A semi-precast kerb

Abstract

This utility model discloses a semi-precast curbstone to solve the technical problems of unstable on-site installation of fully precast curbstones and low construction efficiency of fully cast-in-place curbstones. It includes a cast-in-place base layer, a precast core block layer, and a cast-in-place surface layer connected sequentially from bottom to top. The cast-in-place base layer is a concrete structure cast on-site onto the roadbed. The precast core block layer is located above the cast-in-place base layer and is composed of precast concrete components. The cast-in-place surface layer is cast on-site above the precast core block layer, and its top surface constitutes the functional surface of the curbstone. The cast-in-place base layer, precast core block layer, and cast-in-place surface layer are connected as a whole by a steel reinforcement skeleton. This solves the safety hazard of road shoulders easily loosening and shifting under long-term high-frequency vibration. Compared with the fully cast-in-place process, it significantly reduces the amount of concrete used and the curing time for on-site wet work.

Description

Technical Field

[0001] This utility model relates to the field of road engineering technology, and relates to a semi-prefabricated curbstone, which is particularly suitable for use as a high-stability shoulder for race tracks. Background Technology

[0002] In racetrack construction, curbs (also known as shoulders) are not merely road boundaries, but crucial components of the racing line. When cornering at high speeds, race cars often intentionally run over or even cross curbs to obtain the shortest path. Therefore, the working environment for racetrack curbs is vastly different from that of ordinary municipal roads, presenting them with extremely stringent technical challenges.

[0003] When race cars travel at high speeds (often exceeding 200 km / h) and drive over curbs, they generate enormous instantaneous vertical impact forces and lateral shear forces. Traditional fully precast curbs are typically laid on a base using mortar. Due to the extreme centrifugal force of the track as it curves, the precast blocks are prone to loosening, cracking, or even displacement between themselves and the base due to repeated high-frequency vibrations and powerful impacts. Once a curb loosens and falls off during a race, it becomes a deadly obstacle, seriously threatening the safety of the drivers. To meet the standards of the FIA ​​or FIM, race curbs often have special irregular cross-sections, such as negative angles, serrated edges, and sausage shapes, and the radius and superelevation vary depending on the curve. If a fully precast process is used, special high-precision steel molds need to be made for each curve with different curvatures and cross-sections, resulting in extremely high costs. In addition, precast products with complex edges (such as serrated edges) are extremely prone to chipping and damage during transportation and hoisting, leading to substandard appearance.

[0004] Although cast-in-place curb stones offer good overall integrity, the complex track alignment makes on-site installation of irregularly shaped formwork difficult and time-consuming, and it's challenging to guarantee the smoothness of long-distance curves. Furthermore, the long curing period for cast-in-place concrete impacts the overall track paving progress. Utility Model Content

[0005] The purpose of this utility model is to provide a semi-precast curbstone to solve the technical problems of unstable installation of fully precast curbstones on the construction site and low construction efficiency of fully cast-in-place curbstones.

[0006] This utility model provides a semi-precast curbstone, comprising a cast-in-place base layer, a precast core block layer, and a cast-in-place surface layer connected sequentially from bottom to top; the cast-in-place base layer is a concrete structure cast on-site on the roadbed; the precast core block layer is disposed above the cast-in-place base layer and is composed of precast concrete components; the cast-in-place surface layer is cast on-site above the precast core block layer, and its top surface constitutes the functional surface of the curbstone; the cast-in-place base layer, the precast core block layer, and the cast-in-place surface layer are connected as a whole by a steel reinforcement skeleton.

[0007] As an optimization and / or instantiation of the above-mentioned semi-prefabricated curbstone, further: the steel reinforcement cage includes vertical connecting bars; the lower end of the vertical connecting bars is anchored in the cast-in-place base layer, the middle section passes through or is set in the prefabricated core block layer, and the upper end extends into the cast-in-place surface layer.

[0008] As an optimization and / or instantiation of the aforementioned semi-prefabricated curbstone, the steel reinforcement cage further includes a lower steel reinforcement mesh and an upper steel reinforcement mesh; the lower steel reinforcement mesh is arranged in the cast-in-place base layer and connected to the vertical connecting bars; the upper steel reinforcement mesh is arranged in the cast-in-place surface layer and connected to the vertical connecting bars.

