Floor reinforcement construction method for old building reconstruction

Abstract

The invention relates to a floor reinforcement construction method for old building reconstruction, which can demolish and reconstruct indoor floors of a building on the premise of retaining the original style and appearance of an outer wall, so that an inner wall is completely demolished, pile foundations, frame columns and frame beams are newly added to form a supporting frame system, and the conversion of a stress system is completed; the problem that most of traditional masonry structure construction methods do not change the structure stress system is solved, the service life of a building is prolonged, the dismantling and rebuilding cost is reduced, the construction period is shortened by optimizing the construction technology, the high efficiency and safety of the construction process are ensured, and wide application prospects are achieved.

Description

Technical Field

[0001] The invention relates to the technical field of building construction, and in particular to a floor reinforcement construction method for renovating old buildings. Background Art

[0002] With the acceleration of urban renewal, the supporting facilities of historical and cultural buildings have gradually become outdated, their applicability has decreased, and their coordination with the surrounding environment has decreased. The protection and renewal of historical buildings are imminent, and their structural safety and overall stability have also been significantly reduced. Such buildings generally have safety hazards such as reduced load-bearing capacity and insufficient seismic resistance. In order to ensure the safe use performance of the buildings, they need to be systematically reinforced and renovated.

[0003] Although traditional building-based reinforcement methods such as increasing the cross-section method and external steel reinforcement method can improve the bearing capacity, they also expose some defects in practical applications. First, the original structure needs to be demolished on a large scale during construction, resulting in a high loss rate of internal space in the building. Secondly, the collaborative working mechanism of the new and old structures is weak, especially when the frame beam-column nodes are reinforced, there is a phenomenon of stress discontinuity. In addition, the traditional masonry reinforcement method is to reinforce the original brick masonry project with reinforced concrete surface layer and cement mortar surface layer without changing the original force system and the functional division of the internal space, but such transformation does not cause a qualitative change in the building properties. In addition, although the patent "CN119373334A" discloses a steel frame overall replacement scheme, it still lacks a systematic solution for the spatial reconstruction after the demolition of non-load-bearing interior walls, the reinforcement and protection of the retained exterior walls, and the construction of a concealed reinforcement system. Based on this, it is necessary to study a floor reinforcement construction method for the renovation of old buildings. Summary of the invention

[0004] In view of this, the purpose of the present invention is to provide a floor reinforcement construction method for old building renovation, which effectively solves the irreconcilable contradiction between interior wall demolition and structural reinforcement in the prior art, and overcomes the problems of concealed reinforcement system construction, in-situ reinforcement and protection of exterior walls, and frame nodes.

[0005] To achieve the above object, the technical solution adopted by the present invention is: a construction method for reinforcing floors in old building renovation, comprising the following steps: Step 1: New foundation construction; lay out the frame column construction area according to the construction drawings, cast in-place piles around the new frame columns, make the frame columns located in the middle of the surrounding frame columns, carry out the inner main beam operation opening lintel construction, cut off the overlapping part of the main beam and the outer wall foundation, reserve the lintel construction operation surface, cut the pile head that is over-cast, then anchor the pile head steel bars and the cap steel bars, pour the foundation concrete, and carry out the pre-embedded construction of the tension beam steel bars, and pour the cap main beam concrete; Step 2: Clean the wall and lay out the lines; level the inner wall of the exterior wall and mark the reference datum on the wall; based on the reference datum, lay out the frame beam construction area and the reinforcement wall construction area according to the construction drawings, mark the rebar planting points in the reinforcement wall construction area, and mark the shear key construction points in the frame column construction area and the frame beam construction area; Step 3: Drill holes at the shear key construction points and the reinforcement points, and clean the corresponding holes and grooves; then implant the shear key at the shear key construction points; and implant the tie bars at the reinforcement points on the masonry, and hang the steel mesh on the tie bars extending out of the wall; Step 4: Reinforced wall construction: set up the outer mold of the reinforced wall on the outside of the steel mesh, open grouting holes on the upper floor slab, and inject grout from top to bottom into the outer mold through the grouting holes to form a reinforced wall; Step 5: Remove the outer formwork and set up temporary supports; set up temporary scaffolding supports around the frame column construction area, with the top support reaching the upper floor slab; Step 6: Based on the frame column construction area, cut a hole at the top floor slab, tie the frame column reinforcement and lower it to the frame column construction area, adopt the segmented formwork and segmented pouring method, pour from bottom to top to form the frame column; Step 7: Frame beam construction: Based on the frame beam construction area, holes are opened on the inner wall, frame beam reinforcements are tied in sections, and placed in the frame beam construction area, and the formwork is cast to form the frame beam. The frame beam and frame column are connected to form a reinforced support system; Step 8: Remove the interior walls; remove the temporary indoor supports and inter-layer floor slabs, and then remove the interior walls, and then repair the gaps left in the reinforced walls.

