A new type of support and construction method for laminated slab

Abstract

The present application relates to the technical field of fabricated building construction, and discloses a new type of supporting of laminated slab and a construction method, which comprises a double-steel-pipe main beam arranged perpendicularly to the direction of the steel bar truss of the laminated slab, a special connecting piece arranged at the intersection position of the joint of the laminated slab and the double-steel-pipe main beam and fixed on the double-steel-pipe main beam, a single-steel-pipe secondary beam supported on the special connecting piece, a joint formwork arranged below the joint of the laminated slab, and a backing plate arranged between adjacent special connecting pieces along the upper surface of the double-steel-pipe main beam; the top surface elevation of the joint formwork and the backing plate is consistent with the bottom surface elevation of the laminated slab; the present application guarantees effective load transmission through the special connecting piece, and solves the problems of uneven support of the formwork below the laminated slab, easy leakage of the joint, unclear force transmission path and easy cracking of the laminated slab caused by the deformation of the reused wood blocks in the traditional scheme of the wood-block secondary single-steel-pipe main beam; the single-steel-pipe secondary beam solves the problem of material waste caused by the low bearing capacity and large amount of wood blocks.

Description

Technical Field

[0001] This invention relates to the field of prefabricated building construction technology, specifically to a novel support and construction method for composite slabs. Background Technology

[0002] Composite slabs are important components in prefabricated buildings and are widely used in the construction industry. During construction, there are joints between adjacent composite slabs, requiring the erection of formwork, which must also meet the requirements for load-bearing capacity and deformation.

[0003] Traditional cast-in-place structures require full-span bracing and formwork. Because formwork has low load-bearing capacity, low rigidity, and is prone to deformation, dense timber supports are needed beneath it to ensure construction quality. Projects using composite slabs, however, have a certain load-bearing capacity, as specified in relevant standard drawings. The support method for composite slabs involves setting horizontal beams perpendicular to the steel truss direction, with vertical bracing below the beams. However, using this standard method presents the following problems: Traditional composite slab formwork support schemes require densely arranged secondary timber beams vertically under the joint formwork to support the composite slab joints. This scheme is not economical. At the same time, the lower surface of the composite slab and the timber beams are suspended outside the joint formwork, causing the actual force transmission path of the composite slab to be inconsistent with the design scheme. In severe cases, the composite slab may crack.

[0004] For the special treatment of the joints, the existing technology mainly adopts the suspended formwork solution. The suspended formwork is mainly divided into two categories: one type requires pre-embedded hanging parts in the composite slab, which increases the cost of the composite slab processing stage and is prone to deviations, which are difficult to handle during construction; the other type requires drilling holes in the formwork at the joints to pass through the hanging bars. The hanging bars penetrate the floor slab, which is not conducive to waterproofing and the aesthetics of the floor slab surface. In addition, some construction teams still use the traditional cast-in-place full-span support solution for convenience, completely ignoring the load-bearing capacity of the composite slab itself, resulting in material waste.

[0005] Secondly, in traditional support systems, both formwork and timber have great flexibility, and timber is easily deformed and uneven when reused multiple times. This can easily cause uneven settlement of the composite slab during concrete pouring, leading to quality problems such as grout leakage and excessive deviation in floor flatness.

[0006] Third, in traditional solutions, it is difficult to accurately level the top surface of the joint template with the bottom surface of the composite slab, resulting in unclear force transmission paths and posing quality and safety risks.

[0007] Fourth, the existing support system for projects using composite slabs is still mainly based on traditional cast-in-place support, and a standardized formwork system adapted to the construction characteristics of composite slabs has not been formed.

[0008] Fifth, timber has low load-bearing capacity, requires a large amount, has a high wastage rate, is not economical, and is not environmentally friendly.

[0009] Therefore, a new type of support and construction method for composite slabs is needed to solve the problems raised in the background technology. Summary of the Invention

[0010] To address the shortcomings of existing technologies, this invention provides a novel support and construction method for composite slabs, solving the technical problems of serious timber waste, difficulty in leveling the formwork support at the joints of composite slabs, unclear force transmission, easy cracking, and difficulty in ensuring construction quality in existing composite slab support technologies.

