Bunched basalt fiber reinforced precast concrete pavement

Abstract

The invention relates to a bundle type basalt fiber reinforced precast concrete pavement, which is characterized in that bundle type modified basalt fibers are doped in a lightweight concrete matrix, so that the mechanical property of the pavement surface is obviously improved. The high strength and the high elasticity modulus of the basalt fiber endow the pavement with excellent tensile and bending resistance. The lightweight concrete with the optimized proportion of the cloud concrete stone is adopted, and the characteristics of light weight and high strength of the material are considered. And the basalt fiber grating and the micro truss are embedded in the prefabricated slab body, so that the structural stability and the crack resistance of the pavement are further enhanced. The reverse beating forming process is combined with a polyurethane bottom die and an aluminum alloy side die, and the prefabricating efficiency and the surface quality are improved. And an efficient connecting system ensures reliable connection and integrity of adjacent plate bodies. On the basis that durability and crack resistance of the pavement are guaranteed, the obvious weight reduction effect is achieved, the transportation and construction cost is reduced, and the technology is suitable for occasions such as airfield pavements with high bearing capacity and rapid construction requirements.

Description

Technical Field

[0001] The present invention belongs to the field of road and airport engineering construction, and specifically relates to a modified basalt fiber reinforced assembled lightweight concrete pavement suitable for high-performance, lightweight, prefabricated construction needs. It is particularly suitable for airport runway facility construction projects with extremely high requirements for structural performance and construction efficiency. Background Art

[0002] With the continuous expansion and upgrading of global transportation networks, airports, as national integrated transportation hubs, face higher demands for operational reliability, pavement strength, construction speed, and environmental performance. Traditional airport runways often utilize cast-in-place concrete pavements. While this process offers excellent integrity and structural adaptability, it suffers from long construction cycles, high weather dependence, significant fluctuations in construction quality, and poor environmental performance, severely limiting its adaptability to emergency response, rapid deployment, and complex geological conditions.

[0003] To address these issues, prefabricated concrete pavements, a prefabricated pavement structure that can be standardized in factories and quickly assembled on-site, have gradually become a hot topic in research and engineering practice. This system integrates efficient construction with quality control, offering significant economic and strategic advantages. However, existing prefabricated pavement technologies generally use ordinary concrete or ordinary reinforced concrete as panel materials, resulting in problems such as heavy structural weight, weak force transmission performance, complex joint connections, frequent pavement cracking, and poor overall durability. Especially in airport operating environments, where panels must withstand the impact of high-frequency, high-load aircraft takeoffs and landings, the performance of the material and structural system urgently needs to be upgraded. Summary of the Invention

[0004] In response to the above-mentioned defects of the above-mentioned prior art, the present invention provides a modified basalt fiber reinforced prefabricated lightweight concrete pavement with a lightweight structure, reliable reinforcement and efficient construction, which solves the technical difficulties of the prefabricated concrete pavement panels in the prior art, such as heavy weight, poor crack resistance, weak durability, low construction efficiency and long maintenance period, and realizes the unity of rapid construction and long-term service performance of high-grade airport pavements.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is as follows: A bundled basalt fiber-reinforced precast concrete pavement comprises precast concrete slabs based on lightweight concrete. The lightweight concrete is uniformly doped with bundled modified basalt fibers. The bundled modified basalt fibers are made by bonding multiple basalt fiber filaments with a polymer resin and then wrapping the fiber bundles with an annular connecting coating. The diameter of the bundled modified basalt fibers is 0.4-0.6 mm, and the volume fraction of the bundled modified basalt fibers in the lightweight concrete is 1-2%. The bundled modified basalt fibers have a tensile strength of no less than 4500 MPa and an elastic modulus of no less than 95 GPa. They are resistant to high temperatures, alkalis, and corrosion, and can significantly improve the crack resistance of concrete.

[0006] Furthermore, the raw materials of lightweight concrete also include: cement, fly ash, medium sand, water, cloud concrete stone and admixtures, wherein the volume ratio of water to admixtures is 10:3. Furthermore, the cloud concrete stone includes three different particle sizes: the first cloud concrete stone is 3-5 mm, the second cloud concrete stone is 6-10 mm and the third cloud concrete stone is 11-16 mm, and the volume ratio of the first cloud concrete stone, the second cloud concrete stone and the third cloud concrete stone in the lightweight concrete is 7:8:4. Furthermore, the panel prefabricated structure of the board body is provided with an upper and lower layer of basalt fiber grid, and the basalt fiber grid is formed by warp-knitted coated basalt fiber bundles woven vertically and horizontally. The basalt fiber grid is laid at a distance of 20 mm from the upper protective layer and the lower protective layer of the board cross section; and / or, the micro-truss is 40 mm away from the upper surface and the lower surface of the board body; and / or, the geogrid is 20 mm away from the upper surface and the lower surface of the board body, and the basalt fiber grid is fixed by the aluminum alloy mold limit groove and the pin structure. Furthermore, the upper and lower layers of basalt fiber grids are installed and formed through the gap between the aluminum alloy side formwork and the middle plate. The laying of the basalt fiber grids is carried out simultaneously with the pouring of the concrete slab. The overall structure is realized through two layered pouring. The basalt fiber grids remain in a tensioned state during the embedding process of the concrete. Furthermore, two layers of basalt fiber micro-truss structures are embedded inside the plate body. The micro-trusses are triangular three-dimensional structures. The first layer of micro-trusses is fixed to the bottom of the mold by welding "M"-shaped structural steel bars, and the second layer of micro-trusses is floated about 40mm below the top of the plate. A lightweight concrete filling body is sandwiched between the two layers of micro-trusses. Furthermore, two layers of micro-trusses are spatially positioned at multiple points to form a reinforcement network, and the micro-trusses provide three-dimensional support for the concrete slab. Furthermore, the panel body is prefabricated using a reverse forming process, using a textured polyurethane bottom mold and a quick-release aluminum alloy side mold to achieve one-time texture forming. The polyurethane bottom mold is prefabricated with a roughening depth and groove spacing that meet the requirements.

