Crack control method for ultra-large-volume concrete structure of basement

Abstract

The invention relates to the technical field of concrete construction structures, in particular to a crack control method for an ultra-large-size concrete structure of a basement, and solves the technical problems that in the prior art, the method is not suitable for the ultra-large-size concrete structure of the basement and can not cope with stress bearing generated by a post-cast strip. According to the method, the post-cast strip can stably bear pressure through combination of the construction direction and the structure direction, the stress pressure bearing effect can be achieved in the longitudinal direction and the transverse direction of the anti-floating water pressure structure, the boundary is stably connected through the boundary stabilizing component, high matching of a construction entity and the technical requirement can be achieved through matching with lofting, control is more accurate, and the construction efficiency is improved. Control of the construction direction and the structure direction of the post-cast strip is achieved, and then factors of cracks generated by the super-large-size concrete structure of the basement are controlled.

Description

Technical Field

[0001] This invention relates to the field of concrete construction structure technology, and in particular to a method for controlling cracks in ultra-large volume concrete structures in basements. Background Technology

[0002] In current practices, the conventional method for crack control in large-volume concrete structures in basements is almost exclusively to use post-cast strips. The advantages of post-cast strips include controlling concrete shrinkage cracks, reducing structural stress, facilitating segmented construction, improving waterproofing performance, and enhancing structural durability. However, the disadvantages of post-cast strips include: if the location is not properly designed, additional tensile stress may be generated at the edge of the post-cast strip when stress concentration occurs; high requirements for interface roughening and cleaning are needed, with a laitance removal rate of ≥95%; in addition, the construction strength of the formwork support for preventing grout leakage and deformation is high. In existing technologies for controlling cracks in large-volume concrete structures in basements, such as Chinese Invention Patent (Publication No. CN117108067B), a method and system for controlling cracks in large-volume concrete focuses on the construction itself. The main technical aspects include: acquiring the dimensional information of the large-volume concrete; determining the distribution positions of the heat dissipation steel pipes corresponding to the large-volume concrete based on the dimensional information and a pre-defined construction method; placing the heat dissipation steel pipes at their respective distribution positions and connecting them to cooling water to cool the interior of the large-volume concrete. This invention improves the bonding force between the large-volume concrete and the heat dissipation steel pipes by using a pre-defined pressure sensor to obtain the pressure value of the heat dissipation steel pipes in real time; and by using a pre-defined temperature sensor to obtain the cooling water temperature, the internal temperature of the large-volume concrete, and the surface temperature of the large-volume concrete in real time, improving the heat dissipation accuracy of the large-volume concrete. This controls the deformation of the large-volume concrete during the heat dissipation process, thereby effectively controlling cracks in the large-volume concrete. Even with control measures implemented from the perspective of the construction itself, the configuration of post-pouring strips is still essential. However, there is still the issue of how to deal with the lateral stress after construction when using post-pouring strips in the construction of ultra-large volume concrete in basements. Improvements should be made from both the perspective of construction control and the configuration of post-pouring strip structures. Summary of the Invention

[0003] The present invention aims to address the lack of existing technologies applicable to ultra-large volume concrete structures in basements and capable of handling stress and pressure generated by post-pouring strips, and provides a method for controlling cracks in such ultra-large volume concrete structures in basements.

