Construction method of concrete floor deformation joint with sliding support

Abstract

The application provides a concrete floor deformation joint construction method with a sliding support, which ingeniously combines a deformation joint formwork and a sliding layer steel plate together, forms an integral whole in advance, realizes modular installation, improves construction efficiency while ensuring construction quality, and solves the problem of sliding layer failure caused by cement slurry penetrating into the sliding layer in the traditional construction method; in the deformation joint formwork installation project, the application uses a steel plate to replace the traditional wooden formwork, solving the problem of difficult removal of the wooden formwork; in the deformation joint cleaning project, the application uses an alkyd paint thinner to clean the polyphenyl board in the deformation joint, which is simple and efficient, and solves the problem of deformation joint failure caused by incomplete cleaning in the traditional technology.

Description

Technical Field

[0001] This invention relates to the field of industrial building construction technology, and in particular to a construction method for expansion joints in concrete floor slabs with sliding supports. Background Technology

[0002] In modern large industrial buildings (such as coke oven roofs), due to their large individual dimensions, several transverse expansion joints are often designed to eliminate the influence of longitudinal temperature stress. Simultaneously, to enable them to withstand large vertical loads, these expansion joints are often designed at load-bearing beams. In this case, sliding supports need to be designed between the slab and the beam to ensure that the slab is unrestrained in the deformation direction and that the slab's deformation does not affect the beam. In engineering practice, a reinforced concrete floor slab with a sliding support at one end and a fixed support at the other end can meet its deformation requirements.

[0003] A key characteristic of this type of building structure is that the reinforcing bars on both sides of the expansion joint and above and below the sliding layer are disconnected, each independently fulfilling its design function. Simultaneously, the presence of the sliding layer makes the structure exceptionally complex, requiring numerous embedded civil engineering components and high construction precision. It also places higher demands on the concrete pouring sequence and methods, making it a challenging aspect of the project. Traditional construction methods, such as installing wooden formwork on both sides of the expansion joint, suffer from low efficiency, high labor intensity, low construction precision, and incomplete formwork cleaning. Furthermore, loose joints between the wooden formwork and the steel plate of the sliding layer allow mud and other debris to seep into the sliding layer, resulting in poor construction quality. Especially after the project is put into operation, these issues lead to poor performance of the sliding layer and expansion joint, posing safety hazards to production. Therefore, a mature and efficient construction method is urgently needed to solve these problems. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a construction method for expansion joints in concrete floor slabs with sliding supports. By redesigning the expansion joint formwork system and optimizing the concrete pouring process, the method achieves precise and efficient construction of expansion joints in floor slabs and excellent quality of the sliding layer.