[0007] Furthermore, the connection of the plate bodies is achieved by embedding parts and connecting parts to realize the connection of adjacent plate bodies; wherein, when the separate silicone connecting parts on the plate body are detached, a concave tongue and groove is formed, and an embedded part is provided in the concave tongue and groove, and the embedded parts of adjacent plate bodies are connected by connecting parts; a polyurethane concave tongue and groove embedded part is provided in the middle part of the aluminum alloy side mold; the bottom of the aluminum alloy side mold is provided with double-sided tape to fit with the PU polyurethane bottom mold to prevent the slurry from flowing out.

[0008] Compared with the prior art, the present invention has the following beneficial effects: The present invention discloses a bundled basalt fiber reinforced precast concrete pavement, which significantly improves the mechanical properties of the pavement surface by doping bundled modified basalt fibers into a lightweight concrete matrix. The high strength and high elastic modulus of basalt fibers give the pavement excellent tensile and bending resistance. Lightweight concrete with an optimized ratio of cloud concrete stone is used, which takes into account the lightweight and high-strength properties of the material. Basalt fiber grids and micro-truss structures are embedded in the precast panels, further enhancing the structural stability and crack resistance of the pavement. The reverse molding process combined with a polyurethane bottom mold and an aluminum alloy side mold improves the prefabrication efficiency and surface quality. The efficient connection system ensures the reliable connection and integrity of adjacent panels. This technology achieves a significant weight reduction effect on the basis of ensuring the durability and crack resistance of the pavement, reduces transportation and construction costs, and is suitable for scenarios with high load-bearing and rapid construction requirements such as airport pavements. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 This is a physical picture of the bundled modified basalt fiber in this application; Figure 2 This is a schematic diagram of the composition structure of the bundled basalt fiber in this application; Figure 3 It is a schematic diagram of the structure of the basalt fiber grid in this application; Figure 4 is a schematic diagram of the basalt fiber micro-truss structure in this application; Figure 5 It is a structural diagram of the medium-quality aluminum alloy mold of this application; Figure 6 This is a schematic structural diagram of the first type of plate in this application; Figure 7 This is a schematic structural diagram of the first embedded part and connector in this application; Figure 8 This is a schematic structural diagram of the second type of plate in this application; Figure 9 This is a schematic structural diagram of the second embedded part and connector in this application; Figure 10 This is a schematic structural diagram of the second type of plate in this application; Figure 11 This is a schematic structural diagram of the second embedded part and connector in this application; Figure 12 This is a schematic diagram of the connection of rectangular plates in this application; Figure 13 This is a schematic diagram of the connection of hexagonal plates in this application; Figure 14 This is a schematic diagram of the plate processing steps in this application; Figure 15 This is a schematic diagram of the board installation in this application.

[0010] Figure 16 This is a schematic diagram of the classification of cloud concrete stone in this application; Figure 17 is a schematic diagram of an example of a project demonstration area in this application. DETAILED DESCRIPTION

[0011] The following is combined with Figure 1-17 The present invention will be further described in detail with specific implementations to facilitate a clear understanding of the present invention, but they do not constitute a limitation to the present invention.

[0012] As attached Figure 1-17 As shown, an embodiment of the present application relates to a bundle-type basalt fiber reinforced precast concrete pavement, which includes a precast concrete slab with lightweight concrete as the matrix material, wherein the lightweight concrete is uniformly doped with bundle-type modified basalt fibers, wherein the bundle-type modified basalt fibers are formed by bonding a plurality of basalt fiber filaments through a polymer resin, wherein the diameter of the bundle-type modified basalt fibers is 0.4-0.6 mm, and the volume proportion of the bundle-type modified basalt fibers in the lightweight concrete is 1-2%.