[0004] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows: Methods for controlling cracks in ultra-large volume concrete structures in basements include: Step S101: At the basement construction location, measure and set out the lines, excavate the earthwork, form the post-pouring strip configuration location 1, and set up a cleaning pit 2; Step S102: At the post-pouring strip location 1, a foundation layer and concrete are constructed to form a concrete foundation layer 3. A waterproof layer 4 is laid on the concrete foundation layer 3 at the post-pouring strip location 1, and a protective layer 5 for the waterproof layer 4 is provided. Step S103: An external rubber waterstop 10 is arranged at the bottom center of the concrete cushion layer 3 along both sides. An anti-buoyancy water pressure structure 100 is built above the external rubber waterstop 10. The ends of the longitudinal steel bars of the anti-buoyancy water pressure structure 100 extend to the main post-cast area D. A positioning block 101 is provided at the end of a transverse reinforcing bar; Step S104: Based on the distance of the positioning block 101 to the protective layer 5, the line is measured and laid out to form the boundary line 102 of the main post-cast area D. The prefabricated boundary stabilizing component 200 is on the layout line and the boundary line 102. A cement trough 103 is reserved on one side of the boundary stabilizing component 200. Step 105: Tie the bottom layer of the bottom plate reinforcement 7, fix the reinforcement formwork support structure 210 on the boundary stabilizing member 200, connect the water-stop steel plate 220 above the reinforcement formwork support structure 210, and connect the wire mesh structure 230 above the water-stop steel plate 220. Step S106: Tie the top layer of reinforcing steel bars 8 and lay the closed cover plate 9.

[0005] Furthermore, a pressure plate 11 is provided above the external rubber waterstop 10; Multiple threaded connectors 12 are connected above the pressure plate 11 along the width direction of the pressure plate 11.

[0006] Furthermore, the anti-buoyancy water pressure structure 100 includes: Multiple main connecting posts 13, the second end of which can be screwed onto the threaded connecting seat 12; Before pouring the bottom post-pouring zone B, multiple horizontal bars of different widths 14 and multiple horizontal bars of different lengths 15 are connected to the main connecting column 13 to form staggered nodes. The end of the transverse bar 14 is used as the end of the transverse reinforcing bar, and the positioning block 101 is configured thereon; The staggered nodes can be used as a reference for the layout elevation.

[0007] Furthermore, an auxiliary positioning block 102 is provided at the top edge of the slope of the bottom post-cast area B; The auxiliary positioning block 102 is used as a support point for the bottom layer steel reinforcement 7 of the base plate.

[0008] Furthermore, the bottom post-casting zone B is poured, and the width transverse bar 14 forms a precast casting zone C between the bottom post-casting zone B; The anchoring end of the boundary stabilizing member 200 is connected to the precast casting area C; The boundary stabilizing component 200 includes: Anchor rod 211 is connected to a stabilizing positioning block 212. A precast groove is formed on one side of the stabilizing positioning block 212. The precast groove serves as a reserved cement trough 103 for masonry. A cement masonry layer is built in the reserved cement trough 103.

[0009] Furthermore, the reinforced concrete formwork support structure 210 includes: Two sets of parallel connecting plates 21 are connected by a support rod 22. A wire mesh is arranged between the connecting plates 21. The wire mesh has three layers, and each layer has a specification of 10 mesh, 5 mesh, and 3 mesh.

[0010] Furthermore, the wire mesh structure 230 has the same structural configuration as the rebar formwork support structure 210; The steel reinforcement formwork support structure 210, the steel wire mesh structure 230, and the water-stop steel plate 220 are located between the upper post-cast area A and the main post-cast area D.

[0011] Furthermore, it also includes: a post-cast support rod 401, which is fixedly connected to the top of the main connecting column 13; The post-cast support rod 401 can be tied and connected to the bottom reinforcement 7 of the tied bottom slab and the top reinforcement 8 of the tied bottom slab; Polystyrene foam board layers 10 can be arranged between the post-cast support rods 401.

[0012] Furthermore, the contact surface of the cement masonry layer is coated with a concrete interface treatment agent or a cement penetrating crystallization treatment coating. The main pouring zone D of the post-pouring strip is poured using shrinkage-compensating concrete.

[0013] Furthermore, the waterproof layer 4 also includes a waterproof additional layer 41 and a waterproof main layer 42, the thickness of which exceeds the height of the layout preset plane formed by the width transverse bar 14.

