Thick plate construction method

Abstract

The invention provides a thick plate construction method, the thick plate comprises a first pouring layer, a second pouring layer and a third pouring layer, in the construction process, the first pouring layer, the second pouring layer and the third pouring layer are formed in sequence, the self-supporting prestress function is achieved through the structure of the thick plate, and the supporting load borne by a supporting formwork can be greatly reduced; therefore, the reliability and the stability of the temporary supporting system are ensured, the preset construction load of the lower layer of the thick plate for the construction of the thick plate is reduced, and the project construction cost is saved remarkably.

Description

Technical Field

[0001] This invention relates to the field of building structure technology, and to a construction method for thick reinforced concrete slabs that utilize prestressing to achieve self-supporting loads. Background Technology

[0002] Rapid urbanization is accompanied by iterative advancements in engineering and construction technologies. Modern buildings, in addition to serving as residences and offices, also integrate functions such as public transportation and large-scale shopping malls. When the columns and shear walls of the upper and lower parts of a building are not aligned (for example, a large-scale shopping mall at the bottom and a shear wall structure residential building at the top), a structural layer is needed in the middle to connect the upper and lower sections and transfer the enormous load of the upper tower. This structural layer can be a very thick reinforced concrete slab, called a "transfer slab" or "thick slab," characterized by extremely high stiffness and load-bearing capacity.

[0003] Thick slabs are a crucial structural component in this type of project. To ensure sufficient space for the lower commercial floors and basement to fulfill their architectural functions, a common approach is to have framed columns at the bottom and a transfer slab above. Residential towers or other structural components discontinuous with the lower framed columns are then designed above the transfer slab. This type of structure is most common in transit-oriented development (TOD) projects in large cities, integrating residential, office, and public transportation functions into a single building by using thick slabs to provide load-bearing capacity.

[0004] The biggest problem currently facing thick slab construction is the enormous amount of concrete required, making it difficult to pour in a single operation. Simultaneously, the weight of the thick slab places high demands on the support system during construction, and conventional construction methods struggle to provide sufficient temporary load-bearing capacity, leading to a significant increase in civil engineering investment costs. The industry urgently needs to propose a new solution to address these issues. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a thick plate construction method that addresses the above-mentioned deficiencies of the prior art by forming a first pouring layer, a second pouring layer and a third pouring layer through layered pouring, thereby enabling the thick plate to self-support the construction load of the thick plate by utilizing its own structure and prestressing technology.

[0006] The technical solution adopted by this invention to solve the technical problem is as follows: A method for constructing a thick slab, the thick slab comprising a first pouring layer, a second pouring layer, and a third pouring layer, the method comprising the following steps: S1. Obtain construction design data, which includes support structure data, thickness of the first pouring layer, number of steel bars in the first pouring layer, steel bar layout data of the first pouring layer, thickness of the second pouring layer, number of steel bars in the second pouring layer, steel bar layout data of the second pouring layer, thickness of the third pouring layer, number of steel bars in the third pouring layer, and steel bar layout data of the third pouring layer. S2. Construct a support formwork based on the support structure data. The support formwork includes multiple vertically arranged temporary support columns and multiple horizontally arranged temporary support templates. The bottom end of the temporary support column is fixedly set on the lower floor slab, and the temporary support template is fixedly set on the top end of the temporary support column. Multiple temporary support templates form a temporary support platform. S3. Based on the quantity and arrangement data of the first-layer reinforcement, lay the first-layer bottom reinforcement, shear reinforcement, prestressed tensioning duct, prestressed reinforcement, and first-layer top reinforcement on the temporary support platform. Pour concrete onto the upper surface of the temporary support platform according to the thickness of the first-layer to form the first-layer. The prestressed reinforcement passes through the prestressed tensioning duct, with both ends of the prestressed reinforcement exposed at both ends of the prestressed tensioning duct. The concrete on the first-layer completely covers the first-layer bottom reinforcement, the prestressed tensioning duct, the prestressed reinforcement, and the first-layer top reinforcement, and partially covers the shear reinforcement. S4. After the concrete on the first pouring layer has initially set, roughen the upper surface of the initially set concrete on the first pouring layer. S5. After the concrete strength of the first pouring layer reaches the design strength, the prestressed steel bars are tensioned for the first time; S6. Based on the number of reinforcing bars in the second pouring layer and the arrangement data of the reinforcing bars in the second pouring layer, lay the top reinforcement of the second pouring layer on the first pouring layer, and tie the shear reinforcement to the top reinforcement of the second pouring layer; pour concrete on the upper surface of the first pouring layer according to the thickness of the second pouring layer to form the second pouring layer; the concrete on the second pouring layer completely covers the top reinforcement of the second pouring layer, and the concrete on the second pouring layer partially covers the shear reinforcement; S7. When pouring the second layer, the prestressed steel bars are tensioned for the second time simultaneously, and tensioning is stopped after the prestressed tension value reaches a level that can balance the structural self-weight of the first and second layers. S8. After the concrete on the second pouring layer has initially set, roughen the upper surface of the initially set concrete on the second pouring layer. S9. Based on the number of reinforcing bars in the third pouring layer and the arrangement data of the reinforcing bars in the third pouring layer, lay the vertical reinforcing bars and top longitudinal bars of the transfer member on the second pouring layer, and pour concrete on the upper surface of the second pouring layer according to the thickness of the third pouring layer to form the third pouring layer; wherein, the concrete on the third pouring layer completely covers and overlaps the shear reinforcement and the top longitudinal bars, and the concrete on the third pouring layer partially covers the vertical reinforcing bars of the transfer member.