[0005] To achieve this technical objective, the present invention adopts the following solution: This invention provides a construction method for expansion joints in concrete floor slabs with sliding supports, comprising the following steps: S1: Template installation. Install the templates for beams and floor slabs according to the design requirements. Use wooden templates commonly used in civil engineering. The template support system must be firm and reliable. S2: Tie the reinforcing bars of the beam. The fabrication and installation accuracy of the reinforcing bars of the beam must meet the design requirements. After the reinforcing bars are tied, concrete spacers should be set according to the specifications. S3: Construct templates for the sliding layer and expansion joints. The templates for this part are designed as "L"-shaped installation modules and are made of steel plates. The lower sliding layer and the expansion joint fixed end template include a lower sliding layer steel plate and an expansion joint fixed end steel plate, which together form an "L" shaped installation module; the upper sliding layer and the expansion joint sliding end template include an upper sliding layer steel plate and an expansion joint sliding end steel plate, which together form an "L" shaped installation module. S4: Install the expansion joint fixed end steel plate and the lower sliding layer steel plate. The outer side of the lower sliding layer steel plate abuts against the edge of the floor slab bottom formwork and is supported on the first pad at the top of the beam. The expansion joint fixed end steel plate abuts against the second pad at the end of the expansion joint fixed end. S5: Apply graphite to the steel plate under the sliding layer, smooth the graphite, and ensure that the coating thickness meets the design requirements; S6: Install the expansion joint sliding end steel plate and the upper sliding layer steel plate. The upper sliding layer steel plate sits directly on the graphite layer. The outer side of the upper sliding layer steel plate overlaps with the bottom formwork of the floor slab. The expansion joint sliding end steel plate abuts against the third pad at the end of the expansion joint sliding end. Then, use iron nails to fix the upper sliding layer steel plate to the bottom formwork of the floor slab with a fixing point spacing of 500mm. S7: Fill the expansion joint with polystyrene board, filling from one end to the other in a compact and full manner; S8: Install the floor slab reinforcement according to the design requirements, and fix the concrete spacers in time after the reinforcement is tied. S9: For the pouring of concrete for beams and floor slabs, a reasonable concrete pouring plan should be formulated based on the structural characteristics of the beams and floor slabs and the direction of deformation and sliding of the floor slabs, and the correct pouring sequence should be determined. S10: Demolition and cleaning of expansion joints. Use a short steel bar with one end sharpened to break a notch in the upper part of the polystyrene board at the expansion joint. Then pour alkyd paint thinner into the notch in the upper part of the polystyrene board. The polystyrene board melts after contact with the alkyd paint thinner, thus achieving the purpose of cleaning the expansion joint. S11: Sliding layer treatment. After the template is removed, the nails fixing the sliding layer steel plate should be cut off in time and coated with anti-rust paint.

[0006] Furthermore, in step S2, the top of the first pad at the sliding layer should be at the same elevation as the bottom of the sliding layer and should remain on the same plane.

[0007] Furthermore, in step S3, the lower layer of the sliding layer and the template of the fixed end of the expansion joint are made of a steel plate bent or made of two steel plates spliced ​​and welded together; when two steel plates are spliced ​​and welded together, the distance between the welding points is 300~500mm.

[0008] Furthermore, in step S3, the upper sliding layer and the sliding end template of the expansion joint are formed by bending a steel plate or by splicing and welding two steel plates; when two steel plates are spliced ​​together, continuous weld seam welding is used.

[0009] Furthermore, in step S6, the overlap width between the upper steel plate of the sliding layer and the bottom formwork of the floor slab is 20mm.

[0010] Furthermore, in step S6, when setting up expansion joints during construction, their width can be 5mm larger than the design size.

[0011] Furthermore, in step S9, when pouring concrete, the concrete for the lower beam of the sliding layer is poured first, and the concrete is vibrated while pouring. Only after the concrete for the lower beam of the sliding layer has initially set can the concrete for the upper part of the sliding layer be poured. At the fixed end of the expansion joint, before pouring the floor slab concrete, the surface scum of the beam concrete must be cleaned and kept moist.

[0012] Furthermore, in step S9, the concrete pouring direction of the floor slab is from the fixed end to the sliding end of the floor slab.

[0013] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention ingeniously combines expansion joint templates and sliding layer steel plates, prefabricating them into a single unit for modular installation. This ensures construction quality while improving efficiency, and solves the problem of sliding layer failure caused by cement slurry seeping into the sliding layer in traditional construction methods. In expansion joint template installation, this invention uses steel plates instead of traditional wooden templates, solving the problem of difficult wooden template removal. In expansion joint cleaning, this invention uses alkyd paint thinner to clean the polystyrene board inside the expansion joint, which is simple and efficient, solving the problem of expansion joint failure caused by incomplete cleaning in traditional techniques. Attached Figure Description

[0014] Figure 1 This is a diagram showing the layout of expansion joints in the top slab (floor slab) of a coke oven foundation in an embodiment of the present invention.

[0015] Figure 2 This is a cross-sectional view of the expansion joint and sliding layer in an embodiment of the present invention.

[0016] Figure 3 This is a schematic diagram of the construction of a floor slab expansion joint with a sliding support in an embodiment of the present invention.