[0014] Through the above technical solution, this method combines the construction and structural directions to enable the post-cast strip to bear pressure stably. The anti-buoyancy water pressure structure can achieve stress bearing effect in both the longitudinal and transverse directions. Furthermore, the stable connection of the boundary through boundary stabilizing components can also be coordinated with the layout to achieve a high degree of coordination between the construction entity and technical requirements, resulting in more precise control. This achieves control from the construction and structural directions of the post-cast strip, thereby controlling the factors that cause cracks in the ultra-large volume concrete structure of the basement. Attached Figure Description

[0015] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0016] Figure 1 This is a schematic diagram of the configuration structure of the method of the present invention; Figure 2 This is a schematic diagram of the external rubber waterstop of the method of the present invention; Figure 3 This is an example of the method of the present invention using polystyrene foam board layers as fillers; Figure 4 This is an embodiment of the auxiliary positioning block of the method of the present invention; Figure 5 This is an embodiment of the boundary stabilizing component of the method of the present invention; Figure 6 This is an embodiment of the wire mesh structure of the method of the present invention.

[0017] Post-pouring strip placement location 1, cleaning pit 2; 3. Concrete foundation layer; 4. Waterproof layer; 5. Protective layer; External rubber waterstop 10, anti-buoyancy water pressure structure 100, main post-cast area D, positioning block 101; 102, boundary stabilizing component 200, cement trough 103, auxiliary positioning block 104; 7. Binding the bottom layer of the base slab reinforcement; 210. Reinforcement formwork support structure; 220. Waterstop steel plate; 230. Wire mesh structure. 8. Tie the top layer of the bottom slab reinforcement; 9. Lay the closed cover plate; 11. Pressure plate; 12. Threaded connection seat; 13. Main connecting column; B. Post-cast zone of the bottom layer. 14 horizontal bars of width, 15 horizontal bars of length, 102 auxiliary positioning blocks, and C precast casting area; Anchor rod 211, connecting plate 21, support rod 22, upper post-cast zone A, main post-cast zone D; Post-cast support rod 401, polystyrene foam board layer 10, waterproof additional layer 41, waterproof main layer 42. Detailed Implementation

[0018] The technical solutions of 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 of ordinary skill in the art without creative effort are within the scope of protection of the present invention. It should be noted that, for ease of description, in this application, "left side" is referred to as "first end", "right side" as "second end", "upper side" as "first end", and "lower side" as "second end" in the current view. The purpose of such description is to clearly express the technical solution and should not be construed as an improper limitation of the technical solution of this application.

[0019] This invention addresses the lack of existing technologies applicable to ultra-large volume concrete structures in basements and capable of handling stress-bearing pressure generated by post-pouring strips. It provides a method for controlling cracks in such ultra-large volume concrete structures in basements. The stress in this application primarily originates from the ultra-large volume concrete structure itself and the influence of the generated stress on the location of the post-pouring strip. Improvements are needed from both the construction and structural perspectives to achieve controllable structural cracking. For specific solutions, please refer to the appendix. Figure 1 As shown: Starting from the construction direction, in step S101, at the basement construction location, survey and set out the lines, excavate the earthwork, form the post-pouring strip configuration location 1, and set up a cleaning pit 2; Step S102: At the post-pouring strip configuration position 1, the foundation layer and concrete are constructed to form a concrete foundation layer 3. A waterproof layer 4 is laid on the concrete foundation layer 3 at the post-pouring strip configuration position 1, and a protective layer 5 is set on the waterproof layer 4. Step S103: In order to eliminate the influence of stress, controlling the waterproofing of the concrete slurry during construction is the main way to avoid stress generation. The purpose is to block the leakage path and block the capillary penetration of liquid water and water vapor. An external rubber waterstop 10 is arranged on both sides of the bottom center of the concrete pad 3. An anti-buoyancy water pressure structure 100 is built above the external rubber waterstop 10. The longitudinal steel bars of the anti-buoyancy water pressure structure 100 extend to the main post-pouring area D. The anti-buoyancy water pressure structure 100 serves as a fixing component of the external rubber waterstop 10. Its function is to resist the upward stress of the concrete pad 3. The anti-buoyancy water pressure structure 100 is composed of interlaced steel bars, with φ12 steel bars in the longitudinal direction and φ8 steel bars in the transverse direction; A positioning block 101 is provided at one end of a transverse steel bar and is welded to the transverse steel bar; Step S104: Based on the distance of the positioning block 101 to the protective layer 5, the distance is measured and laid out to form the boundary line 102 of the main post-pouring area D. The prefabricated boundary stabilizing component 200 is laid out on the layout line and the boundary line 102. A cement trough 103 is reserved on one side of the boundary stabilizing component 200. The traditional method of reserving the cement trough 103 is to roughen and clean it through the manhole, which is prone to construction deviation. In this solution, the cement trough is equivalent to being split into the boundary stabilizing component 200 and the cement filling method. That is, the boundary stabilizing component 200 is used to eliminate some of the deviation caused by roughening and cleaning and layout positioning, so that the subsequent protection and water stop can be stably configured and constructed. Step 105: Tie the bottom reinforcement 7 of the base plate, fix the reinforcement formwork support structure 210 on the boundary stabilizing member 200, connect the waterstop steel plate 220 above the reinforcement formwork support structure 210, and connect the wire mesh structure 230 above the waterstop steel plate 220. Step S106: Tie the top layer of reinforcing steel bars 8 and lay the closed cover plate 9.

