Compensation structure for post-cast strip-free super-long structure construction concrete shrinkage crack

Abstract

The utility model relates to a compensation structure for a post-cast strip-free super-long structure construction concrete shrinkage crack, a super-long structure is divided into a plurality of construction sections, a compensation structure which is simultaneously cast with a post-construction section is adopted between adjacent construction sections to replace a post-cast strip, the compensation structure comprises a compensation shrinkage strip, and a construction joint is arranged between the compensation shrinkage strip and a pre-construction section. The compensation contraction band adopts a steel bracket and a net stubble barrier as a support body, and forms an integrated structure with compensation contraction concrete; the net stubble blocking section is adjacent to the post-construction section; the device is arranged between a construction joint and a compensation contraction band. The expansion coefficient of the shrinkage-compensating concrete is larger than that of concrete adopted by the first construction section and the later construction section, and the strength of the shrinkage-compensating concrete is larger than that of the concrete adopted by the first construction section and the later construction section. According to the utility model, a temperature post-cast strip is omitted, and construction operations which are interspersed with main body structure construction, such as masonry engineering, equipment installation and the like, can be carried out in advance. And various quality risks caused by the arrangement of the temperature post-cast strip are eliminated.

Description

Technical Field

[0001] This utility model relates to the field of concrete crack compensation technology, and more specifically to a compensation structure for shrinkage cracks in concrete during the construction of ultra-long structures without post-pouring strips. Background Technology

[0002] With the rapid development of large-scale public buildings in recent years and the increasing demand for office space, the scale and functions of underground structures in comprehensive public buildings are constantly expanding. Given the current situation of densely packed and limited underground space in urban areas, the interconnection of multiple main buildings' underground spaces has attracted considerable attention, and ultra-long spatial connections have become a new development trend in underground architecture. However, this has also brought about the problem of cracking in ultra-long concrete structures, making the technology for controlling cracking in ultra-long concrete structures crucial.

[0003] Currently, concrete cracking is typically controlled by using post-cast strips to release significant amounts of temperature and shrinkage stress. While this method effectively releases the shrinkage and settlement deformation of the concrete, the presence of post-cast strips also introduces a series of quality and construction challenges, such as basement flooding during rainy seasons and difficulties in manual cleaning. These problems not only increase construction difficulty but may also affect the overall quality and schedule of the project.

[0004] Therefore, how to effectively address these adverse effects and overcome the construction challenges brought about by the post-cast strip design is a problem that urgently needs to be solved by those skilled in the art. Utility Model Content

[0005] Therefore, the purpose of this utility model is to propose a compensation structure for shrinkage cracks in ultra-long structures without post-pouring strips, thereby solving the problems existing in the current method of using post-pouring strips.

[0006] The technical solution of this utility model is a compensation structure for concrete shrinkage cracks in ultra-long structures without post-pouring strips. The ultra-long structure is divided into multiple construction sections, and a compensation structure, poured simultaneously with the subsequent construction section, replaces the post-pouring strip between adjacent construction sections, including:

[0007] A shrinkage compensation strip is located at the rear of the first construction section. A construction joint is set between the shrinkage compensation strip and the first construction section. The shrinkage compensation strip is supported by a steel frame and a mesh retainer, and forms an integral structure with the shrinkage compensation concrete. The mesh retainer is adjacent to the rear construction section.

[0008] A waterstop is placed between the construction joint and the shrinkage compensation strip;

[0009] Among them, the expansion coefficient of the shrinkage-compensating concrete is greater than that of the concrete used in the first and second construction sections, and the strength of the shrinkage-compensating concrete is greater than that of the concrete used in the first and second construction sections.

[0010] According to the technical solution of this utility model, the width of each of the compensation shrinkage strips is 0.8-1.2m.

[0011] According to the technical solution of this utility model, the steel support is composed of vertical steel bars and horizontal steel bars, and the spacing between the vertical steel bars is equal to the spacing between the horizontal steel bars.

[0012] According to the technical solution of this utility model, the netting stubble is a quick-closing netting stubble.

[0013] According to the technical solution of this utility model, the joint surface at the construction joint is a rough surface structure, and a shrinkage compensation strip is provided between the rough surface structure and the shrinkage compensation strip, which is tied to the first construction section.

[0014] According to the technical solution of this utility model, the waterstop is horizontally positioned between the compensating shrinkage strip and the pre-constructed section, and is arranged with both sides bent downwards.

