Reinforced concrete joist for reinforcing lintel crack of masonry structure and construction method of reinforced concrete joist
By setting up reinforced concrete joists and transverse steel bars at the cracks of the lint beam of masonry structures, combined with pouring concrete and cement polymer grouting liquid, the problem of difficult to bear tensile stress and high engineering costs in the existing technology is solved, and the structure is efficient Improvement of reinforcement and earthquake resistance.
Patent Information
- Application Number
- CN202411473369.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-21
- Publication Date
- 2025-01-14
AI Technical Summary
When strengthening cracks of masonry structure lintels, it is difficult to effectively bear the tensile stress caused by pressure grouting reinforcement, and the project volume is large, material consumption is high, and the construction cost is high.
Reinforced concrete joists are used to reinforce the cracks of the masonry structure. By setting up reinforced concrete joists at the lower part of the cracks, and horizontal steel bars and stirrups are arranged on them for binding and fixing. After pouring concrete, a certain strength is reached, and then pressure-filled cement polymerization is carried out. Grout liquid.
It effectively bears the tensile stress generated by pressure grouting reinforcement, improves structural ductility and collapse resistance, saves engineering volume and materials, reduces engineering cost, and provides a cost-effective reinforcement method.
Smart Images
Figure CN119308529A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a reinforced concrete support beam for reinforcing cracks in a masonry structure lintel and a construction method thereof, and belongs to the technical field of comprehensive reconstruction of old residential areas. Background Art
[0002] For cracks in existing masonry lintels, pressure grouting is usually used to reinforce them. Pressure grouting is to inject cement polymer grouting liquid into cracks, unsaturated mortar joints, holes and loose masonry structures with the help of compressed air to restore the integrity of the structure, improve the strength and durability of the masonry structure, and improve the waterproof and anti-seepage performance of the masonry structure. After multiple earthquake verifications, this method is safe and reliable, significantly improving the ductility of the structure and enhancing the anti-collapse ability of the structure. Cement polymer grouting liquid is the most commonly used masonry grouting liquid. It is a quantitative colloidal suspension added to pure cement slurry to improve the bonding ability of the slurry, improve the pourability of the slurry, and enhance the strength of the masonry structure. For cracks in masonry lintels, before using pressure grouting to reinforce them, the cracks should be reinforced. Usually, reinforced concrete joists are used at the bottom around the cracks to reinforce the masonry lintel to bear the tensile stress generated by pressure grouting reinforcement. The invention mainly adopts reinforced concrete joists to reinforce cracks in the lintel of the masonry structure, and then performs pressure grouting reinforcement on the cracks. Summary of the invention
[0003] The present invention proposes a reinforced concrete joist to reinforce cracks in a masonry structure lintel and a construction method thereof, mainly for reinforcing cracks in an existing masonry structure lintel by using a pressure grouting reinforcement method. The present invention adopts the following technical solutions:
[0004] Reinforced concrete joists to strengthen cracks in masonry structures and their construction methods, such as Figures 1-2 As shown, it includes reinforced concrete joists, transverse steel bars and stirrups; the reinforced concrete joists are arranged at the lower part of the crack of the masonry structure lintel, and the reinforced concrete joists are symmetrically arranged on both sides of the lower part of the original structure lintel; the two ends of the reinforced concrete joists are extended 300mm along the wall to form a reinforced concrete joist support section, and the reinforced concrete joists on the reinforced concrete joist support section are all embedded in the wall; the transverse steel bars in the reinforced concrete joists are tied and fixed by stirrups; four transverse steel bars are arranged and distributed at the four corners of the reinforced concrete joists; after the transverse steel bars and stirrups are all tied and fixed, the support formwork is poured with concrete, and the concrete strength grade is not less than C30; after the reinforced concrete joists reach a certain strength, cement polymerization grouting liquid is poured at the cracks.
[0005] Furthermore, the cross-sectional size of the reinforced concrete joist is 200 mm×120 mm.
[0006] Furthermore, the transverse steel bars are φ8 HPB300 grade hot-rolled steel bars.
[0007] Furthermore, the stirrups are φ6 HPB300 grade hot-rolled steel bars.
[0008] Furthermore, the stirrups in the reinforced concrete joist are arranged at intervals of 200 mm.
