Method for reinforcing concrete floor hole through steel-polypropylene fiber concrete

Abstract

The invention provides a method for reinforcing a concrete floor hole through steel-polypropylene fiber concrete, and relates to the technical field of building construction. The method comprises the steps that the position of a structural floor hole is determined, a supporting frame is built below the structural floor hole, and a supporting formwork is installed to cover a bottom opening of the hole; then breaking and chiseling the edge of the hole to be step-shaped and the expansion size of the upper part is larger than that of the lower part, reserving lower reinforcing steel bars of the hole and bending to the upper part; removing hole waste and cleaning the cross section; then steel-polypropylene fiber concrete is poured in the expansion area and vibrated; and removing the supporting template after the solidification strength of the concrete reaches the standard. According to the reinforcing method, the problems of shrinkage cracks and tensile cracks easily generated at the junction of the new concrete and the old concrete are solved, steel bar corrosion is prevented, and the safety of the reinforced structure is improved. Meanwhile, the original structure space is not occupied, the influence on pipeline arrangement is small, construction can be conducted in a limited space, and the technology is simple and easy to popularize.

Description

Technical Field

[0001] The invention relates to the technical field of building construction, and in particular to a method for reinforcing a concrete floor opening by using steel-polypropylene fiber concrete. Background Art

[0002] In the process of new house construction and old house renovation, it is often necessary to make holes in the structural floor slab in order to meet diverse design requirements. For new houses, it is usually to meet personalized space design requirements. For example, some owners are eager to install indoor stairs to create a duplex structure, which requires holes to be made in the appropriate position of the structural floor slab to achieve seamless connection between the upper and lower floors. Or in order to install large ventilation ducts, central air conditioners and other equipment, making holes in the structural floor slab can facilitate the laying and installation of equipment. For old houses, it is largely due to the need for renovation and upgrading of the house function. For example, converting an old house for commercial use into a loft-style living space, by making holes in the floor slab to install stairs, the sense of hierarchy and practicality of the space can be increased. In addition, with the continuous development of technology, the electrical, drainage and other systems of old houses need to be upgraded, and making holes in the floor slab is conducive to laying new pipelines. However, whether it is a new house or an old house, the holes in the floor slab must be professionally evaluated and carefully designed to ensure that there will be no adverse effects on the overall structural safety of the house.

[0003] After a hole is opened in the structural floor of a new or old house, reinforcement must be carried out at the hole. In the prior art, the reinforcement methods for the structural floor hole mainly include the steel structure reinforcement method and the concrete expansion area reinforcement method. The steel structure reinforcement method requires adding new steel structure components at the hole, which has a complex construction process and high cost. In addition, the new components occupy a large space, and the construction is extremely difficult when the pipelines are densely arranged. In the concrete expansion area reinforcement method, the hole area is first expanded, and the concrete structure is poured in the expanded area and connected to the original floor concrete. However, shrinkage cracks and bending-tensile cracks are prone to occur at the junction of the new and old concrete, and the integrity is poor. Once cracks occur, the steel bars are prone to rust at the cracked part, and the safety is low. Both of these reinforcement methods have obvious disadvantages, which seriously affect the stability and safety of the floor structure.

[0004] Therefore, it is urgent to develop a more efficient and reliable method for reinforcing structural floor openings. Summary of the invention

[0005] The purpose of the present invention is to provide a method for reinforcing a concrete floor opening with steel-polypropylene fiber concrete, aiming to solve the technical problems in the above-mentioned background technology.

[0006] The technical solution of the present invention is achieved in this way: The technical solution of the present application provides a method for reinforcing a concrete floor opening with steel-polypropylene fiber concrete, comprising the following steps: Determine the position of the opening of the structural floor, build a support frame below the opening, and install a support template on the top of the support frame so that the support template fits on the bottom side of the structural floor and covers the bottom opening of the opening; Chiseling the edge of the hole so that the edge of the hole expands outward, while ensuring that the expansion size of the upper part of the hole is greater than the expansion size of the lower part, so as to form a stepped cross-section; When the above-mentioned opening is being chiseled, the steel bars in the lower extension area of ​​the above-mentioned opening are retained, and after the opening is chiseled, the steel bars are bent to the upper extension area of ​​the opening; Remove the waste material from the above-mentioned opening and clean the stepped section of the opening; Cast steel-polypropylene fiber concrete in the extended area of ​​the opening and vibrate it; After the solidification strength of the steel-polypropylene fiber concrete reaches the set requirements, the above-mentioned supporting formwork is removed.

[0007] A further technical solution is to set up protective railings and warning signs around the hole before the hole is broken.