[0013] In this embodiment, the pavement system is assembled from precast concrete slab units, each measuring 5m x 2.5m x 0.24m (length x width x thickness). The pavement comprises precast concrete slabs based on lightweight concrete. The lightweight concrete uses tarmac lightweight aggregate (density 1100 kg / m³) as the primary aggregate, achieving an optimal packing density through a three-graded optimization (3-5mm:6-10mm:11-16mm = 7:8:4). The lightweight concrete is uniformly doped with bundled modified basalt fibers. These bundles are composed of multiple 7-13μm basalt fiber strands bonded together with epoxy resin. The fiber bundles have a nearly circular cross-section, with a diameter of 0.4-0.6mm (preferably 0.5mm) and a length of 20-30mm. The bundled modified basalt fibers comprise 1-2% (optimally 1.5%) of the lightweight concrete by volume. This fiber reinforcement system increased the flexural tensile strength of concrete from 6.8MPa of the baseline group to 8.2MPa (an increase of 20.6%), while maintaining the working performance of concrete slump at 160±20mm.

[0014] In this embodiment, the tensile strength of the bundled modified basalt fiber is not less than 4500 MPa, the diameter is not less than 0.4-0.6 mm, and the elastic modulus is not less than 95 GPa. Specifically, the tensile strength of the bundled modified basalt fiber is not less than 4500 MPa (measured value 4500-4800 MPa), and the elastic modulus is not less than 95 GPa (measured value 95-110 GPa). The fiber surface is treated with a silane coupling agent, and the bonding strength with the concrete matrix reaches 2.8 MPa, which is 86% higher than that of untreated fiber. The uniform dispersion of the fiber in the concrete is ensured by the following measures: (1) dry mixing process: first mix the fiber with the dry material and stir for 30 seconds; (2) staged feeding: aggregate → fiber → cementitious material → water + admixture; (3) control the total mixing time to 150 ± 10 seconds. CT scanning analysis shows that the standard deviation of the fiber spacing distribution is ≤ 0.8 mm, and there is no significant agglomeration (agglomeration rate < 1%).

[0015] In this embodiment, the panel prefabricated structure of the board body is equipped with two layers of basalt fiber grids. These basalt fiber grids are composed of warp-knitted, coated basalt fiber bundles interwoven vertically and horizontally. The basalt fiber grids are laid 40 mm below the upper protective layer and 50 mm below the neutral axis of the board cross section. The basalt fiber grids are secured by aluminum alloy mold retaining grooves and latch structures. Specifically, the panel prefabricated structure of the board body is equipped with two layers of basalt fiber grids. These basalt fiber grids are composed of warp-knitted, coated basalt fiber bundles (single bundle diameter 0.8 mm) interwoven vertically and horizontally, using a plain weave process, with a 25 mm spacing between both warp and weft fiber bundles. The basalt fiber grids are laid 40 mm below the upper protective layer and 50 mm below the neutral axis of the board cross section, forming a double line of defense against cracking. The basalt fiber grating is secured by a custom aluminum alloy mold with slots and latches. The slots are 5mm deep and 1.2mm wide, and the latches are 10mm in diameter and spaced 500mm apart, ensuring that the grating does not move more than 2mm during the pouring process. The grating has a tensile strength of ≥90kN / m (equivalent to φ8@150 steel mesh), while weighing only one-fifth of that.

[0016] In a further embodiment, the upper and lower layers of basalt fiber grids are installed and formed through the gap between the aluminum alloy side molds and the middle plate. The basalt fiber grid is laid and the concrete slab is poured simultaneously. The overall structure is realized by two-layer pouring. The basalt fiber grid is kept in a tensioned state during the process of embedding into the concrete. Specifically, the upper and lower layers of basalt fiber grids are installed and formed by an innovative split aluminum alloy mold system. The system includes: 6 2500mm long aluminum alloy side molds (each weighing 5kg), 12 2500mm×60mm aluminum alloy middle plates, and special positioning pins. The basalt fiber grid laying and the concrete slab are poured simultaneously using a "sandwich" process: (1) After the lower grid is installed, 70mm thick concrete is poured; (2) After vibrating and compacting, the upper grid is installed; (3) the remaining concrete is poured. The overall structure is realized by two-layer pouring, and the pouring interval is controlled within 30 minutes. During the embedding process of the basalt fiber grid into concrete, a constant tensioning state of 1.5kN / m is maintained by a tensioner to ensure that the straightness deviation of the grid in the concrete is ≤3mm / m.

[0017] In this embodiment, two layers of basalt fiber micro-trusses are embedded within the panel. These micro-trusses are arranged in a triangular configuration. The first layer is welded to the mold base using "M"-shaped steel bars. The second layer floats approximately 40mm below the top of the panel. A lightweight concrete filler is sandwiched between the two layers. Specifically, the panel features two layers of basalt fiber micro-trusses in a triangular configuration (10mm high, 15mm wide). The first layer is welded to the mold base using "M"-shaped steel bars (6mm diameter, 200mm apart), with weld points spaced 300mm apart. The second layer floats 40mm below the top of the panel (with a protective layer 35mm thick), maintaining its position with support provided by the first layer. A lightweight concrete filler is sandwiched between the two layers. During concrete pouring, 50mm-diameter insert vibrators are used, spaced 300mm apart, to avoid disturbing the micro-trusses. The micro-truss unit size is 20mm×20mm, the nodes are reinforced with epoxy resin, and the overall bending strength is ≥28.6MPa.