[0017] Figure 4 This is a detailed drawing of the expansion joint and sliding layer module in an embodiment of the present invention.

[0018] Figure 5 This is a detailed view of the connection and fixation of the expansion joint and sliding layer in an embodiment of the present invention.

[0019] Figure 6 This is an implementation diagram of the beam and slab concrete pouring scheme in an embodiment of the present invention; in the diagram, Roman numerals represent expansion joint numbers, circled Arabic numerals represent floor slab numbers, and arrows indicate the direction of floor slab concrete pouring.

[0020] The markings in the diagram are as follows: 1. Floor slab; 2. Fixed end of expansion joint; 3. Sliding end of expansion joint; 4. Expansion joint; 401. Steel plate at the sliding end of expansion joint; 402. Steel plate at the fixed end of expansion joint; 403. Polystyrene board; 5. Sliding layer; 501. Upper steel plate of sliding layer; 502. Lower steel plate of sliding layer; 503. Graphite; 6. Beam; 7. Bottom formwork of floor slab; 8. Side formwork of beam; 9. Iron nail; 10. Concrete pad; 1001. First pad; 1002. Second pad; 1003. Third pad. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments.

[0022] See Figures 1 to 6 This invention provides a construction method for expansion joints in concrete floor slabs with sliding supports. More specifically, this embodiment provides a construction method for expansion joints in the top slab (floor slab) of a coke oven foundation with sliding supports, including the following steps: S1: First, install the bottom formwork 7 of the floor slab and the bottom formwork of the beam 6, as well as the side formwork 8 of the beam on one side (the other side is the reserved working surface for tying steel bars) according to the design requirements. All formwork uses 14mm thick commonly used wooden formwork in civil engineering. The formwork support system must be stable and reliable. The bottom formwork 7 of the floor slab at the connection with the sliding layer 5 must be accurately positioned.

[0023] S2: Tie the reinforcing bars of beam 6. The fabrication and installation accuracy of the reinforcing bars of beam 6 must meet the design requirements. Note that positive tolerances are not allowed in the upper reinforcing bars of beam 6 at the sliding layer 5. After the reinforcing bars are tied, concrete spacers 10 are set according to the specifications. The top of the first spacer 1001 at the sliding layer 5 should be at the same elevation as the bottom of the sliding layer 5 and should be on the same plane.

[0024] S3: Install the beam side formwork 8 on the other side and take reinforcement measures. During this process, make the formwork for the sliding layer 5 and the expansion joint 4. The formwork for this part is designed as an "L" shaped installation module and is made of steel plate.

[0025] Specifically, the template for the lower layer of sliding layer 5 and the fixed end 2 of expansion joint includes a lower layer steel plate 502 of sliding layer and a fixed end steel plate 402 of expansion joint, the two steel plates forming an "L"-shaped installation module; the template for the upper layer of sliding layer 5 and the sliding end 3 of expansion joint includes an upper layer steel plate 501 of sliding layer and a sliding end steel plate 401 of expansion joint, the two steel plates forming an "L"-shaped installation module.

[0026] The templates for the lower layer of the sliding layer 5 and the fixed end 2 of the expansion joint can be formed by bending a single steel plate or by splicing and spot welding two steel plates. When splicing and spot welding two steel plates, the spacing between the welding points is 300~500mm.

[0027] The upper layer of the sliding layer 5 and the sliding end 3 of the expansion joint template can be formed by bending a single steel plate or by splicing and welding two steel plates. When using two steel plates spliced ​​together, continuous welding should be used to prevent mortar from seeping into the sliding layer 5 during concrete pouring.

[0028] S4: Install the expansion joint fixed end steel plate 402 and the lower sliding layer steel plate 502 according to the pre-measured positioning line. The outer side of the lower sliding layer steel plate 502 abuts against the edge of the floor slab bottom formwork 7. This part does not directly contact the concrete and is supported on the first pad 1001 set on the top of the beam 6. The expansion joint fixed end steel plate 402 abuts against the second pad 1002 at the end of the expansion joint fixed end 2.