[0009] Furthermore, the cement used in the cement polymerization grouting fluid is ordinary Portland cement with a cement strength grade of 42.5, the sand is fine sand with a particle size not greater than 0.5 mm, and the water is drinking water or natural clean water.
[0010] The above-mentioned reinforced concrete joist reinforces the cracks in the masonry structure lintel and the construction method thereof, and the specific implementation steps are as follows:
[0011] Step 1: Provide temporary support for the cracked lintel.
[0012] Step 2: According to the design drawings, draw lines on the walls and lintels to mark the locations of the reinforced concrete joists.
[0013] Step 3: Cut grooves on the wall and lintel, chisel out the masonry grooves at the installation site of the reinforced concrete support beam, and blow away the dust.
[0014] Step 4: Tie and fix the transverse steel bars and stirrups. After all the steel bars are tied, support the formwork and pour the reinforced concrete joists.
[0015] Step 5: Water and maintain the surface layer of reinforced concrete beams to prevent exposure to sunlight and take anti-freeze measures in winter.
[0016] Step 6: After the reinforced concrete beam reaches a certain strength, pressure grouting is carried out on the cracks of the wall and lintel, and cement polymer grouting liquid is poured. After standing for 1 to 2 days, the temporary support is removed.
[0017] Beneficial effects:
[0018] The use of reinforced concrete joists to reinforce cracks in masonry lintels can bear the tensile stress generated by pressure grouting reinforcement, improve the ductility of the structure, and enhance its ability to resist collapse. It also saves engineering workload, engineering materials, and reduces engineering costs. This method is one of the most cost-effective methods for seismic reinforcement of cracks in existing masonry lintels. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 Schematic diagram of cracks in lintels of masonry structures reinforced with reinforced concrete joists;
[0020] Figure 2 for Figure 1 AA cross-section diagram.
[0021] In the figure, 1: reinforced concrete joist; 2: transverse reinforcement; 3: stirrups; 4: reinforced concrete joist supporting section; 5: wall; 6: lintel; 7: crack. DETAILED DESCRIPTION
[0022] The specific implementation methods of the present invention are as follows:
[0023] Reinforced concrete joists to strengthen cracks in masonry structures and their construction methods, such as Figures 1-2 As shown, it is characterized in that: it includes a reinforced concrete joist 1, transverse steel bars 2, and stirrups 3; the reinforced concrete joist 1 is arranged at the lower part of the crack of the masonry structure lintel 6, and the reinforced concrete joist 1 is symmetrically arranged on both sides of the lower part of the original structure lintel 6; the two ends of the reinforced concrete joist 1 are extended 300mm along the wall to form a reinforced concrete joist support section 4, and the reinforced concrete joist 1 on the reinforced concrete joist support section 4 is fully embedded in the wall 5; the transverse steel bars 2 in the reinforced concrete joist 1 are tied and fixed by stirrups 3; four transverse steel bars 2 are arranged and distributed at the four corners of the reinforced concrete joist 1; after the transverse steel bars 2 and stirrups 3 are all tied and fixed, the support formwork is poured with concrete, and the concrete strength grade is not less than C30; after the reinforced concrete joist 1 reaches a certain strength, cement polymerization grouting liquid is poured at the crack 7.
[0024] Furthermore, the cross-sectional size of the reinforced concrete joist 1 is 200 mm×120 mm.
[0025] Furthermore, the transverse steel bars 2 are φ8 HPB300 grade hot-rolled steel bars.
[0026] Furthermore, the stirrups 3 are HPB300 grade hot-rolled steel bars with a diameter of φ6.
[0027] Furthermore, the stirrups 3 in the reinforced concrete joist 1 are arranged at intervals of 200 mm.
[0028] Furthermore, the cement used in the cement polymerization grouting fluid is ordinary Portland cement with a cement strength grade of 42.5, the sand is fine sand with a particle size not greater than 0.5 mm, and the water is drinking water or natural clean water.
[0029] The above-mentioned reinforced concrete joist reinforces the cracks in the masonry structure lintel and the construction method thereof, and the specific implementation steps are as follows:
[0030] Step 1: Provide temporary support for the cracked lintel 6.