[0007] Compared with existing technologies, the beneficial effects of this technical solution are: the sequential formation of the first pouring layer, the second pouring layer, and the third pouring layer, and the self-supporting prestressing function achieved by utilizing its own structure, can significantly reduce the support load borne by the support formwork, thereby ensuring the reliability and stability of the temporary support system, and playing a very significant role in saving project construction costs.

[0008] Furthermore, the bottom reinforcement of the first pouring layer, the prestressed steel bars, the top reinforcement of the first pouring layer, the top reinforcement of the second pouring layer, and the top longitudinal reinforcement are arranged in both horizontal and transverse directions; The shear reinforcement and the vertical reinforcement of the conversion member are arranged in the vertical direction; The bottom reinforcement of the first pouring layer and the prestressed steel reinforcement are set on the temporary support formwork, and the top reinforcement of the first pouring layer is located above the corresponding bottom reinforcement of the first pouring layer and the prestressed steel reinforcement; the top reinforcement of the second pouring layer is set above the first pouring layer; the top longitudinal reinforcement is set on the second pouring layer; The top reinforcement of the first pouring layer is parallel to the bottom reinforcement of the first pouring layer and the prestressed reinforcement; the top reinforcement of the second pouring layer is parallel to the top reinforcement of the first pouring layer and the bottom reinforcement of the first pouring layer.

[0009] The beneficial effects of adopting the above scheme are: crisscrossing steel bars are set on the first, second, and third pouring layers, which effectively improves the stiffness and bearing capacity of each layer; at the same time, shear bars and vertical steel bars of transfer members are set along the vertical direction, which can improve the shear resistance when the layers are bonded together.

[0010] Furthermore, the thickness of the first pouring layer is 30% of the overall thickness of the slab, the thickness of the second pouring layer is 25% of the overall thickness of the slab, and the thickness of the third pouring layer is 45% of the overall thickness of the slab.

[0011] The beneficial effects of adopting the above scheme are: unlike the existing technology of casting thick plates in one go, this technical scheme casts the thick plates that were originally directly formed in stages, effectively utilizing the thick plate's own structure to achieve the self-supporting prestressed function.

[0012] Furthermore, in steps S4 and S8, the roughening treatment on the upper surface of the initially set concrete specifically involves: Place the wooden strips on the top surface of the initially set concrete and apply vertical downward pressure to the wooden strips to form longitudinal and transverse grooves on the top surface of the initially set concrete.

[0013] The beneficial effects of adopting the above scheme are: using wooden strips placed on the upper surface of the initially set concrete to press out longitudinal and transverse grooves, increasing the roughness between layers and improving the stability of the joints between layers.

[0014] Furthermore, in steps S5 and S7, tensioning the prestressed steel bars specifically involves: The fixed end of the prestressed steel bar is fixed to the side of the first pouring layer by means of the anchor head, and the tensioning end of the prestressed steel bar is fixed by means of the tapered anchor and tensioning force is applied by means of the jack to tension the prestressed steel bar in the prestressing tensioning duct.

