Anti-cracking air-floating floor system capable of adapting to large temperature change and design method of anti-cracking air-floating floor system

Abstract

The invention relates to the technical field of computer-aided engineering, and discloses an anti-cracking air floating terrace system capable of adapting to large temperature change and a design method of the anti-cracking air floating terrace system. The plate top sliding layer reduces friction between the steel fiber reinforced concrete plate and the base plate to release temperature stress; the steel fiber reinforced concrete plate is laid above the sliding layer, the steel fiber reinforced concrete plate releases boundary constraint stress with expansion joints between peripheral columns and walls, a plate top induction joint releases local stress, reinforcing steel bars are additionally arranged at the bottom to reinforce and avoid crack warping, and meanwhile temperature reinforcing steel bars are arranged according to non-uniform gradient temperature in the short-time large alternating temperature field environment. Under the combined action of the technical characteristics of the expansion joints, the induction joints, the sliding layers and the like, the temperature stress is released more comprehensively and effectively, the adaptability of the terrace to temperature changes is improved, the cracking risk caused by the temperature stress is reduced, and the stability of a terrace system is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of computer-aided engineering, and in particular to an anti-cracking air-floating floor system that can adapt to large temperature changes and a design method thereof. Background Art

[0002] As a technology that utilizes gas dynamics to distribute and support loads, air flotation plays a crucial role in heavy-duty industrial environments and possesses significant application value. It is widely used in a wide range of fields, including aerospace, precision manufacturing, and scientific experiments, with its significant advantages of high precision and high payloads.

[0003] However, air-floating floors face a key issue in practical use: cracking of the surface. Temperature effects are a primary factor contributing to this cracking. Typically, air-floating floors are used in constant-temperature workshops (such as transformer plants). In these environments, where the temperature is relatively stable, the temperature effects on the air-floating floor and the resulting effects are relatively limited.

[0004] However, with the continuous advancement and development of technology, the demand for air-floating floors has also changed. There is now a demand for large-scale, ultra-long air-floating floors that can withstand significant temperature fluctuations. These external conditions present significant challenges for flooring. Due to the increased temperature fluctuations and the increased floor size, floors are prone to cracking and deformation. Therefore, ensuring sufficient load-bearing capacity while achieving the required precision and effectively controlling the development of cracks has become a critical issue that needs to be addressed. Summary of the Invention

[0005] The purpose of the present invention is to provide an anti-cracking air-floating floor system and design method that can adapt to large temperature changes. Through the joint action of the expansion joints, induced joints and sliding layers, the temperature stress can be released more comprehensively and effectively. In a short-term large alternating temperature field environment, the temperature steel bars are configured according to the uneven gradient temperature, which further improves the floor's adaptability to temperature changes and reduces the risk of cracking due to temperature stress.

[0006] In one aspect, the present invention provides an anti-cracking air-floating floor system that can adapt to large temperature changes, comprising: A structural base layer, which is provided below the finished surface elevation of 200 mm and serves as a bearing layer, and a sliding layer is provided on top of the structural base plate; A steel fiber concrete slab is laid on the sliding layer, and expansion joints are provided between the steel fiber concrete slab and the columns and walls of the surrounding main structure for releasing constraints at the boundaries; Wherein, the top of the steel fiber concrete slab is provided with induced joints at the same intervals, and additional steel bars are arranged at the bottom of the induced joints.

[0007] In this solution, the structural base layer is set below the finished surface elevation of 200mm as a vertical load-bearing layer to provide stable support and load transfer for the floor. The sliding layer on the top of the slab can reduce the friction between the steel fiber concrete slab and the base slab and release temperature stress. The steel fiber concrete slab is laid above the sliding layer, and the expansion joints between the slab and the surrounding columns and walls can release boundary constraint stress. The induced joints on the top of the slab can release local stress and are reinforced by additional steel bars at the bottom to avoid cracks and warping. These technical features jointly ensure that the floor system can adapt to large temperature changes and effectively reduce the risk of cracking caused by temperature stress.