[0011] To achieve the above objectives, the present invention provides the following technical solution: a novel support device for composite slabs, comprising: a double steel pipe main rib, arranged perpendicular to the direction of the composite slab's steel truss, wherein the double steel pipe main rib is a rectangular or round steel pipe main rib; a specially designed connector, comprising a fastener, a support member, and a connecting member, disposed at the intersection of the composite slab joint and the double steel pipe main rib, and fixed to the double steel pipe main rib; a single steel pipe secondary rib, supported on the specially designed connector, wherein the single steel pipe secondary rib is a rectangular or round steel pipe secondary rib; the double steel pipe main rib and the single steel pipe secondary rib are perpendicular to each other on the same horizontal plane and connected by the specially designed connector; a joint template, disposed below the composite slab joint; and a pad, disposed along the top of the double steel pipe main rib between adjacent specially designed connectors; the top surface elevation of the joint template and the pad is consistent with the bottom surface elevation of the composite slab.

[0012] Preferably, the double steel pipe main rib is a rectangular steel pipe main rib, and the single steel pipe secondary rib is a rectangular steel pipe secondary rib.

[0013] Preferably, the special connector includes: a Z-shaped special steel fastener, through which the main rib of the rectangular steel pipe passes; a square steel pipe support, supporting the bottom of the main rib of the rectangular steel pipe; and a bolt, which passes through the Z-shaped special steel fastener and the square steel pipe support and is locked in place; the main rib of the rectangular steel pipe and the secondary rib of the rectangular steel pipe are perpendicular to each other on the same horizontal plane and are connected by the special connector.

[0014] Preferably, the square steel tube support is replaced with a channel steel support. The channel steel support rests on the bottom of the main rib of the rectangular steel tube and is locked and fixed to the special Z-shaped steel fasteners by bolts. Compared with the square steel tube support, the channel steel support has a flange structure, and its cross-sectional shape can provide a larger support area, allowing the secondary ribs of the rectangular steel tube to obtain more stable support on the support surface. At the same time, the cross-sectional shape of the channel steel is more conducive to bending load bearing than that of the rectangular steel tube. In this preferred embodiment, the connection method between the channel steel and the bolts is the same as that of the square steel tube. No changes are required to the special Z-shaped steel fasteners. The solution can be switched simply by replacing the support, which has the advantages of strong versatility and good interchangeability.

[0015] Preferably, the double steel pipe main rib is a round steel pipe main rib, and the single steel pipe secondary rib is a round steel pipe secondary rib.

[0016] Preferably, the special connector includes: a support member, which is a square steel pipe support member or a channel steel support member, supporting the bottom of the main rib of the round steel pipe; small steel plate clips, which are fixedly installed on both sides of the support member to clamp and limit the secondary rib of the round steel pipe; and a special steel component, which is an integrated fastener and connector structure, with threads at the bottom, and is locked to the main rib of the round steel pipe by a nut; the main rib of the round steel pipe and the secondary rib of the round steel pipe are perpendicular to each other on the same horizontal plane and are connected by the special connector.

[0017] Preferably, the pad is placed on the main rib of the double steel pipe, between two adjacent specially made connectors. The purpose of leaving an adjustment gap is to facilitate the placement and demolding of the pad, and to avoid interference between the pad and the connector due to processing or installation errors. The adjustment gap is generally 5mm to 20mm, and the specific value is determined according to the construction accuracy requirements and the processing accuracy of the connector. The pad is set in sections on the main rib of the double steel pipe, and the elevation of each section is adjusted independently to ensure that each part can be in close contact with the bottom surface of the composite slab. The pad and the main rib of the double steel pipe are in direct pressure contact, without the need for other connectors, making installation and removal extremely convenient.

[0018] Preferably, the length of the double steel pipe main rib is the net distance between the beams or walls at both ends of the room in the direction perpendicular to the composite slab steel truss, minus the operating space required for the formwork of the beams or walls. The double steel pipe main rib is set along the entire length perpendicular to the direction of the composite slab steel truss, and its length is determined according to the actual dimensions of the room. The operating space required for the formwork of the beams or walls at both ends is generally 100mm to 200mm, and the specific value is determined according to the formwork support scheme of the beams or walls. By reserving operating space, it is ensured that the double steel pipe main rib can completely cover the bottom surface of the composite slab and the joint area, and positional conflicts with the beam or wall formwork are avoided, ensuring that each process does not interfere with each other. The double steel pipe main rib is set along the entire length, which reduces on-site cutting operations, improves construction efficiency, and at the same time ensures the continuity of the main rib and the overall stress performance.

[0019] Preferably, the joint template is made of plywood, and its width is greater than the joint width between adjacent composite slabs. It overlaps the bottom surface of the composite slabs by no less than 100mm on each side to ensure that the post-poured concrete at the joint is adequately supported and to prevent concrete leakage. The length of the joint template is consistent with the joint length of the composite slabs and is set along the joint direction. The thickness of the joint template is determined according to the load-bearing capacity calculation, and generally 15mm thick plywood is used, which can meet the load-bearing requirements and is convenient for handling and installation.

