Universal drawing test device and universal shearing test device for asphalt bonding layer

Abstract

The utility model is suitable for the field of civil engineering material testing, and provides a general test device for shearing and drawing of an asphalt bonding layer, which comprises an outer top die, an outer bottom die, a nut, a screw rod and a combined device, the combined device comprises an inner top mold, inner top mold adhesive layer asphalt, an inner bottom mold, a preformed asphalt mixture and inner bottom mold adhesive layer asphalt, the inner top mold adhesive layer asphalt and the inner bottom mold adhesive layer asphalt are arranged on the upper surface and the lower surface of the preformed asphalt mixture respectively, and the inner top mold adhesive layer asphalt is bonded to the inner top mold. The inner bottom die adhesive layer asphalt is adhered to the inner bottom die; and holes are formed in four corners of the outer top die, the inner top die, the inner bottom die and the outer bottom die. The universal shear test device for the asphalt bonding layer comprises the combined device, a long screw rod and a fixing nut, the long screw rod is connected with the inner top die and the inner bottom die of the combined device, and the fixing nut is in threaded connection with the long screw rod. The device solves the problem that the drawing shear strength of the adhesive layer material cannot be tested.

Description

Technical Field

[0001] The utility model belongs to the field of civil engineering material testing, and in particular relates to a universal asphalt bonding layer pulling test device and a universal shearing test device. Background Art

[0002] Asphalt bonding layer is of great significance in road engineering. Asphalt bonding layer can effectively connect the upper and lower adjacent asphalt structural layers or asphalt layers with non-asphalt base layers (such as cement concrete pavement or stabilized soil base layers), ensure a strong bond between them, avoid pavement damage caused by interlayer slippage or peeling, and thus improve the stability and durability of the entire pavement structure. It can fill and seal the tiny pores on the surface of the base layer, prevent water from penetrating upward, prevent water from entering the pavement structure, reduce the occurrence of various water damage phenomena such as frost heave, peeling, and mud pumping caused by water, and protect the pavement structure from water erosion. The existence of the bonding layer makes the stress distribution between different layers more uniform, ensures that the load can be effectively transmitted, reduces the local stress concentration phenomenon, and enhances the ability of the pavement to resist fatigue damage. Asphalt bonding layer is one of the key technical links to ensure the coordinated work between the multi-layer structures of the pavement, and its construction quality directly affects the safety, comfort and service life of the entire road project. Therefore, in actual engineering, it is very important to test the strength of the bonding layer structure.

[0003] The adhesive layer is an important functional layer to maintain the long-term effective bonding of the various structural layers of the asphalt pavement. The adhesive layer material is usually hot asphalt or emulsified asphalt. In order to maintain the bonding between the layers, the adhesive layer material should have sufficient shear and pull-out resistance. At present, the industry test standard "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering" (JTG E20-2011) has not yet included the test methods and devices for the shear and pull-out strength of the adhesive layer material. In geotechnical tests, single-sided direct shear, oblique shear test and other devices are often used to test soil samples. If the geotechnical test method is used to test the shear strength of the adhesive layer material, there are problems such as cumbersome parts and difficult test control; if the oblique shear method is used, the shear failure surface is often inconsistent with the adhesive layer interface, and effective data cannot be obtained. There is currently no better test method for the pull-out strength of the adhesive layer material.

[0004] In order to solve the above technical problems, the utility model designs a universal asphalt bonding layer pulling test device and a universal shearing test device. Utility Model Content

[0005] The utility model provides a universal testing device for pulling out an asphalt bonding layer and a universal testing device for shearing, aiming to solve the problem that the pulling and shearing strength of bonding layer materials cannot be tested.

[0006] A universal test device for pulling out an asphalt bonding layer, characterized in that it comprises an outer top mold, an outer bottom mold, a nut, a screw and a combination device, wherein the combination device comprises an inner top mold, an inner top mold bonding layer asphalt, an inner bottom mold, a preformed asphalt mixture and an inner bottom mold bonding layer asphalt, the upper and lower surfaces of the preformed asphalt mixture are respectively provided with an inner top mold bonding layer asphalt and an inner bottom mold bonding layer asphalt, the inner top mold bonding layer asphalt is bonded to the inner top mold, the inner bottom mold bonding layer asphalt is bonded to the inner bottom mold, the outer top mold, the inner top mold, the inner bottom mold and the outer bottom mold are provided with holes at the four corners, the screw connects the outer top mold and the inner top mold through the hole, the screw connects the inner bottom mold and the outer bottom mold through the hole, and the nut is threadedly connected to the screw.

