Semi-flexible pavement material test piece manufacturing device and method
By using a novel grouting method and mold design, the problems of non-reusable molds and uneven molding in the production of semi-flexible pavement material specimens were solved, achieving flatness and controllable height of the specimens and improving testing efficiency.
Patent Information
- Application Number
- CN202510871838.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-26
- Publication Date
- 2026-02-03
AI Technical Summary
In the current semi-flexible pavement material specimen preparation process, the operation of wrapping with plastic wrap is cumbersome, resulting in surface wrinkles that affect the molding effect. In addition, the mold cannot be reused, and the grouting height on the top surface is uncontrollable.
A novel grouting method and mold design are adopted, using cylindrical molds, clamps, chassis and pressure mold top covers, combined with vibration or pressure-assisted grouting, to ensure that the surface of the specimen is flat and the top height is controllable after grouting, and the mold can be reused.
It achieves the flat molding and dimensional regularity of semi-flexible pavement material specimens, improves testing efficiency, and the mold can be reused to adapt to matrices and grouting materials with different porosities and fluidities.
Smart Images
Figure CN121453471A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of pavement materials, and particularly relates to a semi-flexible pavement material test piece manufacturing device and method. BACKGROUND
[0002] At present, the existing highway and urban road pavement is basically divided into two categories, namely, asphalt concrete pavement and cement concrete pavement. Among them, the asphalt concrete pavement has the advantages of no joint, good surface flatness, strong flexibility, smooth and comfortable driving, high degree of mechanization, fast progress, good quality, simple maintenance, etc., so the asphalt concrete pavement has been widely popularized and applied in highway construction. However, due to the viscoelastic and plastic properties of asphalt material, the strength and rheological property of the asphalt pavement structure layer are greatly affected by temperature changes. In summer, the reduction of the viscosity of the asphalt material leads to the weakening of the cohesion between the aggregate particles, and if under the action of horizontal force, the asphalt mixture particles are prone to slip and displacement, which leads to the shear deformation damage of the asphalt pavement structure layer such as rutting, displacement, wave, and bumping, and reduces the driving comfort.
[0003] The cement concrete pavement material has the characteristics of strong anti-deformation ability, long service life, and low daily maintenance cost, but this pavement structure has the problems of poor driving comfort and difficult repair of pavement structure diseases.
[0004] Combining the advantages of asphalt concrete pavement and cement concrete pavement, the semi-flexible pavement material emerges as the times require, which is a new type of pavement material with rigidity and flexibility. It refers to the pavement formed by pouring a special slurry mainly composed of cement into the base asphalt mixture (with a void ratio of 20% to 30%) rolled into shape. Compared with asphalt mixture, the semi-flexible pavement improves the anti-rutting ability, and improves the low-temperature crack resistance and durability. On the other hand, compared with cement concrete, the semi-flexible material reduces its modulus, improves its crack resistance, and improves its driving comfort and durability. In addition, the semi-flexible pavement material also has the characteristics of oil resistance, acid resistance, heat resistance, water resistance, slip resistance, and easy coloring.
[0005] In the design, construction, and quality acceptance process of the semi-flexible pavement material, the technical indicators of the material need to be detected, and the semi-flexible pavement material test piece is manufactured in the laboratory. In the existing test piece manufacturing process, the test piece is surrounded by a preservative film, the bottom is sealed to prevent the slurry from flowing out during grouting, and the preservative film is wrapped and fixed by using transparent tape. This mold has the advantage of convenient material selection, but the operation is complicated, and the surface of the preservative film will wrinkle during the wrapping process, which causes the test piece surface to form wrinkle texture after grouting, affects the molding effect after grouting, the grouting height of the top surface is uncontrollable, and the mold cannot be reused. SUMMARY
[0006] In order to overcome the above problems, the present application provides a semi-flexible pavement material test piece manufacturing device and method, which uses a new grouting method to manufacture semi-flexible pavement material, selects asphalt mixture matrix meeting the porosity requirement and grouting material meeting the flowability requirement, selects the grouting mold material, designs the mold form, so that the new mold can be reused, vibration or pressurization is used to assist grouting during the grouting process, the grouting time is shortened, the test piece surface is smooth after grouting, the top grouting height is controllable, and the test piece size is regular after grouting.