[0006] Furthermore, after the bored pile construction in step 1 is completed, partial earth excavation is carried out in the foundation chamber, a cutting machine is used to cut off the rigid hardened layer of the ground, and then the lintel of the inner main beam operation opening is constructed.

[0007] Furthermore, during the lintel construction, a cutting machine is first used to cut a groove of 1 / 2 thickness of the outer wall on the inner side of the wall, and then the lintel reinforcement and formwork are carried out in the groove, and C50 high-strength grouting material is poured; after the inner grouting strength reaches the preset strength, the outer lintel operation is carried out in the same way.

[0008] Furthermore, in step 3, the shear key holes are opened on the exterior wall by using the skipping method; the self-compacting grouting material is mixed according to the proportion and injected into the formwork from the reserved grouting port.

[0009] Furthermore, after the shear key is constructed, tie bars are implanted at the anchor points on the outer wall of the masonry, and a steel mesh is hung on the tie bars extending out of the wall.

[0010] Furthermore, in step 4, before pouring the reinforced wall, a grouting hole is opened at the top floor position, and then C25 self-compacting fine stone concrete is used to pour the reinforced concrete reinforced wall through the self-grouting hole, and the slump is 180-220 mm.

[0011] Furthermore, in step 5, a double-row socket-type scaffold is set up to support the top floor slab, and a pad is set at the bottom when setting up the support, and the square wood is fixed to the bottom position of the floor slab at the top with top screws.

[0012] Furthermore, in step 6, a static cutting method is adopted to open a hole at the overlap position of the newly built frame column and the top floor slab. The size of the hole is 100mm larger than the cross-sectional size of the frame column on one side, and the reinforcement of the structural column is tied simultaneously.

[0013] Furthermore, in step 6, the frame columns are constructed by using the skipping method, and the main concrete of the frame columns at each position is poured in three batches. After the pouring is completed, the top of the frame column extends to above the top floor slab.

[0014] Furthermore, in step 7, a frame beam is set along the inner edge of the outer wall above the floor slab and corresponding to the frame column, and the frame beam and the frame column are cast and constructed simultaneously. After the construction of the new frame beam and frame column is completed, the outer wall and the new structure are connected as a whole. After the force form is changed, the demolition of the original indoor walls of the building begins.

[0015] The beneficial effects of the above technical solution are: The floor reinforcement construction method for old building renovation provided by the present invention adopts the technical route of "internal demolition and external protection", that is, the non-load-bearing walls inside the building are demolished as a whole, and the main load-bearing components such as the building's exterior walls, frame columns, frame beams, etc. are systematically reinforced, and finally the reinforcement system is completely covered in the retained exterior wall structure. This renovation method can not only significantly improve the overall structural strength of the building and meet the safety use requirements of current specifications, but also can maximize the maintenance of the historical features of the building, thereby achieving the dual goals of improving the building's functions and protecting its historical value.

[0016] The renovation and demolition method provided by the present invention can change a residential building into a commercial building while retaining the original appearance of the exterior wall, so that all interior walls are demolished, and pile foundations, frame columns, and frame beams are added to form a supporting frame system, completing the conversion of the force system, solving the problem that most traditional masonry structure construction methods do not change their structural force system. The method of the present invention can be promoted and applied under similar construction conditions and environments, and has broad application prospects.

[0017] In addition, the present invention sets support beams and structural tension beams between the pedestals to form a mesh foundation structure, which can redistribute the load through the bending stiffness of the beams when the foundation settles unevenly, avoiding overloading of single piles. This redundant design enhances the adaptability of the system to foundation deformation. The newly built reinforced concrete reinforced wall not only bears the vertical load, but also forms a dual lateral force resistance system with the frame column through horizontal reinforcement anchoring. Under the action of earthquake or wind load, the two work together to optimize the dynamic response through the combination of components with different stiffness, and finally achieve the dual improvement of safety and durability in the functional transformation of historical buildings.