[0008] As a further technical solution for the floor system, when the foundation bearing layer is a soil layer (i.e., a soft layer) such as a recent fill or a soft soil layer, whose bearing capacity is less than the heavy load requirement, the structural base layer includes a pile foundation raft and foundation piles, and the foundation piles pass through the foundation bearing layer to the lower stable soil layer or rock layer to support the pile foundation raft; When the foundation bearing layer is a soil layer with strong bearing capacity (i.e., a hard layer) such as moderately weathered bedrock, the structural base layer includes a natural foundation raft foundation; When the foundation bearing layer is the soil layer of the above two cases at the same time, the structural base layer includes a pile foundation raft, foundation piles and a natural foundation raft foundation, and a slope transition is set between the pile foundation raft and the bottom of the natural foundation raft foundation, and the slope angle is not greater than 45°.

[0009] In this plan, depending on the geological conditions, the structural base can be made of pile raft (consisting of raft slab and foundation piles) or natural foundation raft slab foundation. When different foundations exist on the same site, a slope transition is set between the different foundations. The slope angle should not be greater than 45°, which ensures the stability of the foundation and provides solid support for the floor system, which can withstand large loads and meet heavy load requirements.

[0010] As a further technical solution for the floor system, the sliding layer is a double-layer PE film, the thickness of each layer of the film is not less than 0.5 mm, and the overlap length between adjacent films is not less than 400 mm.

[0011] In this solution, the setting of a double-layer PE film can significantly reduce the friction coefficient between the steel fiber concrete slab and the structural base slab. When the temperature changes, the floor system will expand and contract due to thermal expansion and contraction. If there is no sliding layer, the friction between the concrete slab and the base slab will hinder this deformation, thereby generating large temperature stress. The low friction characteristics of the PE film enable the concrete slab to slide more smoothly relative to the base slab, effectively weakening the boundary constraint, releasing the overall temperature stress caused by temperature changes, and reducing the risk of floor cracking; at the same time, sufficient film thickness (not less than 0.5mm) and appropriate overlap length (not less than 400mm) ensure that the sliding layer can function evenly over the entire floor area. The thicker film can better withstand and disperse stress, avoid local stress concentration, and sufficient overlap length ensures the tightness and continuity of the connection between the films, so that stress can be evenly transmitted over the entire sliding layer, further improving the stress release effect, thereby enhancing the floor system's adaptability to temperature changes.

[0012] As a further technical solution of the floor system, the width of the expansion joint is B, where B≥1×10 -5 ×L×T and not less than 30mm, where L is the long side dimension of the floor and T is the temperature load.

[0013] In this solution, when the floor system experiences temperature changes, thermal expansion and contraction will occur. The setting of the expansion joint provides space for the expansion and contraction of the floor, allowing the steel fiber concrete slab to expand and contract freely when the temperature changes, thereby releasing the stress caused by temperature changes; if the expansion joint width is insufficient, the floor cannot fully expand and contract when the temperature changes, and excessive self-stress will be generated inside, which may easily cause the floor to crack. Determining the expansion joint width through a calculation method related to the floor size and temperature difference can ensure that the expansion joint can adapt to floors of different sizes and various possible temperature changes.

[0014] As a further technical solution for the floor system, after the steel fiber concrete slab is poured, the expansion joint is filled with a buffer filler, and the top of the expansion joint is sealed with a sealant.

[0015] In this solution, after the steel fiber concrete slab is poured, the expansion joint is buffered, filled and sealed to maintain the expansion space, prevent the influence of debris, avoid stress concentration, and at the same time enhance air tightness, improve structural integrity, ensure that the expansion joint effectively releases stress, and improve the overall performance of the floor.

[0016] As a further technical solution for the floor system, the depth of the induced joint is one third of the thickness of the steel fiber concrete slab, and the width of the induced joint is not less than 5 mm.