[0007] In order to achieve the above purpose, the technical scheme adopted by the present application is as follows: A semi-flexible pavement material test piece manufacturing device, comprising a cylindrical mold, a clamp, a base plate, a pressurized mold top cover and a matrix test piece, the cylindrical mold is sleeved outside the circumference of the matrix test piece, the bottom end of the cylindrical mold is arranged on the base plate, the clamp is sleeved outside the circumference of the cylindrical mold, the cylindrical mold and the matrix test piece are fastened together, and the pressurized mold top cover is arranged on the top of the cylindrical mold.
[0008] Further, the pressurized mold top cover comprises a rubber top cover, a rubber tube and a pressurized air cylinder, the rubber top cover is arranged on the top of the cylindrical mold, the middle part of the rubber top cover is provided with an inflation hole, one end of the rubber tube extends to the inside of the rubber top cover through the inflation hole, and the other end of the rubber tube is in communication with the air hole of the pressurized air cylinder.
[0009] Further, the rubber top cover is made of rubber material and can be stretched, so that the rubber top cover can be tightly combined with the cylindrical mold, the rubber top cover is connected with the sealed cylindrical mold, and a pressurized environment is formed.
[0010] Further, the cylindrical mold is a cylinder with one side open, which is bent from a rectangular steel plate, and the height size scale is arranged on the side wall of the cylindrical mold. Further, when the cylindrical mold is sleeved outside the matrix test piece, the two sides of the opening of the cylindrical mold are overlapped. Further, the clamp is provided with a plurality of clamps, and the clamp and the cylindrical mold are arranged as a detachable device. Further, the base plate is arranged as a cylinder structure with an open top end and a sealed bottom end, and the base plate and the cylindrical mold are arranged as a detachable device. Further, the matrix test piece is a cylinder made of asphalt mixture with a porosity of 20%-30%.
[0011] A semi-flexible pavement material test piece manufacturing method, comprising the following steps: Step one, remove the pressurized mold top cover, sleeve the cylindrical mold outside the matrix test piece, so that the two sides of the opening of the cylindrical mold are overlapped, and then wrap the matrix test piece inside the cylindrical mold; Step two, put the clamp on the outside of the cylindrical mold, tighten the clamp, make the cylindrical mold and the base body specimen fit, and then put the cylindrical mold into the base plate; Step three, grouting, pour the grouting material on the base body specimen in the cylindrical mold, make the grouting material flow into the gap inside the base body specimen, and continue until the grouting material fills the gap of the base body specimen; Step four, open the clamp, take out the base body specimen filled with grouting material, and obtain the semi-flexible pavement material specimen.
[0012] Further, the grouting specifically includes the following cases: (1) For the base body specimen made of asphalt mixture with a void ratio in the range of 25%-30%, self-flowing grouting is adopted: pour the grouting material on the base body specimen in the cylindrical mold, so that the grouting material covers the top of the base body specimen, and the grouting material flows into the gap inside the base body specimen by itself under the action of gravity, and after the grouting material enters the gap inside the base body specimen, repeat pouring the grouting material on the base body specimen in the cylindrical mold for multiple times until the grouting material flows into the gap inside the base body specimen and fills the gap; (2) For the base body specimen made of asphalt mixture with a void ratio in the range of 20%-24%, vibration or pressurization assisted grouting is adopted: Vibration assisted grouting: place the semi-flexible pavement material specimen manufacturing device as a whole on the vibration table and vibrate, and gradually pour the grouting material into the base body specimen during the vibration process, so that the grouting material flows into the gap inside the base body specimen until the grouting material flows into the gap inside the base body specimen and fills the gap; Pressurization assisted grouting: first pour the grouting material on the base body specimen in the cylindrical mold, then cover the pressurization mold top cover on the cylindrical mold, so that the rubber top cover tightly fits on the top of the cylindrical mold, and then pressurize the inside of the cylindrical mold by the pressurization air cylinder through the rubber pipe, and press the grouting material into the gap of the base body specimen by pressure until the grouting material flows into the inside of the base body specimen and fills the gap; Further, in step three, the filling standard is that the overflow height of the grouting material from the base body specimen is flush with the top of the base body specimen, and the error is not more than 1mm, that is, the grouting material no longer penetrates into the base body specimen.