[0018] In a further embodiment, two layers of micro-trusses are positioned at multiple points in space to form a reinforcement network, and the micro-trusses provide three-dimensional support for the concrete slab. Specifically, the two layers of micro-trusses are positioned at multiple points in space to form a three-dimensional reinforcement network. The bottom micro-truss is fixed to the mold through 16 positioning points (4×4 array), and the top micro-truss is connected to the bottom micro-truss through 8 suspension points. The micro-trusses provide multi-directional support for the concrete slab: (1) vertically improve bending stiffness by 18%; (2) laterally enhance shear resistance by 23%; and (3) diagonally improve impact toughness by 35%. Digital image correlation (DIC) testing shows that the crack propagation rate of the micro-truss reinforced slab is reduced by 42%, and the deformation energy at the final failure is increased by 3.5 times.

[0019] The present application relates to a method for constructing a bundled basalt fiber reinforced precast concrete pavement, which specifically includes the following steps: Mix Design: Lightweight concrete is formulated using dolomite as the primary lightweight aggregate, optimized through grade. Using a volumetric design approach, the concrete meets requirements for a 28-day compressive strength greater than 56 MPa, a flexural tensile strength greater than 6.5 MPa, a permeability rating of at least P12, and freeze-thaw resistance exceeding 300 cycles. In addition to the dolomite, raw materials include cement, fly ash, medium sand, water, admixtures, and basalt fiber. The dolomite is categorized by particle size (3-5 mm, 6-10 mm, and 11-16 mm) and mixed in a volume ratio of 7:8:4 to form a well-defined skeleton structure, enhancing concrete strength and workability. Bundled modified basalt fiber, composed of multiple basalt fiber strands bonded together by a polymer resin, has a diameter of 0.4-0.6 mm and accounts for 1-2% of the volume of lightweight concrete. These fibers possess high strength and elastic modulus, effectively enhancing the tensile and flexural properties of concrete.

[0020] Mixing: Add the weighed amount of shale aggregate, cement, fly ash, medium sand, water, admixtures, and basalt fiber to the mixer. Dry mix is ​​performed first to thoroughly premix the aggregate and powder. Water and admixtures are then added for wet mix to ensure uniform concrete and proper fluidity. This dry mix method bypasses the traditional pre-wetting step for lightweight aggregate, improving prefabrication efficiency.

[0021] Panel Preparation: In the prefabrication workshop, a textured polyurethane base form and aluminum alloy side forms are prepared. The polyurethane base form features a roughened and grooved texture to meet functional requirements such as anti-slip pavement. The aluminum alloy side forms are constructed from multiple aluminum alloy formwork pieces, making them lightweight, easy to assemble, and highly strong. The aluminum alloy side forms are placed on the polyurethane base form and secured with connectors to ensure integrity and a tight seal. Flatness and dimensional accuracy are inspected to prepare for subsequent pouring. Two layers of basalt fiber grids and two layers of basalt fiber micro-truss structures are installed within the mold. The basalt fiber grids are composed of warp-knitted, coated basalt fiber bundles interwoven vertically and horizontally. The basalt fiber grids are placed 20 mm from the upper and lower protective layers of the panel cross-section; and / or the micro-trusses are placed 40 mm from the upper and lower surfaces of the panel; and / or the geogrids are placed 20 mm from the upper and lower surfaces of the panel, secured by retaining grooves and latches in the aluminum alloy mold. The basalt fiber micro-truss structure is a triangular, three-dimensional structure. The first layer of micro-trusses is welded to the bottom of the mold using "M"-shaped structural steel bars. The second layer of micro-trusses floats approximately 40mm below the top of the slab, with a lightweight concrete filler sandwiched between the two layers. The prepared lightweight concrete is evenly poured into the mold and poured in layers. The bottom concrete is poured first and vibrated to compact it. The first layer of basalt fiber grid and micro-trusses is then laid. The concrete is then poured again, and the second layer is laid again. Finally, the top concrete is poured. Vibration is performed to expel air bubbles to ensure the concrete is dense. Using a reverse-blow, one-shot molding technique, the pavement slab is formed in a single step, creating a textured surface. The concrete is then cured at an appropriate temperature and humidity. The side forms are removed after initial set, and the bottom form is removed after final set. After demolding, the concrete is covered and cured to ensure proper strength development.

[0022] Embedded Sleeves: Select sleeves of appropriate specifications and materials to ensure they meet lifting, leveling, and grouting requirements. Place at least three sleeves evenly throughout the slab, located in key areas such as the corners and center. Place the sleeves in the concrete through pre-set holes or embedded devices. Secure them in place to prevent shifting during concrete pouring and ensure a tight bond with the surrounding concrete.