[0017] In this solution, reasonable induced joint size design is used to release local stress, avoiding stress concentration in local areas caused by factors such as uneven load and temperature changes during the use of the floor, thereby preventing local warping and cracks. At the same time, additional steel bars are configured at the bottom to locally strengthen the concrete around the induced joints, ensure structural strength, and further improve the floor's crack resistance.

[0018] As a further technical solution for the floor system, the induced joint is primed and caulked with caulking glue, and the caulking glue is filled to the top of the steel fiber concrete slab and has a slightly convex structure. The apex of the slightly convex structure is 0.5 to 1 mm higher than the top of the steel fiber concrete slab.

[0019] In this solution, the caulking adhesive fills the induced joint with a micro-convex structure to ensure the airtightness of the induced joint, effectively preventing impurities such as moisture and dust from entering the joint and preventing these impurities from adversely affecting the induced joint's stress-releasing function. Secondly, with temperature changes and during the use of the floor, the floor will inevitably undergo slight deformation. The micro-convex structure can better adapt to this deformation, allowing the induced joint to maintain a good stress-relieving effect under various working conditions. In addition, this design can further enhance the floor's crack resistance. By ensuring the normal function of the induced joint and effectively releasing local stress, it can reduce the occurrence of cracks caused by local stress concentration and improve the overall quality and service life of the floor.

[0020] As a further technical solution for the floor system, an epoxy resin mortar layer and a wear-resistant cover are laid on the top of the steel fiber concrete slab in sequence.

[0021] In this solution, the epoxy mortar layer continuously covers the induced joints to ensure overall airtightness. It also fills the tiny pores on the concrete slab surface, enhancing the integrity and strength of the floor surface, making it denser and more resistant to external forces. The wear-resistant cover, with its inherent wear resistance, significantly improves the floor's wear resistance, effectively resisting friction and abrasion from external objects. The synergistic effect of the two not only improves the floor's surface quality, making it smoother and flatter, but also greatly enhances its durability and extends its service life, better meeting the needs of various usage scenarios and reducing performance degradation and increased maintenance costs caused by wear and damage during use.

[0022] On the other hand, the present invention provides a method for designing an anti-cracking air-floating floor that can adapt to large temperature changes, using an anti-cracking air-floating floor system that can adapt to large temperature changes according to any one of the above technical solutions. The design steps of the floor system are as follows: S1. Structural base design: Calculate the foundation bearing capacity according to the specifications and select a reasonable foundation form. During the calculation, control the foundation deformation to no more than 2mm / m. This step can ensure that the foundation has sufficient bearing capacity and provide a stable and solid support base for the entire floor system. S2. Steel Fiber Reinforcement Design for Steel Fiber Reinforced Concrete Slabs: A geometric model of the steel fiber reinforced concrete slab and foundation raft slab was established in finite element software, and numerical analysis meshing was performed. The mesh side length was ≤0.2m. A fixed constraint was set on the bottom of the foundation raft slab. A friction contact was established between the foundation raft slab and the steel fiber reinforced concrete slab, with a friction coefficient of 0.05-0.1. A temperature load T was set on the steel fiber reinforced concrete slab. After the calculation was completed, the principal stresses at the top and bottom of the steel fiber reinforced concrete slab under this temperature load were extracted. The area of the bidirectional reinforcement was obtained based on the obtained principal stresses. This step accurately analyzed and considered the stress effects of temperature changes on the steel fiber reinforced concrete slab. By rationally configuring the bidirectional reinforcement, the structural strength of the slab was enhanced, enabling it to effectively resist damage caused by temperature stress, thereby improving the overall stability and crack resistance of the floor. S3. Design of the width and spacing of the induced joints: First, determine the spacing L1 of the induced joints on the upper layer of the steel fiber concrete slab. Then, calculate the width B1 of the induced joints based on the determined spacing L1. B1 ≥ 1×10 -5 ×L1×T and not less than 5mm, providing stress release space for the floor surface when the temperature changes. When the floor expands and contracts due to temperature changes, the induced joint can effectively alleviate the stress concentration phenomenon, avoid the surface cracking problem caused by the inability to release stress, and further ensure the floor's anti-cracking performance and overall stability in a large temperature change environment.

