without reinforced concrete structural columns 1. Multiple horizontal FRP bars 5 are spaced apart on both sides of the pre-reinforced brick masonry wall, and multiple FRP structural columns are also spaced apart on both sides of the pre-reinforced brick masonry wall. Specifically: for pre-reinforced brick masonry walls with reinforced concrete structural columns 1 at the beginning, FRP structural columns are installed starting less than 4m from the reinforced concrete structural columns; for pre-reinforced brick masonry walls without reinforced concrete structural columns 1 at the beginning, FRP structural columns are installed starting from the beginning. The distance between the multiple FRP structural columns spaced apart on both sides of the pre-reinforced brick masonry wall is less than 4m. The FRP structural column includes multiple longitudinal FRP bars 6 spacedly press-fitted onto horizontal FRP bars 5, and FRP stirrups 7 spacedly passing through the wall and binding the multiple longitudinal FRP bars 6 attached to the side walls. The multiple horizontal FRP bars spaced apart on the side walls are held together by tie bolts passing through the wall. The multiple horizontal FRP bars 5 and multiple longitudinal FRP bars 6 are located in mortar joints, with the groove depth of the mortar joint being 1.2 to 1.5 times the diameter of the FRP bars. The spacing between the multiple horizontal FRP bars 5 is the distance of four brick courses, and the spacing between the multiple longitudinal FRP bars 6 is the length of one brick. The diameter of the horizontal FRP bars 5 is 6 to 8 mm; the diameter of the longitudinal FRP bars 6 is 10 to 12 mm. The top of the multiple longitudinal FRP reinforcement bars 6 extends to the upper ring beam 4, and the bottom extends to the lower ring beam 3. After the FRP structural columns are installed, a layer of high-toughness concrete surface layer 9 is coated on both sides of the wall surface. A fiber mesh 10 is then laid across the entire wall on top of the high-toughness concrete surface layer 9, followed by another layer of high-toughness concrete surface layer 9. The thickness of the high-toughness concrete surface layer 9 is 10–20 mm. The number of layers of fiber mesh 10 laid across the entire wall is 1–3, with a 5 mm thick layer of high-toughness concrete between each layer of fiber mesh. The high-toughness concrete surface layer 9 comprises the following components: 379 kg / m³ of ordinary Portland cement, 885 kg / m³ of fly ash, 455 kg / m³ of quartz sand, 379 kg / m³ of water, 17.4 kg / m³ of water-reducing agent, 1.26 kg / m³ of thickener, and 26 kg / m³ of polyvinyl alcohol fiber, wherein the volume ratio of chopped polyvinyl alcohol fiber is 2%. The spacing of the FRP stirrups 7 along the height direction of the structural column is 150-300mm; both the FRP bars and the stirrups 7 are reinforcements of fiber fabrics, which are composite materials formed with resin as the matrix. The fiber fabrics include one of glass fiber, carbon fiber, basalt fiber or aramid fiber; the fiber mesh is woven from one or two of carbon fiber, glass fiber, basalt fiber, aramid fiber and polyethylene fiber.

[0033] The cement used is PO42.5R silicate cement, the fly ash is Grade I fly ash, the quartz sand is 140-280 mesh quartz sand, and the polyvinyl alcohol short-cut fibers are K-II Kuraray polyvinyl alcohol fibers manufactured by Kuraray Corporation of Japan, with a length of 12mm, a tensile strength of 1600MPa, and an elastic modulus of 42GPa. High-performance polycarboxylate superplasticizer manufactured by Sika Corporation and thickener manufactured by Shandong Heda Corporation are also included. The high-toughness concrete contains a water-reducing agent with a water reduction rate of over 30%, with the amount of water-reducing agent added being 0.8% of the total mass of all components of the high-toughness concrete, and the amount of thickener added being 0.06% of the total mass of all components.

