Reinforced concrete joist for reinforcing lintel crack of masonry structure
By setting reinforced concrete support beams under the cracks in the masonry structure lintel and pouring concrete, the problem of difficulty in bearing pressure grouting to reinforce tensile stress in the existing technology is solved, and the high efficiency and economy of structural reinforcement are achieved.
Patent Information
- Application Number
- CN202422542990.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-21
- Publication Date
- 2025-09-16
- Estimated Expiration
- 2034-10-21
AI Technical Summary
When treating cracks in lintels of existing masonry structures, the existing technology is unable to effectively bear the tensile stress generated by pressure grouting reinforcement, and the engineering materials and costs are high.
Reinforced concrete joists are used to reinforce cracks in masonry structure lintels. Reinforced concrete joists are set at the bottom of the cracks, and transverse steel bars and stirrups are tied inside them. Then concrete and cement polymer grouting liquid are poured into them to form a reinforced concrete joist support section to bear tensile stress.
It improves the ductility and anti-collapse ability of the structure, saves engineering work and materials, reduces project costs, and provides a cost-effective reinforcement method.
Smart Images
Figure CN223343744U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to a reinforced concrete support beam for reinforcing cracks in a masonry structure lintel, and belongs to the technical field of comprehensive reconstruction of old residential areas. Background Art
[0002] Cracks in existing masonry lintels are typically reinforced using pressure grouting. Pressure grouting involves injecting a cement-polymer grouting solution into cracks, incomplete joints, holes, and loose, incomplete masonry structures using compressed air. This method aims to restore structural integrity, enhance strength and durability, and improve waterproofing and anti-seepage properties. This method has been proven safe and reliable in multiple earthquakes, significantly improving the ductility and collapse resistance of the structure. Cement-polymer grouting, the most commonly used masonry grouting solution, is a pure cement slurry mixed with a defined amount of colloidal suspending agent to enhance the grout's bonding capacity, improve its pourability, and enhance the strength of the masonry structure. Before pressure grouting is used to reinforce cracks in masonry lintels, the cracks should be reinforced. Typically, reinforced concrete joists are used below the cracks to absorb the tensile stresses generated by the pressure grouting. The utility model mainly adopts reinforced concrete supporting beams to reinforce cracks in the lintels of the masonry structure, and then performs pressure grouting reinforcement on the cracks. Utility Model Content
[0003] The utility model proposes a method for reinforcing cracks in masonry lintels by using reinforced concrete joists. The method mainly adopts the pressure grouting method to reinforce cracks in existing masonry lintels. The utility model adopts the following technical solutions:
[0004] Reinforced concrete joists to strengthen cracks in masonry lintels, 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 strength grade of the concrete is not less than C30; after the reinforced concrete joists reach a certain strength, cement polymer grouting liquid is poured at the crack.
[0005] Furthermore, the cross-sectional dimensions of the reinforced concrete joist are 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 polymer grouting fluid uses ordinary Portland cement with a 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 positions of the reinforced concrete joists.
[0013] Step 3: Cut grooves on the walls and lintels, remove the masonry grooves at the installation site of the reinforced concrete joists, 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 reinforced concrete beams.
[0015] Step 5: Water and maintain the surface layer of reinforced concrete beams to prevent exposure to sunlight. Anti-freeze measures should be taken in winter.
[0016] Step 6: After the reinforced concrete joist reaches a certain strength, pressure grouting is performed 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 the structure's ability to resist collapse. At the same time, it also saves engineering volume, 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 support section; 5: wall; 6: lintel; 7: crack. DETAILED DESCRIPTION
[0022] The specific implementation of the utility model is as follows:
[0023] Reinforced concrete joists to strengthen cracks in masonry lintels, 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 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 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 polymer grouting liquid is poured into 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 HPB300 grade hot-rolled steel bars with a diameter of 8.
[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 polymer grouting fluid uses ordinary Portland cement with a 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: Temporarily support the cracked lintel 6.
[0031] Step 2: According to the design drawings, draw lines on the wall 5 and lintel 6 to mark the position of the reinforced concrete joist 1.
[0032] Step 3: Cut grooves on the wall 5 and lintel 6, remove the masonry grooves at the installation location of the reinforced concrete joist 1, and blow away the dust powder.
[0033] Step 4: Tie and fix the transverse reinforcement 2 and stirrups 3. After all reinforcements are tied, support the formwork and pour reinforced concrete joists 1.
[0034] Step 5: Water and maintain the surface layer of reinforced concrete beam 1 to prevent exposure to sunlight. Anti-freeze measures should be taken 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 joists to strengthen cracks in masonry lintels, characterized by: The invention comprises a reinforced concrete support beam (1), transverse steel bars (2), and stirrups (3); the reinforced concrete support beam (1) is arranged at the lower part of the crack of the masonry structure lintel (6), and the reinforced concrete support beam (1) is symmetrically arranged on both sides of the lower part of the original structure lintel (6); both ends of the reinforced concrete support beam (1) are extended 300 mm along the wall to form a reinforced concrete support beam support section (4), and the reinforced concrete support beam (1) on the reinforced concrete support beam support section (4) is completely embedded in the wall (5); the transverse steel bars (2) in the reinforced concrete support beam (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 support beam (1); after the transverse steel bars (2) and stirrups (3) are all tied and fixed, the support formwork is poured with concrete, and the strength grade of the concrete is not less than C30; after the reinforced concrete support beam (1) reaches a certain strength, cement polymer grouting liquid is poured into the crack (7).
2. The reinforced concrete joist for strengthening cracks in masonry lintels according to claim 1, characterized in that: The cross-sectional size of the reinforced concrete supporting beam (1) is 200 mm×120 mm.
3. The reinforced concrete joist for strengthening cracks in masonry lintels 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 for strengthening cracks in masonry lintels according to claim 1, characterized in that: The stirrups (3) are HPB300 grade hot-rolled steel bars with a diameter of 6.
5. The reinforced concrete joist for strengthening cracks in masonry lintels according to claim 1, characterized in that: The stirrups (3) in the reinforced concrete supporting beam (1) are arranged at intervals of 200 mm.
6. The reinforced concrete joist for strengthening cracks in masonry lintels according to claim 1, characterized in that: The cement polymer grouting fluid uses ordinary Portland cement with a 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.