[0015] The advantages of adopting the above scheme are: one end of the prestressed steel bar fixed by the anchor at the pier head forms a fixed end, while the other end of the prestressed steel bar forms a tensioning end through the tapered anchor. Based on this structure, tensioning force can be applied by jacks when it is necessary to tension the prestressed steel bar, which has the advantages of convenient operation and stable force application process.

[0016] Furthermore, the prestressed steel bars are parallel to each other, and the fixed ends and tensioning ends on adjacent prestressed steel bars are staggered.

[0017] The beneficial effects of adopting the above scheme are: the role of prestressed steel bars is to bear the weight of the first and second pouring layers, and to improve the overall prestress level of the prestressed steel bars by interlacing the ends of multiple parallel prestressed steel bars.

[0018] Furthermore, in step S7, after the second tensioning of the prestressed steel bars is completed, concrete slurry is injected into the prestressed tensioning duct under pressure and the concrete in the prestressed tensioning duct is allowed to solidify.

[0019] The beneficial effects of adopting the above scheme are: after tensioning, the prestressed steel bars in the prestressed tensioning duct are completely fixed by concrete, and additional fixation is carried out on the basis of tensioning, which effectively improves the prestress level of the prestressed steel bars. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the lower floor slab in the thick plate construction method of the present invention.

[0021] Figure 2 This is a schematic diagram of the first pouring layer in the thick plate construction method of the present invention.

[0022] Figure 3 This is a schematic diagram of the second pouring layer in the thick plate construction method of the present invention.

[0023] Figure 4 This is a schematic diagram of the third pouring layer in the thick plate construction method of the present invention.

[0024] The components represented by each number in the diagram are listed below: First pouring layer 1, second pouring layer 2, third pouring layer 3, temporary support column 4, temporary support formwork 5, lower floor slab 6; 11. Bottom reinforcement of the first pouring layer; 12. Shear reinforcement; 13. Prestressed tensioning duct; 14. Prestressed steel bar; 15. Top reinforcement of the first pouring layer; 21 top reinforcement bars for the second pouring layer; Vertical reinforcement 31 and top longitudinal reinforcement 32 of the transfer member. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this invention clearer and more explicit, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0026] In the description of this invention, it should be understood that the terms "center," "upper," "lower," "front," "rear," "left," and "right," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0027] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. When a component is referred to as being "fixed to" or "set on" another element, it can be directly on the other component or there may be an intervening component. When a component is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intervening component. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0028] Rapid urbanization is accompanied by iterative advancements in engineering and construction technologies. Modern buildings, in addition to serving as residences and offices, also integrate functions such as public transportation and large-scale shopping malls. In such planning scenarios, the building's base is a large-scale shopping mall, while the upper part is a shear wall structure residential building. The columns and shear walls in the upper and lower parts of the building are not aligned. In this case, a structural layer is needed in the middle to support the upper structure and transfer the enormous load of the upper tower. This structural layer can be a very thick reinforced concrete slab, called a "transfer slab" or simply a "thick slab," characterized by extremely high stiffness and load-bearing capacity. This type of structure is most common in transit-oriented development (TOD) projects in large cities, integrating residential, office, and public transportation functions into a single building by using a thick slab to provide load-bearing capacity.

[0029] Thick slabs are a very critical and important structural component in this type of project. To ensure that the lower commercial floors and basement have more space to meet their building functions, they are often designed with frame columns at the bottom and transfer thick slabs at the top. Residential towers and other structural components that are discontinuous with the lower frame columns are designed on the transfer thick slabs.

[0030] The biggest problem in current thick slab construction is the enormous amount of concrete required, making it difficult to pour in a single operation. Simultaneously, the weight of the thick slab places high demands on the support system during construction, and conventional construction methods struggle to provide sufficient temporary load-bearing capacity, leading to a significant increase in civil engineering costs. The industry urgently needs a new solution to address these issues. To address these problems, this invention provides a method for thick slab construction.

[0031] like Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown, in order to solve the above problems, the present invention provides a thick plate construction method, wherein the thick plate includes a first pouring layer 1, a second pouring layer 2 and a third pouring layer 3.