[0020] A construction method for a novel support for composite slabs includes the following steps: S1: Determine the spacing and number of double steel pipe main ribs and single steel pipe secondary ribs based on the load-bearing capacity calculation; S2: Erect the support frame, and install the double-steel-pipe main joist on the top of the frame; S3: Install the special connecting member at the intersection node of the double-steel-pipe main joist and the joint of the composite slab: when the double-steel-pipe main joist is a rectangular steel pipe main joist, fit the several-shaped special steel fastener onto the rectangular steel pipe main joist and lock and fix it with the supporting member, and place the rectangular steel pipe secondary joist on the supporting surface of the square steel pipe supporting member or the channel steel supporting member; when the double-steel-pipe main joist is a circular steel pipe main joist, fit the special steel member onto the circular steel pipe main joist and lock and fix it with the supporting member, place the circular steel pipe secondary joist on the supporting surface of the square steel pipe supporting member or the channel steel supporting member, and perform clamping and limiting through a small steel plate fastener; S4: Lay the joint formwork on the single steel pipe secondary joist, the joint formwork is arranged at the joint in a full length parallel to the direction of the steel bar truss of the composite slab, and the width thereof is greater than the width of the joint between adjacent composite slabs, so that the two side edges of the joint formwork are respectively lapped under the bottom edges of the composite slabs on both sides of the joint; adjust the elevation of the top surface of the joint formwork to be consistent with the elevation of the bottom surface of the composite slab, and realize precise control of the formwork elevation by adjusting the adjustable top support of the support frame, so as to ensure that the top surface of the joint formwork and the bottom surface of the composite slab are on the same horizontal plane, and ensure that the bottom surface of the floor slab is flat and consistent after pouring is completed; S5: Place the backing plate on the double-steel-pipe main joist between two adjacent special connecting members along the double-steel-pipe main joist, and adjust the elevation of the top surface of the backing plate to be consistent with the designed elevation of the bottom surface of the composite slab; S6: Hoist the composite slab, so that the bottom surface of the composite slab is pressed on the joint formwork and the backing plate; S7: Check whether the joint between the joint formwork and the bottom surface of the composite slab is tight, adjust the joint formwork to make the top surface of the joint formwork and the bottom surface of the composite slab tightly pressed, and take sealing measures if there is a gap to prevent slurry leakage; S8: Pour post-cast concrete at the joint and above the composite slab.

[0021] The present invention provides a novel support and construction method for composite slabs. The following beneficial effects are achieved: 1. According to the present invention, a reliable linear support is formed by the double-steel-pipe main joist and the backing plate, the force transmission path is clear, the spacing and number of the main and secondary joists are determined through bearing capacity calculation, which can meet the construction load requirement of not less than 2.5kN / m² specified in "Safety Technical Code for Building Construction Formwork" JGJ162-2008 and "Code for Construction of Concrete Structure Engineering" GB50666-2011; 2. According to the present invention, through double elevation control where the elevations of the top surfaces of the backing plate and the joint formwork are both consistent with the elevation of the bottom surface of the composite slab, the main joist and the bottom surface of the composite slab are in gapless contact, which ensures effective load transmission, solves the problems of difficult leveling and unclear force transmission in the traditional method, and avoids the unevenness and cracking of the bottom surface of the floor slab; 3. This invention completely eliminates the use of timber. The main and secondary beams and special connectors are all made of steel components, which have a high turnover rate and low loss rate, thus avoiding the waste of resources caused by the large amount of timber used in traditional support schemes. 4. All components of this invention are assembled and connected, eliminating the need to pre-embed hanging parts on the composite slab or drill holes in the template for hanging bars. This makes installation and disassembly convenient, construction speed fast, and can effectively save construction time. Attached Figure Description

[0022] Figure 1 This is a perspective view of the overall application of the present invention; Figure 2 This is a schematic diagram of the square steel tube support component of the present invention; Figure 3 This is a schematic diagram of the channel steel support component of the present invention; Figure 4 This is a schematic diagram of the small steel plate clip of the present invention; Figure 5 This is a schematic diagram of the joint template and backing plate of the present invention; Figure 6 This is a schematic diagram of the main and secondary ribs of the rectangular steel pipe of the present invention; Figure 7 This is a schematic diagram of the specially made steel component of the present invention; Figure 8 This is a schematic diagram of the main and secondary ribs of the round steel pipe of the present invention; Figure 9 This is a perspective view of the horizontal system of the present invention.

