Anti-cracking air floating floor system adaptable to large temperature change and design method thereof

Abstract

The present application relates to the technical field of computer aided engineering, and discloses a crack-proof air floating floor system adaptable to large temperature change and a design method thereof, wherein a load bearing layer is arranged below a surface elevation of 200mm of a structural base layer to transfer load and stably support the floor, a top sliding layer of the plate reduces friction between the steel fiber reinforced concrete plate and the base layer to release temperature stress, the steel fiber reinforced concrete plate is laid above the sliding layer, and boundary constraint stress is released through expansion joints between the plate and surrounding columns and walls, local stress is released through an induced joint at the top of the plate, and the bottom of the plate is additionally provided with steel bars to avoid crack warping, meanwhile, temperature steel bars are arranged according to uneven gradient temperature in a short time and under a large alternating temperature field environment, and these technical features such as expansion joints, induced joints and sliding layers jointly act to more comprehensively and effectively release temperature stress, improve the adaptability of the floor to temperature change, reduce the risk of cracking caused by temperature stress, and ensure the stability of the floor system.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of computer-aided engineering, in particular to a crack-proof air floating floor system adaptable to large temperature changes and a design method thereof. BACKGROUND

[0002] As a technology that utilizes gas power principle to achieve load distribution and support, air floating transportation occupies a crucial position in heavy-load industrial environments and has an application value that cannot be ignored. It is widely used in aerospace, precision manufacturing, scientific experiments and many other fields, and has the advantages of high precision and large load.

[0003] However, the air floating floor system faces a key problem in actual use, that is, the surface layer is prone to cracking. Among them, temperature effect is the main factor leading to cracking. Generally, the use scenarios of air floating floor systems are mostly concentrated in constant temperature workshops (such as transformer workshops, etc.). In such constant temperature environments, the temperature is relatively stable, and the temperature effect on the air floating floor system and the effect caused by it are relatively limited.

[0004] However, with the continuous progress and development of science and technology, the demand for air floating floor systems has also changed. Today, there is a demand for large-scale and long air floating floor systems that can adapt to large temperature changes. Under such external conditions, the floor is facing great challenges. Due to the increase in temperature change range and the increase in floor size, the floor is prone to cracking and deformation. Therefore, how to ensure that the floor has sufficient bearing capacity while achieving the required precision and effectively controlling the development of cracks has become an important problem to be solved. SUMMARY

[0005] The purpose of the present application is to provide a crack-proof air floating floor system adaptable to large temperature changes and a design method. Through the combined action of the expansion joint, the induced joint and the sliding layer, the temperature stress can be more comprehensively and effectively released. In the short-term and large alternating temperature field environment, temperature reinforcement is also configured according to the uneven gradient temperature, further improving the adaptability of the floor to temperature changes and reducing the risk of cracking caused by temperature stress.

[0006] In one aspect, the present application provides a crack-proof air floating floor system adaptable to large temperature changes, comprising:

[0007] A structural base layer is set below 200mm of the finished surface elevation and serves as a bearing layer. A sliding layer is provided on the top of the structural base layer plate.

[0008] A steel fiber reinforced concrete plate is laid above the sliding layer. Expansion joints for releasing the constraints at the boundaries are provided between the steel fiber reinforced concrete plate and the columns and walls of the surrounding main structure.

[0009] The steel fiber reinforced concrete slab is provided with an induced joint at the top of the slab at the same interval, and the induced joint is provided with an additional steel bar at the bottom.

[0010] In the scheme, the structural base layer is provided as a vertical force transmission bearing layer below the finished surface elevation of 200 mm, and provides stable support and load transmission for the floor, and the sliding layer at the top of the slab can reduce the friction between the steel fiber reinforced concrete slab and the base layer slab and release the temperature stress; the steel fiber reinforced concrete slab is laid above the sliding layer, and the boundary restraint stress can be released through the expansion joints between the surrounding columns and walls, and the induced joint at the top of the slab can release local stress and be strengthened through the additional steel bar at the bottom to avoid cracking and warping, and these technical features together ensure that the floor system can adapt to larger temperature changes and effectively reduce the risk of cracking caused by temperature stress.