[0032] Combination Figure 1 , Figure 2 , Figure 3 and Figure 4 In this technical solution, the method includes the following steps: S1. Obtain construction design data, which includes supporting structure data, thickness of the first pouring layer, number of reinforcing bars in the first pouring layer, and reinforcement layout data for the first pouring layer; thickness of the second pouring layer, number of reinforcing bars in the second pouring layer, and reinforcement layout data for the second pouring layer; thickness of the third pouring layer, number of reinforcing bars in the third pouring layer, and reinforcement layout data for the third pouring layer. In step S1, the design unit performs structural calculations based on the design scheme, current regulations, specifications, and standards to determine the thickness, number of reinforcing bars, and reinforcement layout data for the first pouring layer 1, the second pouring layer 2, and the third pouring layer 3, ensuring that each layer of the structure meets safety requirements under gravity loads, wind, and earthquakes. This technical solution involves construction in the order of the first pouring layer 1, the second pouring layer 2, and the third pouring layer 3. The supporting structure data is the data corresponding to the first pouring layer 1 before pouring; the thickness of each layer is the thickness of the concrete after it has solidified; the number of reinforcing bars is the number of reinforcing bars to be laid before pouring that layer; and the reinforcing bar layout data is the arrangement of the corresponding reinforcing bars in that layer, such as whether the reinforcing bars are set horizontally or vertically, which reinforcing bars are laid on top, and which reinforcing bars are laid on the bottom, etc. After the design unit obtains the supporting structure data, the thickness of the first pouring layer, the number of reinforcing bars in the first pouring layer, the reinforcing bar layout data of the first pouring layer, the thickness of the second pouring layer, the number of reinforcing bars in the second pouring layer, the reinforcing bar layout data of the second pouring layer, the thickness of the third pouring layer, the number of reinforcing bars in the third pouring layer, and the reinforcing bar layout data of the third pouring layer, the construction unit will then carry out construction according to the above data requirements and continue to implement the subsequent steps.

[0033] S2. Construct a support formwork based on the support structure data. The support formwork includes multiple vertically arranged temporary support columns 4 and multiple horizontally arranged temporary support templates 5. The bottom ends of the temporary support columns 4 are fixed to the lower floor slab 6, and the temporary support templates 5 are fixed to the top ends of the temporary support columns 4. The multiple temporary support templates 5 form a temporary support platform. One function of the support formwork is to provide temporary support for the first pouring layer 1. The support structure data specifically includes the number of temporary support columns 4 and temporary support templates 5 used, the spacing between each temporary support column 4, etc. After setting multiple temporary support columns 4 vertically at intervals on the lower floor slab 6, multiple temporary support templates 5 are then set horizontally on the temporary support columns 4. The multiple temporary support columns 4 support the multiple temporary support templates 5, forming a temporary support platform. With this temporary support platform, steel reinforcement can be laid and concrete poured on it.

[0034] S3. Based on the quantity and arrangement data of the first-layer reinforcement, lay the first-layer bottom reinforcement 11, shear reinforcement 12, prestressed tensioning duct 13, prestressed reinforcement 14, and first-layer top reinforcement 15 on the temporary support platform. Pour concrete onto the upper surface of the temporary support platform according to the thickness of the first-layer to form the first-layer 1. The prestressed reinforcement 14 passes through the prestressed tensioning duct 13, with both ends of the prestressed reinforcement 14 exposed at both ends of the prestressed tensioning duct 13. The concrete on the first-layer 1 completely covers the first-layer bottom reinforcement 11, the prestressed tensioning duct 13, the prestressed reinforcement 14, and the first-layer top reinforcement 15. The concrete on the first-layer 1 partially covers the shear reinforcement 12. In step S3, the construction unit lays the reinforcement on the temporary support platform according to the quantity and arrangement data of the first-layer reinforcement. After the reinforcement is laid, concrete is poured onto the upper surface of the temporary support platform. The amount of concrete poured depends on the thickness of the first pouring layer. On the first pouring layer 1, on one hand, the concrete completely covers the bottom reinforcement 11, the prestressed tensioning duct 13, the prestressed reinforcement 14, and the top reinforcement 15, forming the stress structure of the first pouring layer 1 through the concrete and the aforementioned reinforcement. On the other hand, the concrete partially covers the shear reinforcement 12, i.e. Figure 1 , Figure 2 , Figure 3 and Figure 4 The lower half of the shear tie 12, the part of the shear tie 12 not covered by the first pouring layer 1, serves to make the bond between the first pouring layer 1, the second pouring layer 2, and the third pouring layer 3 more secure. That is, the lower half of the shear tie 12 is fixed to the first pouring layer 1, the middle part of the shear tie 12 is fixed to the second pouring layer 2, and the upper half of the shear tie 12 is fixed to the third pouring layer 3.