[0018] The newly built structure in the present invention is a concrete frame structure, which adopts means such as adding lintels, shear keys, embedded steel bars, and pre-embedded tension bolts in holes in the original outer wall to innovate a suitable masonry structure. Only the outer wall is retained and reinforced, and all the inner walls are demolished, so that the original three-story residential building is transformed into a two-story commercial building, changing the existing historical building reinforcement construction method of the entire force system.

[0019] The reinforcement construction method provided by the present invention increases the service life of the building and reduces the cost of demolition and reconstruction with minimal disturbance to the original exterior wall structure. By optimizing the construction process, the construction period is shortened, ensuring the efficiency and safety of the construction process. The seismic resistance of the reinforced building is significantly improved, which can better adapt to the seismic requirements of modern buildings and provide an innovative solution for the protective transformation of historical buildings in urban renewal. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the cross-sectional structure of an embodiment of the present invention; Figure 2 Schematic diagram of the arrangement of cast-in-place piles for foundation construction; Figure 3 Sectional drawing of earth excavation for foundation construction; Figure 4 This is a cross-sectional structural diagram of the lintel construction; Figure 5 Schematic diagram of the layout of the steel mesh for reinforcing the wall; Figure 6 This is a schematic diagram of the construction structure for pouring concrete for the reinforcement wall; Figure 7 A schematic diagram of the structure of the temporary support erected; Figure 8 This is a schematic diagram comparing the cross-section of an old building before and after construction.

[0021] Figure numerals: 1-exterior wall, 2-reinforced wall, 3-frame beam, 4-frame column, 5-roof, 7-cast-in-place piles, 8-new floor slab, 9-concrete cap, 10-concrete connecting beam, 11-shear key, 12-second floor slab, 13-temporary support. DETAILED DESCRIPTION

[0022] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments: Embodiment 1, this embodiment aims to provide a floor reinforcement construction method for the renovation of old buildings, which is mainly suitable for the protective reinforcement project of historical masonry buildings, specifically for the demolition of the internal wall structure of the old masonry building and the reinforcement construction of the external wall, so that the internal structure of the old brick-concrete building is transformed and replaced without basically changing the appearance of the original external wall of the building, and only the external facade wall is retained, and a reinforcement wall is set on the inner side (indoor) of the external wall of the building, and the redundant internal wall is demolished, so as to meet the structural requirements and functional needs of modern commercial use, and relatively completely retain the original appearance of the external wall of the original building, and not only can it significantly improve the overall structural strength of the building, but also can maximize the preservation of the historical features of the old masonry building, effectively reducing the disturbance to the original building structure.

[0023] The present embodiment provides a method for reinforcing the floors of old buildings. Figure 1 As shown, the original three-story building structure is mainly reinforced and demolished, the outer wall is retained and reinforced, and the inner wall is completely demolished, so that the original three-story residential building is transformed into a two-story commercial building. This embodiment takes one floor as an example, and specifically includes the following construction steps: Step 1: New foundation construction; According to the existing status of the original building structure surveyed in advance, the bored pile method is first used for the bored pile foundation construction. According to the position of the frame column marked in advance on the drawing, the bored piles 7 are poured around the new frame column so that the frame column 4 is located in the middle of the surrounding frame columns. Figure 2 shown.

[0024] Then, the foundation indoor part of the earthwork is excavated, and the rigid hardened layer of the ground is removed by using a cutting machine, and then the inner main beam operation hole lintel is constructed. When the lintel structure is implemented, a cutting machine is used to cut a groove of 1 / 2 thickness of the outer wall on the inner side of the wall, and then the lintel reinforcement and formwork are carried out in the groove, and C50 high-strength grouting material is poured; after the inner grouting strength reaches the preset strength, the outer earthwork excavation and outer lintel construction are carried out in the same way, such as Figure 4 As shown, an angle steel lintel is installed outside the corner of the outer wall. In addition, before the lintel is constructed, a settlement observation nail is installed 300 mm above the lintel. In this embodiment, four settlement observation nails are arranged in a rectangular structure above the lintel to avoid the need to open a large number of holes before the construction of the structural connecting beam at the outer wall foundation during foundation construction, which may cause partial settlement of the original building structure. Therefore, the settlement amount of the construction process is monitored through the settlement nail observation data.