[0023] Preset stoppers: Before installing the panels on site, use measuring instruments to accurately locate them according to the design drawings, providing accurate coordinates for subsequent construction. Based on the positioning results, stoppers are installed on the foundation using precast reinforced concrete blocks or steel structures. Adjust the stoppers based on the panel's installation height and angle requirements to accurately guide and position the panels and ensure installation precision.

[0024] Lightweight concrete is prepared using tarmac as the primary raw material, which is then graded and optimized, followed by the preparation of the lightweight concrete. Specifically, a high-performance lightweight concrete mix ratio is first designed, using tarmac as the primary lightweight aggregate. Graded optimization and volumetric methods are then used to design a concrete mix ratio that meets 28-day compressive strength greater than 56 MPa, flexural strength greater than 6.5 MPa, impermeability grade no less than P12, and freeze-thaw resistance exceeding 300 cycles.

[0025] The panels are prepared using a reverse-blow one-step molding technique. Specifically, the panels are formed in a prefabrication workshop using a polyurethane base mold and aluminum alloy side molds. This molding process completes the texture creation in one go and bypasses the traditional lightweight aggregate pre-wetting step through a dry-mixing method, improving prefabrication efficiency.

[0026] Panel Connections: During panel prefabrication, embedded components are placed at designated locations according to design requirements, serving as the foundation for connections. Connectors connect the embedded components of adjacent panels. Bolts, rebar welding, or specialized connectors can be used to ensure a secure, reliable connection capable of withstanding loads and deformation. The appropriate connection method is selected based on the panel type and stress characteristics. For example, rigid connections are used where high strength and rigidity are required, while flexible connections are used for deformation tolerance and stress buffering.

[0027] Grouting: Divide the grouting area according to design and construction requirements, using templates or partitions to ensure that the compartment sizes meet the grouting process requirements. Select suitable grouting materials, such as cement-based grouting materials or resin-based grouting materials, to ensure good fluidity and strength development. Use grouting equipment to evenly inject the slurry into the gap between the bottom of the slab and the foundation. Maintain pressure after filling to ensure the slurry is densely filled and forms a uniform cushion layer. After the slurry has initially set, cover and maintain moisture retention. Control the curing time, temperature, and humidity to ensure the slurry's strength develops normally, so that the pavement reaches the designed strength and performance.

[0028] In this embodiment, the limiter is a T-shaped steel limiter, and the common point area of ​​4 adjacent panels is set on the limiter in the horizontal and vertical directions to ensure that the actual height of the panel is no more than 2mm away from the preset height. Specifically, each set of limiters is used to accurately locate the boundaries of both sides of a road panel. The top surface of the limiter is consistent with the elevation of the base layer. Its structure includes a base, a column and a limit flange. Through the positioning of the laser instrument and the coordinate system, the boundary error of the road panel can be further controlled within ±0.5mm, avoiding the problem of misalignment, tilting and other problems of the panel during the paving process. The limiter can be used repeatedly to meet the needs of batch paving. In this embodiment, the connection of the plate bodies is achieved by pre-embedded parts and connectors to realize the connection of adjacent plate bodies. In this process, it is necessary to assist in the leveling of the plate bodies, and the height adjustment of the plate bodies is achieved by ball joints and push screws. Specifically, a push screw system is used to adjust the height difference during the leveling process of the plate body paving. The end of the screw is provided with a ball head structure, which acts on the center of the preset concave steel pad below the paving area to achieve point-to-point vertical pushing. The leveling process uses a level meter in conjunction with a laser level meter for elevation control. Each plate body is provided with no less than three leveling points, and the single point can be fine-tuned with an accuracy of 1mm to ensure that the overall pavement flatness meets the requirements of the International Civil Aviation Organization (ICAO) standards and avoid structural stress concentration and early damage due to local unevenness.

[0029] In this embodiment, the raw materials for lightweight concrete also include: cement, fly ash, medium sand, water, and admixtures. The admixture dosage is 0.4%-0.8% by weight of the lightweight concrete. The admixture includes at least one of a water reducer, an expansive agent, and / or a coagulant. The mix ratio of the cloudstone lightweight aggregate concrete is shown in Table 1 below.

[0030] Table 1 Mix proportions of bundled basalt fiber reinforced lightweight concrete

[0031] Although lightweight aggregate has the advantages of being lightweight, high-strength, thermally insulating, durable, and environmentally friendly, its water absorption and buoyancy properties are the biggest limiting factor in its application in construction. Due to the different densities of different batches and types of lightweight aggregate, the water absorption performance is affected by the aggregate preparation process and on-site temperature conditions. The working performance of lightweight aggregate concrete prepared on-site is difficult to control. Under experimental conditions, saturated water absorption treatment is often carried out first, and the concrete mix ratio is prepared after the lightweight aggregate water absorption stabilizes. However, in the actual large-scale prefabrication of lightweight aggregate concrete, in order to fully achieve saturated water absorption of the lightweight aggregate, professional control, special sealed containers, a specific amount of additional water, and a specific water absorption time are required. In other words, a specific lightweight aggregate pre-wetting process is required to meet this condition. However, the refined operation of this process severely limits the large-scale application of lightweight aggregate concrete.