[0029] If the reinforcement at the fixed end 2 of the expansion joint is tied afterward, and the reinforcement at the floor slab 1 has not yet been installed, short-cut reinforcement bars can be used to temporarily fix the steel plate 402 at the fixed end of the expansion joint. If the reinforcement at the fixed end 2 of the expansion joint is tied first, the second spacer 1002 should be installed promptly after the reinforcement tying is completed. In this case, the steel plate 402 at the fixed end of the expansion joint can directly abut against the second spacer 1002.

[0030] S5: Apply graphite 503 to the lower steel plate 502 of the sliding layer. Before applying graphite 503, clean the debris, dust, rust and other stains on the lower steel plate 502 of the sliding layer. Then, apply graphite 503 evenly to the lower steel plate 502 of the sliding layer and use a scraper or other tools to smooth the graphite 503.

[0031] S6: Install the expansion joint sliding end steel plate 401 and the upper sliding layer steel plate 501 according to the pre-measured positioning lines, and control the width of the expansion joint 4 (considering the compressibility of polystyrene board 403, the width of the expansion joint 4 can be 5mm larger than the design size to allow for compression of polystyrene board 403). After positioning, the upper sliding layer steel plate 501 sits directly on the graphite layer 503 without pressing. The outer side of the upper sliding layer steel plate 501 overlaps with the bottom formwork 7 of the floor slab (the overlap width should be 20mm). Adjust the size of the expansion joint 4 and the position of the expansion joint sliding end steel plate 401. The expansion joint sliding end steel plate 401 abuts against the third pad 1003 at the end of the expansion joint sliding end 3. Then, use small iron nails 9 to fix the upper sliding layer steel plate 501 to the bottom formwork 7 of the floor slab, with a fixing point spacing of 500mm.

[0032] S7: Fill the interior of expansion joint 4 with polystyrene board 403, filling from one end to the other in a compact and full manner.

[0033] S8: Install the reinforcing bars of floor slab 1 according to the design requirements. Before installation, mark the positions of the longitudinal and transverse reinforcing bars. Start marking the transverse reinforcing bars from the fixed end of floor slab 1 to ensure that the distance between the ends of the first row of transverse and longitudinal reinforcing bars at the fixed end and the steel plate 402 at the fixed end of the expansion joint meets the requirements for the concrete cover. At the sliding end of floor slab 1, ensure the concrete cover size at the ends of the longitudinal main reinforcing bars to avoid the ends of the main reinforcing bars directly abutting against the steel plate 401 at the sliding end of the expansion joint. After the reinforcing bars are tied, fix the concrete pads 10 at the ends of the longitudinal main reinforcing bars in a timely manner. Through the aforementioned operations, the steel plates 401 at the sliding end of the expansion joint and the steel plates 402 at the fixed end of the expansion joint on both sides of the expansion joint 4 should abut against the concrete pads 10. Finally, make appropriate adjustments to ensure that the steel plates 401 at the sliding end of the expansion joint and the steel plates 402 at the fixed end of the expansion joint on both sides of the expansion joint 4 are stable.

[0034] S9: After inspection and acceptance, the concrete pouring work for beam 6 and floor slab 1 can begin. Based on the structural characteristics of beam 6 and floor slab 1 and the direction of deformation and sliding of floor slab 1, a reasonable concrete pouring plan should be formulated, and the correct pouring sequence determined. When pouring concrete, first pour the concrete for the lower part of beam 6 under the sliding layer 5, vibrating it as you pour. Only after the concrete for the lower part of beam 6 under the sliding layer 5 has initially set can the concrete for the upper part of the sliding layer 5 be poured. At the fixed end 2 of the expansion joint, before pouring the concrete for floor slab 1, the surface of the concrete of beam 6 must be cleaned of any loose material and kept moist.