[0009] As an optimization and / or instantiation of the above-mentioned semi-prefabricated curbstone, further: the prefabricated core block layer is formed by splicing several prefabricated concrete blocks along the extension direction of the curbstone; the prefabricated concrete blocks have reserved through holes for the vertical connecting bars to pass through, or the vertical connecting bars are set at the splicing gaps of adjacent prefabricated concrete blocks.

[0010] As an optimization and / or instantiation of the above-mentioned semi-prefabricated curbstone, further: the top surface structure of the cast-in-place surface layer is a non-planar irregular structure, which is formed by on-site formwork or manual troweling.

[0011] As an optimization and / or instantiation of the aforementioned semi-precast curbstone, further: the bottom of the cast-in-place base layer is in direct contact with the graded crushed stone layer or the soil subgrade, and the concrete of the cast-in-place base layer fills the voids on the subgrade surface.

[0012] As an optimization and / or instantiation of the above-mentioned semi-prefabricated curbstone, further: the cross-section of the prefabricated core block layer is rectangular or trapezoidal, and its material strength grade is not lower than the concrete strength grade of the cast-in-place base layer and the cast-in-place surface layer.

[0013] The semi-precast curbstone provided by this utility model differs from traditional fully precast curbstones, which rely solely on mortar for laying. This utility model employs a cast-in-place base layer. The cast-in-place concrete directly fills the tiny gaps on the roadbed surface, forming an excellent interlocking surface, firmly securing the foundation like plant roots. Combined with a three-layer steel reinforcement framework, the curbstone can withstand the enormous lateral shear forces and vertical impact forces generated by racing cars cornering at high speeds, completely solving the safety hazard of track shoulders easily loosening and shifting under long-term high-frequency vibration.

[0014] The precast core layer can use standardized, simple cross-sections (such as rectangles) for easy mass production in factories; while complex track-specific lines (such as sawtooth, sausage, and negative angles) are directly shaped on-site using a "cast-in-place surface layer." This not only avoids the cost of creating expensive, irregularly shaped molds for different curve radii but also perfectly solves the problem of controlling the smoothness of the track lines during construction. Track shoulders often have sharp edges (such as sawtooth shoulders), and if fully precast, they are prone to collisions and chipping during transportation and hoisting. This invention leaves the most fragile and complex surface layer to be cast on-site, thus avoiding transportation losses and ensuring that the final appearance quality of the track meets international competition standards.

[0015] Compared to the fully cast-in-place process, this utility model utilizes precast core blocks to occupy the main volume of the curbstone, greatly reducing the amount of concrete used and the curing time for on-site wet work. Furthermore, the precast core blocks can serve as positioning references during construction, reducing the difficulty of formwork and significantly improving the construction speed of track paving.

[0016] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. Additional aspects and advantages provided by the present invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice. Attached Figure Description

[0017] The accompanying drawings, which form part of this specification, are used to aid in understanding the present invention. The contents provided in the drawings and their related descriptions in this specification can be used to explain the present invention, but do not constitute an undue limitation on the present invention.

[0018] Figure 1 This is a cross-sectional view of the installation of the prefabricated curb stones on the track.

[0019] Figure 2 This is a schematic diagram of the structure of a semi-prefabricated curbstone according to an embodiment of this application.

[0020] The markings in the diagram are: 11-Extension of the track cross slope, 12-Curve stone, 13-Dry-mixed cement mortar, 14-Graded crushed stone, 15-Graded crushed stone, 16-Graded crushed stone roadbed, 21-Cast-in-place base layer, 22-Precast core block layer, 23-Cast-in-place surface layer. Detailed Implementation

[0021] The present invention will now be clearly and completely described in conjunction with the accompanying drawings. Those skilled in the art will be able to implement the present invention based on these descriptions. Before describing the present invention in conjunction with the accompanying drawings, it should be particularly noted that: The technical solutions and features provided in the various sections, including the following description, can be combined with each other without conflict. Furthermore, where possible, these technical solutions, features, and related combinations can be given specific technical subject matter and protected by relevant patents.