[0034] The construction method of the high-toughness concrete composite fiber mesh combined rebar brick masonry wall of the present invention includes the following steps: Step 1: Remove the loose layer on the surface of the pre-reinforced brick masonry wall with or without reinforced concrete structural column 1. Groove the horizontal mortar joints of the pre-reinforced brick masonry wall every 4 courses of bricks. Groove longitudinally at the position of the pre-set longitudinal FRP reinforcement 6 of the structural column. The depth and width of all grooves are 1.2 to 1.5 times the diameter of the FRP reinforcement. Step 2: Place the horizontal FRP reinforcement 5 into the groove of the horizontal mortar joint and fix it to the wall with tie bolts 8. Then, lay multiple longitudinal FRP reinforcements 6 at the location of the FRP structural column and arrange a ring of FRP stirrups 7 every 150-300mm along the longitudinal FRP reinforcement. Step 3: After the FRP structural column is installed, apply a layer of high-toughness concrete to both sides of the wall. Wet the fiber mesh 10 used for reinforcement with cement slurry, lay it on the surface of the high-toughness concrete, and gently press the fiber mesh 10 into the surface to ensure good adhesion between the fiber mesh 10 and the substrate and enhance the synergistic stress. Then apply another layer of high-toughness concrete to the surface of the fiber mesh. Depending on the project requirements, one, two, or three layers of fiber mesh 10 may be laid.

[0035] Example 1: Figure 1This is a schematic diagram of a pre-reinforced brick masonry wall with reinforced concrete structural columns 1. The brick masonry wall 2 has reinforced concrete structural columns 1 on both sides, an upper ring beam 4, and a lower ring beam 3. The dimensions of the coal gangue sintered bricks are 235mm × 115mm × 53mm. The brick masonry wall 2 has a length of 4.5m, a height of 2.4m, and a thickness h of 240mm. The cross-sectional dimensions of the structural columns 1 are 120mm × 240mm; the cross-sectional dimensions of the lower ring beam 3 are 400mm × 400mm; and the cross-sectional dimensions of the upper ring beam 4 are 200mm × 240mm. The structure is as follows: FRP bars 6 and stirrups 7 are embedded in the vertical mortar joints at the pre-set structural column positions in the brick masonry wall 2; the width L of the pre-set structural column is 740mm; horizontal FRP bars 5 are embedded in the horizontal mortar joints of the brick masonry wall 2; and a high-toughness concrete surface layer 9 and fiber mesh 10 are coated on the outer surface of the brick masonry wall 2. The specific construction process is as follows: Step 1: Construct brick masonry wall 2, then pour structural column 1, lower ring beam 3, and upper ring beam 4; Step 2: Arrange 8 FRP bars 6 with a diameter of 10mm at the preset structural column position. Then, make holes every 200mm along the vertical mortar joint along the height of the structural column and insert 6mm diameter stirrups 7. The stirrups are two nested rectangular closed stirrups. Next, grooves are made every 4 brick courses along the horizontal mortar joint of the structural column wall. Place the FRP bars 5 into the grooves and fix them with tie bolts 8. The diameter of the FRP bars is 8mm. Clean the wall surface and apply a layer of high-toughness concrete surface layer 9 with a thickness of 5mm. Then attach the fiber mesh 10 to the high-toughness concrete and straighten the carbon fibers in the fiber mesh horizontally. Apply another 5mm thick layer of high-toughness concrete surface layer 9 and smooth the surface.

[0036] In this example, the lower ring beam 3, the upper ring beam 4, and the structural column 1 are all reinforced according to structural requirements. In order to enhance the integrity and shear bearing capacity of the upper brick masonry wall 2, structural columns are pre-installed in the brick masonry wall 2 and horizontal reinforcement bars are embedded in the horizontal mortar joints to enhance shear resistance. In order to enhance the seismic performance and safety of the wall, the brick masonry wall 2 is reinforced with a high-toughness concrete surface layer 9 and a fiber mesh surface layer 10, which further improves the seismic bearing capacity, safety, and durability of the wall.

[0037] In this embodiment, FRP reinforcements 5 and 6 are composite materials formed by carbon fiber fabric as reinforcement and resin as matrix, with a tensile strength of 1400MPa, an elastic modulus of 64GPa, a diameter of 10mm, and a length of 2400mm; the length of FRP reinforcement in the horizontal mortar joint is 4500mm.

[0038] The high-toughness concrete of this embodiment is composed of cement, fly ash, quartz sand, polyvinyl alcohol chopped fibers, thickener, water-reducing agent, and water. The components of the high-toughness concrete are: ordinary Portland cement 379 kg / m³, fly ash 885 kg / m³, quartz sand 455 kg / m³, water 379 kg / m³, water-reducing agent 17.4 kg / m³, thickener 1.26 kg / m³, polyvinyl alcohol fiber 26 kg / m³, and the volume ratio of polyvinyl alcohol chopped fibers is 2%. The cement used was PO42.5R silicate cement, the fly ash was Grade I fly ash, the quartz sand was 140-280 mesh quartz sand, and the polyvinyl alcohol short-cut fiber was K-II Kuraray polyvinyl alcohol fiber produced by Kuraray Corporation of Japan, with a length of 12mm, tensile strength of 1600MPa, and elastic modulus of 42GPa. In this example, the ECC matrix contained a high-performance polycarboxylate superplasticizer with a water reduction rate of more than 30% produced by Sika Corporation and a thickener produced by Shandong Heda Corporation.