[0035] Figure 6This is the concrete pouring scheme for the top slab of a coke oven foundation in this embodiment. In the figure, Roman numerals represent the number of expansion joint 4, and circled Arabic numerals represent the number of floor slab 1. The left side of expansion joint 4 is the fixed end, and the right side is the sliding end. First, pour the concrete for the beam 6 corresponding to expansion joint 4 at locations I and II, and then start pouring the concrete for floor slab 1 at location ①. The concrete pouring direction for floor slab 1 is from right to left (i.e., from the fixed end to the sliding end of floor slab 1 in sequence), and vibrate the concrete while pouring.

[0036] When using a pump truck for concrete pouring, the pump truck's position is as follows: Figure 6 As shown on the right, the pouring sequence is: Ⅰ、Ⅱ → ① → Ⅲ → ② → Ⅳ → ③ → Ⅴ → ④ → Ⅵ → ⑥ → ⑤ → ⑦.

[0037] If two pump trucks are used for concrete pouring, one pump truck will be positioned on the right and the other on the left, with their pouring sequence essentially mirroring the above scheme. The pump truck on the right will pour concrete in the aforementioned sequence; the pump truck on the left will pour concrete in the following sequence: VI → ⑦ → V → ⑥ → Ⅳ → ⑤ → Ⅲ → ④ → Ⅱ → ③ → Ⅰ → ② → ①. The pouring sequence for each floor slab 1 will still be from right to left.

[0038] S10: Demolition and cleaning of expansion joint 4. Use a short steel bar with one end sharpened to break a notch in the upper part of the polystyrene board 403 at expansion joint 4. Then pour alkyd paint thinner into the notch in the upper part of the polystyrene board 403. The polystyrene board 403 melts after contact with the alkyd paint thinner. As the polystyrene board 403 melts, it separates from the sliding end steel plate 401 and the fixed end steel plate 402 of the expansion joint on both sides. At this time, use a hook-shaped tool to hook the polystyrene board 403 and clean it out of expansion joint 4.

[0039] S11: Treatment of sliding layer 5. After the template is removed, cut off the iron nails 9 at the fixing point of sliding layer 5. If the surface is designed with a decorative layer, the decorative layer can be directly constructed. Otherwise, apply anti-rust paint to the cut surface of the iron nails 9.

[0040] Compared with existing technologies, the construction method of the present invention has the following advantages: (1) Achieve modular and efficient installation: This invention cleverly combines the expansion joint template and the sliding layer steel plate together. By prefabricating them into a whole, modular installation is achieved. While ensuring construction quality, it improves construction efficiency and solves the problem of sliding layer failure caused by cement slurry seeping into the sliding layer in traditional construction methods.

[0041] (2) Solving the problem of difficult removal of wooden formwork: In the installation of expansion joint formwork, the present invention uses steel plates instead of traditional wooden formwork, which solves the problem of difficult removal of wooden formwork and improves the forming quality of expansion joint.

[0042] (3) Simple and efficient cleaning of polystyrene board: In the cleaning of expansion joints, the present invention uses alkyd paint thinner to clean the polystyrene board in the expansion joint, which is simple and efficient and solves the problem of expansion joint failure caused by incomplete cleaning in the expansion joint in traditional technology.

[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; if these modifications and variations fall within the scope of the claims of the present invention and their equivalents, they should all be considered to be within the protection scope of the present invention.