[0023] Among them, 1. Double steel pipe main rib; 11. Rectangular steel pipe main rib; 12. Round steel pipe main rib; 2. Special connectors; 211. Z-shaped special steel fasteners; 212. Special steel components; 221. Square steel pipe support; 222. Channel steel support; 223. Small steel plate clips; 231. Bolts; 3. Single steel pipe secondary rib; 31. Rectangular steel pipe secondary rib; 32. Round steel pipe secondary rib; 4. Joint template; 5. Base plate. Detailed Implementation

[0024] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] Example 1: Please refer to the appendix. Figure 1 -Appendix Figure 9 This invention provides a novel support device for composite slabs, comprising a double steel pipe main rib 1, a special connector 2, a single steel pipe secondary rib 3, a joint template 4, and a pad 5.

[0026] The special connector 2 includes fasteners and support components. The fasteners are used to connect and fix the main rib 11 of the rectangular steel pipe and the secondary rib 31 of the rectangular steel pipe. The fasteners are special steel fasteners 211 or special steel components 212 in the shape of a "Z". The support components include square steel pipe support components 221 or channel steel support components 222.

[0027] In this embodiment, the double steel pipe main rib 1 adopts two rectangular steel pipe main ribs 11 arranged side by side. The purpose of using double steel pipes is: on the one hand, it is convenient to place and fix the special connector 2 and the pad 5, which facilitates construction operations; on the other hand, compared with single steel pipes, double steel pipes have stronger load-bearing capacity and a more reliable safety factor.

[0028] like Figure 1 and Figure 6 As shown, in this embodiment, the double steel pipe main rib 1 adopts a rectangular steel pipe main rib 11, and the single steel pipe secondary rib 3 adopts a rectangular steel pipe secondary rib 31. Specifically, the double steel pipe main rib 1 adopts two rectangular steel pipe main ribs 11 arranged side by side, which are set on the bottom surface of the composite slab along the direction perpendicular to the steel truss of the composite slab. The length of the double steel pipe main rib 1 is the clear distance between the beams or walls at both ends of the room in the direction perpendicular to the steel truss of the composite slab minus the operating space required for the beams or walls to support the formwork. The pad plate 5 is set on the double steel pipe main rib 1. The length of the pad plate 5 is the clear distance between two adjacent special connectors 2 along the direction of the double steel pipe main rib 1 minus the reserved adjustment gap. The top surface elevation of the pad plate 5 is consistent with the bottom surface elevation of the composite slab, ensuring that there is no gap between the double steel pipe main rib 1 and the bottom surface of the composite slab, and that they can make full contact to ensure effective load transfer. By controlling the elevation of the pad plate 5, a reliable line support is formed between the main rib and the composite slab, solving the problems of difficult leveling and unclear force transmission in traditional schemes.

[0029] Specifically, the joint template 4 is installed along the entire length of the composite slab's steel truss direction at the joint, with a width greater than the joint width between adjacent composite slabs. The top surface elevation of the joint template 4 is consistent with the bottom surface elevation of the composite slab, bearing the load of the concrete poured at the joint. The joint template 4 is made of 15mm plywood, possessing certain rigidity and load-bearing capacity, and can form a reliable pouring bottom surface at the joint. The single steel pipe secondary rib 3 is a rectangular steel pipe secondary rib 31, supported at the bottom of the joint template 4. The number and spacing of the single steel pipe secondary rib 3 are determined through load-bearing capacity calculations, designed with a construction load requirement of not less than 2.5kN / m². The length of the single steel pipe secondary rib 3 is the support spacing between two adjacent specially made connectors 2 along the composite slab's steel truss direction. The function of the single steel pipe secondary rib 3 is to support the joint template 4 and bear the load of the joint template 4 and the cast-in-place concrete on it.

[0030] like Figure 2 and Figure 3As shown, the fastener is a special steel fastener 211 in the shape of a zigzag. The special connector 2 includes the special steel fastener 211 in the shape of a zigzag, a square steel tube support 221, and a bolt 231. The special steel fastener 211 is fitted onto the main rib of the rectangular steel tube 11, and the main rib of the rectangular steel tube 11 passes through the inner cavity of the special steel fastener 211. The square steel tube support 221 supports the bottom of the main rib of the rectangular steel tube 11, and the bolt 231 passes through the special steel fastener 211 and the square steel tube support 221. The steel pipe support component 221 is locked and fixed. The rectangular steel pipe main rib 11 and the rectangular steel pipe secondary rib 31 are perpendicular to each other on the same horizontal plane and are connected by a special connector 2. The function of the special connector 2 is to support the single steel pipe secondary rib 3 and effectively transfer the load borne by the single steel pipe secondary rib 3 to the double steel pipe main rib 1. The support frame adopts the existing general support frame, which is supported at the bottom of the double steel pipe main rib 1 and bears the double steel pipe main rib 1 and all the loads it bears.