[0011] As a further technical scheme of the floor system, when the ground bearing stratum is a soft soil layer or other soil layer with a bearing capacity less than the requirement of heavy load (i.e. soft layer), the structural base layer comprises a pile raft and a pile, the pile penetrates the ground bearing stratum to a lower stable soil layer or rock layer, and is used to support the pile raft.

[0012] When the ground bearing stratum is a medium weathered bedrock or other soil layer with a relatively strong bearing capacity (i.e. hard layer), the structural base layer comprises a natural ground raft foundation.

[0013] When the ground bearing stratum is a soil layer of the above two cases, the structural base layer comprises a pile raft, a pile and a natural ground raft foundation, and a sloping transition is provided between the bottom of the pile raft and the natural ground raft foundation, and the slope angle is not greater than 45°.

[0014] In the scheme, according to different geological conditions, the structural base layer can be selected as a pile raft (composed of a raft and a pile) or a natural ground raft foundation, and when different foundations exist in the same site, a sloping transition is provided between different foundations, and the slope angle is not greater than 45°, which ensures the stability of the foundation and provides a solid support for the floor system, can bear a larger load and meet the requirement of heavy load.

[0015] As a further technical scheme of the floor system, the sliding layer is a double-layer pe film, each layer of the film has a thickness of not less than 0.5 mm, and the overlapping length between adjacent films is not less than 400 mm.

[0016] In this scheme, the setting of the double-layer PE film can significantly reduce the friction coefficient between the steel fiber reinforced concrete slab and the structural base slab. When the temperature changes, the floor system will expand and contract. If there is no sliding layer, the friction between the concrete slab and the base slab will hinder the deformation, resulting in a large temperature stress. The low friction characteristic of the PE film allows 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 uniformly function throughout the floor area. The thicker film can better withstand and distribute stress, avoiding local stress concentration. The sufficient overlap length ensures the tightness and continuity of the connection between the films, allowing stress to be evenly transmitted throughout the sliding layer, further improving the stress release effect, thereby enhancing the adaptability of the floor system to temperature changes.

[0017] As a further technical scheme of the floor system, the width of the expansion joint is B, wherein B≥1×10 -5 ×L×T and is not less than 30mm, wherein L is the long side size of the floor, and T is the temperature load.

[0018] In this scheme, when the floor system undergoes temperature changes, it will expand and contract. The setting of the expansion joint provides space for the expansion of the floor, allowing the steel fiber reinforced concrete slab to freely expand and contract when the temperature changes, thereby releasing the stress caused by temperature changes. If the expansion joint is not wide enough, the floor cannot fully expand and contract when the temperature changes, resulting in excessive internal stress, which can easily lead to floor cracking. By determining the width of the expansion joint based on the size of the floor and the temperature difference, the expansion joint can adapt to different sizes of floors and various possible temperature changes.

[0019] As a further technical scheme of the floor system, after the steel fiber reinforced concrete slab is poured, the expansion joint is filled with a buffer, and the top of the expansion joint is sealed with sealant.

[0020] In this scheme, the expansion joint is filled with a buffer and sealed after the steel fiber reinforced concrete slab is poured, which can maintain the expansion space, prevent the influence of debris, avoid stress concentration, and at the same time enhance the air tightness and improve the overall structure of the structure, ensuring that the expansion joint effectively releases stress and improves the overall performance of the floor.

[0021] As a further technical scheme of the floor system, the depth of the induced joint is one-third of the thickness of the steel fiber reinforced concrete slab, and the width of the induced joint is not less than 5mm.

[0022] In the present scheme, by reasonably designing the induced joint size to release local stress, stress concentration in local area caused by uneven load, temperature change and other factors during the use of the floor is avoided, thereby preventing the generation of local warping and cracks, and meanwhile, additional steel bars are arranged at the bottom to locally strengthen the concrete around the induced joint, so as to ensure the structural strength and further improve the crack resistance of the floor.