[0015] According to the technical solution of this utility model, the shrinkage-compensating concrete is made of slag silicate cement.

[0016] According to the technical solution of this utility model, the compensation shrinkage strip also includes additional structural steel bars. The additional structural steel bars are made of a single-layer bidirectional steel mesh and are set at the bottom of the compensation shrinkage strip, with both ends inserted into the first construction section and the second construction section, respectively.

[0017] As can be seen from the above technical solution, compared with the prior art, the technical effects of this utility model are as follows:

[0018] This invention eliminates the need for a post-cast strip, employing a shrinkage compensation strip to release significant stress and temperature in the early stages of concrete construction. Later, the strip utilizes its own expansion stress to resist concrete shrinkage stress, thus controlling cracks in ultra-long concrete structures. By omitting the temperature-controlled post-cast strip, masonry work, equipment installation, and other construction operations that overlap with the main structure can be carried out earlier under the same construction conditions. This eliminates the various quality risks and schedule constraints associated with the use of temperature-controlled post-cast strips.

[0019] This invention is applicable to the construction of ultra-long concrete structures and building projects significantly affected by temperature-dependent post-pouring strips, especially high-rise and large-span buildings. This technology effectively solves the problem of post-pouring strip interference encountered in the construction of ultra-long concrete structures.

[0020] Dividing the extra-long concrete block into several smaller blocks for intermittent construction eliminates the need for temperature-controlled post-cast strips and their associated adverse effects. This not only allows for the earlier commencement of subsequent construction processes, providing favorable conditions for the earlier insertion of masonry, plastering, and decoration works, thus saving construction time, but also reduces the amount of work required for post-cast strip maintenance and support, saving on costs associated with preventative measures and subsequent repair expenses due to leakage, resulting in significant economic benefits. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0022] Figure 1 A cross-sectional view of a compensation structure for shrinkage cracks in concrete during the construction of an ultra-long structure without post-pouring strip, provided by this utility model.

[0023] Figure 2 The diagram illustrates the application of this utility model. Detailed Implementation

[0024] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this utility model, and should not be construed as limiting this utility model.

[0025] In the description of this utility model, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0026] Current technology for controlling cracks in ultra-long concrete structures generally involves using post-cast strips to release significant amounts of temperature and shrinkage stress, thereby controlling concrete cracking. While this method effectively releases shrinkage and settlement deformation of the concrete, the placement of post-cast strips presents a series of quality and construction challenges, including basement flooding during rainy seasons and difficulties in manual cleaning.

[0027] Therefore, the technical solution of this utility model is a compensation structure for shrinkage cracks in concrete during the construction of ultra-long structures without post-pouring strips, see appendix. Figure 1 The ultra-long structure is divided into multiple construction sections. Adjacent construction sections are connected by a compensating structure, poured simultaneously with the subsequent construction section 6, instead of a post-pouring strip. This includes:

[0028] The compensating shrinkage strip 4 is located at the rear of the first construction section 1. A construction joint 3 is set between the compensating shrinkage strip 4 and the first construction section 1. The compensating shrinkage strip 4 uses a steel bracket and a mesh retainer 5 as the support body and forms an integral structure with the compensating shrinkage concrete. The mesh retainer 5 is adjacent to the rear construction section 6.

[0029] Waterstop 2 is arranged between the construction joint 3 and the compensating shrinkage strip 4;

[0030] Among them, the expansion coefficient of the shrinkage-compensating concrete is greater than that of the concrete used in the first construction section 1 and the second construction section 6, and the strength of the shrinkage-compensating concrete is greater than that of the concrete used in the first construction section 1 and the second construction section 6.

[0031] In this invention, a structure exceeding 50m is considered an ultra-long structure.

[0032] The above technical solution eliminates the post-pouring strip and sets up a compensating shrinkage strip 4. This allows the concrete to release a significant amount of stress and temperature in the early stages, and later utilizes its own expansion stress to resist the shrinkage stress, thus controlling cracks in ultra-long concrete structures. The waterstop 2 achieves waterproofing. This technical solution requires dividing the ultra-long structure into multiple construction units, with intermittent construction. This allows for the earlier commencement of subsequent construction processes, providing favorable conditions for the earlier insertion of masonry, plastering, and decoration works, thereby saving construction time. It also saves a significant amount of work related to the maintenance and support of the post-pouring strip, reducing costs associated with preventative measures and subsequent repair costs due to leakage, resulting in significant economic benefits.