[0039] The preparation process of the above-mentioned high-toughness concrete is as follows: pour the cement, fly ash and quartz sand in the set proportion into the mixer and mix evenly. Pour the water-reducing agent into the water and then into the mixer and mix for 3 minutes. Finally, add the thickener and polyvinyl alcohol short fiber and mix evenly to obtain high-toughness concrete.

[0040] The following are the mechanical property tests and results of high-toughness concrete from the examples: (1) 70.7mm×70.7mm×70.7mm cubic specimens were used and cured according to standard for 28 days, and then the cubic compressive strength test was carried out. The test results showed that the compressive strength of the high-toughness concrete specimen was 58MPa. After the specimen reached the peak load, it had an obvious load stabilization stage, and the compressive strength decreased slowly, showing good toughness.

[0041] (2) Tensile test blocks were prepared using a dog bone mold measuring 50mm×15mm×350mm, cured for 28 days according to standard, and then subjected to tensile strength tests. The test results showed that the average ultimate tensile strength of the high-toughness concrete block was 4.21MPa, the ultimate strain was 3.70%, the tensile strength of the specimen remained basically unchanged after cracking, showing good tensile toughness, and more than 20 fine horizontal cracks appeared in the middle of the specimen when it failed.

[0042] The above tests show that the ultimate tensile strain of the high-toughness concrete used in the surface layer is much greater than that of the concrete material. The material has high tensile and compressive toughness, which is significantly different from the brittle failure of other inorganic cement-based materials.

[0043] The mechanical property tests of the above-mentioned high-toughness concrete show that the application of high-toughness concrete to masonry walls can improve the compressive strength and deformation performance of the masonry walls, and has good bonding performance with the masonry walls. The degree of cracking of the walls is relatively small, thus improving the brittle failure characteristics of the masonry walls.

[0044] Example 2: Figure 2 The brick masonry wall 2 is a pre-reinforced brick masonry wall without reinforced concrete structural columns 1. The brick masonry wall 2 does not have structural columns. The dimensions of the coal gangue sintered bricks are 235mm×115mm×53mm. The length of the brick masonry wall 2 is 4.5m, the height is 2.4m, and the thickness is 235mm. The cross-sectional dimensions of the lower ring beam 3 are 400mm×400mm. Other procedures are the same as in Example 1, and the similarities are omitted.

[0045] Through the combined action of FRP reinforcement and high-toughness concrete composite fiber mesh surface layer, the integrity of the wall can be improved, providing stronger constraint on the wall, and the shear strength and seismic performance of the wall can be significantly improved. It effectively inhibits the development of cracks in the masonry wall, improves the integrity and stiffness of the wall, and the specimens show the characteristics of slip failure, with a slow decrease in bearing capacity. It significantly improves the displacement ductility and energy dissipation capacity of the wall, effectively mitigating the failure mode and degree of damage to the masonry wall under seismic loading.

[0046] The tensile strength of FRP bars is 1400MPa and the elastic modulus is 64GPa, while the tensile strength of fiber woven mesh is 4660MPa and the elastic modulus is 231GPa. Both can significantly improve the integrity and shear bearing capacity of the wall. The high elastic modulus of the material and good deformation capacity can significantly improve the energy dissipation of the wall.

[0047] Implanting FRP bars in mortar joints can improve the overall integrity of the wall and enhance its shear bearing capacity. Furthermore, the FRP bars do not occupy space when placed in the groove, reducing the thickness of the reinforcement layer. The high-toughness concrete surface layer has good durability, and the cracks in the specimens are minor, which extends the service life of masonry buildings, reduces the risk of masonry structure collapse, reduces social costs, ensures the safety of people's lives and property, and reduces the need for reinforcement and repair work on masonry buildings after earthquakes.