[0023] Furthermore, in step S2, the principal stress includes compressive stress and tensile stress, the compressive stress is borne by the steel fiber concrete slab, and the tensile stress is borne by the bidirectional reinforcement. When the calculated tensile stress is σ1, the area of the bidirectional reinforcement per meter of slab width is A S Should be ,in f y is the design value for the tensile strength of the steel. The effects of uneven temperature gradients must be considered when designing reinforcement for steel fiber reinforced concrete slabs. Based on calculations, the reinforcement should be arranged asymmetrically: when the top temperature is higher than the bottom, more reinforcement should be placed at the bottom; when the top temperature is lower than the bottom, more reinforcement should be placed at the top. This reinforcement arrangement can better resist stress caused by temperature unevenness and enhance the structural strength and stability of steel fiber reinforced concrete slabs in alternating temperature environments.

[0024] Compared with the prior art, the present invention has the following advantages and beneficial effects: The present invention reduces the friction between the steel fiber concrete slab and the structural base slab by arranging a sliding layer on the top of the structural base slab, weakens the boundary constraint, and thus releases the overall temperature stress. At the same time, expansion joints are arranged between the steel fiber concrete slab and the columns and walls of the surrounding main structure, and induced joints are arranged at the top intervals of the steel fiber concrete slab, which can release local stress and avoid local warping and cracks. With the combined effect of these measures, the floor system can adapt to larger temperature changes and effectively reduce the risk of cracking caused by temperature stress. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, constitute a part of this application, and do not constitute a limitation of the embodiments of the present invention. In the drawings: Figure 1 Schematic diagram of the longitudinal cross-section structure of the air-floating floor system of the present invention; Figure 2 Schematic diagram of the transverse cross-section structure of the air-floating floor system of the present invention; Figure 3 for Figure 1 Schematic diagram of the enlarged structure marked A; Figure 4 for Figure 1 An enlarged structural diagram of the part marked B (h in the figure is the thickness of the steel fiber concrete slab); In the picture: 1-soft soil layer, 2-structural base layer, 2a-pile foundation raft, 2b-foundation piles, 3-moderately weathered bedrock, 4-natural foundation raft, 5-sliding layer, 6-steel fiber concrete slab, 7-expansion joint, 7a-buffer filling, 7b-sealant, 8-induced joint, 8a-additional steel bar, 8b-caulking glue, 9-epoxy resin mortar layer, 10-wear-resistant cover, 11-bidirectional steel bar. DETAILED DESCRIPTION

[0026] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with examples and drawings. The exemplary embodiments of the present invention and their descriptions are only used to explain the present invention and are not intended to limit the present invention.

[0027] Example 1: This embodiment 1 provides an anti-cracking air-floating floor system that can adapt to large temperature changes, such as Figures 1-4 As shown, it includes a structural base 2 and a steel fiber concrete slab 6; Among them, see Figure 1As shown, the structural base 2 is set below the finished surface elevation of 200mm and serves as a bearing layer. Different structural forms can be selected according to different geological conditions. For example, when the foundation bearing layer is a soil layer (i.e., soft layer) such as a recent fill or a soft soil layer 1 with a bearing capacity less than the heavy load requirement, the structural base 2 includes a pile foundation raft 2a and foundation piles 2b. The foundation piles 2b are inserted into the foundation bearing layer to support the pile foundation raft 2a. When the foundation bearing layer is a soil layer (i.e., hard layer) with a strong bearing capacity such as a moderately weathered bedrock 3, the structural base 2 is a natural foundation raft foundation 4. When the foundation bearing layer is a mixture of the soil layers of the above two situations, the structural base 2 includes pile foundations. The foundation raft 2a, foundation piles 2b and natural foundation raft foundation 4, the pile foundation raft 2a is laid on the recent fill or soft soil layer 1, the foundation piles 2b pass through the recent fill or soft soil layer 1 to the lower stable soil layer or rock layer, which is used to support the pile foundation raft 2a, and the natural foundation raft foundation 4 is laid on the moderately weathered bedrock 3. The tops of the pile foundation raft 2a and the natural foundation raft foundation 4 are at the same elevation and a slope transition is set between the bottoms of the pile foundation raft 2a and the natural foundation raft foundation 4. The slope angle is not greater than 45°, and appropriate earth excavation and finishing methods are used to ensure that the slope and slope flatness meet the requirement that the deformation difference is less than 2mm / 2m.