[0023] As a further technical scheme of the floor system, the induced joint is embedded by caulking, the caulking is filled to the top of the steel fiber reinforced concrete slab and forms a micro-convex structure, and the vertex of the micro-convex structure is 0.5-1 mm higher than the top of the steel fiber reinforced concrete slab.

[0024] In the present scheme, the micro-convex structure filled with caulking in the induced joint can ensure the air tightness of the induced joint, effectively prevent impurities such as water vapor and dust from entering the joint, and avoid the adverse effects of these impurities on the stress releasing function of the induced joint. Secondly, during the use of the floor and the temperature change, the floor will inevitably undergo slight deformation, and the micro-convex structure can better adapt to such deformation, so that the induced joint can maintain good stress releasing effect under various working conditions. In addition, this design can further enhance the crack resistance of the floor, effectively release local stress by ensuring the normal function of the induced joint, thereby reducing the generation of cracks caused by local stress concentration, and improving the overall quality and service life of the floor.

[0025] As a further technical scheme of the floor system, an epoxy resin mortar layer and a wear-resistant cover are sequentially laid on the top of the steel fiber reinforced concrete slab.

[0026] In the present scheme, the continuous covering of the induced joint by the epoxy resin mortar layer can ensure the air tightness of the whole, and the epoxy resin mortar layer can also fill the small pores on the surface of the concrete slab, enhance the integrity and strength of the surface of the floor, make it more dense, and improve the ability to resist external damage. The wear-resistant cover can significantly improve the wear resistance of the floor by virtue of its own wear-resistant properties, effectively resisting the friction and wear of external objects. The two work together to not only improve the surface quality of the floor, making it smoother, but also greatly enhance the durability of the floor, prolonging the service life of the floor, thereby better meeting the needs of various use scenarios, reducing the performance decline and maintenance cost increase caused by wear and damage during the use of the floor.

[0027] On the other hand, the present application provides a design method of a crack-resistant air floating floor system that can adapt to large temperature changes, which adopts any one of the crack-resistant air floating floor systems that can adapt to large temperature changes in the above technical schemes, and the design steps of the floor system are as follows:

[0028] S1. Structural base layer design: calculate the bearing capacity of the foundation according to the specification and select a reasonable foundation form, control the foundation deformation to be less than 2mm / m during calculation, which can ensure that the foundation has sufficient bearing capacity and provides stable and solid support foundation for the entire floor system;

[0029] S2. Steel fiber reinforced concrete slab reinforcement design: establish the geometric model of the steel fiber reinforced concrete slab and the foundation raft in the finite element software and perform numerical analysis mesh division, the mesh edge length size is less than or equal to 0.2m, set fixed constraints on the bottom of the foundation raft, set friction contact between the foundation raft and the steel fiber reinforced concrete slab, the friction coefficient is 0.05-0.1, set temperature load T on the steel fiber reinforced concrete slab, extract the principal stress of the top and bottom of the steel fiber reinforced concrete slab under the temperature load after calculation, obtain the area of the two-way steel bar according to the obtained principal stress, which accurately analyzes and considers the stress influence of temperature change on the steel fiber reinforced concrete slab, and the two-way steel bar is reasonably configured to enhance the structural strength of the slab, so that the slab can effectively resist the damage caused by temperature stress, thereby improving the overall stability and crack resistance of the floor;

[0030] S3. Induced joint width and joint spacing design: first determine the spacing L1 of the upper layer induced joint of the steel fiber reinforced concrete slab, then calculate the joint width B1 of the induced joint according to the determined induced joint spacing L1, B1≥1×10 -5 ×L1×T and is not less than 5mm, which provides a stress release space for the floor surface layer when the temperature changes, and the induced joint can effectively alleviate the stress concentration phenomenon when the floor is affected by temperature changes and produces expansion, thereby avoiding the surface layer cracking problem caused by the inability to release stress, and further ensuring the crack resistance and overall stability of the floor in the environment of large temperature changes.