[0020] Through the above technical solution, this method combines the construction direction and the structural direction to enable the post-cast strip to bear pressure stably. The anti-buoyancy water pressure structure 100 can achieve stress bearing effect in both the longitudinal and transverse directions. Furthermore, the boundary stabilizing member 200 can stably connect the boundary and cooperate with the layout to achieve a high degree of coordination between the construction entity and the technical requirements, resulting in more precise control. This achieves control from the construction direction and the structural direction of the post-cast strip, thereby controlling the factors that cause cracks in the ultra-large volume concrete structure of the basement.

[0021] For a specific implementation method, please refer to Figure 2 , 3 As shown, a pressure plate 11 is set above the external rubber waterstop 10; multiple threaded connecting seats 12 are connected above the pressure plate 11 along the width direction of the pressure plate 11. The pressure plate 11 serves as a basic component for subsequent layout accuracy control, that is, the layout positioning point is set on the horizontal bar 14, and the connection of the horizontal bar 14 is based on the main connecting column 13 of the threaded connecting seat 12. For a specific implementation method, please refer to Figure 2 , 3 As shown, the anti-buoyancy water pressure structure 100 includes: Multiple main connecting posts 13, the second end of which can be screwed onto the threaded connecting seat 12; Before pouring the bottom post-pouring zone B, multiple horizontal bars of different widths 14 and multiple horizontal bars of different lengths 15 are connected to the main connecting column 13 to form staggered nodes. The end of the transverse bar 14 is used as the end of the transverse reinforcing bar, and a positioning block 101 is provided thereon; Intersecting nodes can be used as a reference for layout elevation.

[0022] For a specific implementation method, please refer to Figure 4 As shown, an auxiliary positioning block 102 is set at the top edge of the slope of the bottom post-cast zone B; the auxiliary positioning block 102 is used as a support point for the bottom reinforcement 7 of the bottom slab.

[0023] For a specific implementation method, please refer to Figure 1 , 2 As shown in Figure 3, the bottom post-pouring zone B is poured, and the width of the transverse bar 14 forms a precast pouring zone C between the bottom post-pouring zone B; The anchoring end of the boundary stabilizing member 200 is connected to the precast casting area C; As attached Figure 5 As shown, the boundary stabilizing member 200 includes: Anchor rod 211 is connected to a stabilizing positioning block 212. A precast groove is formed on one side of the stabilizing positioning block 212. The precast groove serves as a reserved cement trough 103 for masonry. A cement masonry layer is built inside the reserved cement trough 103. By anchoring and prefabricating the anchor rod 211, the stable positioning block 212 has a stable position strength after pouring. In conjunction with the reserved cement groove 103, the cement masonry layer in the reserved cement groove 103 further stabilizes the stable positioning block 212, which replaces the cement edge of the existing technology, and the actual roughening and cleaning difficulty is also reduced. For a specific implementation method, please refer to Figure 3 , 6 As shown, the steel reinforcement formwork support structure 210 includes: two sets of parallel connecting plates 21, which are connected by support rods 22; A wire mesh is arranged between the connecting plates 21. There are three layers of wire mesh, and each layer of wire mesh has a specification of 10 mesh, 5 mesh, and 3 mesh.