[0031] Step 2: According to the design drawings, draw lines on the wall 5 and the lintel 6 to mark the position of the reinforced concrete joist 1.
[0032] Step 3: Cut grooves on the wall 5 and the lintel 6, chisel out the masonry grooves at the installation location of the reinforced concrete joist 1, and blow away the ash powder.
[0033] Step 4: Tie and fix the transverse reinforcement 2 and stirrups 3. After all reinforcements are tied, support the formwork and pour the reinforced concrete joist 1.
[0034] Step 5: Water and maintain the surface layer of reinforced concrete beam 1 to prevent exposure to sunlight, and take anti-freeze measures in winter.
[0035] Step 6: After the reinforced concrete joist 1 reaches a certain strength, pressure grouting is performed on the cracks 7 of the wall 5 and the lintel 6, and cement polymer grouting liquid is poured. After standing for 1 to 2 days, the temporary support is removed.
[0036] The above is a typical implementation of the present invention, and the specific implementation of the present invention is not limited thereto.
Claims
1. Reinforced concrete joist beams to strengthen cracks in masonry structures and a construction method thereof, characterized in that: The invention comprises a reinforced concrete joist (1), transverse steel bars (2) and stirrups (3); the reinforced concrete joist (1) is arranged at the lower part of the crack of the masonry structure lintel (6), and the reinforced concrete joist (1) is symmetrically arranged on both sides of the lower part of the original structure lintel (6); both ends of the reinforced concrete joist (1) are extended by 300 mm along the wall to form a reinforced concrete joist support section (4), and the reinforced concrete joist (1) on the reinforced concrete joist support section (4) is completely embedded in the wall (5); the transverse steel bars (2) in the reinforced concrete joist (1) are tied and fixed by stirrups (3); four transverse steel bars (2) are arranged and distributed at the four corners of the reinforced concrete joist (1); after the transverse steel bars (2) and stirrups (3) are all tied and fixed, the supporting formwork is poured with concrete, and the concrete strength grade is not less than C30; after the reinforced concrete joist (1) reaches a certain strength, cement polymer grouting liquid is poured at the crack (7).
2. The reinforced concrete joist reinforced masonry structure lintel crack and construction method thereof according to claim 1, characterized in that: The cross-sectional dimensions of the reinforced concrete joist (1) are 200 mm×120 mm.
3. The reinforced concrete joist reinforced masonry structure lintel crack and construction method thereof according to claim 1, characterized in that: The transverse steel bars (2) are φ8 HPB300 grade hot-rolled steel bars.
4. The reinforced concrete joist reinforced masonry structure lintel crack and construction method thereof according to claim 1, characterized in that: The stirrups (3) are φ6 HPB300 grade hot-rolled steel bars.
5. The reinforced concrete joist reinforced masonry structure lintel crack and construction method thereof according to claim 1, characterized in that: The stirrups (3) in the reinforced concrete joist (1) are arranged at intervals of 200 mm.
6. The reinforced concrete joist reinforced masonry structure lintel crack and construction method thereof according to claim 1, characterized in that: The cement polymerized grouting liquid uses ordinary silicate cement with a cement strength grade of 42.5, the sand is fine sand with a particle size not greater than 0.5 mm, and the water is drinking water or natural clean water.
7. The reinforced concrete joist reinforced masonry structure lintel cracks and the construction method thereof according to any one of claims 1 to 6, characterized in that: Use the following steps: Step 1: Temporarily support the cracked lintel (6). Step 2: According to the design drawings, draw lines on the wall (5) and the lintel (6) to mark the position of the reinforced concrete joist (1). Step 3: Cut grooves on the wall (5) and the lintel (6), chisel out the masonry grooves at the installation position of the reinforced concrete joist (1), and blow away the ash powder. Step 4: Tie and fix the transverse reinforcement (2) and stirrups (3). After all reinforcements are tied, the support formwork is poured with reinforced concrete joists (1). Step 5: (1) Water and maintain the surface of reinforced concrete beams, prevent them from being exposed to the sun, and take anti-freeze measures in winter. Step 6: After the reinforced concrete joist (1) reaches a certain strength, pressure grouting is performed on the cracks (7) of the wall (5) and the lintel (6) by pouring cement polymer grouting liquid. After standing for 1 to 2 days, the temporary support is removed.