[0033] Advantageously, each of the aforementioned compensating shrinkage bands 4 has a width of 0.8-1.2m. The maximum spacing between adjacent compensating shrinkage bands 4 is controlled between 40-50m. This avoids excessive stress concentration caused by excessively narrow post-cast strips, allows for more uniform stress distribution, and reduces the risk of cracks or damage due to excessive local stress.

[0034] In the above embodiment, the steel support is constructed using vertical and horizontal reinforcing bars, with the spacing between the vertical bars being equal to the spacing between the horizontal bars. The vertical and horizontal reinforcing bars can form a 150×150mm spacing, which ensures a good retaining effect and prevents concrete from entering the shrinkage compensation zone.

[0035] Advantageously, the aforementioned mesh retainer 5 is a quick-closing mesh retainer. The quick-closing mesh retainer is a template made of thin hot-dip galvanized steel sheet, with a unidirectional U-shaped dense rib skeleton and a unidirectional three-dimensional network structure, which intercepts concrete during the pouring process.

[0036] More advantageously, the joint surface at the construction joint 3 is a rough surface structure, and a shrinkage duct is provided between the rough surface structure and the compensation shrinkage band 4, which is tied to the first construction section 1.

[0037] See appendix Figure 1 , attached Figure 1 The longitudinal sectional view shows the waterstop 2 horizontally positioned between the compensating shrinkage strip 4 and the pre-constructed section 1, with both sides bent downwards. This downward bend extends the water penetration path. When water comes into contact with the waterstop, it needs to bypass the bend, increasing the difficulty of penetration and effectively preventing water infiltration, improving waterproofing performance, and reducing the risk of leakage in the basement structure.

[0038] In this invention, the shrinkage-compensating concrete uses slag silicate cement. Slag silicate cement is a type of cement with expansive properties, made by grinding blast furnace slag as the basic raw material and adding appropriate additives. It features low heat of hydration, good impermeability, and strong resistance to sulfate attack. The expansive agent in the slag silicate cement reacts with calcium aluminate in the cement to form ettringite crystals, generating expansive force. This expansive force can compensate for the shrinkage stress of the concrete, prevent structural cracking, and improve the overall durability and stability of the concrete.

[0039] Under the constraint of reinforcing steel and adjacent concrete, shrinkage-compensating concrete generates a certain prestress within the reinforced concrete, appropriately compensating for the shrinkage tensile stress in the structure and thus preventing cracking and damage. Simultaneously, the shrinkage displacement of the concrete on both sides of the shrinkage-compensating zone is also compensated, resulting in better bonding between the concrete and the adjacent concrete.

[0040] More advantageously, the compensating shrinkage strip 4 also includes additional structural steel bars 8, which are single-layer bidirectional steel meshes and are set at the bottom of the compensating shrinkage strip 4, with both ends inserted into the first construction section 1 and the second construction section 6 respectively.

[0041] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0042] See appendix Figure 2 In a specific embodiment of the above-described structure of this utility model, it is divided into the main building construction section on the left, which is divided into the first construction section 1 of the main building and the last construction section 6 of the main building, and the auxiliary building construction section 1 and the last construction section 6 on the right. The compensation shrinkage belt 4 will be located between different construction sections.

[0043] Specifically, the first construction section 1 of the main building is poured first. Two to three days later, the second construction section 6 of the main building, the first construction section 1 of the auxiliary building, the shrinkage compensation zone between the first construction section 1 of the main building and the first construction section 1 of the auxiliary building, and the shrinkage compensation zone between the first construction section 1 of the main building and the second construction section 6 of the main building are poured. Two to three days later, the last construction section 6 of the auxiliary building, the shrinkage compensation zone between the second construction section 6 of the auxiliary building and the first construction section 1 of the auxiliary building, and the shrinkage compensation zone between the second construction section 6 of the auxiliary building and the second construction section 6 of the main building are poured.

[0044] The slag silicate cement used should have a hydration heat of less than 240 KJ / kg after 3 days and less than 270 KJ / kg after 7 days.

[0045] To improve the water-stopping effect at the joint between the compensating shrinkage strip 4 and the first constructed section 1, a water-stopping steel plate with a thickness of 3mm and a width of 300mm and bent downwards is installed at the middle of the structural thickness at the joint.