[0013] The present application has the following beneficial effects due to the adoption of the above technical scheme: 1. In the present application, by referring to the specification on the material to make the voids meet the requirements of the asphalt mixture matrix and the flowability of the grouting material, the thin steel plate is used as the basic material of the mold, the opening design of the enclosure structure is adopted in the mold form, so that the new mold can be reused, the surface of the test piece is smooth after grouting, the top grouting height is controllable by using the scale mark in the enclosure structure, and the size of the test piece is regular after grouting.
[0014] 2. In the present application, the mold material is easy to obtain, and the assembly is simple and convenient. When the matrix with different voids and the grouting material with different flowability are matched for use, different auxiliary grouting methods are adopted for grouting, which improves the test efficiency. BRIEF DESCRIPTION OF DRAWINGS
[0015] Figure 1 is the overall structure schematic diagram of the test piece manufacturing device of the present application; Figure 2 is the partial structure schematic diagram of the test piece manufacturing device of the present application; Figure 3 is the structure schematic diagram of the pressurized mold top cover of the present application; Figure 4 is the structure schematic diagram of the cylindrical mold of the present application; Figure 5 is the top view of the base plate of the present application; Figure 6 is the front view of the base plate of the present application.
[0016] In the drawings, 1 is a cylindrical mold, 2 is a clamp, 3 is a base plate, 4 is a pressurized mold top cover, 41 is a rubber top cover, 42 is a rubber tube, 43 is a pressurized air cylinder, 44 is an inflation hole, and 5 is a matrix test piece. DETAILED DESCRIPTION
[0017] In order to make the purpose, technical scheme and advantages of the present application more clear and explicit, the following preferred embodiments are given with reference to the drawings, and the present application is further described in detail. However, it should be noted that many details in the description are only to make the reader have a thorough understanding of one or more aspects of the present application, and the aspects of the present application can be realized without these specific details.
[0018] As Figures 1-2As shown in the figure, a kind of semi-flexible pavement material test piece manufacturing device, including cylinder mould 1, clamp 2, base 3, pressurized mould top cover 4 and base test piece 5, the cylinder mould 1 is set on the circumference outside of base test piece 5, the bottom end of the cylinder mould 1 is arranged on the base 3, the clamp 2 is set on the circumference outside of cylinder mould 1, the cylinder mould 1 is fastened together with base test piece 5, the pressurized mould top cover 4 is arranged at the top of cylinder mould 1.The bottom end of cylinder mould 1 is tightened by base 3, the upper part of the bottom end of cylinder mould 1 is fastened by clamp 2, so that the cylinder mould 1 is fastened together with base test piece 5, without affecting the forming effect after grouting.The mould material of the application is easy to obtain, and the device is easy to assemble and simple to use, and the device can be reused.
[0019] As Figure 3 Shown, the pressurized mould top cover 4 includes rubber top cover 41, rubber tube 42 and pressurized air cylinder 43, the rubber top cover 41 is sealed and arranged at the top of cylinder mould 1, the middle part of the rubber top cover 41 is provided with inflation hole 44, one end of the rubber tube 42 extends to the inside of the rubber top cover 41 through the inflation hole 44, and the other end of the rubber tube 42 is in communication with the air hole of the pressurized air cylinder 43.In the process of using pressurized auxiliary grouting, the cylinder mould 1 is inflated by the pressurized air cylinder 43 through the rubber tube 42, the inside of the cylinder mould 1 is pressurized, the grouting material is pressed into the gap of the base test piece 5 by pressure, until the grouting material flows into the inside of the base test piece 5, and the gap of the base test piece 5 is filled.