[0031] Further, in step S2, the principal stress includes compressive stress and tensile stress, the compressive stress is borne by the steel fiber reinforced concrete slab, and the tensile stress is borne by the two-way steel bar, when the calculated tensile stress is σ1, the area of the two-way steel bar per meter of slab width A S should be , wherein f y is the tensile strength design value of the steel bar. The influence of non-uniform gradient temperature needs to be considered during the reinforcement design of the steel fiber reinforced concrete slab, according to the calculation result, the steel bar should be configured in an asymmetric form, more steel bars should be configured at the bottom when the top temperature is greater than the bottom temperature, and more steel bars should be configured at the top when the top temperature is less than the bottom temperature. By this reinforcement mode, the stress caused by non-uniform temperature can be better resisted, and the structural strength and stability of the steel fiber reinforced concrete slab in the alternating temperature field environment can be enhanced.

[0032] Compared with the prior art, the present application has the following advantages and beneficial effects:

[0033] The application reduces the friction between the steel fiber concrete slab and the structural base layer, weakens the boundary constraint, thereby releasing the overall temperature stress, and at the same time, the expansion joints arranged between the steel fiber concrete slab and the columns and walls of the surrounding main structure and the induced joints arranged at intervals on the top of the steel fiber concrete slab can release local stress, avoid local warping and cracking, and under the joint action of these measures, the floor system can adapt to larger temperature changes, and the cracking risk caused by temperature stress is effectively reduced. BRIEF DESCRIPTION OF DRAWINGS

[0034] The accompanying drawings, which are included to provide a further understanding of the embodiments of the application and are incorporated in and constitute a part of this application, illustrate embodiments of the application and together with the description serve to explain the principles of the application. In the drawings:

[0035] Figure 1 It is a schematic diagram of the longitudinal section structure of the air floating floor system of the application;

[0036] Figure 2 It is a schematic diagram of the transverse section structure of the air floating floor system of the application;

[0037] Figure 3 It is Figure 1 It is an enlarged structural schematic diagram of the mark A;

[0038] Figure 4 It is Figure 1 It is an enlarged structural schematic diagram of the mark B (h in the figure is the thickness of the steel fiber concrete slab);

[0039] In the figure:

[0040] 1-soft soil layer, 2-structural base layer, 2a-pile raft, 2b-pile, 3-moderately weathered bedrock, 4-natural foundation raft foundation, 5-sliding layer, 6-steel fiber concrete slab, 7-expansion joint, 7a-cushioning filling, 7b-sealing glue, 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

[0041] In order to make the purpose, technical scheme and advantages of the application more clear and obvious, the application will be further described in detail below in combination with embodiments and drawings, and the illustrative embodiments of the application and the description thereof are only used to explain the application, and do not limit the application.

[0042] Example 1:

[0043] Example 1 provides a crack-resistant air floating floor system that can adapt to large temperature changes, as shown in Figures 1-4 which comprises a structural base layer 2 and a steel fiber concrete slab 6;

[0044] Among them, see Figure 1 As 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.

[0045] 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.

[0046] 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.

[0047] Among them, such as Figure 3As shown, when pouring the steel fiber reinforced concrete slab 6, expansion joints 7 are arranged between the columns and walls of the peripheral main structure and the steel fiber reinforced concrete slab 6 for releasing the constraints at the boundaries. The width of the expansion joints 7 is determined according to the overall size of the floor and the temperature conditions. Assuming that the temperature load (or temperature difference) is T ℃, the length of the floor is L (in meters), and the width of the expansion joint is B, then B≥1×10 -5 ×L×T and is not less than 30 mm. After the pouring of the steel fiber reinforced concrete slab 6 is completed, the expansion joints 7 are filled with a buffer filling 7a, 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.

[0048] At the same time, as shown in Figure 2 and Figure 4 , an induced joint 8 is arranged at the top of the steel fiber reinforced concrete slab 6 with the same interval L1. The interval L1 of the induced joint 8 is generally between 6-12 m. The depth of the induced joint 8 is 1 / 3 of the thickness of the steel fiber reinforced concrete slab 6, and the width of the induced joint 8 is ≥1×10 -5 ×L1×T and is not less than 5 mm. T is the temperature load (or temperature difference). 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 cracking. The induced joint 8 is embedded with a sealant 8b. The sealant 8b can be high-strength polyurethane or other elastomer materials. The sealant 8b is filled to the top of the steel fiber reinforced concrete slab 6 and forms a micro-convex structure with the top of the micro-convex structure being 0.5-1 mm higher than the top of the steel fiber reinforced concrete slab 6.