[0035] S4. After the initial setting of the concrete in the first pouring layer 1, the upper surface of the initially set concrete in the first pouring layer 1 is roughened. Initial setting refers to the stage when the concrete loses its fluidity and begins to harden. At this stage, the plasticity of the concrete decreases significantly, but it has not yet acquired strength. Roughening is to make the relatively smooth concrete surface rough in order to enhance the adhesion between layers and provide a solid and reliable base layer for subsequent processes.

[0036] S5. After the concrete strength of the first pouring layer 1 reaches the design strength, the prestressed steel bars 14 are tensioned for the first time. The function of the prestressed steel bars 14 is to improve the compressive strength of the structure. In step S5, the design strength of the concrete of the first pouring layer 1 refers to the strength corresponding to the concrete after solidification. That is, after the concrete on the first pouring layer 1 has solidified, the prestressed steel bars 14 are tensioned for the first time. During the first tensioning, the prestressed steel bars 14 are not fully stretched, but the tensioning force is controlled according to the self-weight of the first pouring layer 1 and the second pouring layer 2 to ensure that the first pouring layer 1 can withstand the entire self-weight and construction load of the second pouring layer 2 during the construction stage.

[0037] S6. Based on the quantity and arrangement data of the second pouring layer reinforcement, lay the top reinforcement 21 of the second pouring layer on the first pouring layer 1, and tie the shear reinforcement 12 to the top reinforcement 21 of the second pouring layer; pour concrete on the upper surface of the first pouring layer 1 according to the thickness of the second pouring layer to form the second pouring layer 2; the concrete on the second pouring layer 2 completely covers the top reinforcement 21 of the second pouring layer, and partially covers the shear reinforcement 12. In step S6, the construction unit lays reinforcement on the first pouring layer 1 according to the quantity and arrangement data of the second pouring layer reinforcement. After completing the reinforcement laying, concrete is poured on the upper surface of the first pouring layer 1, and the amount of concrete poured is determined by the thickness of the second pouring layer. On the second pouring layer 2, on the one hand, the concrete completely covers the top reinforcement 21 of the second pouring layer, forming the stress structure of the second pouring layer 2 through the concrete and the top reinforcement 21 of the second pouring layer; on the other hand, the concrete partially covers the shear reinforcement 12. The part of the shear reinforcement 12 not covered by the second pouring layer 2 serves to make the bond between the second pouring layer 2 and the third pouring layer 3 stronger. When the third pouring layer 3 is poured, it will be completely covered, that is, the middle part of the shear reinforcement 12 is fixed to the second pouring layer 2, and the upper part of the shear reinforcement 12 is fixed to the third pouring layer 3.

[0038] S7. During the pouring of the second pouring layer 2, the prestressed steel bars 14 are simultaneously tensioned for the second time, and tensioning is stopped after the prestressed tension value reaches a level sufficient to balance the structural self-weight of the first pouring layer 1 and the second pouring layer 2. Throughout the construction process, the prestressed steel bars 14 need to be tensioned twice. The first tensioning is performed after the concrete in the first pouring layer 1 has completely solidified, as detailed in step S5; the second tensioning is performed during the pouring of the concrete in the second pouring layer 2, that is, while pouring the concrete in the second pouring layer 2, the tension force is gradually increased until the prestressed tension value reaches a level sufficient to balance the structural self-weight of the first pouring layer 1 and the second pouring layer 2.

[0039] S8. After the concrete on the second pouring layer 2 has initially set, roughen the upper surface of the initially set concrete on the second pouring layer 2.