[0031] During construction, follow these steps: S1: According to Article 4.1.2 of the Technical Specification for Safety of Formwork in Building Construction JGJ 162-2008, the bearing capacity is calculated with a construction load of not less than 2.5kN / m² to determine the spacing and number of double steel pipe main ribs 1 and single steel pipe secondary ribs 3.

[0032] S2: Erect a support frame and install double steel pipe main beams 1 on the top of the frame along the direction perpendicular to the composite slab steel truss.

[0033] S3: Install a special connector 2 at the intersection of the double steel pipe main rib 1 and the composite plate joint, put the zig-shaped special steel fastener 211 on the rectangular steel pipe main rib 11 and lock it in place, and place the rectangular steel pipe secondary rib 31 on the support surface of the square steel pipe support 221.

[0034] S4: Lay the joint template 4 on the single steel pipe secondary rib 3. The joint template 4 is set along the entire length of the composite slab steel truss parallel to the joint direction. Its width is greater than the joint width between adjacent composite slabs, so that the two sides of the joint template 4 overlap the bottom edge of the composite slab on both sides of the joint. Adjust the top elevation of the joint template 4 to be consistent with the bottom elevation of the composite slab. The precise control of the template elevation is achieved by adjusting the adjustable top support of the support frame to ensure that the top surface of the joint template 4 and the bottom surface of the composite slab are on the same horizontal plane, and to ensure that the bottom surface of the floor slab is flat and consistent after the pouring is completed.

[0035] S5: Place the pad 5 on the double steel pipe main rib 1 between two adjacent special connectors 2, and adjust the top surface elevation of the pad 5 to be consistent with the bottom surface elevation of the composite plate.

[0036] S6: Hoist the composite slab so that the bottom surface of the composite slab presses onto the joint template 4 and the pad 5.

[0037] S7: Check whether the joint between the splicing template 4 and the bottom surface of the composite slab is tight. Adjust the splicing template 4 so that the top surface of the splicing template 4 is tightly pressed against the bottom surface of the composite slab. If there are gaps, sealing measures should be taken to prevent grout leakage.

[0038] S8: Pour concrete at the joints and above the composite slab. After pouring, the concrete and the composite slab will form an integral whole and jointly bear the load during the service stage.

[0039] like Figure 3 and Figure 4 As shown, Example 2: The difference between this example and Example 1 is that the square steel pipe support 221 in Example 1 is replaced with a channel steel support 222. The channel steel support 222 supports the bottom of the main rib of the rectangular steel pipe 11 and is locked and fixed with the special steel fastener 211 in the shape of a zigzag using bolts 231. The connection method of the other special steel fasteners 211 and bolts 231 is exactly the same as in Example 1. The flange of the channel steel can better support the secondary rib of the rectangular steel pipe 31, increase the contact area, and improve the support stability. The remaining structures, including the joint template 4, the pad 5, the secondary rib of the rectangular steel pipe 31, the main rib of the rectangular steel pipe 11, and the construction steps are the same as in Example 1.

[0040] like Figure 1 and Figure 8 As shown in Example 3: The difference between this example and Example 1 is that the double steel pipe main rib 1 uses a round steel pipe main rib 12, the single steel pipe secondary rib 3 uses a round steel pipe secondary rib 32, and the fastener is a special steel component 212; specifically, the double steel pipe main rib 1 uses two round steel pipe main ribs 12 arranged side by side, the single steel pipe secondary rib 3 uses a round steel pipe secondary rib 32, and the special connector 2 includes a support component, a small steel plate clamp 223, and a special steel component 212. The support component is a square steel pipe support component 221, which supports the bottom of the round steel pipe main rib 12. The small steel plate clamp 223 is fixedly installed on both sides of the support component, clamping and limiting the round steel pipe secondary rib 32. To prevent the circular secondary rib from rolling or shifting laterally under stress, the specially designed steel component 212 is an integrated fastener and connector structure. Its structural concept is derived from tie bolts, with threads at the bottom, and is locked to the main rib 12 of the circular steel pipe by a nut. The main rib 12 of the circular steel pipe and the secondary rib 32 of the circular steel pipe are perpendicularly overlapped to each other on the same horizontal plane on the specially designed connector 2. In this embodiment, the small steel plate clamp 223 is a specially designed anti-offset structure to address the characteristic that the secondary rib 32 of the circular steel pipe is prone to rolling, ensuring that the secondary rib of the circular steel pipe remains stable under stress and does not experience lateral displacement or torsion, thereby ensuring the reliability of the force transmission path.