[0049] In this embodiment, if the steel fiber reinforced concrete slab 6 is still in a short-term large alternating temperature field environment, and the temperature distribution in the concrete slab is not uniform, in addition to the above stress release measures, bidirectional steel bars 11 should be arranged according to the non-uniform gradient temperature in the steel fiber reinforced concrete slab 6. More bidirectional steel bars 11 should be arranged at the bottom when the temperature at the top of the slab is greater than the temperature at the bottom of the slab, and more bidirectional steel bars 11 should be arranged at the top when the temperature at the top of the slab is less than the temperature at the bottom of the slab. The reinforcement value is calculated by temperature stress analysis in ANSYS or ABAQUS software.

[0050] After the above measures are completed, a 6 mm epoxy resin mortar layer 9 and a wear-resistant cover 10 are sequentially laid on the top of the steel fiber reinforced concrete slab 6. The epoxy resin mortar layer 9 is continuously covered over the induced joint 8 during construction to ensure air tightness. The wear-resistant cover 10 is made of a 320-mesh wear-resistant layer, and the smoothness Ra reaches 6.125 μm.

[0051] Example 2:

[0052] The embodiment 2 provides a crack-proof air floating floor design method suitable for large temperature change for the floor system in the embodiment 1, and the design steps are as follows:

[0053] S1. Structure base layer design:

[0054] Firstly, according to relevant building specifications and geological survey reports, the bearing capacity of the foundation is accurately calculated, through comprehensive analysis of factors such as the physical properties of the soil (such as soil type, density, water content, etc.) and underground water level, and by using appropriate calculation formula (for example, according to different foundation bearing capacity theories such as Terzaghi theory, Hansen formula, etc.), the maximum load capacity that the foundation can bear is obtained, and the deformation of the foundation is controlled to be less than 2mm / m during calculation, and then a reasonable foundation form is selected according to the calculated foundation bearing capacity in the specification.

[0055] For the selection of the foundation form, in the embodiment, when the foundation bearing layer is newly filled soil, soft soil layer 1 and the like, and the bearing capacity is less than the heavy load requirement, a pile raft foundation is adopted, the pile raft foundation is composed of a pile raft slab 2a and a foundation pile 2b, the pile raft slab 2a uniformly transmits the upper load to the foundation pile 2b, and can also enhance the integrity and stability of the foundation, the foundation pile 2b penetrates the newly filled soil or the 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 or the like with relatively strong bearing capacity, a natural foundation raft foundation 4 is adopted, the natural foundation raft foundation 4 directly utilizes the natural bearing capacity of the foundation, adjusts the stress distribution of the foundation by setting the raft, and uniformly transmits the upper load to the foundation; when the same site simultaneously exists the two kinds of foundations, it is necessary to ensure that the deformation difference is less than 2mm / 2m, so as to avoid floor cracking caused by uneven settlement, in order to realize the above target, a sloping transition is arranged between the pile raft slab 2a and the bottom of the natural foundation raft foundation 4, and the slope angle is not greater than 45°.

[0056] S2. Steel fiber reinforced concrete slab reinforcement design:

[0057] After determining the basic form of the structural base, a geometric model of the steel fiber reinforced concrete slab and the structural base 2 is established in the finite element software (ANSYS or ABAQUS) and numerical analysis meshing is performed, with the grid edge length size ≤ 0.2 m, to ensure that the stress and deformation of the structure can be accurately simulated during the calculation process. Fixed constraints are set at the bottom of the structural base 2 to simulate the actual connection between the foundation and the ground, i.e. the bottom of the foundation is fixed relative to the ground during actual stress process. At the same time, friction contact is set between the structural base 2 and the steel fiber reinforced concrete slab 6, with a friction coefficient of 0.05-0.1. Temperature load T is set on the steel fiber reinforced concrete slab, which needs to reflect the temperature change in the thickness direction of the slab according to the process requirements, for example, if the terrace may be directly exposed to sunlight, indoor temperature adjustment and other factors during use, resulting in uneven temperature distribution in the slab, then these factors need to be considered when setting the temperature load, and through reasonable temperature field simulation, the calculation results can more accurately reflect the actual situation.