[0007] Based on the above technical solution, the top of the outer top mold is fixedly connected to a pull rod, and a round hole is provided on the pull rod.

[0008] Based on the above technical solution, the pull rod is cylindrical.

[0009] Based on the above technical solution, a threaded tie rod is arranged on the bottom surface of the outer bottom mold, and the threaded tie rod is threadedly connected to the bottom plate of the mechanical testing machine.

[0010] Based on the above technical solution, a steel strand quick-locking device is connected to the circular hole, and the steel strand quick-locking device is connected to a loading rod of a mechanical testing machine.

[0011] Based on the above technical solution, the outer top mold, inner top mold, inner bottom mold and outer bottom mold are made of steel or aluminum alloy.

[0012] A universal asphalt bonding layer shear test device: characterized in that it includes the above-mentioned combined device, a long screw and a fixing nut, the long screw connects the inner top mold and the inner bottom mold of the combined device, and the fixing nut is threadedly connected to the long screw.

[0013] Based on the above technical solution, the inner top mold and the inner bottom mold are provided with notches of the same size as the preformed asphalt mixture.

[0014] Based on the above technical solution, the length of the long screw is greater than the width of the preformed asphalt mixture.

[0015] Based on the above technical solution, the preformed asphalt mixture is a cube.

[0016] Beneficial Effects

[0017] Compared with the prior art, the utility model has the following beneficial effects: the shear and pull strength tests of the adhesive layer material can be completed by loading with a common mechanical testing machine. Since the loading method is consistent with the working state of the asphalt pavement adhesive layer, and the test failure surface is always the weak adhesive layer material interface, the test results are accurate and intuitive, and have reliability and effectiveness guarantees.

[0018] This device can perform both shear and pull-out tests simultaneously, and can fully reflect the mechanical behavior of the interlayer joint of the asphalt pavement when subjected to stress. It can measure both the shear strength between layers and the tensile or peel strength, which helps to fully understand and evaluate the comprehensive mechanical properties of the bonding layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only one embodiment of the utility model. For ordinary technicians in this field, other implementation drawings can be derived from the provided drawings without creative work.

[0020] Figure 1 : A schematic diagram of the structure of the universal drawing test device of the utility model;

[0021] Figure 2 : A front view of the universal drawing test device of the utility model;

[0022] Figure 3 : A schematic diagram of the structure of the shear universal test device of the utility model;

[0023] Figure 4 : A schematic diagram of the structure of the combined device of the utility model;

[0024] Figure 5 : A schematic diagram of the structure of the outer top mold of the utility model;

[0025] Figure 6 : A schematic diagram of the structure of the outer bottom mold of the utility model;

[0026] In the accompanying drawings, there are an outer top mold 1, an inner top mold 2, an inner top mold adhesive layer of asphalt 21, an inner bottom mold 3, an inner bottom mold adhesive layer of asphalt 31, a hole 32, an outer bottom mold 4, a long screw 5, a fixing nut 51, a nut 6, a screw 7, a threaded pull rod 8, a pull rod 9, a round hole 91, a combined device 10, and a preformed asphalt mixture 101. DETAILED DESCRIPTION

[0027] The utility model is further described below with reference to the accompanying drawings and examples:

[0028] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0029] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0030] In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0031] See also Figure 1 and Figure 4 The utility model provides a technical solution: a universal test device for pulling out an asphalt bonding layer, characterized in that it comprises an outer top mold 1, an outer bottom mold 4, a nut 6, a screw 7 and a combination device 10, wherein the combination device 10 comprises an inner top mold 2, an inner top mold adhesive layer asphalt 21, an inner bottom mold 3, a preformed asphalt mixture 101 and an inner bottom mold adhesive layer asphalt 31, the upper and lower surfaces of the preformed asphalt mixture 101 are respectively provided with an inner top mold adhesive layer asphalt 21 and an inner bottom mold adhesive layer asphalt 31, the inner top mold adhesive layer asphalt 21 is bonded to the inner top mold 2, the inner bottom mold adhesive layer asphalt 31 is bonded to the inner bottom mold 3, holes 32 are provided at the four corners of the outer top mold 1, the inner top mold 2, the inner bottom mold 3 and the outer bottom mold 4, the screw 7 connects the outer top mold 1 with the inner top mold 2 through the hole 32, the screw 7 connects the inner bottom mold 3 with the outer bottom mold 4 through the hole 32, and the nut 6 is threadedly connected with the screw 7.