[0028] At the same time, a PE film is laid on the top of the structural base plate 2 as a sliding layer 5. The film should be laid in double layers, with each layer not less than 0.5 mm thick. When laying, ensure that the film is flat and wrinkle-free, and the overlap length between the two layers of film is not less than 400 mm. Special adhesives or heat welding methods can be used to ensure a firm connection between the films to prevent the sliding layer from separating during use.

[0029] After the sliding layer 5 is laid, the steel fiber concrete slab 6 is laid on the PE film layer, wherein the steel fiber concrete slab 6 should be constructed after the structural base 2 has finally set and reached strength and the early shrinkage and creep have fully developed, generally at an interval of 1-2 months, to avoid excessive stress in the steel fiber concrete slab 6 caused by the shrinkage and creep of the base, thereby causing cracking; when pouring, the steel fiber concrete is prepared according to the mix ratio required by the design, and cold-drawn steel wire cut-type steel fiber is used, with a dosage of 45kg per cubic meter. At the same time, before pouring, the surface of the base should be cleaned and moistened to ensure good bonding between the base and the concrete, and then concrete pouring is carried out, and a suitable vibration method, such as flat vibrator vibration, is used to make the concrete dense. At the same time, attention should be paid to controlling the pouring thickness to ensure that the design requirement of 200mm thickness is achieved. During the pouring process, attention should be paid to avoiding steel fiber agglomeration, which affects the performance of the concrete.

[0030] Among them, Figure 3As shown, when pouring the steel fiber concrete slab 6, expansion joints 7 are set between the columns and walls of the surrounding main structure and the steel fiber concrete slab 6 to release the constraints at the boundary. The width of the expansion joint 7 is determined according to the overall size of the floor and the temperature conditions. Assuming that the temperature load (or temperature rise / fall difference) is T℃, the long side size of the floor is L (in meters), and the expansion joint width is B, then B ≥ 1×10 -5 ×L×T and not less than 30mm. After the steel fiber concrete slab 6 is poured, the expansion joint 7 is filled with a buffer filler 7a, such as a buffer material such as polyethylene foam plastic, and the top of the expansion joint 7 is sealed with a sealant 7b, such as a sealing paste to ensure air tightness.

[0031] In the meantime, see Figure 2 and Figure 4 As shown, the induced joints 8 are set at the same interval L1 on the top of the steel fiber concrete slab 6. Here, the induced joints 8 generally have a spacing L1 value between 6 and 12m. The depth of the induced joints 8 is 1 / 3 of the thickness of the steel fiber concrete slab 6, and the width of the joints is ≥1×10 -5 ×L1×T and should not be less than 5mm, T is the temperature load (or called the temperature rise / fall difference), and the bottom position of the induced joint 8 is configured with additional steel bars 8a for local reinforcement to release local stress and avoid local warping and cracks. At the same time, the induced joint 8 is primed and caulked by caulking glue 8b. The caulking glue 8b can be made of high-strength polyurethane or other elastomeric materials. The caulking glue 8b is filled to the top of the steel fiber concrete slab 6 and has a slightly convex structure. The apex of the slightly convex structure is 0.5 to 1 mm higher than the top of the steel fiber concrete slab 6.