[0020] As Figure 4 Shown, the cylinder mould 1 is an open cylinder bent from a rectangular steel plate, and the side wall of the cylinder mould 1 is provided with a height size scale.The cylinder mould 1 is bent from a rectangular steel plate, and when bending, the two ends of the rectangular steel plate are not connected, so that it becomes a cylinder structure with openings at the upper and lower ends and one side, which can also be convenient for different diameters of base test piece 5.When the cylinder mould 1 is set on the outside of the base test piece 5, the two ends of the one side opening of the cylinder mould 1 are overlapped to ensure that the cylinder mould 1 is fastened with the circumference outside of the base test piece 5. The clamp 2 is provided with a plurality of clamps, and the clamp 2 and the cylinder mould 1 are provided as detachable devices, which are convenient for later maintenance and management, and can be disassembled and reused.
[0021] As Figures 5-6 Shown, the base 3 is provided as a cylinder structure with an open upper end and a sealed lower end, and the base 3 and the cylinder mould 1 are provided as detachable devices.The base 3 is provided as a cylinder structure with an open upper end and a sealed lower end, which can fix and seal the bottom end of the cylinder mould 1, and further strengthen the fastening strength of the cylinder mould 1 and the base test piece 5.
[0022] The base test piece 5 is a cylinder made of asphalt mixture with a void ratio of 20%-30%. The base test piece 5 can be made of asphalt mixture with a void ratio in the range of 25%-30%; the base test piece 5 can also be made of asphalt mixture with a void ratio in the range of 20-24%.
[0023] A method for manufacturing a semi-flexible pavement material test piece, comprising the following steps: Step one, remove the top cover of the pressure mold, place the cylindrical mold outside the base test piece, so that the two sides of the opening of the cylindrical mold overlap, and then wrap the base test piece inside the cylindrical mold; Step two, place the clamp outside the cylindrical mold, tighten the clamp, make the cylindrical mold fit the base test piece, and then put the cylindrical mold into the bottom plate; Step three, grouting, which specifically includes the following cases: (1) For the base test piece made of asphalt mixture with a void ratio in the range of 25%-30%, use self-flowing grouting: pour the grouting material onto the base test piece in the cylindrical mold, so that the grouting material covers the top of the base test piece, and the grouting material flows into the internal void of the base test piece by its own gravity, repeat pouring the grouting material onto the base test piece in the cylindrical mold until the grouting material flows into the internal void of the base test piece and fills the void; (2) For the base test piece made of asphalt mixture with a void ratio in the range of 20%-24%, use vibration or pressure-assisted grouting: Use vibration-assisted grouting, place the semi-flexible pavement material test piece manufacturing device on the vibration table for vibration, gradually pour the grouting material into the base test piece during the vibration process, so that the grouting material flows into the internal void of the base test piece until the grouting material flows into the internal void of the base test piece and fills the void; Use pressure-assisted grouting, first pour the grouting material onto the base test piece in the cylindrical mold, then cover the top cover of the pressure mold on the cylindrical mold, so that the rubber top cover tightly fits the top of the cylindrical mold, then use the pressure cylinder to inflate the cylindrical mold through the rubber tube, pressurize the inside of the cylindrical mold, and press the grouting material into the void of the base test piece by pressure until the grouting material flows into the inside of the base test piece and fills the void; The filling standard is that the overflow height of the grouting material from the base test piece is flush with the top of the base test piece, with an error of not more than 1mm, i.e. the grouting material no longer penetrates into the base test piece.
[0024] Step four, open the clamp, take out the base test piece filled with grouting material, and obtain the semi-flexible pavement material test piece.
[0025] Example 1 Large-void asphalt mixture matrix: an asphalt mixture matrix with a void ratio of 20%-30%, and cylindrical matrix specimens made from this asphalt mixture; Grouting material: Cement paste or cement mortar with a fluidity of 10-14s; Enclosure structure (cylindrical mold): A flexible rectangular enclosure structure made from a single 0.5mm steel plate (e.g., Figure 4 ); Chassis: 1 chassis with an inner diameter of D1 and an outer diameter of D2 (e.g., 3 chassis). Figure 5 , Figure 6 ); Clamp 2: Two stainless steel clamps with an inner diameter of D3; Auxiliary grouting pressurization device: Rubber pressurization mold top cover 4 with air cylinder (e.g.) Figure 3 ).