[0032] Therefore, it is necessary to measure the amount of water absorbed by lightweight aggregate at different mixing times, and then add this water amount as additional water to the design of the water amount of lightweight aggregate concrete mix ratio. That is, in the process of preparing lightweight aggregate concrete, the pre-wetting step of lightweight aggregate is omitted, and the dry mix is ​​directly put into the mixing container. The additional water absorption of the aggregate is not included in the water-binder ratio of lightweight aggregate concrete, but is directly put into the mixing container together with the water amount of the concrete water-binder ratio. Combined with the preparation conditions and temperature on site, the appropriate mixing time is selected to complete the prefabrication of lightweight aggregate concrete.

[0033] In this embodiment, the cloud concrete stone comprises three different particle sizes: a first cloud concrete stone of 3-5 mm, a second cloud concrete stone of 6-10 mm, and a third cloud concrete stone of 11-16 mm. The volume ratio of the first cloud concrete stone, the second cloud concrete stone, and the third cloud concrete stone in the lightweight concrete is 7:8:4. The cloud concrete stone lightweight aggregate is prepared using industrial solid waste as raw material, and the mixed gradation is designed based on the load characteristics of the airport pavement. The aggregate used includes cloud concrete stone of different particle sizes and natural river sand, of which fine aggregate accounts for no less than 25%. The component weight is reduced by controlling the dry density to no more than 1950 kg / m³. At the same time, the working performance is adjusted by adding admixtures, thereby achieving a component weight reduction of more than 20% without sacrificing pavement strength and durability. The resulting concrete exhibits multiple properties such as high strength, durability, impermeability, wear resistance, and environmental protection, making it suitable for large-scale factory production of panels and prefabricated construction site applications.

[0034] In this embodiment, the panel body is formed by compartment grouting, which is achieved through a preset compartment system through the compartment grouting process. The compartment system is composed of a 5mm thick steel plate and a fast-hardening high-bonding mortar, which is used to construct an independent grouting unit at the end of the road panel to ensure that the grouting pressure in each area is independently controllable; the grouting material is a three-component high-strength slightly expansive cement-based slurry, which is connected to the multi-functional sleeve channel through the grouting sleeve, and the grouting pressure is controlled to 0.5MPa in a partitioned manner. After the grouting is completed, the curing time is controlled within 68 hours to ensure that the bottom of the structure is dense and free of hollows, thereby improving the overall durability.

[0035] In this embodiment, after the plate body is formed, the edge chamfer is chamfered by an arc-shaped dry grinding method, the chamfer radius is 5mm-10mm, and the chamfer depth is controlled within 2mm. It is formed by horizontally and evenly grinding along the edge of the plate using a handheld angle grinder to avoid damage to the edges and corners during transportation, lifting and use, thereby improving the edge integrity of the road panel. At the same time, this process does not affect the mold structure design and concrete pouring, and can be completed within 1 day after the plate body is demolded, ensuring that the overall construction period is not delayed.

[0036] In this embodiment, the slab is prepared using a one-step reverse molding technique. The mold comprises a polyurethane base mold and an aluminum alloy side mold. The polyurethane base mold is roughened and grooved, and a polyurethane tongue-and-groove embedded part is provided in the middle of the alloy side mold. The bottom of the aluminum alloy side mold is provided with 10mm thick double-sided tape to fit the PU polyurethane base mold and prevent the slurry from flowing out. Specifically, a textured and grooved mold surface is first processed on a steel or polyurethane base mold according to airport pavement specifications. The aluminum alloy side mold is then laid on the mold platform. This side mold is composed of six spliced ​​pieces, has a lightweight structure, and is designed to be operated by one person. Double-sided tape and channel steel supports ensure the mold's stability. During the pouring process, a lightweight aggregate dry mix method without pre-wetting is used. When adding materials, the additional water absorption is included in the total water consumption and added simultaneously to the mixing equipment. The concrete mixing time is adjusted in combination with the mixing method of a self-mixing truck. Finally, through vibration, curing, and mold reversal, the lightweight concrete pavement slab with a smooth surface and satisfactory strength is prepared.

[0037] Among them, compared with the steel base membrane, the polyurethane base mold has the problems of high cost, heavy weight and easy rust. Therefore, the polyurethane material with a cost less than 1 / 5 of the steel mold is used to design the base mold. The advantages of the polyurethane base mold are strong plasticity, low cost, light weight, easy transportation, corrosion resistance, etc. The main disadvantage is obvious thermal expansion and contraction.