[0032] In this embodiment, if the steel fiber concrete slab 6 is still in a short-term large alternating temperature field environment, the temperature distribution inside the concrete slab itself is uneven. In addition to taking the above-mentioned stress release measures, bidirectional steel bars 11 should be configured according to the uneven gradient temperature inside the steel fiber concrete slab 6. When the top temperature of the slab is greater than the bottom temperature of the slab, more bidirectional steel bars 11 should be configured at the bottom. When the top temperature of the slab is less than the bottom temperature of the slab, more bidirectional steel bars 11 should be configured at the top. The reinforcement value is obtained by performing temperature stress analysis and calculation in ANSYS or ABAQUS software.

[0033] After the above measures are completed, a 6mm epoxy resin mortar layer 9 and a wear-resistant cover 10 are laid on the top of the steel fiber concrete board 6 in sequence. During construction, the epoxy resin mortar layer 9 must continuously cover the induced joint 8 to ensure air tightness. The wear-resistant cover 10 uses a 320 mesh wear-resistant layer to make the smoothness Ra reach 6.125μm.

[0034] Example 2: This embodiment 2 provides a method for designing a crack-resistant air-floating floor that can adapt to large temperature changes for the floor system in embodiment 1. The design steps are as follows: S1. Structural base design: First, the bearing capacity of the foundation is accurately calculated based on relevant building codes and geological survey reports. Through a comprehensive analysis of factors such as the physical properties of the soil (such as soil type, density, moisture content, etc.) and groundwater level, appropriate calculation formulas are used (for example, based on different foundation bearing capacity theories, such as the Terzaghi theory and the Hansen formula) to determine the maximum load capacity that the foundation can withstand. During the calculation, the foundation deformation is controlled to not exceed 2mm / m. Then, a reasonable foundation form is selected based on the foundation bearing capacity calculated according to the code.

[0035] As for the selection of foundation form, in this embodiment, when the foundation bearing layer is a soil layer such as a recent fill or a soft soil layer 1, and its bearing capacity is less than the heavy load requirement, a pile raft foundation is adopted. The pile raft foundation consists of a pile foundation raft plate 2a and foundation piles 2b. The pile foundation raft plate 2a transfers the upper load evenly to the foundation piles 2b, and at the same time can enhance the integrity and stability of the foundation. The foundation piles 2b pass through the recent fill or soft soil layer 1 to the lower stable soil layer or rock layer to provide sufficient bearing capacity. When the foundation bearing layer is a medium-weathered bedrock 3 with a relatively high bearing capacity, When the soil layer is strong, a natural foundation raft foundation 4 is used. The natural foundation raft foundation 4 directly utilizes the natural bearing capacity of the foundation, and adjusts the force distribution of the foundation by setting the raft, so that the upper load is evenly transferred to the foundation; when the above two different foundations exist at the same site at the same time, it is necessary to ensure that the deformation difference is less than 2mm / 2m to avoid floor cracking due to uneven settlement. In order to achieve this goal, a slope transition is set between the pile foundation raft 2a and the bottom of the natural foundation raft foundation 4, and the slope angle is not greater than 45°.

[0036] S2. Steel fiber concrete slab reinforcement design: After determining the foundation form of the structural base, a geometric model of the steel fiber reinforced concrete slab and structural base 2 is established in finite element software (ANSYS or ABAQUS) and meshed for numerical analysis. The mesh side length is ≤0.2m to ensure accurate simulation of the structural stress and deformation during the calculation process. A fixed constraint is set at the bottom of the structural base 2 to simulate the actual connection between the foundation and the subgrade. That is, the bottom of the foundation is fixed relative to the subgrade during the actual load process. Simultaneously, friction contact is established between the structural base 2 and the steel fiber reinforced concrete slab 6, with a friction coefficient of 0.05 to 0.1. A temperature load T is set on the steel fiber reinforced concrete slab. The setting of the temperature load T needs to accurately reflect the temperature changes in the thickness of the slab according to the process requirements. For example, if the floor may be affected by direct sunlight or indoor temperature adjustment during use, resulting in uneven temperature distribution within the slab, these factors must be taken into account when setting the temperature load. Through reasonable temperature field simulation, the calculation results can more accurately reflect the actual situation.