[0040] S9. Based on the quantity and arrangement of the reinforcing bars in the third pouring layer, lay the vertical reinforcing bars 31 and the top longitudinal reinforcing bars 32 of the transfer member on the second pouring layer 2. Then, pour concrete on the upper surface of the second pouring layer 2 according to the thickness of the third pouring layer to form the third pouring layer 3. The concrete on the third pouring layer 3 completely covers and overlaps the shear reinforcement 12 and the top longitudinal reinforcing bars 32, and partially covers the vertical reinforcing bars 31 of the transfer member. Step S9 details the specific technical aspects of the third pouring layer 3, and the process is similar to steps S3 and S6. It will not be elaborated upon here.

[0041] This technical solution adopts the concept of composite components, casting the thick slab in layers. The thick slab is composed of a first layer (1), a second layer (2), and a third layer (3), which improves the hydration heat effect generated by large-volume concrete casting and helps improve the quality of concrete casting. The first layer (1) serves as the supporting structure for the second and third layers (2), and the second layer (2) serves as the supporting structure for the third layer (3). By forming a multi-layer floor slab, a "prestressed" effect is achieved, reducing the load on the supporting formwork and ensuring its reliability and stability. This reduces the temporary load-bearing requirements of the lower floor slab and saves investment costs. Simultaneously, shear reinforcement bars (12) are pre-installed.

[0042] It should be noted that, for the thick plate itself, its density is generally based on 26 kN / m³. 2 Therefore, the weight of the thick plate can be calculated by multiplying the density by the volume of the thick plate.

[0043] like Figure 2 As shown, preferably, the bottom reinforcement 11 of the first pouring layer, the prestressed reinforcement 14, the top reinforcement 15 of the first pouring layer, the top reinforcement 21 of the second pouring layer, and the top longitudinal reinforcement 32 are arranged in both horizontal and transverse directions; the shear reinforcement 12 and the vertical reinforcement 31 of the transfer member are arranged in the vertical direction. The top reinforcement 15 of the first pouring layer is parallel to the bottom reinforcement 11 of the first pouring layer and the prestressed reinforcement 14; the top reinforcement 21 of the second pouring layer is parallel to the top reinforcement 15 and the bottom reinforcement 11 of the first pouring layer. The top reinforcement 15, the bottom reinforcement 11, and the prestressed reinforcement 14 of the first pouring layer are all arranged in the horizontal direction. The bottom reinforcement 11 and the prestressed reinforcement 14 of the first pouring layer are parallel to each other, while the top reinforcement 15 of the first pouring layer is perpendicular to the bottom reinforcement 11 and the prestressed reinforcement 14 of the first pouring layer.

[0044] On the first pouring layer 1, the bottom reinforcement 11, the prestressed reinforcement 14, and the top reinforcement 15 of the first pouring layer serve to increase the strength of the first pouring layer 1. These reinforcements are arranged horizontally, which, in conjunction with the concrete structure, results in higher overall strength for the first pouring layer 1 and the second pouring layer 2.

[0045] The bottom reinforcement 11 of the first pouring layer and the prestressed steel reinforcement 14 are set on the temporary support formwork 5, and the top reinforcement 15 of the first pouring layer is located above the bottom reinforcement 11 and the prestressed steel reinforcement 14 of the first pouring layer; the top reinforcement 21 of the second pouring layer is set above the first pouring layer 1; the top longitudinal reinforcement 32 is set on the second pouring layer 2.

[0046] Based on the above structure, crisscrossing steel bars are respectively set on the first pouring layer 1, the second pouring layer 2 and the third pouring layer 3, which effectively improves the stiffness and bearing capacity of each layer; at the same time, shear bars 12 and vertical steel bars 31 of the transfer member are set in the vertical direction, which can improve the shear resistance when the layers are bonded together.

[0047] Preferably, the thickness of the first pouring layer is 30% of the overall thickness of the slab, the second pouring layer 2 is 25% of the overall thickness of the slab, and the third pouring layer 3 is 45% of the overall thickness of the slab.

[0048] The core of this technical solution is to provide prestress through layered casting, thereby achieving self-supporting loads. Taking the thick slab as a unit 1, on the cross-section, the first casting layer 1 accounts for 30%, the second casting layer 2 accounts for 25%, and the third casting layer 3 accounts for 45%.

[0049] Unlike existing technologies that form thick slabs in a single pour, this technical solution involves pouring the thick slabs in stages, where the first pouring layer 1 serves as the self-supporting prestressed structure for the second pouring layer 2 and the third pouring layer 3. The first pouring layer 1 and the second pouring layer 2 serve as the self-supporting prestressed structure for the third pouring layer 3, thus effectively utilizing the slab's own structure to achieve the self-supporting prestressing function.