[0032] like Figure 2 and Figure 5 As shown, the top of the outer top mold 1 is fixed with a tie rod 9, and a circular hole 91 is provided on the tie rod 9. The tie rod 9 is cylindrical, and the cylindrical structure has good mechanical properties, especially when subjected to axial tension or compression, its stress distribution is uniform, and it can provide higher strength and rigidity, and is particularly suitable for the situation of bearing forces in a linear direction without being affected by bending moments. Under the same cross-sectional area, the cylindrical structure provides a larger axial bearing capacity and a relatively high material utilization rate. The cylindrical tie rod is easy to cooperate with other circular or annular accessories (such as bearings, sleeves, etc.) to achieve precise positioning and guiding.

[0033] like Figure 6As shown, a threaded tie rod 8 is provided on the bottom surface of the outer bottom mold 4, and the threaded tie rod 8 is threadedly connected to the bottom plate of the mechanical testing machine.

[0034] The circular hole 91 is connected to a steel strand quick locking device, and the steel strand quick locking device is connected to a loading rod of a mechanical testing machine.

[0035] The outer top mold 1, the inner top mold 2, the inner bottom mold 3, and the outer bottom mold 4 are made of steel or aluminum alloy. The asphalt is tightly bonded with the steel or aluminum alloy to provide stable structural mechanical properties, effectively disperse the load, and prevent interlayer peeling or movement.

[0036] like Figure 3 As shown, a universal asphalt bonding layer shear test device includes the above-mentioned combined device 10, a long screw rod 5 and a fixing nut 51, wherein the long screw rod 5 connects the inner top mold 2 and the inner bottom mold 3 of the combined device 10, and the fixing nut 51 and the long screw rod 5 are threadedly connected.

[0037] The length of the long screw 5 is greater than the width of the preformed asphalt mixture 101 .

[0038] The preformed asphalt mixture 101 is a cube. The preformed asphalt mixture 101 is obtained by forming a large-size test piece and cutting. The cube test block is an internationally used standard test piece for concrete compressive strength testing, which is convenient for unified performance comparison and standard formulation between different regions and countries. The cube test block is easy to make, the operation procedure is relatively standardized, the test result has good repeatability, and is suitable for the needs of multiple tests.

[0039] The inner top mold 2 and the inner bottom mold 3 are provided with notches of the same size as the preformed asphalt mixture 101 to facilitate smooth positioning during assembly.

[0040] Pull-out test assembly test process and pull-out strength calculation method:

[0041] A preset amount of sticky asphalt is applied to the lower surface of the preformed asphalt mixture 101 to form an inner top mold sticky asphalt 21, which is bonded to the inner bottom mold 3. When the sticky asphalt is a hot asphalt material, the bonding is completed in a hot state; when it is an emulsified asphalt material, the bonding is completed before demulsification. After the hot asphalt on the lower surface is cooled or the emulsified asphalt is demulsified, the next step of assembly is performed.

[0042] A preset amount of sticky asphalt is applied to the upper surface of the preformed asphalt mixture 101 to form an inner bottom mold sticky asphalt 31, which is bonded to the inner top mold 2. When the sticky asphalt is a hot asphalt material, the bonding is completed in a hot state; when it is an emulsified asphalt material, the bonding is completed before demulsification. After the hot asphalt on the upper surface is cooled or the emulsified asphalt is demulsified, the combined device 10 of "inner top mold 2+inner top mold sticky asphalt 21+preformed asphalt mixture 101+inner bottom mold sticky asphalt 31+inner bottom mold 3" is obtained.

[0043] After the outer bottom mold 4 is locked with the bottom plate of the mechanical testing machine, the lower part of the combined device 10, the inner bottom mold 3, is connected to the outer bottom mold 4 by using screws 7 and nuts 6, and then the outer top mold 1 is connected to the upper inner top mold 2 of the combined device 10 by using screws 7 and nuts 6, and the outer top mold 1 is connected to the loading rod of the mechanical testing machine by using a steel strand quick locking device.

[0044] Start the mechanical testing machine, perform a pull-out test at a preset loading rate, and obtain a load-deformation curve.