[0026] This method first requires the preparation of a large-void asphalt mixture matrix with a void ratio that meets the requirements, controlled between 20% and 30%. The asphalt mixture specimens are prepared using the compaction method, referring to the "Test Procedures for Asphalt and Asphalt Mixtures" T0702-2011.
[0027] When selecting grouting materials, refer to the technical requirements of grouting material technology in the "Technical Specification for Grouting Semi-Flexible Pavement" to select grouting materials with acceptable flowability and strength.
[0028] The core component is the cylindrical mold 1 used for grouting. The flexible rectangular retaining structure is made of 0.5mm thick steel plate. The rectangular steel plate is bent into an open cylindrical shape using a bending process, and corresponding height markings are engraved on the inside of the cylinder. After the cylindrical mold 1 is fitted onto the large-pore asphalt mixture matrix (see...),... Figure 2Place clamp 2 onto cylindrical mold 1 and tighten clamp 2 so that cylindrical mold 1 is tightly attached to the substrate specimen 5 (see Figure 1). Place the substrate specimen 5, after tightening cylindrical mold 1, into base plate 3. After the operation is completed, pour the calculated amount of grout into cylindrical mold 1 to cover substrate specimen 5. For the top, for the substrate specimen 5 with a porosity of 25%-30%, grouting can be performed by gravity flow. The grout is poured into the cylindrical mold 1 in three stages for layered grouting. The grout flows into the internal voids of the substrate specimen 5 by its own gravity, filling the voids. For the substrate with a porosity of 20%-24%, after pouring the required amount of grout into the cylindrical mold 1, vibration or pressure assisted grouting is required. Vibration assisted grouting involves placing the entire mold on a vibration table and vibrating it until all the grout is poured into the internal voids of the substrate specimen 5. Pressure assisted grouting involves installing the pressure mold top cover 4, which is matched with the cylindrical mold 1, onto the cylindrical mold 1 for pressure application. Since the pressure mold top cover 4 is made of rubber and is telescopic, it can fit tightly with the cylindrical mold 1 to form a pressure environment until all the grout flows into the internal voids of the substrate specimen 5 and fills the voids. After grouting is completed, the grouting material will completely fill the internal voids of the substrate specimen 5. The overflow height of the grouting material should be controlled to be flush with the top of the substrate specimen 5, with an error of no more than 1 mm. This can be controlled by the scale inside the cylindrical mold 1.
[0029] Different asphalt mixtures require different specimen sizes for different tests. Commonly used specimens and their corresponding dimensions are shown in Table 1. Mold dimensions and specifications are shown in Table 2 for different specimen sizes. The selection of grouting methods for matrices with different porosities and grouting materials with different flowability is shown in Table 3.
[0030] Table 1 Commonly Used Specimen Dimensions Table 2 Mold Dimensions and Specifications Table 3 Reference Table for Grouting Methods Example 2 The method for preparing semi-flexible pavement material specimens includes the following: 1. Place the asphalt mixture matrix specimen 5 with a void ratio of 22% flat on the table and completely surround the matrix specimen 5 with the enclosure structure; 2. Place the two clamps 2 onto the enclosure structure (cylindrical mold 1) in sequence, and tighten the clamps 2 with a screwdriver so that the enclosure structure is in close contact with the substrate specimen 5; 3. Place the fixed part on the chassis 3; 4. The base body specimen 5 in the mold is grouted with cement slurry or mortar with a flow degree of 20 s, and the grouting material is poured into the mold according to the calculated pouring amount; 5. The pressurized mold top cover 4 with the pressurizing device is installed on the cylindrical mold 1, the air feeding device is turned on to slowly pressurize, the grouting condition is checked, and the specimen manufacturing is ended after the grouting material is completely poured in.
[0031] 6. The mold is placed in the curing box for normal temperature curing for one day, and then the mold is removed, and the specimen manufacturing is completed.
[0032] The above only describes the preferred embodiments of the present application, and it should be noted that, for those skilled in the art, some improvements and refinements can be made without departing from the principles of the present application, and these improvements and refinements should also be considered as the protection scope of the present application.