[0050] Preferably, in steps S4 and S8, roughening the surface of the initially set concrete specifically involves placing a wooden strip on the surface of the initially set concrete and applying a vertically downward pressure to the wooden strip to form longitudinal and transverse grooves on the surface of the initially set concrete.

[0051] As mentioned above, during the initial setting stage, before the concrete has fully hardened, wooden strips are placed on the surface of the initially set concrete to press out longitudinal and transverse grooves. This increases the roughness between layers and improves the stability of the joints between layers. The core purpose of roughening is not to damage the concrete, but to create a base layer that can bond firmly to subsequent pours of new concrete.

[0052] Preferably, in steps S5 and S7, tensioning the prestressed steel bar 14 specifically involves: fixing the fixed end of the prestressed steel bar 14 to the side of the first pouring layer 1 using a pier head anchor; fixing the tensioning end of the prestressed steel bar 14 using a conical anchor and applying tension force using a jack to tension it, so that the prestressed steel bar 14 is in a taut state within the prestressed tensioning pipe 13.

[0053] The purpose of tensioning the prestressed steel bars 14 is to provide greater prestress to balance the construction load and achieve self-support by keeping the prestressed steel bars 14 under continuous tension after the first pouring layer is completed and the load of the second and third pouring layers increases.

[0054] Based on the above structural scheme, one end of the prestressed steel bar 14, which is fixed by the anchor at the pier head, forms a fixed end, while the other end of the prestressed steel bar 14 forms a tensioning end through a tapered anchor. Based on this structure, tensioning force can be applied by jacks when it is necessary to tension the prestressed steel bar 14, which has the advantages of convenient operation and stable force application process.

[0055] Preferably, the plurality of prestressed steel bars 14 are parallel to each other, and the fixed ends and tensioning ends of adjacent prestressed steel bars 14 are staggered. Simply put, each prestressed steel bar 14 has a fixed end and a tensioning end at both ends, and on two adjacent prestressed steel bars 14, the fixed end of the first prestressed steel bar 14 and the tensioning end of the second prestressed steel bar 14 are located on the same side. All the prestressed steel bars 14 form a mesh-like structure, with the fixed ends and tensioning ends staggered, thus increasing the overall prestress level of the prestressed steel bars 14.

[0056] Preferably, in step S7, after the second tensioning of the prestressed steel bar 14 is completed, concrete grout is injected into the prestressing tensioning duct 13 under pressure, and the concrete in the prestressing tensioning duct 13 is allowed to solidify. In addition to the tension force, after tensioning is completed, the prestressed steel bar 14 in the prestressing tensioning duct 13 is completely fixed by concrete, which, on the basis of tight tension, provides additional fixation and effectively improves the prestress level of the prestressed steel bar 14.