[0025] See also Figure 2 and Figure 3After the overall construction of the lintel above the outer wall opening is completed, the subsequent hole opening construction is carried out; the overlapping part of the main beam and the outer wall foundation is cut off, and the lintel construction working surface is reserved. At the same time, the pile head that is over-cast is cut, and then the pile head reinforcement and the pedestal reinforcement are anchored. The foundation concrete is poured with brick tire membrane construction, and then the foundation pedestal and beam reinforcement are tied. The structural beam reinforcement on both sides is punched through the wall and anchored to the pedestal. After the construction is completed, the brick tire membrane is laid for the second time, and the outer side is backfilled while laying. After the construction of the pedestal beam reinforcement is completed, the frame column position is measured and set on the reinforcement beam. The frame column reinforcement is anchored into the foundation beam according to the design requirements. At the same time, the concrete connecting beam 10 reinforcement is pre-buried. Finally, the concrete is poured to the lintel position, and only the pedestal main beam concrete is poured at this time. After the construction of the new reinforcement body on the inner side of the first layer of the outer wall is completed, the hole opening construction of the remaining structural tension beam of the pedestal foundation is carried out, and the tension beam brick tire membrane, reinforcement binding, concrete pouring and maintenance and earthwork backfilling work are carried out according to the elevation required by the drawings.

[0026] The newly built foundation structure of the present invention passes through the outer wall of the original building, cancels the template support, and chooses to build brick membranes only inside and outside the wall, which effectively ensures the structural construction while reducing the outer wall opening area and the foundation earth excavation area. In addition, before the outer wall opening construction of the original building, the cast-in-place concrete lintel is made twice indoors and outdoors, avoiding the change of the local force form of the building caused by the one-time opening of the lintel hole, and reducing the disturbance of the building to the whole process of lintel construction.

[0027] In this step, after the indoor and outdoor cast-in-place pile construction is completed, the pile foundation pedestals are connected by passing through the connecting beams of the original building's outer wall. A cast-in-place concrete lintel is made before the outer wall opening construction, which effectively ensures the stress stability of the outer wall foundation structure. After that, the lintel holes are opened and the foundation pedestal is reinforced and concrete is poured to complete the construction of the new pile foundation structure in the historical building.

[0028] In this embodiment, the foundation form of the newly built structure is a pile foundation; the foundation form is a foundation composed of a single pile cap and a column-lifting beam and a tension beam. Specifically, for example, in this embodiment, according to the characteristics of the original building structure, there are a total of 18 foundation caps, and 18 foundation caps are composed of 4 piles lifting 1 frame column, 3 foundation caps are composed of 6 piles lifting 2 frame columns, and one cap is composed of 10 piles lifting 4 frame columns. The cast-in-place piles at the bottom and the concrete caps on the pile tops are used as the foundation to support the frame columns above.

[0029] Step 2: Clean and lay out the wall surface; scrape the inner wall surface of the exterior wall 1. After it is basically cleaned, use a high-pressure water gun to rinse the wall surface; mark the axis and structural line on the wall before construction as a reference for the construction phase, and based on the reference, lay out the frame column construction area, frame beam construction area, and reinforced wall construction area according to the construction drawings, mark the reinforcement points in the reinforced wall construction area, including the layout positions of horizontal bars, vertical bars, and tie bars, and mark the shear key construction points in the frame column construction area and the frame beam construction area.

[0030] Step 3: Drill holes at the shear key construction points and the reinforcement points, and clean the corresponding holes; then implant the shear keys at the shear key construction points. In this embodiment, the shear key construction points are arranged on the masonry wall at the corresponding positions of the frame columns and frame beams, and are evenly spaced to ensure the stability of the exterior wall.

[0031] When constructing the shear key 11, first, after the building elevation line and axis are measured and introduced into the interior of the exterior wall, the frame column and frame beam position lines are released, and then the beam and column dimension lines are released, and then the shear key position and size are clearly marked on the wall according to the drawings. After that, the construction personnel will cut and chisel around the shear key to ensure that the size of the shear key hole meets the requirements and try to avoid construction too deep. After the shear key steel bars are pre-tied in advance, the formwork is supported and a round hole is opened in the middle of the formwork to facilitate the exposure of the shear key steel bars, and the formwork is fixed to the exterior wall.

[0032] Then, the mixed self-compacting grouting material (50 kg of grouting material is added with 5-6 kg of water in proportion, that is, 12% of water) is injected into the shear key template from the reserved grouting port. After the self-compacting grouting material solidifies, the template is removed and the surface is treated. It should be noted that when the shear key is opened, it cannot be in place at one time. The shear key holes at the corresponding positions of the frame beam and frame column are opened twice. The construction should be skipped, that is, the holes are opened at intervals. After the shear key grouting of the first opening reaches the strength requirement, the second opening construction can be carried out.