[0041] Specifically, during construction, in step S3: the special steel component 212 is locked to the main rib of the round steel pipe 12 with a nut, the secondary rib of the round steel pipe 32 is placed on the supporting surface of the square steel pipe support 221, and is clamped and limited by the small steel plate clamp 223. The remaining construction steps are the same as in Example 1.

[0042] like Figure 3 , Figure 4 and Figure 8 As shown, Example 4: The difference between this example and Example 3 is that the square steel pipe support 221 is replaced with a channel steel support 222. Specifically, the support is a channel steel support 222, which supports the bottom of the main rib of the round steel pipe 12. Small steel plate clips 223 are fixedly installed on both sides of the channel steel support 222, clamping and limiting the secondary rib of the round steel pipe 32. The special steel component 212 is locked to the main rib of the round steel pipe 12 with nuts. The main rib of the round steel pipe 12 and the secondary rib of the round steel pipe 32 are perpendicularly connected to each other on the same horizontal plane on the special connector 2. By utilizing the flange structure of the channel steel support 222, the secondary rib of the round steel pipe 32 can be better supported, increasing the contact area and improving the support stability. At the same time, the setting of the small steel plate clips 223 ensures the accurate positioning of the secondary rib of the round steel pipe 32 and prevents it from rolling off. The rest of the structure and construction steps are the same as in Example 3.

[0043] Based on the above technical solution, this invention also provides a working principle for a novel support and construction method for composite slabs, including the following: This invention uses a specially designed connector 2 to vertically overlap the double steel pipe main rib 1 and the single steel pipe secondary rib 3 on the same horizontal plane, and with the help of a pad 5, achieves consistent elevation control, forming a composite slab joint support system with a clear and reliable force transmission path; the load transmission path is as follows: the post-cast concrete load at the joint is transmitted to the single steel pipe secondary rib 3 via the joint template 4, and then to the double steel pipe main rib 1 via the specially designed connector 2; the construction load of the composite slab and the upper cast-in-place layer is transmitted to the main rib 1 via the pad 5; the main rib 1 transmits the load to the support frame; and finally, all the load is borne by the support frame; the top surface elevation of the pad 5 is consistent with the bottom surface elevation of the composite slab, ensuring sufficient force transmission between the main rib 1 and the bottom surface of the composite slab; the joint template 4… The top surface elevation is consistent with the bottom surface elevation of the composite slab, ensuring that the joint is flush with the bottom surface of the composite slab. This solves the problems of difficult leveling and unclear force transmission in traditional methods. In the specially designed connector 2, the rectangular steel pipe scheme uses a special steel fastener 211 in the shape of a "Z" to be fitted onto the main rib 11 of the rectangular steel pipe and is locked by bolts 231 to the square steel pipe support 221 or channel steel support 222 to support the secondary rib 31 of the rectangular steel pipe. The round steel pipe scheme uses a special steel component 212 of tie bolts to be locked onto the main rib 12 of the round steel pipe and small steel plate clips 223 to prevent the secondary rib 32 of the round steel pipe from shifting. This makes the main and secondary ribs locked together at the intersection, forming a stable grid-like support system. All the main and secondary ribs are made of steel components, eliminating the need for timber, resulting in low loss rate, high turnover rate, and convenient installation and dismantling. It can meet the construction load requirement of not less than 2.5kN / m².

[0044] Example 5 combined with appendix Figure 1 To be continued Figure 9The difference between this embodiment and Embodiment 1 is that the main structure of the novel composite plate support device remains unchanged, while the structures of the double steel pipe main rib 1, the special connector 2, the single steel pipe secondary rib 3, the joint template 4, and the pad 5 are all the same as in Embodiment 1. During construction, follow these steps: S1: According to Article 4.1.2 of the Technical Specification for Safety of Formwork in Building Construction JGJ 162-2008, the bearing capacity is calculated with a construction load of not less than 2.5kN / m², taking into account the self-weight of the composite slab, the self-weight of the post-cast layer, pumping impact, and personnel and equipment loads. The position, spacing, and number of double steel pipe main ribs 1, single steel pipe secondary ribs 3, special connectors 2, and pads 5 are determined through BIM pre-layout.