[0037] After completing the above software settings and calculations, the principal stresses at the top and bottom of the steel fiber concrete slab 6 are extracted. Under the combined effects of temperature changes and structural stress, stresses of different natures will be generated at the top and bottom of the slab. The principal stresses include compressive stress and tensile stress. The compressive stress is borne by the steel fiber concrete slab 6, and the tensile stress is borne by the bidirectional steel bars 11. When the calculated tensile stress is σ1, the area of the bidirectional steel bars 11 per meter of slab width should be ,in f y is the design value of the tensile strength of the reinforcement, for example, if f y Taking a value of 300 MPa and a tensile stress of σ1 of 2 MPa, the area of bidirectional reinforcement 11 per meter of slab width is 0.2 × 2 / 300 = 0.00133 m². This calculation can determine the amount of bidirectional reinforcement 11 required to resist the tensile stress caused by temperature changes, thereby ensuring the structural strength and stability of the steel fiber reinforced concrete slab 6 during temperature fluctuations.

[0038] S3. Design of the width and spacing of the induced seams: First, determine the spacing L1 of the induced joints 8 on the upper layer of the steel fiber concrete slab 6. The value can be between 6 and 12m. The determination of this spacing needs to comprehensively consider factors such as the size of the floor, the use environment, the temperature variation range, and the material properties of the concrete. A smaller spacing can more effectively release local stress, but it will increase construction costs and difficulty; a larger spacing may not be able to release stress in time, resulting in the generation of local cracks.

[0039] The induced seam width is then calculated based on the determined spacing L1 between the induced seams 8. This slit width ensures that the floor surface has sufficient space to release stress during temperature fluctuations, preventing cracks caused by stress concentration. A reasonable slit width also helps maintain the flatness and aesthetics of the floor surface, ensuring that the floor's functionality is not affected.

[0040] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. The anti-cracking air-floating floor system can adapt to large temperature changes, characterized by: include: A structural base layer (2), the structural base layer (2) serving as a bearing layer, and a sliding layer (5) being provided on the top of the structural base layer (2); A steel fiber concrete slab (6), the steel fiber concrete slab (6) being laid above the sliding layer (5), and expansion joints (7) for releasing constraints at the boundaries being provided between the steel fiber concrete slab (6) and the columns and walls of the surrounding main structure; The steel fiber concrete slab (6) is provided with induced joints (8) at the same intervals on the top of the slab, and additional steel bars (8a) are arranged at the bottom of the induced joints (8).

2. The anti-cracking air-floating floor system that can adapt to large temperature changes according to claim 1 is characterized in that: The structural base layer (2) is located above the foundation bearing layer; when the foundation bearing layer is a soft layer with a bearing capacity less than the heavy load requirement, the structural base layer (2) includes a pile foundation raft (2a) and foundation piles (2b), and the foundation piles (2b) pass through the foundation bearing layer to the lower stable soil layer or rock layer, and are used to support the pile foundation raft (2a); When the foundation bearing layer is a hard layer with a bearing capacity greater than or equal to the heavy load requirement, the structural base layer (2) includes a natural foundation raft foundation (4); When the foundation bearing layer has both the soft layer and the hard layer, the structural base layer (2) includes a pile foundation raft (2a), foundation piles (2b) and a natural foundation raft foundation (4); the pile foundation raft (2a) is fixed to the soft soil layer through the foundation piles (2b); the natural foundation raft foundation (4) is located in the hard layer; and a slope transition is provided between the bottoms of the pile foundation raft (2a) and the natural foundation raft foundation (4).