[0033] After the shear key construction is completed, tie bars are implanted at the anchor points on the outer wall of the masonry, and steel mesh is hung on the tie bars extending out of the wall; in specific implementation, holes are drilled and implanted into the original wall masonry according to the position of the tie bars at the required markings, and the wall surface is processed according to the actual requirements. This embodiment provides an explanation of the anchor method, for example, the entire length of the wall is glued within the thickness range, the anchor depth is 120mm, the first row of anchors is 80mm away from the beam edge, column edge, and window edge, and the anchor spacing is 500mm in principle. If the window edge is less than 500mm from the column, 2 rows of bars are planted, if it is less than 1000mm, it is evenly divided and 3 rows of bars are planted, and so on.

[0034] After the tie bars are implanted, the horizontal and vertical reinforcements are tied in advance. In principle, the spacing between the vertical and horizontal reinforcements is 250mm, which can be adjusted appropriately according to the actual situation. The horizontal reinforcement of the reinforced concrete reinforced wall is anchored in the frame column, and the vertical reinforcement is anchored in the frame beam. Figure 5 and Figure 6 shown.

[0035] Step 4: Reinforcement wall construction; set up the outer formwork of the reinforcement wall on the outside of the steel mesh. To ensure the accurate thickness of the shear wall, use 14mm steel bars (length 150mm, 180mm) planted on the wall as the formwork support, with a spacing of 600*700mm; insert the reserved steel bars into the side formwork openings at the shear key 11 and the frame column 4 and frame beam 3 to seal; if there is a window, make side formwork around the window, that is, use double-sided adhesive strips and foam clips to seal the gaps in the formwork to avoid slurry leakage during concrete pouring. Double 40*80mm wooden squares are used on the back of the formwork, with a spacing of 300mm; the horizontal steel pipe spacing is 450mm, and the steel pipe, wooden square, and top screw are used to support the formwork on the inner wall and tighten it. After the formwork construction is completed, it will be inspected and accepted. Concrete pouring can only be carried out after it is qualified.

[0036] Before pouring concrete, a grouting hole is opened above the top floor slab, and grouting is injected from the grouting hole into the outer mold from top to bottom to form a reinforced wall 2; further, commercial C25 self-compacting fine stone concrete is used for pouring, and the slump is 180-220mm. The concrete is poured continuously before the initial setting, and a layer of reinforced concrete reinforced wall is poured to the bottom surface of the second floor slab at one time. Figure 6 shown.

[0037] Step 5: Remove the outer formwork of the reinforced wall and set up temporary support; set up temporary scaffolding support 13 around the frame column construction area, and support the top to the second floor slab 12; set up temporary support as follows Figure 7 As shown, a double-row scaffolding with sockets and spigots is set up in the frame column construction area with steel pipes to support the top floor. The horizontal distance between the vertical poles is 600mm and the vertical distance between the vertical poles is 900mm. When setting up the support, a pad is set at the bottom and the square wood is fixed to the bottom of the floor with top screws at the top. Step 6: Frame column construction; According to the structural form and load requirements of the building, the position and spacing of the columns are reasonably determined to ensure that the columns can bear and transfer the load, forming a frame column construction area. Then, based on the frame column construction area, a static cutting method is used to open a hole at the overlap position of the newly built frame column and the original second-floor slab. The hole size is 100mm on one side of the column cross-section size. Then, the frame column reinforcement is tied and lowered to the frame column construction area. The top of the frame column reinforcement extends to the top of the second-floor slab. Then, the segmented formwork and segmented pouring method is used to pour from bottom to top to form frame column 4.

[0038] When supporting the frame column formwork, use M14 tension bolts pre-buried in the reinforced wall at the column position to fix it firmly, and adopt the alternate construction method. First, mark the positions of the indoor frame columns, and then pour concrete in the order of even then odd or odd then even. When pouring, adopt the principle of segmented pouring. For example, the first column pouring is to 1.5m, the second column pouring is to 3.2m at the bottom of the upper beam, and the third column pouring is to 3.7m. The frame beams are poured at the same time, and the frame columns are demoulded after pouring.