[0045] S2: Erect a support frame and install double steel pipe main beams 1 at the top of the frame along the direction perpendicular to the composite slab steel truss. After installation, use a straight line to check the elevation and straightness of the main beams, and make initial adjustments using the adjustable top support of the frame.

[0046] S3: Install a special connector 2 at the intersection of the main rib 1 of the double steel pipe and the joint of the composite plate. Fit the special steel fastener 211 in the shape of a zigzag onto the main rib 11 of the rectangular steel pipe, and first tighten the bolts 231; place the secondary rib 31 of the rectangular steel pipe on the supporting surface of the square steel pipe support 221 or the channel steel support 222; after the main and secondary ribs are in place, tighten the bolts 231 again and check whether the connector is locked and whether it is loose.

[0047] S4: Lay the joint template 4 on the single steel pipe secondary rib 3. The joint template 4 is set along the entire length of the composite slab steel truss parallel to the joint direction, and its width is greater than the joint width between adjacent composite slabs, so that the two sides of the joint template 4 overlap the bottom edge of the composite slab on both sides of the joint. Double-sided tape or sponge strips can be pasted at the joint of the joint template 4, and the top surface elevation of the joint template 4 is adjusted to be consistent with the bottom surface elevation of the composite slab.

[0048] S5: Place a pad 5 on the double steel pipe main rib 1, between two adjacent specially made connectors 2. Use a laser level or a spirit level to control the elevation of the top surface of the pad 5, making it consistent with the designed bottom elevation of the composite slab. The pad 5 can be clamped and limited by the two steel pipes of the double steel pipe main rib 1 to prevent displacement during the hoisting of the composite slab.

[0049] S6: Hoist the composite slab, allowing the bottom surface of the composite slab to slowly fall and press onto the joint template 4 and pad 5 to avoid impacting the support system.

[0050] S7: Check whether the joint between the joint template 4 and the bottom surface of the composite slab is tight, adjust the joint template 4 so that the top surface of the joint template 4 is tightly against the bottom surface of the composite slab; if there are gaps, use sealing material to prevent grout leakage.

[0051] S8: Pour concrete at the joints and above the composite slab. Pour symmetrically and in layers, first pouring the joints, then pouring the layer above the composite slab. During the pouring process, a designated person should observe the support system, connectors, and joint formwork 4. If any abnormality is found, stop pouring immediately and reinforce the structure.

[0052] S9: After pouring, curing is carried out, and test blocks cured under the same conditions are made to determine the timing of demolding and removal of the support system.

[0053] S10: After the post-cast concrete reaches the design strength, dismantle the support system in the following order: first loosen the adjustable supports, then remove the joint template 4, pad 5, and single steel pipe secondary rib 3; then remove the special connector 2 and double steel pipe main rib 1; finally, dismantle the support frame. Do not throw components during dismantling to prevent damage to the bottom surface of the composite slab.

[0054] The working principle of this embodiment is the same as that of Embodiment 1. The load transfer path is still as follows: the load of the post-cast concrete at the joint is transferred to the single steel pipe secondary rib 3 through the joint template 4, and then transferred to the double steel pipe main rib 1 through the special connector 2; the construction load of the composite slab and the upper cast-in-place layer is transferred to the double steel pipe main rib 1 through the pad plate 5; the double steel pipe main rib 1 transfers the load to the support frame, which is finally borne by the support frame.

[0055] The beneficial effects of this embodiment are: without adding new components or new drawings, by optimizing the construction method, the accuracy of the elevation control of the main and secondary ribs is improved, the sealing and anti-leakage effect of the joints is improved, the loosening of the connectors is prevented, the concrete pouring and support removal sequence is clarified, and the construction safety and flatness of the bottom surface of the composite slab are further improved.

[0056] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A novel support device for composite slabs, characterized in that, It includes a double steel pipe main rib (1), a special connector (2), a single steel pipe secondary rib (3), a joint template (4), and a base plate (5); The double steel pipe main rib (1) is set along the direction perpendicular to the composite slab steel truss. The double steel pipe main rib (1) is a rectangular steel pipe main rib (11) or a round steel pipe main rib (12). The special connector (2) is fixed on the double steel pipe main rib (1), and the special connector (2) includes fasteners and support components; The single steel pipe secondary rib (3) is supported on the special connector (2) and is set perpendicular to the double steel pipe main rib (1). The single steel pipe secondary rib (3) is a rectangular steel pipe secondary rib (31) or a round steel pipe secondary rib (32). The joint template (4) is set along the joint length parallel to the direction of the composite slab steel truss, and the top surface elevation of the joint template (4) is consistent with the bottom surface elevation of the composite slab. The pad (5) is set on the double steel pipe main rib (1), and the top surface elevation of the pad (5) is consistent with the bottom surface elevation of the composite plate.