[0038] In this embodiment, the panels are connected by embedded parts and connectors. When the detachable silicone connectors on the panels are detached, a recessed groove is formed, in which the embedded parts are located. The embedded parts of the adjacent panels are connected by the connectors. Specifically, specially designed, reusable detachable silicone connectors are used in conjunction with the embedded parts for precise positioning, ensuring the flatness and verticality of the connectors. After the pavement panels are cured and formed, the 1:1 silicone connectors are removed to accurately position the steel connectors. The greatest advantage of the silicone connectors is that the embedded parts are separated from the aluminum alloy side forms. This eliminates the need for issues like re-molding, ensuring the proper curing of the reserved connection holes, and damaging the edges during removal. The detachable silicone connectors can be removed automatically after the concrete pavement panels are cured. This design increases the speed of prefabricated pavement prefabrication, achieving a turnover efficiency nearly three times that of aluminum alloy side forms. The original three-day curing and demolding process for the concrete pavement has been shortened to just one day.

[0039] In this embodiment, the recessed grooves include a recessed groove formed on the surface of the plate, a recessed groove extending through the middle of the plate, and a recessed groove formed on the bottom of the plate. Different embedded parts and connectors are provided for different recessed grooves, specifically including a first type of embedded parts and connectors, a second type of embedded parts and connectors, and a third type of embedded parts and connectors.

[0040] The first type of embedded parts and connecting parts, in which a recessed groove is provided on the surface of the plate body, and a first embedded part is provided in the recessed groove. The first embedded part adopts a threaded sleeve, and the connecting part adopts two sections of metal keys with connecting holes. The two ends of the metal key are respectively connected to the threaded sleeves of the two plates. The adjacent plates are fixed by fixing bolts that pass through the connecting parts and the threaded sleeves in sequence.

[0041] The second type of embedded components and connectors features a tongue-and-groove cutout along the thickness of the panel's side. The connectors are connected to the mid-plate. The embedded components include ribs, end plates, and lugs. The ribs and end plates are embedded in the middle of the panel. The ribs are connected to the end plates on the side facing away from the panel, and the end plates are connected to the lugs on the side facing away from the ribs. The lugs of adjacent panels are connected via the mid-plate. The concealed design of the connectors on the side of the panel not only enhances the overall aesthetics and safety of the pavement but also addresses the high positioning requirements and low installation efficiency of traditional pavements.

[0042] The third type of embedded parts and connecting parts has a recessed groove at the bottom of the plate body, and the embedded parts use connecting sleeves, which are arranged in the recessed groove. Fixed parts are provided at both ends of the connecting parts. By matching the two ends of the connecting parts with the connecting sleeves of the adjacent plates respectively, an effective connection between the plates is achieved, thereby constructing the structural system of the entire pavement.

[0043] In comparison with the actual cases of this application, in a certain project, the project demonstration area covers an area of ​​about 1,500m2. According to the different pavement forms, it is divided into prefabricated ordinary concrete pavement, prefabricated lightweight concrete pavement and cast-in-place concrete pavement, of which the prefabricated concrete pavement is about 650m2. The foundation treatment and water-stabilizing layer paving of the three types of pavement in the project area are basically the same. During the same period, the prefabrication and maintenance of nearly 60 prefabricated concrete pavement panels were completed. The cast-in-place concrete area took 2 days to complete the on-site pouring in advance, and after entering the maintenance period for half a month, the grooving and chamfering of the cast-in-place concrete pavement were completed; the prefabricated concrete pavement area carried out on-site marking, lifting, paving and leveling work, which actually took 1.5 days to complete; high-strength micro-expansion grouting material was used for the prefabricated pavement compartment grouting work. The compressive strength of this material can reach about 35MPa after 3 days of on-site testing. Two grouting machines and two teams worked in different compartments respectively, and it took 2 days to complete the entire grouting task. In terms of time alone, it saved nearly 20 days of construction time.

[0044] This application solves many problems of traditional prefabricated airport pavements in terms of material weight reduction, construction efficiency, connection accuracy and durability through systematic technological innovation. It achieves full process optimization from material preparation, panel prefabrication to on-site installation, significantly improving the quality and efficiency of airport pavement construction, reducing costs and environmental impact, and providing strong support for the widespread application and sustainable development of prefabricated airport pavements. In terms of materials, through the optimization of cloud concrete stone aggregate grading and the additional water compensation process, a lightweight concrete with low density, high strength, excellent durability and wear resistance was successfully prepared, which reduced the weight of the pavement panel while ensuring its load-bearing capacity, reduced transportation and lifting costs, and was fully verified in the demonstration project. In terms of process, the innovative reverse-hitting one-time molding technology combined with a polyurethane bottom mold and an aluminum alloy side mold greatly shortens the mold disassembly and assembly time, improves prefabrication efficiency, and ensures the one-time molding of the pavement texture and surface flatness. The combination of portable aluminum alloy formwork and separate silicone embedded parts further simplifies the mold disassembly and assembly process and improves construction efficiency. In terms of connection and leveling technology, the synergistic effect of T-shaped limiters, a ball joint push system, and split silicone connectors achieves high-precision control of inter-slab gaps and height differences, ensuring smooth aircraft takeoff and landing and the integrity of the pavement. In terms of grouting technology, compartmentalized grouting technology combined with a threaded sleeve sealing design improves grouting density, enhances the stability of the pavement structure, and eliminates the risk of cavitation in the base layer.