[0039] Step 7: Frame beam construction; In the above step 6, the frame columns are constructed in sections, and the third frame column concrete is poured to the top of the second floor slab. Before the third concrete pouring, the frame column reinforcement binding and formwork support operations are first carried out. Based on the preset frame beam construction area, holes are opened on the inner wall, the frame beam reinforcement is tied in sections, and placed in the frame beam construction area, so that the third frame column and frame beam 3 are constructed at the same time, so that the formed frame beam and frame column are connected correspondingly to form a reinforced support system.

[0040] Step 8: According to the above steps 2-7, the second and third floors can be reinforced using the same construction process as the first floor. After the corresponding reinforcement and demolition construction of the second and third floors and the roof 5 is completed, the second floor slab 8 is constructed, and finally the temporary indoor support and inter-layer slab are removed. The original second-floor interior walls and slabs are removed, the construction waste is cleaned up, and the scaffolding system is removed simultaneously; finally, the remaining gaps in the remaining structural walls are repaired. The reconstructed building structure is as follows: Figure 8 shown.

[0041] The floor reinforcement construction method for old building renovation provided by the present invention adopts the technical route of "internal demolition and external protection", that is, the non-load-bearing walls inside the building are demolished as a whole, and the main load-bearing components such as the building's exterior walls, frame columns, frame beams, etc. are systematically reinforced, and finally the reinforcement system is completely covered in the retained exterior wall structure. This renovation method can not only significantly improve the overall structural strength of the building and meet the safety use requirements of current specifications, but also can maximize the maintenance of the historical features of the building, thereby achieving the dual goals of improving the building's functions and protecting its historical value.

[0042] Furthermore, through the modified construction method of the present invention, a set of efficient, stable and coordinated force-bearing system is formed. The reinforced wall serves as the main vertical load-bearing component, which evenly distributes the upper load to the foundation beam; the foundation beam transfers the load to the frame column through the tension beam system, and is finally borne by the deep cast-in-place piles. The newly applied load is transmitted step by step through the reinforced wall → foundation beam → frame column → cast-in-place pile, with a clear path and distinct levels. This layered transfer mechanism avoids local stress concentration and improves the overall load-bearing efficiency.

[0043] Embodiment 2, the above embodiment 1 is only for the construction of the first floor building structure. This embodiment introduces the second and third floor operations proposed in the above step 8 on the basis of embodiment 1. The construction method of the second floor newly built reinforced concrete reinforcement body, frame column, frame beam is the same as the construction method of the first floor in embodiment 1. It should be noted that after the construction of the second and third floor frame beams and frame columns of the original building is completed, in order to ensure the overall structural stability when the internal wall is demolished, a temporary steel structure support is installed first, and then the internal wall is demolished. Then, after the internal wall, such as the T-shaped wall is demolished, the wall surface needs to be cleaned, the two sides are roughened, and the template is supported after cleaning. The micro-expansion concrete is used for secondary pouring, so that the fine stone concrete reinforced concrete reinforcement bodies on both sides of the internal wall are connected as a whole. Before the original second floor slab is demolished, the roof frame beam scaffolding template is first demolished. After the template and scaffold are demolished and cleaned, the prefabricated slab floor is first demolished. After the crane fixes the prefabricated slab, a static cutting saw is used to cut along the inner side of the outer wall at the floor slab to disconnect it from the building wall, and finally the garbage is removed.