[0022] The embodiments of the present invention described below are generally only some embodiments and not all embodiments. Based on these embodiments, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of patent protection.

[0023] The terms "comprising," "including," "having," and any variations thereof in this specification, the corresponding claims, and related sections are intended to cover non-exclusive inclusion. Other related terms and units can be reasonably interpreted based on the relevant content provided in this specification.

[0024] Figure 1 This is a cross-sectional view of the current fully precast curb installation on the track. Curb 12 is a complete precast concrete block, laid on a foundation (composed of a 16cm thick layer of graded crushed stone 15 and a 7cm thick layer of graded crushed stone 14 as a base layer, with a graded crushed stone roadbed 16 as the foundation) using dry-mixed cement mortar 13. The installation position and top surface shape of curb 12 must be controlled with reference to the track's cross slope extension line 11 to ensure the continuity and smoothness of the track's edge alignment. Under the enormous lateral shear forces generated by high-speed cornering, the bonding surface between the precast block and the foundation is prone to loosening, causing curb 12 to shift and posing a safety hazard.

[0025] To solve the above problems, such as Figure 2 As shown, this utility model provides a semi-prefabricated curbstone, which has a three-layer structure connected from bottom to top: a cast-in-place base layer 21, a prefabricated core block layer 22, and a cast-in-place surface layer 23.

[0026] The cast-in-place base layer 21 is a concrete structure cast on-site onto the roadbed. In this embodiment, the bottom of the cast-in-place base layer 21 is in direct contact with the graded crushed stone layer or soil subgrade of the track. Due to the cast-in-place process, the concrete slurry can flow and fill the tiny voids on the roadbed surface, forming a very strong physical interlocking force after solidification, gripping the foundation firmly like a plant taking root, thereby effectively resisting horizontal shear forces.

[0027] The precast core block layer 22 is disposed above the cast-in-place base layer 21 and is composed of several precast concrete components (precast concrete blocks) spliced ​​along the extension direction of the curbstone. The cross-section of the precast core block layer 22 is preferably a regular rectangle or trapezoid. This standardized shape facilitates large-scale, high-precision mass production in the factory and is easy to transport. The material strength grade of the precast core block layer 22 should not be lower than the concrete strength grade of the cast-in-place base layer 21 and the cast-in-place surface layer 23 to ensure the overall compressive strength of the curbstone.

[0028] The cast-in-place surface layer 23 is poured on-site above the precast core block layer 22, and its top surface forms the functional surface of the curbstone. To meet the needs of different curves in the racetrack, the top surface of the cast-in-place surface layer 3 is constructed as a non-planar irregular structure, such as a negative angle, a sawtooth shape, or a sausage shape. These complex irregular structures are formed on-site using formwork or manual finishing, avoiding damage from bumps during the transportation of precast components and saving the cost of creating expensive irregular molds.

[0029] To ensure that the above three-layer structure works as a whole when under stress, the cast-in-place base layer 21, the precast core block layer 22 and the cast-in-place surface layer 23 are connected as a whole by a steel reinforcement skeleton.

[0030] from Figure 2 As can be seen, the steel reinforcement cage mainly includes vertical connecting bars, a lower layer of steel mesh, and an upper layer of steel mesh. The vertical connecting bars extend through the height of the curbstone. Specifically, the lower end of the vertical connecting bar is anchored in the cast-in-place base layer 21, the middle section passes through or is set in the precast core block layer 22, and the upper end extends into the cast-in-place surface layer 23.

[0031] In this embodiment, the precast concrete block has pre-drilled through holes for the vertical connecting bars to pass through. During construction, the vertical connecting bars pass through the through holes, and the gap between the through holes and the reinforcing bars can be filled with grout or cast-in-place concrete slurry to further enhance the overall integrity. In another embodiment, the vertical connecting bars can also be placed at the joints between adjacent precast concrete blocks.

[0032] The lower layer of steel mesh is arranged within the cast-in-place base layer 21 and is tied or welded to the lower end of the vertical connecting bar to enhance the crack resistance of the base.