[0046] The reinforcing bars within the shrinkage compensation zone 4 are not cut off. In addition to the structural reinforcement, the shrinkage compensation zone 4 also requires additional structural reinforcement 8. This structural reinforcement 8 is a single-layer, two-way steel mesh, placed at the bottom of the shrinkage compensation zone 4, with both ends extending 200mm into the adjacent structure. The joint between the subsequent construction section 6 and the shrinkage compensation zone 4 is sealed with a quick-closing mesh. The reinforcing bar support uses approximately 12mm diameter steel bars, with vertical and horizontal spacing of 100mm. The quick-closing mesh is tied to one side of the subsequent construction section 6. The reinforcing bar support is securely welded to the main reinforcement 7 of the raft foundation of the preceding construction section 1 and the subsequent construction section to prevent the subsequent construction section 6 from flowing into the shrinkage compensation zone 4. The concrete for the shrinkage compensation zone uses a 14% aluminum sulfate-based expansion agent, and its strength grade is one level higher than the ordinary concrete on both sides.

[0047] In the above embodiments, the concrete is poured in layers.

[0048] This invention features rational design, convenient construction, and controllable quality. It optimizes the design scheme, improves construction efficiency, and enhances project quality. It allows for the earlier integration of various professional processes that were previously hindered by post-cast strips, enabling faster achievement of project milestones within a limited timeframe and reducing construction costs. This technology not only improves the overall quality of the project but also eliminates the leakage risks associated with temperature-controlled post-cast strips, ensuring safe project implementation and offering excellent economic benefits.

[0049] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. In addition, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

[0050] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A compensation structure for shrinkage cracks in concrete during the construction of ultra-long structures without post-pouring strips, characterized in that, The ultra-long structure is divided into multiple construction sections. Between adjacent construction sections, a compensating structure, poured simultaneously with the subsequent construction section (6), replaces the post-cast strip, including: The compensating shrinkage strip (4) is located at the rear of the first construction section (1). A construction joint (3) is set between the compensating shrinkage strip (4) and the first construction section (1). The compensating shrinkage strip (4) is supported by steel brackets and mesh retaining (5) and forms an integral structure with the compensating shrinkage concrete. The mesh retaining (5) is adjacent to the second construction section (6). Waterstop (2) is arranged between the construction joint (3) and the compensation shrinkage strip (4); Among them, the expansion coefficient of the shrinkage-compensating concrete is greater than that of the concrete used in the first construction section (1) and the second construction section (6), and the strength of the shrinkage-compensating concrete is greater than that of the concrete used in the first construction section (1) and the second construction section (6).

2. The compensation structure for shrinkage cracks in ultra-long structures without post-pouring strips according to claim 1, characterized in that, Each of the aforementioned compensating shrinkage bands (4) has a width of 0.8-1.2m.

3. The compensation structure for shrinkage cracks in ultra-long structures without post-pouring strips as described in claim 1, characterized in that, The steel support is constructed using vertical and horizontal reinforcing bars, with the spacing between the vertical reinforcing bars being equal to the spacing between the horizontal reinforcing bars.

4. The compensation structure for shrinkage cracks in ultra-long structures without post-pouring strips according to claim 1, characterized in that, The mesh barrier (5) adopts a quick and easy-to-close mesh barrier.

5. The compensation structure for shrinkage cracks in ultra-long structures without post-pouring strips according to claim 1, characterized in that, The joint surface at the construction joint (3) is a rough surface structure, and a shrinkage closure net tied to the pre-constructed section (1) is provided between the rough surface structure and the compensation shrinkage strip (4).

6. The compensation structure for shrinkage cracks in ultra-long structures without post-pouring strips according to claim 1, characterized in that, The waterstop (2) is horizontally positioned between the compensating shrinkage strip (4) and the pre-construction section (1), and is arranged with both sides bent downwards.

7. The compensation structure for shrinkage cracks in ultra-long structures without post-pouring strips according to claim 1, characterized in that, The shrinkage-compensating concrete is made of slag silicate cement.

8. A compensation structure for shrinkage cracks in ultra-long structures without post-pouring strips as described in any one of claims 1-7, characterized in that, The compensation shrinkage strip (4) also includes additional structural steel bars (8), which are single-layer bidirectional steel meshes and are set at the bottom of the compensation shrinkage strip (4), with both ends inserted into the first construction section (1) and the second construction section (6) respectively.

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