Claims

1. A high-toughness concrete composite fiber mesh combined rebar brick masonry wall, comprising a pre-reinforced brick masonry wall with or without reinforced concrete structural columns (1), characterized in that: Multiple horizontal FRP bars (5) are spaced apart on both sides of the pre-reinforced brick masonry wall, and multiple FRP structural columns are spaced apart on both sides of the pre-reinforced brick masonry wall. Specifically: for pre-reinforced brick masonry walls with a reinforced concrete structural column (1) at the beginning, FRP structural columns are installed starting less than 4m from the reinforced concrete structural column (1); for pre-reinforced brick masonry walls without a reinforced concrete structural column (1) at the beginning, FRP structural columns are installed starting from the beginning. The FRP structural columns include multiple longitudinal FRP bars (6) spaced apart and press-fitted onto the horizontal FRP bars (5). The FRP stirrups (7) of multiple longitudinal FRP bars (6) attached to the two side walls are tied together by tie bolts (8) through the wall. The top of the multiple longitudinal FRP bars (6) extends to the upper ring beam (4) and the bottom extends to the lower ring beam (3). After the FRP structural columns are installed, a layer of high-toughness concrete surface layer (9) is applied to the two side walls, and fiber mesh (10) is laid on the entire wall on the applied tough concrete surface layer (9), and then another layer of high-toughness concrete surface layer (9) is applied. The multiple horizontal FRP bars (5) and multiple longitudinal FRP bars (6) are located in the mortar joints. The groove depth of the mortar joints is 1.2 to 1.5 times the diameter of the FRP bars. The spacing between the multiple horizontal FRP bars (5) is the distance of four brick courses, and the spacing between the multiple longitudinal FRP bars (6) is the length of one brick. The number of layers of the full-wall fiber mesh (10) is 1 to 3, and each layer of fiber mesh is coated with high-toughness concrete with a thickness of 5mm. The high-toughness concrete surface layer (9) comprises the following components: 379 kg / m3 of ordinary Portland cement, 885 kg / m3 of fly ash, 455 kg / m3 of quartz sand, 379 kg / m3 of water, 17.4 kg / m3 of water-reducing agent, 1.26 kg / m3 of thickener, and 26 kg / m3 of polyvinyl alcohol fiber, wherein the volume ratio of polyvinyl alcohol short-cut fiber is 2%. FRP reinforcement and stirrups (7) are both reinforcements of fiber fabrics, composite materials formed with resin as the matrix. The fiber fabrics include one of glass fiber, carbon fiber, basalt fiber or aramid fiber; the fiber web is woven from one or two of carbon fiber, glass fiber, basalt fiber, aramid fiber and polyethylene fiber.

2. The high-toughness concrete composite fiber mesh combined rebar brick masonry wall according to claim 1, characterized in that: The distance between multiple FRP structural columns spaced apart on both sides of the pre-reinforced brick masonry wall is less than 4m.

3. The high-toughness concrete composite fiber mesh combined rebar brick masonry wall according to claim 1, characterized in that: The diameter of the horizontal FRP bar (5) is 6-8 mm; the diameter of the longitudinal FRP bar (6) is 10-12 mm.

4. The high-toughness concrete composite fiber mesh combined rebar brick masonry wall according to claim 1, characterized in that: The spacing of the FRP stirrups (7) along the height direction of the structural column is 150-300mm.

5. The high-toughness concrete composite fiber mesh combined rebar brick masonry wall according to claim 1, characterized in that: The thickness of the high-toughness concrete surface layer (9) is 10-20 mm.

6. A construction method for a high-toughness concrete composite fiber mesh combined rebar brick masonry wall according to any one of claims 1-5, characterized in that, Includes the following steps: Step 1: Remove the loose layer on the surface of the pre-reinforced brick masonry wall with or without reinforced concrete structural columns (1), and groove the horizontal mortar joints of the pre-reinforced brick masonry wall every 4 courses of bricks. Groove longitudinally at the position of the pre-set longitudinal FRP reinforcement (6) of the structural column. The depth and width of all grooves are 1.2 to 1.5 times the diameter of the FRP reinforcement. Step 2: Place the horizontal FRP reinforcement (5) into the groove of the horizontal mortar joint and fix it to the wall with tie bolts (8). Then, lay multiple longitudinal FRP reinforcements (6) at the location of the FRP structural column and arrange a ring of FRP stirrups (7) every 150-300mm along the longitudinal FRP reinforcement. Step 3: After the FRP structural column is set up, apply a layer of high-toughness concrete to the two side walls. Wet the fiber mesh (10) used for reinforcement with cement slurry, lay it on the surface of the high-toughness concrete, and gently press the fiber mesh (10) into its surface to ensure good bonding performance between the fiber mesh (10) and the substrate and enhance the synergistic stress. Then apply another layer of high-toughness concrete to the surface of the fiber mesh. Depending on the project requirements, the fiber mesh (10) can be laid in one, two or three layers.

Images