[0008] A further technical solution is that the process of breaking the hole mainly includes the following steps: Step 1: Use an electric pick to break the edge of the hole, so that the edge of the hole is expanded outward by 200mm-300mm to form an extended hole; Step 2: Continue to expand the upper half of the edge of the above-mentioned expanded opening outward by 100 mm to make the edge cross-section of the expanded opening into a stepped shape.

[0009] A further technical solution is that the steel bar is bent into a concave shape, and reinforcing ribs are provided at two corners inside the concave steel bar.

[0010] A further technical solution is to roughen the stepped cross section of the opening before pouring the steel-polypropylene fiber concrete, and then flush it with a high-pressure water gun; The depth of the roughening is in the range of 10mm-20mm.

[0011] A further technical solution is to brush a layer of cement slurry on the stepped section of the hole after flushing with a high-pressure water gun.

[0012] A further technical solution is that the mass percentage of the steel fiber in the steel-polypropylene fiber concrete is 1.2%; The mass percentage of the polypropylene fiber in the steel-polypropylene fiber concrete is 0.5%.

[0013] A further technical solution is that the steel-polypropylene fiber concrete is vibrated by a vibrating rod, and the vibrating time of the vibrating rod inserted into the steel-polypropylene fiber concrete once is 20s-30s.

[0014] A further technical solution is that after the supporting formwork is removed, water is sprinkled on the concrete surface and covered with plastic film for curing, and the curing time is ensured to be greater than or equal to 14 days.

[0015] Compared with the prior art, the technical solution of the present invention has at least the following advantages or beneficial effects: The reinforcement method of the present application has significant advantages. In this method, steel-polypropylene fiber concrete is used to replace ordinary concrete, and stepped construction measures are implemented at the junction of new and old concrete. This method greatly improves the strength of the newly added concrete structure and effectively guarantees its integrity. It effectively avoids the problem of concrete shrinkage cracks and bending tensile cracks that are easy to occur at the junction of new and old concrete, prevents the steel bars from rusting at the cracks, and significantly improves the safety of the reinforced structure. At the same time, the reinforcement method enhances the integrity of the reinforced concrete components and the original structural floor slab, and has high safety. After reinforcement, it does not occupy the original structural space and has little effect on the pipeline layout. Even in a limited space, construction can be carried out, the construction process is simple and convenient, and it is easy to promote and apply, providing a reliable, efficient and practical solution for building structure reinforcement. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0017] Figure 1 A schematic diagram of a process for reinforcing a concrete floor opening with steel-polypropylene fiber concrete according to an embodiment of the present invention; Figure 2 The present invention is a schematic diagram of the structure after construction of a method for reinforcing a concrete floor opening with steel-polypropylene fiber concrete according to an embodiment of the present invention. DETAILED DESCRIPTION Example

[0018] Please refer to Figure 1 and Figure 2 The present application discloses a method for reinforcing a concrete floor opening with steel-polypropylene fiber concrete, comprising the following steps: Determine the position of the opening of the structural floor, build a support frame below the opening, and install a support formwork on the top of the support frame so that the support formwork fits on the bottom side of the structural floor and covers the bottom opening of the opening.

[0019] Guardrails and warning signs are installed around the top of the hole. The guardrails can form a solid barrier on the physical level, effectively preventing people from accidentally approaching the hole and falling. Whether it is busy workers in the construction process or pedestrians passing through the completed buildings, they can be effectively protected. At the same time, it can also prevent building materials, tools and other items from accidentally rolling into the hole, avoiding serious harm to the people and equipment below. The warning sign clearly informs people of the existence of the hole and its dangers through eye-catching signs and text, plays a strong warning role, greatly improves people's safety awareness, and allows people to remain highly vigilant when passing near the hole to avoid safety accidents caused by negligence.

[0020] The edge of the hole is broken and chiseled to expand the edge of the hole outward, and at the same time, it is ensured that the expansion size of the upper part of the hole is greater than the expansion size of the lower part to form a stepped cross-section.

[0021] When the above-mentioned opening is being chiseled, the steel bars in the lower extension area of ​​the above-mentioned opening are retained, and after the opening is chiseled, the steel bars are bent to the upper extension area of ​​the opening.

[0022] Remove the waste material from the above holes and clean the stepped section of the holes.

[0023] Steel-polypropylene fiber concrete is poured in the extended area of ​​the opening and vibrated.

[0024] After the solidification strength of the steel-polypropylene fiber concrete reaches the set requirements, the above-mentioned supporting formwork is removed.

[0025] Specifically, the supporting formwork is made of smooth bamboo plywood and wooden keels, and the joints are tightly sealed with rubber strips to meet the requirements of clear concrete, eliminating the need for plastering. The supporting frame adopts a steel pipe scaffolding support system, which is easy to assemble and disassemble, fast, and labor-saving and material-saving. Wooden blocks should be added under the supporting formwork.