[0033] The upper steel mesh is arranged within the cast-in-place surface layer 23 and is tied or welded to the upper end of the vertical connecting bars. The upper steel mesh can effectively prevent surface cracking caused by repeated rolling and impact from racing cars.

[0034] The construction process of this semi-prefabricated curbstone is as follows: First, the roadbed is cleaned and leveled. A lower layer of steel mesh is laid on the roadbed, and vertical connecting bars are positioned and installed. Then, the base formwork is erected, and concrete is poured to form the cast-in-place base layer 21. Before the concrete initially sets, or by pre-installing reinforcing bars, the vertical connecting bars are ensured to stand firmly.

[0035] After the cast-in-place base layer 21 reaches a certain strength, the precast core block layer 22, which was manufactured in the factory, is hoisted onto the base. During installation, the vertical connecting bars are arranged to pass through the reserved through holes on the precast core blocks or be located at the block joints. The precast core block layer 22 not only constitutes the main volume of the curbstone, but also serves as the "internal formwork" and positioning benchmark for subsequent surface layer construction.

[0036] Then, a top layer of steel mesh is laid on top of the precast core block layer 22 and connected to the vertical connecting bars. The surface layer formwork is erected according to the specific alignment (such as curve superelevation and curvature) and cross-sectional shape (such as sawtooth shape) of the track design. Concrete is then poured to form the cast-in-place surface layer 23.

[0037] After the cast-in-place surface layer 23 concrete is poured, the surface is manually smoothed or a special tool is used to create the required surface texture (such as anti-slip texture), and then cured.

[0038] The foregoing has described the relevant content of this utility model. Those skilled in the art will be able to implement this utility model based on these descriptions. All other embodiments obtained by those skilled in the art based on the foregoing content of this specification without inventive effort should fall within the scope of this utility model.

Claims

1. A semi-prefabricated curbstone, characterized in that: It includes a cast-in-place base layer, a precast core block layer, and a cast-in-place surface layer connected sequentially from bottom to top; the cast-in-place base layer is a concrete structure cast on the roadbed in situ; the precast core block layer is located above the cast-in-place base layer and is composed of precast concrete components; the cast-in-place surface layer is cast on the site above the precast core block layer, and its top surface constitutes the functional surface of the curb; the cast-in-place base layer, the precast core block layer, and the cast-in-place surface layer are connected as a whole by a steel reinforcement skeleton.

2. The semi-prefabricated curbstone according to claim 1, characterized in that: The steel reinforcement cage includes vertical connecting bars; the lower end of the vertical connecting bars is anchored in the cast-in-place base layer, the middle section passes through or is set in the precast core block layer, and the upper end extends into the cast-in-place surface layer.

3. A semi-prefabricated curbstone according to claim 2, characterized in that: The steel reinforcement cage also includes a lower steel reinforcement mesh and an upper steel reinforcement mesh; the lower steel reinforcement mesh is arranged in the cast-in-place base layer and connected to the vertical connecting bars; the upper steel reinforcement mesh is arranged in the cast-in-place surface layer and connected to the vertical connecting bars.

4. A semi-prefabricated curbstone according to claim 2, characterized in that: The precast core block layer is formed by splicing several precast concrete blocks along the extension direction of the curbstone; the precast concrete blocks have through holes for the vertical connecting bars to pass through, or the vertical connecting bars are set at the splicing gaps of adjacent precast concrete blocks.

5. A semi-prefabricated curbstone according to claim 1, characterized in that: The top surface of the cast-in-place surface layer is a non-planar irregular structure, which is formed by on-site formwork or manual troweling.

6. A semi-prefabricated curbstone according to claim 1, characterized in that: The bottom of the cast-in-place base layer is in direct contact with the graded crushed stone layer or the soil subgrade, and the concrete of the cast-in-place base layer fills the voids on the subgrade surface.

7. A semi-prefabricated curbstone according to claim 1, characterized in that: The cross-section of the precast core block layer is rectangular or trapezoidal, and its material strength grade is not lower than that of the concrete strength grade of the cast-in-place base layer and the cast-in-place surface layer.

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