[0044] The above-described embodiments of the present invention do not constitute a limitation on the protection scope of the present invention. The basic concept of the present invention is to transform and replace the internal structure of the old brick-concrete building without substantially changing the appearance of the original exterior wall, retaining only the exterior wall, and setting a reinforcement wall on the inside of the exterior wall of the building, and demolishing the redundant interior walls, adding pile foundations, frame columns, and frame beams to form a supporting frame system, completing the transformation of the force system, and significantly improving the overall structural strength of the building. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A construction method for reinforcing floors in old building renovation, characterized in that: The following steps are involved: Step 1: New foundation construction; lay out the frame column construction area according to the construction drawings, cast in-place piles around the new frame columns, make the frame columns located in the middle of the surrounding frame columns, carry out the inner main beam operation opening lintel construction, cut off the overlapping part of the main beam and the outer wall foundation, reserve the lintel construction operation surface, cut the pile head that is over-cast, then anchor the pile head steel bars and the cap steel bars, pour the foundation concrete, and carry out the pre-embedded construction of the tension beam steel bars, and pour the cap main beam concrete; Step 2: Clean the wall and lay out the lines; level the inner wall of the exterior wall and mark the reference datum on the wall; based on the reference datum, lay out the frame beam construction area and the reinforcement wall construction area according to the construction drawings, mark the rebar planting points in the reinforcement wall construction area, and mark the shear key construction points in the frame column construction area and the frame beam construction area; Step 3: Drill holes at the shear key construction points and the reinforcement points, and clean the corresponding holes and grooves; then implant the shear key at the shear key construction points; and implant the tie bars at the reinforcement points on the masonry, and hang the steel mesh on the tie bars extending out of the wall; Step 4: Reinforced wall construction: set up the outer mold of the reinforced wall on the outside of the steel mesh, open grouting holes on the upper floor slab, and inject grout from top to bottom into the outer mold through the grouting holes to form a reinforced wall; Step 5: Remove the outer formwork and set up temporary supports; set up temporary scaffolding supports around the frame column construction area, with the top support reaching the upper floor slab; Step 6: Based on the frame column construction area, cut a hole at the top floor slab, tie the frame column reinforcement and lower it to the frame column construction area, adopt the segmented formwork and segmented pouring method, pour from bottom to top to form the frame column; Step 7: Frame beam construction: Based on the frame beam construction area, holes are opened on the inner wall, frame beam reinforcements are tied in sections, and placed in the frame beam construction area, and the formwork is cast to form the frame beam. The frame beam and frame column are connected to form a reinforced support system; Step 8: Remove the interior walls; remove the temporary indoor supports and inter-layer floor slabs, and then remove the interior walls, and then repair the gaps left in the reinforced walls.

2. The method for reinforcing floors in old building reconstruction according to claim 1 is characterized in that: After the cast-in-place pile construction in step 1 is completed, the earthwork of the foundation chamber is partially excavated, a cutting machine is used to cut off the rigid hardened layer of the ground, and then the lintel construction of the inner main beam operation opening is carried out.

3. The floor reinforcement construction method for old building reconstruction according to claim 2 is characterized in that: During the lintel construction, a cutting machine is first used to cut a groove 1 / 2 thick on the inner side of the wall, and then the lintel reinforcement and formwork are carried out in the groove, and C50 high-strength grouting material is poured; after the inner grouting strength reaches the preset strength, the outer lintel operation is carried out in the same way.

4. The method for reinforcing floors in old building reconstruction according to claim 1 is characterized in that: In step 3, the shear key holes are opened on the exterior wall by using the skipping method; the self-compacting grouting material is mixed according to the proportion and injected into the template from the reserved grouting port.

5. The method for reinforcing floors in old building reconstruction according to claim 4 is characterized in that: After the shear key is constructed, tie bars are implanted at the anchor points on the outer wall of the masonry, and a steel mesh is hung on the tie bars extending out of the wall.

6. The method for reinforcing floors in old building reconstruction according to claim 1 is characterized in that: In step 4, before pouring the reinforcement wall, a grouting hole is opened at the top floor position, and then C25 self-compacting fine stone concrete is used to pour the reinforced concrete reinforcement wall through the self-grouting hole, and the slump is 180-220mm.

7. The old building renovation floor reinforcement construction method according to claim 1 is characterized by: In step 5, a socket-and-spigot double-row scaffold is set up to support the top floor slab, a pad is set at the bottom when setting up the support, and the square wood is fixed to the bottom position of the floor slab with a top screw at the top.

8. The method for reinforcing floors in old building reconstruction according to claim 1 is characterized in that: In step 6, a static cutting method is adopted to open a hole at the overlap position of the newly built frame column and the top floor slab. The size of the hole is 100mm larger than the cross-sectional size of the frame column, and the reinforcement of the structural column is tied simultaneously.

9. The method for reinforcing floors in old building reconstruction according to claim 1 is characterized in that: In step 6, the frame columns are constructed by the skipping method, and the main concrete of the frame columns at each position is poured in three batches. After the pouring is completed, the top of the frame column extends to above the top floor slab.

10. The floor reinforcement construction method for old building reconstruction according to claim 1 is characterized in that: In step 7, frame beams are set along the inner edge of the exterior wall above the floor slab and corresponding to the frame columns, and the frame beams and frame columns are cast and constructed simultaneously. After the construction of the new frame beams and frame columns is completed, the exterior wall and the new structure are connected as a whole, and then the demolition of the original interior walls of the building begins.

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