[0045] The above is merely a preferred embodiment of the present invention and does not constitute any formal limitation on the structure of the present invention. The layout and number of the present invention are not limited to this example and can be optimized according to actual engineering practices. Any modifications, equivalent changes, and decorations to the above embodiment based on the technical principles of the present invention that do not depart from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A bundled basalt fiber reinforced precast concrete pavement, characterized in that: The pavement includes a precast concrete slab with lightweight concrete as the matrix material. The lightweight concrete is evenly doped with bundled modified basalt fibers. The bundled modified basalt fibers are made by bonding multiple basalt fiber filaments with a polymer resin and then wrapping an annular connecting coating around the outside of the fiber bundle. The diameter of the bundled modified basalt fibers is 0.4-0.6 mm, and the volume proportion of the bundled modified basalt fibers in the lightweight concrete is 1-2%. The diameter tensile strength of the bundle-type modified basalt fiber is not less than 4500MPa, and the elastic modulus is not less than 95GPa.

2. The bundled basalt fiber reinforced precast concrete pavement according to claim 1, characterized in that: The raw materials of the lightweight concrete also include: cement, fly ash, medium sand, water, cloud concrete stone and admixtures, wherein the addition amount of the admixture is 0.4%-0.8% of the weight of the lightweight concrete, and the admixture includes at least one of a water reducer, an expansion agent and / or a coagulant.

3. The bundled basalt fiber reinforced precast concrete pavement according to claim 2, characterized in that: The cloud concrete stone includes three different particle sizes: the first cloud concrete stone is 3-5 mm, the second cloud concrete stone is 6-10 mm, and the third cloud concrete stone is 11-16 mm, and the volume ratio of the first cloud concrete stone, the second cloud concrete stone and the third cloud concrete stone in the lightweight concrete is 7:8:

4.

4. The bundled basalt fiber reinforced precast concrete pavement according to claim 1, characterized in that: The panel prefabricated structure of the plate body is provided with an upper and lower layer of basalt fiber grid, and the basalt fiber grid is formed by warp-knitted coated basalt fiber bundles interwoven vertically and horizontally. The basalt fiber grid is laid at a distance of 20 mm from the upper protective layer and the lower protective layer of the plate cross section; and / or, the micro-truss is 40 mm away from the upper surface and the lower surface of the plate body; and / or, the geogrid is 20 mm away from the upper surface and the lower surface of the plate body, and the basalt fiber grid is fixed by the aluminum alloy mold limit groove and the pin structure.

5. The bundled basalt fiber reinforced precast concrete pavement according to claim 4, characterized in that: The upper and lower layers of basalt fiber grids are installed and formed through the gap between the aluminum alloy side formwork and the middle plate. The laying of the basalt fiber grid is carried out simultaneously with the pouring of the concrete slab. The overall structure is realized through two layered pouring. The basalt fiber grid is kept in a tensioned state during the embedding process of the concrete.

6. The bundled basalt fiber reinforced precast concrete pavement according to claim 1, characterized in that: Two layers of basalt fiber micro-trusses are embedded inside the plate body. The micro-trusses are arranged in a triangular three-dimensional structure. The first layer of micro-trusses is fixed to the bottom of the mold by welding "M"-shaped structural steel bars, and the second layer of micro-trusses is floated about 40mm below the top of the plate. A lightweight concrete filler is sandwiched between the two layers of micro-trusses.

7. The bundled basalt fiber reinforced precast concrete pavement according to claim 6, characterized in that: Two layers of micro-trusses are positioned at multiple points in space to form a reinforcement network, and the micro-trusses provide three-dimensional support for the concrete slab.

8. The bundled basalt fiber reinforced precast concrete pavement according to claim 1, characterized in that: The panel body is prefabricated by a reverse forming process, using a textured polyurethane bottom mold and a quick-release aluminum alloy side mold to achieve one-time texture forming. The polyurethane bottom mold is prefabricated with a roughening depth and groove spacing that meet the requirements.

9. The bundled basalt fiber reinforced precast concrete pavement according to claim 8, characterized in that: The plate bodies are connected to adjacent plate bodies through embedded parts and connecting parts. When the plate bodies are detached through the separate silicone connecting parts, a concave tongue and groove is formed. The embedded parts are provided in the concave tongue and groove, and the embedded parts of adjacent plate bodies are connected through the connecting parts; a polyurethane concave tongue and groove embedded part is provided in the middle part of the aluminum alloy side mold, and a double-sided tape is provided on the bottom of the aluminum alloy side mold to fit with the PU polyurethane bottom mold to prevent the slurry from flowing out.

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