[0057] It should be understood that the application of the present invention is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A method for constructing thick plates, characterized in that, The thick plate includes a first pouring layer, a second pouring layer, and a third pouring layer. The method includes the following steps: S1. Obtain construction design data, which includes support structure data, thickness of the first pouring layer, number of steel bars in the first pouring layer, steel bar layout data of the first pouring layer, thickness of the second pouring layer, number of steel bars in the second pouring layer, steel bar layout data of the second pouring layer, thickness of the third pouring layer, number of steel bars in the third pouring layer, and steel bar layout data of the third pouring layer. S2. Construct a support formwork based on the support structure data. The support formwork includes multiple vertically arranged temporary support columns and multiple horizontally arranged temporary support templates. The bottom end of the temporary support column is fixedly set on the lower floor slab, and the temporary support template is fixedly set on the top end of the temporary support column. Multiple temporary support templates form a temporary support platform. S3. Based on the quantity and arrangement data of the first-layer reinforcement, lay the first-layer bottom reinforcement, shear reinforcement, prestressed tensioning duct, prestressed reinforcement, and first-layer top reinforcement on the temporary support platform. Pour concrete onto the upper surface of the temporary support platform according to the thickness of the first-layer to form the first-layer. The prestressed reinforcement passes through the prestressed tensioning duct, with both ends of the prestressed reinforcement exposed at both ends of the prestressed tensioning duct. The concrete on the first-layer completely covers the first-layer bottom reinforcement, the prestressed tensioning duct, the prestressed reinforcement, and the first-layer top reinforcement, and partially covers the shear reinforcement. S4. After the concrete on the first pouring layer has initially set, roughen the upper surface of the initially set concrete on the first pouring layer. S5. After the concrete strength of the first pouring layer reaches the design strength, the prestressed steel bars are tensioned for the first time; S6. Based on the number of reinforcing bars in the second pouring layer and the arrangement data of the reinforcing bars in the second pouring layer, lay the top reinforcement of the second pouring layer on the first pouring layer, and tie the shear reinforcement to the top reinforcement of the second pouring layer; pour concrete on the upper surface of the first pouring layer according to the thickness of the second pouring layer to form the second pouring layer; the concrete on the second pouring layer completely covers the top reinforcement of the second pouring layer, and the concrete on the second pouring layer partially covers the shear reinforcement; S7. When pouring the second layer, the prestressed steel bars are tensioned for the second time simultaneously, and tensioning is stopped after the prestressed tension value reaches a level that can balance the structural self-weight of the first and second layers. S8. After the concrete on the second pouring layer has initially set, roughen the upper surface of the initially set concrete on the second pouring layer. S9. Based on the number of reinforcing bars in the third pouring layer and the arrangement data of the reinforcing bars in the third pouring layer, lay the vertical reinforcing bars and top longitudinal bars of the transfer member on the second pouring layer, and pour concrete on the upper surface of the second pouring layer according to the thickness of the third pouring layer to form the third pouring layer; wherein, the concrete on the third pouring layer completely covers and overlaps the shear reinforcement and the top longitudinal bars, and the concrete on the third pouring layer partially covers the vertical reinforcing bars of the transfer member.

2. The thick plate construction method according to claim 1, characterized in that, The bottom reinforcement of the first pouring layer, the prestressed steel bars, the top reinforcement of the first pouring layer, the top reinforcement of the second pouring layer, and the top longitudinal reinforcement are arranged in both horizontal and transverse directions; The shear reinforcement and the vertical reinforcement of the conversion member are arranged in the vertical direction; The bottom reinforcement of the first pouring layer and the prestressed steel reinforcement are set on the temporary support formwork, and the top reinforcement of the first pouring layer is located above the corresponding bottom reinforcement of the first pouring layer and the prestressed steel reinforcement; the top reinforcement of the second pouring layer is set above the first pouring layer; the top longitudinal reinforcement is set on the second pouring layer; The top reinforcement of the first pouring layer is parallel to the bottom reinforcement of the first pouring layer and the prestressed reinforcement; the top reinforcement of the second pouring layer is parallel to the top reinforcement of the first pouring layer and the bottom reinforcement of the first pouring layer.

3. The thick plate construction method according to claim 1, characterized in that, The thickness of the first pouring layer is 30% of the overall thickness of the slab, the thickness of the second pouring layer is 25% of the overall thickness of the slab, and the thickness of the third pouring layer is 45% of the overall thickness of the slab.

4. The thick plate construction method according to claim 1, characterized in that, In steps S4 and S8, the roughening treatment on the upper surface of the initially set concrete specifically involves: Place the wooden strips on the top surface of the initially set concrete and apply vertical downward pressure to the wooden strips to form longitudinal and transverse grooves on the top surface of the initially set concrete.

5. The thick plate construction method according to claim 1, characterized in that, In steps S5 and S7, tensioning the prestressed steel bars specifically involves: The fixed end of the prestressed steel bar is fixed to the side of the first pouring layer by means of the anchor head, and the tensioning end of the prestressed steel bar is fixed by means of the tapered anchor and tensioning force is applied by means of the jack to tension the prestressed steel bar in the prestressing tensioning duct.

6. A thick plate construction method according to claim 5, characterized in that, The prestressed steel bars are parallel to each other, and the fixed ends and tensioning ends on two adjacent prestressed steel bars are staggered.

7. A thick plate construction method according to claim 5, characterized in that, In step S7, after the second tensioning of the prestressed steel bars is completed, concrete slurry is injected into the prestressed tensioning duct under pressure and the concrete in the prestressed tensioning duct is allowed to solidify.

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