[0045] Read the peak load Fmax, and its ratio to the area S of the adhesive layer is the tensile strength fT, that is, .

[0046] Shear test assembly test process and shear strength calculation method:

[0047] The combined device 10 is obtained in the same manner as above.

[0048] The inner top mold 2 and the inner bottom mold 3 are connected by a long screw rod 5 and locked by a fixing nut 51. The combined device 10 is rotated 90 degrees and placed in the center on the platform of the mechanical testing machine.

[0049] The mechanical testing machine is started, and a compressive load is applied to the preformed asphalt mixture 101 in the assembly device 10 using a loading rod to obtain a load-deformation curve.

[0050] Read the peak load FMAX, and its ratio to the area 2S of the double adhesive layer is the shear strength fS, that is, .

[0051] This device can perform shear and pull-out tests simultaneously, which can fully reflect the mechanical behavior of the interlayer joint of the asphalt pavement under stress. It can measure the shear strength between layers, as well as the tensile or peel strength, which helps to fully understand and evaluate the comprehensive mechanical properties of the bonding layer. The combination device can be easily and quickly made in the two tests.

[0052] The present invention is described above by way of examples, but the present invention is not limited to the above specific embodiments, and any changes or modifications based on the present invention belong to the scope of protection required by the present invention.

Claims

1. A universal test device for pulling out asphalt bonding layer, characterized by: The invention comprises an outer top mold (1), an outer bottom mold (4), a nut (6), a screw (7) and a combined device (10), wherein the combined device (10) comprises an inner top mold (2), an inner top mold adhesive layer asphalt (21), an inner bottom mold (3), a preformed asphalt mixture (101) and an inner bottom mold adhesive layer asphalt (31), wherein the inner top mold adhesive layer asphalt (21) and the inner bottom mold adhesive layer asphalt (31) are arranged on the upper and lower surfaces of the preformed asphalt mixture (101), respectively, and the inner top mold adhesive layer asphalt (21) and the inner bottom mold adhesive layer asphalt (31) are arranged on the upper and lower surfaces of the preformed asphalt mixture (101). 21) is bonded to the inner top mold (2), the inner bottom mold adhesive layer asphalt (31) is bonded to the inner bottom mold (3), the outer top mold (1), the inner top mold (2), the inner bottom mold (3) and the outer bottom mold (4) are provided with holes (32) at four corners, the screw (7) connects the outer top mold (1) and the inner top mold (2) through the hole (32), the screw (7) connects the inner bottom mold (3) and the outer bottom mold (4) through the hole (32), and the nut (6) is threadedly connected to the screw (7).

2. A universal asphalt bonding layer pulling test device according to claim 1, characterized in that: The top of the outer top mold (1) is fixedly connected to a pull rod (9), and a round hole (91) is provided on the pull rod (9).

3. A universal asphalt bonding layer pulling test device according to claim 2, characterized in that: The pull rod (9) is cylindrical.

4. The universal asphalt bonding layer pulling test device according to claim 1 is characterized by: A threaded pull rod (8) is provided on the bottom surface of the outer bottom mold (4), and the threaded pull rod (8) is threadedly connected to the bottom plate of the mechanical testing machine.

5. The universal asphalt bonding layer pulling test device according to claim 2 is characterized by: The circular hole (91) is connected to a steel strand quick locking device, and the steel strand quick locking device is connected to a loading rod of a mechanical testing machine.

6. The universal asphalt bonding layer pulling test device according to claim 1 is characterized by: The outer top mold (1), the inner top mold (2), the inner bottom mold (3), and the outer bottom mold (4) are made of steel or aluminum alloy.

7. A universal asphalt bonding layer shear test device, characterized in that: It comprises the combination device (10) of claim 1, a long screw rod (5) and a fixing nut (51), wherein the long screw rod (5) connects the inner top mold (2) and the inner bottom mold (3) of the combination device (10), and the fixing nut (51) and the long screw rod (5) are threadedly connected.

8. The universal asphalt bonding layer shear test device according to claim 7, characterized in that: The inner top mold (2) and the inner bottom mold (3) are provided with notches of the same size as the preformed asphalt mixture (101).

9. The universal asphalt bonding layer shear test device according to claim 7, characterized in that: The length of the long screw (5) is greater than the width of the preformed asphalt mixture (101).

10. The universal asphalt bonding layer shear test device according to claim 7, characterized in that: The preformed asphalt mixture (101) is in the shape of a cube.

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