3. The anti-cracking air-floating floor system that can adapt to large temperature changes according to claim 1 is characterized in that: The sliding layer (5) is a double-layer film, each layer of which is not less than 0.5 mm thick, and adjacent films are connected by overlapping; the width B of the expansion joint (7) must satisfy the following formula: B ≥ 1 × 10 -5 ×L×T, where L is the long side of the floor and T is the temperature load.

4. The anti-cracking air-floating floor system that can adapt to large temperature changes according to claim 1 is characterized in that: After the steel fiber concrete slab (6) is poured, the expansion joint (7) is filled with a buffer filler (7a), and the top of the expansion joint (7) is sealed with a sealant (7b); The depth of the induced seam (8) is one-third of the thickness of the steel fiber concrete slab (6), and the width of the induced seam (8) is not less than 5 mm.

5. The anti-cracking air-floating floor system that can adapt to large temperature changes according to claim 4 is characterized in that: The induced joint (8) is primed and caulked with a caulking adhesive (8b), and the caulking adhesive (8b) is filled to the top of the steel fiber concrete slab (6) and presents a micro-convex structure, with the apex of the micro-convex structure being higher than the top of the steel fiber concrete slab (6).

6. The anti-cracking air-floating floor system that can adapt to large temperature changes according to claim 5 is characterized in that: The top of the steel fiber concrete slab (6) is sequentially paved with an epoxy resin mortar layer (9) and a wear-resistant cover (10) from bottom to top.

7. The design method of anti-cracking air-floating floor that can adapt to large temperature changes is characterized by: The anti-cracking air-floating floor system that can adapt to large temperature changes according to any one of claims 1 to 8 is used. The design steps of the anti-cracking air-floating floor system are as follows: S1. Structural base design: Calculate the foundation bearing capacity and select the foundation type. When calculating the foundation bearing capacity, control the foundation deformation to no more than 2mm / m. S2. Steel fiber concrete slab reinforcement design: A geometric model of the steel fiber concrete slab (6) and the structural base (2) is established in finite element software and a numerical analysis mesh is performed. A fixed constraint is set on the bottom of the pile foundation raft (2a) of the structural base (2) or / and the natural foundation raft foundation (4). A friction contact is set between the structural base (2) and the steel fiber concrete slab (6). A temperature load T is set on the steel fiber concrete slab (6). The principal stresses at the top and bottom of the steel fiber concrete slab (6) under the temperature load are extracted. The area of the bidirectional reinforcement (11) is obtained based on the obtained principal stresses. S3. Design of the width and spacing of the induced joints: First, determine the spacing L1 of the induced joints (8) on the upper layer of the steel fiber concrete slab (6), and then calculate the width B1 of the induced joints based on the determined spacing L1 of the induced joints (8), that is, B1 ≥ 1×10 -5 ×L1×T .

8. The method for designing a crack-resistant air-floating floor that can adapt to large temperature changes according to claim 9 is characterized in that: In step S2, the principal stress includes compressive stress and tensile stress, the compressive stress is borne by the steel fiber concrete slab (6), and the tensile stress is borne by the bidirectional reinforcement (11). When the calculated tensile stress is σ1 MPa, the area of the bidirectional reinforcement (11) per meter of slab width is A s The calculation formula is: ,in f y is the design value of tensile strength of bidirectional reinforcement (11).

9. The method for designing a crack-resistant air-floating floor that can adapt to large temperature changes according to claim 8 is further characterized in that: In step S2, the temperature load T set on the steel fiber concrete slab (6) needs to reflect the non-uniform gradient temperature difference of the steel fiber concrete slab (6) along the slab thickness direction.

10. The method for designing a crack-resistant air-floating floor that can adapt to large temperature changes according to claim 9 is further characterized in that: In step S2, bidirectional reinforcement (11) is configured according to the uneven temperature gradient in the steel fiber concrete slab (6). When the temperature at the top of the slab is greater than the temperature at the bottom of the slab, bidirectional reinforcement (11) should be added to the bottom. When the temperature at the top of the slab is less than the temperature at the bottom of the slab, bidirectional reinforcement (11) should be added to the top.

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