[0024] For a specific implementation method, please refer to Figure 1-6 As shown, in the alternative implementation, the wire mesh structure 230 and the rebar formwork support structure 210 have the same structural configuration. The steel reinforcement formwork support structure 210, the wire mesh structure 230, and the water-stop steel plate 220 are located between the upper post-cast area A and the main post-cast area D.

[0025] For a specific implementation method, please refer to Figure 3 As shown, it also includes: a post-cast support rod 401, which is fixedly connected to the top of the main connecting column 13; The post-cast support rod 401 can be tied and connected to the bottom reinforcement 7 and the top reinforcement 8 of the bottom slab. The post-cast support rod 401 plays the role of connecting the bottom reinforcement 7 and the top reinforcement 8 of the bottom slab, and is actually connected to the main connecting column 13, forming a substantial integrated connection. The main connecting column 13 is connected to the pressure plate 11, and the pressure plate 11 also connects the entire external rubber waterstop 10 and the anti-buoyancy water pressure structure 100. These structures are all located in the central area of ​​the post-cast strip configuration position 1, that is, the area where stress is generated, and are also connected to the actual post-cast strip main casting area D. Before the post-cast strip main casting area D is poured, the above structures can ensure the stability of the overall shape. After the post-cast strip main casting area D is poured, the post-cast support rod 401 and the anti-buoyancy water pressure structure 100 can also play the role of stress transmission.

[0026] Polystyrene foam board layers 10 can be arranged between the post-cast support rods 401 for auxiliary filling and to reduce the amount of shrinkage concrete to be filled. For a specific implementation method, please refer to Figure 6 As shown, the contact surface of the cement masonry layer inside the cement trough 103 is coated with concrete interface treatment agent or cement penetration crystallization treatment coating. Shrinkage-compensating concrete was used for the pouring of the main pouring zone D of the post-pouring strip.

[0027] For a specific implementation method, please refer to Figure 4 As shown, the waterproof layer 4 also includes a waterproof supplementary layer 41 and a waterproof main layer 42. The thickness of the waterproof main layer 42 exceeds the height of the layout preset plane formed by the width transverse bar 14.

[0028] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A method for controlling cracks in ultra-large volume concrete structures in basements, characterized in that, include: Step S101: At the basement construction location, measure and set out the lines, excavate the earthwork, form the post-pouring strip configuration location (1), and set up a cleaning pit (2). Step S102: At the post-pouring strip configuration position (1), a cushion layer and concrete are constructed to form a concrete cushion layer (3). A waterproof layer (4) is laid on the concrete cushion layer (3) at the post-pouring strip configuration position (1), and a protective layer (5) of the waterproof layer (4) is set. Step S103: An external rubber waterstop (10) is arranged at the bottom center of the concrete cushion (3) along both sides. An anti-buoyancy water pressure structure (100) is built above the external rubber waterstop (10). The ends of the longitudinal steel bars of the anti-buoyancy water pressure structure (100) extend to the main post-cast area (D). A positioning block (101) is provided at the end of a transverse steel bar. Step S104: Based on the distance of the positioning block (101) to the protective layer (5), the line is measured and laid out to form the boundary line (102) of the main post-cast area (D). The prefabricated boundary stabilizing member (200) is laid out on the line and the boundary line (102). A cement trough (103) is reserved on one side of the boundary stabilizing member (200). Step 105: Tie the bottom reinforcement of the base plate (7), fix the reinforcement formwork support structure (210) on the boundary stabilizing member (200), connect the water-stop steel plate (220) above the reinforcement formwork support structure (210), and connect the wire mesh structure (230) above the water-stop steel plate (220). Step S106: Tie the top layer of the bottom slab reinforcement (8) and lay the closed cover plate (9).