2. The novel support device for composite slabs according to claim 1, characterized in that, The double steel pipe main rib (1) is a rectangular steel pipe main rib (11), and the single steel pipe secondary rib (3) is a rectangular steel pipe secondary rib (31).

3. The novel support device for composite slabs according to claim 2, characterized in that, The special connector (2) includes: a Z-shaped special steel fastener (211), through which the main rib of the rectangular steel pipe (11) passes; a square steel pipe support (221), which supports the bottom of the main rib of the rectangular steel pipe (11); and a bolt (231), which passes through the Z-shaped special steel fastener (211) and the square steel pipe support (221) and is locked in place; the main rib of the rectangular steel pipe (11) and the secondary rib of the rectangular steel pipe (31) are perpendicular to each other on the same horizontal plane and are connected by the special connector (2).

4. A novel support device for composite slabs according to claim 3, characterized in that, The square steel pipe support (221) is replaced by a channel steel support (222). The channel steel support (222) supports the bottom of the rectangular steel pipe main rib (11) and is locked and fixed to the Z-shaped special steel fastener (211) by the bolt (231).

5. A novel support device for composite slabs according to claim 1, characterized in that, The double steel pipe main rib (1) is a round steel pipe main rib (12), and the single steel pipe secondary rib (3) is a round steel pipe secondary rib (32).

6. A novel support device for composite slabs according to claim 5, characterized in that, The special connector (2) includes a support member, which is a square steel pipe support member (221) or a channel steel support member (222), supporting the bottom of the main rib of the round steel pipe (12); a small steel plate clamp (223), which is fixedly installed on both sides of the support member to clamp and limit the secondary rib of the round steel pipe (32); a special steel component (212), which is an integrated fastener and connector structure, with threads at the bottom, and is locked to the main rib of the round steel pipe (12) by a nut; the main rib of the round steel pipe (12) and the secondary rib of the round steel pipe (32) are perpendicular to each other on the same horizontal plane and are connected by the special connector (2).

7. A novel support device for composite slabs according to claim 1, characterized in that, The length of the pad (5) is the net distance between two adjacent special connectors (2) along the main rib of the double steel pipe (1) minus the reserved adjustment gap.

8. A novel support device for composite slabs according to claim 1, characterized in that, The length of the double steel pipe main rib (1) is the net distance between the beams or walls at both ends of the room perpendicular to the direction of the composite slab steel truss, minus the operating space required for the beams or walls to support the formwork.

9. A novel support device for composite slabs according to claim 1, characterized in that, The width of the joint template (4) is greater than the joint width between adjacent composite boards.

10. A construction method for a novel composite slab support, applied to the novel composite slab support device described in any one of claims 1-9, characterized in that, Includes the following steps: S1: Determine the spacing and number of double steel pipe main ribs (1) and single steel pipe secondary ribs (3) based on the bearing capacity calculation; S2: Erect a support frame and install the double steel pipe main beam (1) on the top of the frame. S3: Install the special connector (2) at the intersection of the double steel pipe main rib (1) and the splice of the composite slab, and lock and fix it with bolts (231) or special steel components (212); place the single steel pipe secondary rib (3) on two adjacent special connectors (2) along the direction of the composite slab steel truss: When the double steel pipe main rib (1) is a rectangular steel pipe main rib (11), the special steel fastener (211) in the shape of a zigzag is put on the rectangular steel pipe main rib (11) and locked and fixed, and the rectangular steel pipe secondary rib (31) is placed on the support surface of the square steel pipe support (221) or the channel steel support (222); When the double steel pipe main rib (1) is a round steel pipe main rib (12), the special steel component (212) is locked to the round steel pipe main rib (12) by nuts, and the round steel pipe secondary rib (32) is placed on the support surface of the square steel pipe support (221) or the channel steel support (222), and is clamped and limited by the small steel plate clamp (223); S4: Lay the splicing template (4) on the single steel pipe secondary rib (3); S5: Place the pad (5) between two adjacent special connectors (2) along the main rib of the double steel pipe (1). S6: Hoist the composite slab so that the bottom surface of the composite slab presses onto the joint template (4) and the pad (5); S7: Adjust the top surface of the splicing template (4) to be tightly against the bottom surface of the composite board; S8: Pour concrete at the joints and above the composite slab.

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