Claims

1. A construction method for expansion joints in concrete floor slabs with sliding supports, characterized in that, Includes the following steps: S1: Template installation. Install the templates for beams and floor slabs according to the design requirements. Use wooden templates commonly used in civil engineering. The template support system must be firm and reliable. S2: Tie the reinforcing bars of the beam. The fabrication and installation accuracy of the reinforcing bars of the beam must meet the design requirements. After the reinforcing bars are tied, concrete spacers should be set according to the specifications. S3: Construct templates for the sliding layer and expansion joints. The templates for this part are designed as "L"-shaped installation modules and are made of steel plates. The lower sliding layer and the expansion joint fixed end template include a lower sliding layer steel plate and an expansion joint fixed end steel plate, which together form an "L"-shaped installation module; the upper sliding layer and the expansion joint sliding end template include an upper sliding layer steel plate and an expansion joint sliding end steel plate, which together form an "L"-shaped installation module. The template for the lower layer of the sliding layer and the fixed end of the expansion joint is made of a single steel plate bent into shape, or by splicing and spot welding two steel plates together; when two steel plates are spliced ​​and spot welded together, the spacing between the welding points is 300~500mm. The upper layer of the sliding layer and the sliding end template of the expansion joint are made of a single steel plate bent or two steel plates spliced ​​and welded together; when two steel plates are spliced ​​together, continuous weld seams are used. S4: Install the expansion joint fixed end steel plate and the lower sliding layer steel plate. The outer side of the lower sliding layer steel plate abuts against the edge of the floor slab bottom formwork and is supported on the first pad at the top of the beam. The expansion joint fixed end steel plate abuts against the second pad at the end of the expansion joint fixed end. S5: Apply graphite to the steel plate under the sliding layer, smooth the graphite, and ensure that the coating thickness meets the design requirements; S6: Install the expansion joint sliding end steel plate and the upper sliding layer steel plate. The upper sliding layer steel plate sits directly on the graphite layer. The outer side of the upper sliding layer steel plate overlaps with the bottom formwork of the floor slab. The expansion joint sliding end steel plate abuts against the third pad at the end of the expansion joint sliding end. Then, use iron nails to fix the upper sliding layer steel plate to the bottom formwork of the floor slab with a fixing point spacing of 500mm. S7: Fill the expansion joint with polystyrene board, filling from one end to the other in a compact and full manner; S8: Install the floor slab reinforcement according to the design requirements, and fix the concrete spacers in time after the reinforcement is tied. S9: For the pouring of concrete for beams and floor slabs, a reasonable concrete pouring plan should be formulated based on the structural characteristics of the beams and floor slabs and the direction of deformation and sliding of the floor slabs, and the correct pouring sequence should be determined. S10: Demolition and cleaning of expansion joints. Use a short steel bar with one end sharpened to break a notch in the upper part of the polystyrene board at the expansion joint. Then pour alkyd paint thinner into the notch in the upper part of the polystyrene board. The polystyrene board melts after contact with the alkyd paint thinner, thus achieving the purpose of cleaning the expansion joint. S11: Sliding layer treatment. After the template is removed, the nails fixing the sliding layer steel plate should be cut off in time and coated with anti-rust paint.

2. The construction method for expansion joints in concrete floor slabs with sliding supports according to claim 1, characterized in that, In step S2, the top of the first pad at the sliding layer should be at the same elevation as the bottom of the sliding layer and should remain on the same plane.

3. The construction method for expansion joints in concrete floor slabs with sliding supports according to claim 1, characterized in that, In step S6, the overlap width between the upper steel plate of the sliding layer and the bottom formwork of the floor slab is 20mm.

4. The construction method for expansion joints in concrete floor slabs with sliding supports according to claim 1, characterized in that, In step S6, when setting up expansion joints during construction, their width can be 5mm larger than the design size.

5. The construction method for expansion joints in concrete floor slabs with sliding supports according to claim 1, characterized in that, In step S9, when pouring concrete, first pour the concrete for the lower beam of the sliding layer, vibrating it as you pour. Only after the concrete for the lower beam of the sliding layer has initially set can the concrete for the upper part of the sliding layer be poured. At the fixed end of the expansion joint, before pouring the floor slab concrete, the surface of the beam concrete must be cleaned of any floating debris and kept moist.

6. The construction method for expansion joints in concrete floor slabs with sliding supports according to claim 1, characterized in that, In step S9, the concrete pouring direction of the floor slab is from the fixed end to the sliding end of the floor slab.

Images