2. The method for controlling cracks in ultra-large volume concrete structures in basements as described in claim 1, characterized in that, A pressure plate (11) is provided above the external rubber waterstop (10). Multiple threaded connectors (12) are connected above the pressure plate (11) along the width direction of the pressure plate (11).

3. The method for controlling cracks in ultra-large volume concrete structures in basements as described in claim 2, characterized in that, The anti-buoyancy water pressure structure (100) includes: Multiple main connecting posts (13), the second end of which can be screwed onto the threaded connecting seat (12); Before the bottom post-pouring zone (B) is poured, multiple horizontal bars of different widths (14) and multiple horizontal bars of different lengths (15) are connected to the main connecting column (13) to form staggered nodes; The end of the width transverse bar (14) is used as the transverse steel bar end, and the positioning block (101) is configured. The staggered nodes can be used as a reference for the layout elevation.

4. The method for controlling cracks in ultra-large volume concrete structures in basements as described in claim 3, characterized in that, An auxiliary positioning block (102) is provided at the top edge of the slope of the bottom post-cast area (B). The auxiliary positioning block (102) is used as a support point for the bottom layer steel reinforcement (7) of the base plate.

5. The method for controlling cracks in ultra-large volume concrete structures in basements as described in claim 3, characterized in that, The bottom post-cast zone (B) is poured, and a precast zone (C) is formed between the width transverse bar (14) and the bottom post-cast zone (B). The anchoring end of the boundary stabilizing member (200) is connected to the precast casting area (C). The boundary stabilizing component (200) includes: An anchor rod (211) is connected to a stabilizing positioning block (212). A precast groove is formed on one side of the stabilizing positioning block (212), which serves as a reserved cement trough (103) for masonry. A cement masonry layer is built in the reserved cement trough (103).

6. The method for controlling cracks in ultra-large volume concrete structures in basements as described in claim 5, characterized in that, The reinforced concrete formwork support structure (210) includes: Two sets of parallel connecting plates (21) are connected by a support rod (22); A wire mesh is arranged between the connecting plates (21). The wire mesh has three layers, and each layer has a specification of 10 mesh, 5 mesh, and 3 mesh.

7. The method for controlling cracks in ultra-large volume concrete structures in basements as described in claim 6, characterized in that, The steel wire mesh structure (230) has the same structural configuration as the steel reinforcement formwork support structure (210); The steel reinforcement formwork support structure (210), the steel wire mesh structure (230), and the water-stop steel plate (220) are located between the upper post-cast area (A) and the main post-cast area (D).

8. The method for controlling cracks in ultra-large volume concrete structures in basements as described in claim 7, characterized in that, It also includes: a post-cast support rod (401), which is fixedly connected to the top of the main connecting column (13); The post-cast support rod (401) can be tied and connected with the bottom reinforcement (7) of the tied bottom slab and the top reinforcement (8) of the tied bottom slab; Polystyrene foam board layers (10) can be arranged between the post-cast support rods (401).

9. The method for controlling cracks in ultra-large volume concrete structures in basements as described in claim 8, characterized in that, Apply concrete interface treatment agent or cement penetrating crystallization treatment coating to the contact surface of the cement masonry layer. The main pouring zone (D) of the post-pouring strip is poured using shrinkage-compensating concrete.

10. The method for controlling cracks in ultra-large volume concrete structures in basements as described in claim 1, characterized in that, The waterproof layer (4) also includes a waterproof additional layer (41) and a waterproof main layer (42), the thickness of which exceeds the height of the layout preset plane formed by the width transverse bar (14).

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