[0026] The reinforcement method of the present application has significant advantages. In this method, steel-polypropylene fiber concrete is used to replace ordinary concrete, and stepped construction measures are implemented at the junction of new and old concrete. This method greatly improves the strength of the newly added concrete structure and effectively guarantees its integrity. It effectively avoids the problem of concrete shrinkage cracks and bending tensile cracks that are easy to occur at the junction of new and old concrete, prevents the steel bars from rusting at the cracks, and significantly improves the safety of the reinforced structure. At the same time, the reinforcement method enhances the integrity of the reinforced concrete components and the original structural floor slab, and has high safety. After reinforcement, it does not occupy the original structural space and has little effect on the pipeline layout. Even in a limited space, construction can be carried out, the construction process is simple and convenient, and it is easy to promote and apply, providing a reliable, efficient and practical solution for building structure reinforcement. Example

[0027] Please refer to Figure 1 and Figure 2 The embodiment of the present application is the same as the embodiment 1, and the main difference is that the process of breaking the hole mainly includes the following steps: Step 1: Use an electric pick to break the edge of the hole, so that the edge of the hole is expanded outward by 200mm-300mm to form an extended hole; Step 2: Continue to expand the upper half of the edge of the above-mentioned expanded opening outward by 100 mm to make the edge cross-section of the expanded opening into a stepped shape.

[0028] In the above embodiment, the electric pick can be used to quickly break the hole. The edge of the extended hole adopts a stepped design, which increases the contact area between the steel-polypropylene fiber concrete structure and the original structural floor concrete, thereby improving the stability of the connection between the two and enhancing the reliability of the overall structure.

[0029] In some embodiments of the present invention, the steel bar is bent into a concave shape, and reinforcing ribs are provided at two corners inside the concave steel bar. The bending design of the steel bar can effectively improve the stability of the steel-polypropylene fiber concrete structure in the reinforced area, which has a significant effect.

[0030] In some embodiments of the present invention, before pouring the steel-polypropylene fiber concrete, the stepped cross-section of the hole is roughened and then flushed with a high-pressure water gun; The depth of the roughening is in the range of 10mm-20mm.

[0031] In the above embodiment, a hand-held electric pick is used for roughening. Roughening the edge of the hole has multiple important meanings. First, when the steel-polypropylene fiber concrete structure of the hole is connected to the original structure floor concrete (new and old concrete), roughening can make the concrete surface of the edge of the hole rough, thereby greatly increasing the contact area and mechanical bite force between the new and old concretes, improving the bonding strength, effectively avoiding the occurrence of stratification and hollowing, and ensuring that the new and old concretes are tightly combined to form a stable overall structure. Second, the edge of the hole after roughening is irregular in shape, which is conducive to the infiltration of cement slurry into the pores when the steel-polypropylene fiber concrete is newly poured, filling small gaps, and enhancing the impermeability of concrete. Especially in structures such as basements and pools with high waterproofing requirements, it can effectively prevent water penetration and prevent leakage problems. In addition, the rough surface also provides better anchoring conditions for the installation of steel bars, which is convenient for the steel bars to be firmly fixed in the concrete during subsequent construction. At the same time, it also ensures the density of the newly poured concrete, reduces quality defects such as pores and honeycomb surfaces, improves the pouring quality of steel-polypropylene fiber concrete, and lays a solid foundation for the safety and stability of the structure.

[0032] In some embodiments of the present invention, after flushing with a high-pressure water gun, a layer of cement slurry is brushed on the stepped cross-section of the hole.

[0033] In the above embodiment, brushing a layer of cement slurry on the edge of the hole has many important functions. First, cement slurry can further enhance the bonding force between the new and old concrete. When the cement slurry is brushed on the edge of the hole, it can fill the tiny pores on the surface of the concrete, so that the newly poured steel-polypropylene fiber concrete and the original structural floor concrete are more closely combined on the contact surface, effectively preventing the occurrence of stratification and hollowing. Secondly, for areas with high waterproof requirements, such as basements, pools, etc., cement slurry can play a certain waterproof and sealing role. It can prevent moisture from penetrating through the edge of the hole to a certain extent, avoiding the occurrence of leakage problems.

[0034] In some embodiments of the present invention, the steel fiber accounts for 1.2% by mass of the steel-polypropylene fiber concrete; The mass percentage of the polypropylene fiber in the steel-polypropylene fiber concrete is 0.5%.