Claims
1. A device for fabricating semi-flexible pavement material specimens, characterized in that: The utility model relates to a semi-flexible pavement material test device, including cylinder mould (1), clamp (2), bottom disc (3), pressurized mould top cover (4) and base test piece (5), the cylinder mould (1) is set in the circumference outside base test piece (5), the bottom end of cylinder mould (1) is arranged on bottom disc (3), clamp (2) is set in the circumference outside cylinder mould (1), and cylinder mould (1) is fastened together with base test piece (5), pressurized mould top cover (4) is arranged at the top of cylinder mould (1).
2. The apparatus of claim 1, wherein: The pressurized mould top cover (4) includes rubber top cover (41), rubber pipe (42) and pressurized air cylinder (43), the rubber top cover (41) is arranged at the top of cylinder mould (1), the middle part of rubber top cover (41) is provided with inflation hole (44), one end of rubber pipe (42) extends to the inside of rubber top cover (41) through inflation hole (44), and the other end of rubber pipe (42) is communicated with the air hole of pressurized air cylinder (43).
3. The apparatus of claim 1, wherein: The cylinder mould (1) is the cylinder of one side opening by bending rectangular steel plate, and the height dimension scale is arranged on the side wall of cylinder mould (1).
4. The apparatus of claim 3, wherein: When the cylinder mould (1) is set on the outside of base test piece (5), the both sides of opening of cylinder mould (1) are overlapped.
5. The apparatus of claim 1, wherein: The clamp 2 is provided with a plurality of clamps, and the clamp 2 and the cylinder mould (1) are detachable devices.
6. The apparatus of claim 1, wherein: The bottom disc (3) is provided with the cylinder structure of the open upper end and the sealed lower end, and the bottom disc (3) and the cylinder mould (1) are detachable devices.
7. The apparatus of claim 1, wherein: The base test piece (5) is the cylinder made of the asphalt mixture with the void ratio of 20%-30%.
8. A method of making a semi-flexible pavement material test specimen using the apparatus of any one of claims 1-7, wherein: The utility model includes the following steps: Step one, remove the pressurized mould top cover, set the cylinder mould on the outside of base test piece, make the both sides of opening of cylinder mould overlap, and then wrap the base test piece in the inside of cylinder mould; Step two, set the clamp on the outside of cylinder mould, tighten the clamp, make the cylinder mould and base test piece adhere, and then put the cylinder mould into the bottom disc; Step three, grout, pour the grouting material on the base test piece in the cylinder mould, make the grouting material flow into the void in the inside of base test piece, and until the void of base test piece is filled with the grouting material; Step four, open the clamp, take out the base test piece filled with the grouting material, and obtain the semi-flexible pavement material test piece.
9. The method of claim 8, wherein: The grouting includes the following cases: (1) for the base test piece made of the asphalt mixture with the void ratio in the range of 25%-30%, adopt the self-flowing mode to grout: pour the grouting material on the base test piece in the cylinder mould, make the grouting material cover the top of base test piece, and the grouting material flows into the void in the inside of base test piece by itself gravity, after the grouting material enters the void in the inside of base test piece, repeat pouring the grouting material on the base test piece in the cylinder mould for many times, until the void in the inside of base test piece is filled with the grouting material; (2) for the base test piece made of the asphalt mixture with the void ratio in the range of 20%-24%, adopt the vibration or pressurized mode to assist grouting: The semi-flexible pavement material test piece is made by vibration assisted grouting, the whole device is placed on the vibration table for vibration, and the grouting material is gradually poured into the base test piece during the vibration process, so that the grouting material flows into the gap inside the base test piece until the gap is filled with the grouting material. The grouting material is poured into the base test piece in the cylinder mold, then the pressure mold top cover is covered on the cylinder mold, the rubber top cover is tightly attached to the top of the cylinder mold, the cylinder mold is inflated by the pressure air cylinder through the rubber pipe, the inside of the cylinder mold is pressurized, the grouting material is pressed into the gap of the base test piece by the pressure, and the gap is filled with the grouting material.
10. The method of claim 8, wherein: In step three, the filling standard is that the overflow height of the grouting material from the base test piece is flush with the top of the base test piece, and the error is not more than 1mm, that is, the grouting material no longer penetrates into the base test piece.