[0058] After completing the above software settings and calculations, the principal stress of the top and bottom of the steel fiber reinforced concrete slab 6 is extracted. Under the combined action of temperature change and structural stress, different stresses will be generated at the top and bottom of the slab, including compressive stress and tensile stress. The compressive stress is borne by the steel fiber reinforced concrete slab 6, and the tensile stress is borne by the bidirectional steel bar 11. When the calculated tensile stress is σ1, the area of the bidirectional steel bar 11 per meter of slab width should be wherein f y is the tensile strength design value of the steel bar, for example, if f y the tensile stress σ1 is 2 MPa, then the area of the bidirectional steel bar 11 per meter of slab width is 0.2 x 2 / 300 = 0.00133 m2. Through such calculation, the number of bidirectional steel bars 11 required to resist the tensile stress caused by temperature change can be determined, thereby ensuring the structural strength and stability of the steel fiber reinforced concrete slab 6 during temperature change.

[0059] S3. Design of the width and spacing of the induced joint:

[0060] First, determine the spacing L1 of the upper layer induced joint 8 on the steel fiber reinforced concrete slab 6, which can be between 6-12 m. The determination of this spacing needs to consider factors such as the size of the terrace, the use environment, the temperature change range, and the material properties of the concrete. Smaller spacing can more effectively release local stress, but will increase the construction cost and difficulty; larger spacing may not be able to release stress in time, leading to the generation of local cracks.

[0061] Then, the slit width of the inducing slit 8 is calculated according to the determined inducing slit interval L1. Such a slit width design can ensure that the floor surface layer has enough space to release stress when the temperature changes, avoiding cracks caused by stress concentration. At the same time, reasonable slit width also helps to maintain the flatness and aesthetics of the floor surface, ensuring that the use function of the floor is not affected.

[0062] The above specific embodiments further illustrate the purpose, technical solutions and beneficial effects of the present application. It should be understood that the above description is only a specific embodiment of the present application and is not intended to limit the protection scope of the present application. Any modification, equivalent replacement, improvement, etc. within the spirit and principles of the present application shall be included in the protection scope of the present application.

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 top of the steel fiber concrete slab (6) is provided with induced joints (8) at the same intervals, and additional steel bars (8a) are arranged at the bottom of the induced joints (8). The depth of the induced joints (8) is one third of the thickness of the steel fiber concrete slab (6); The induced joint (8) is primed and caulked with a caulking adhesive (8b), the caulking adhesive (8b) being filled to the top of the steel fiber concrete slab (6) and forming a micro-convex structure, the apex of the micro-convex structure being higher than the top of the steel fiber concrete slab (6); The top of the steel fiber concrete slab (6) is paved with an epoxy resin mortar layer (9) and a wear-resistant cover (10) in sequence from bottom to top; The width of the induced seam B1, B1 ≥ 1×10 -5 ×L1×T, where L1 is the spacing between adjacent induced gaps (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 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 width of the induction seam (8) is not less than 5 mm.

5. The design method of anti-cracking air-floating floor that can adapt to large temperature changes is characterized by: For producing an anti-cracking air-floating floor system that can adapt to large temperature changes as described in any one of claims 1 to 4, the steps of the anti-cracking air-floating floor design method 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 ; Additional steel bars (8a) are arranged at the bottom of the induced seam (8), and the seam depth of the induced seam (8) is one third of the thickness of the steel fiber concrete slab (6).

6. The method for designing a crack-resistant air-floating floor that can adapt to large temperature changes according to claim 5 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).

7. The method for designing a crack-resistant air-floating floor that can adapt to large temperature changes according to claim 6 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.

8. The method for designing a crack-resistant air-floating floor that can adapt to large temperature changes according to claim 7 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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