[0035] In the above embodiment, the length of the polypropylene fiber is 10 mm, the diameter is 48 μm, and the tensile strength is 485 MPa. The steel fiber is selected as shear type, with a specification of 0.6×35 mm, and the tensile strength and compressive strength are both 600 MPa.

[0036] In some embodiments of the present invention, the steel-polypropylene fiber concrete is vibrated by a vibrating rod, and the vibrating time of the vibrating rod inserted into the steel-polypropylene fiber concrete once is 20s-30s.

[0037] In the above embodiment, when vibrating concrete, the vibrator rod should be inserted quickly and pulled out slowly to avoid leaving gaps in the concrete. The vibrator rod insertion points should be evenly arranged and moved in a "determinant" order to prevent confusion and vibration leakage. Each insertion and vibration time is about 20 to 30 seconds, and the appropriate vibration standard is when the concrete no longer sinks significantly, no bubbles appear, and begins to overflow.

[0038] In some embodiments of the present invention, after the support formwork is removed, water is sprinkled on the concrete surface and covered with a plastic film for curing, and the curing time is ensured to be greater than or equal to 14 days.

[0039] In the above embodiment, water can keep the concrete moist and prevent the concrete from drying out and cracking due to rapid evaporation of water. Covering with plastic film can effectively reduce the rate of water loss, so that the concrete can maintain a suitable humidity for a long time, providing good conditions for the full hydration of cement. After 14 days of curing, the concrete strength can be ensured to increase steadily, the occurrence of cracks can be reduced, the durability and overall quality of the concrete can be improved, and the foundation for the safety and stability of the structure can be laid.

[0040] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for reinforcing a concrete floor opening with steel-polypropylene fiber concrete, characterized in that: The following steps are involved: Determine the position of the opening of the structural floor, build a support frame below the opening, and install a support template on the top of the support frame so that the support template fits on the bottom side of the structural floor and covers the bottom opening of the opening; Chiseling the edge of the hole so that the edge of the hole expands outward, while ensuring that the expansion size of the upper part of the hole is greater than the expansion size of the lower part, so as to form a stepped cross-section; When the hole is being chiseled, the steel bars in the lower extension area of ​​the hole are retained, and after the hole is chiseled, the steel bars are bent to the upper extension area of ​​the hole; removing waste material from the hole and cleaning the stepped cross-section of the hole; Cast steel-polypropylene fiber concrete in the extended area of ​​the opening and vibrate it; After the solidification strength of the steel-polypropylene fiber concrete reaches the set requirements, the supporting formwork is removed.

2. The method for reinforcing a concrete floor opening with steel-polypropylene fiber concrete according to claim 1, characterized in that: Before the hole is drilled, protective railings and warning signs are arranged around the hole.

3. The method for reinforcing a concrete floor opening with steel-polypropylene fiber concrete according to claim 1, characterized in that: The main steps of drilling a hole are as follows: Step 1: Use an electric pick to break the edge of the hole, so that the edge of the hole is expanded outward by 200mm-300mm to form an extended hole; Step 2: Continue to expand the upper half of the edge of the expanded hole outward by 100 mm to make the edge cross-section of the expanded hole into a stepped shape.

4. The method for reinforcing a concrete floor opening with steel-polypropylene fiber concrete according to claim 3, characterized in that: The steel bar is bent to form a concave shape, and reinforcing ribs are arranged at two corners inside the concave steel bar.

5. The method for reinforcing a concrete floor opening with steel-polypropylene fiber concrete according to claim 4, characterized in that: Before pouring the steel-polypropylene fiber concrete, the stepped section of the opening is roughened and then flushed with a high-pressure water gun; The depth of the roughening is in the range of 10mm-20mm.

6. The method for reinforcing a concrete floor opening with steel-polypropylene fiber concrete according to claim 5, characterized in that: After flushing with a high-pressure water gun, a layer of cement slurry is brushed on the stepped section of the hole.

7. A method for reinforcing a concrete floor opening with steel-polypropylene fiber concrete according to claim 6, characterized in that: The mass percentage of steel fiber in the steel-polypropylene fiber concrete is 1.2%; Wherein, the mass percentage of the polypropylene fiber in the steel-polypropylene fiber concrete is 0.5%.

8. The method for reinforcing a concrete floor opening with steel-polypropylene fiber concrete according to claim 7, characterized in that: The steel-polypropylene fiber concrete is vibrated by a vibrating rod, and the vibrating time of the vibrating rod inserted into the steel-polypropylene fiber concrete once is 20s-30s.

9. The method for reinforcing a concrete floor opening with steel-polypropylene fiber concrete according to claim 8, characterized in that: After the supporting formwork is removed, sprinkle water on the concrete surface and cover it with plastic film for curing, and ensure that the curing time is greater than or equal to 14 days.

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