Interlaminar shear test device for assembled asphalt pavement
By designing an assembled asphalt pavement interlayer shear test device with adjustment components and shear components, the problem of insufficient applicability of existing devices is solved, flexible adjustment of the plug position and uniformity of shear force are achieved, the experimental accuracy and stability are improved, and the shear stress state of the pavement structure layer is truly simulated.
Patent Information
- Application Number
- CN202422017848.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-20
- Publication Date
- 2025-09-19
- Estimated Expiration
- 2034-08-20
AI Technical Summary
The existing pavement interlayer shear test device has a limited scope of application and cannot adapt to prefabricated asphalt pavement layer specimens of different thicknesses. In addition, during the shear test, fragments interfere with the adjustment of the plug plate, and the uneven shear force leads to low experimental accuracy.
A test device for interlayer shear of prefabricated asphalt pavement was designed. It included a mold placement, an adjustment component, a shearing component, and an ash chute. The position of the plug plate was adjusted by the adjustment component. The shearing component used MTS and a jack for shearing. The guide groove and guide block guided the movement of the load-bearing plate to ensure uniform and stable shear force.
The equipment's test range has been expanded, the interference of debris in the plug plate adjustment has been avoided, the accuracy and stability of the specimen shear test have been improved, the shear stress state of the pavement structure layer has been truly simulated, and the accuracy of the experiment has been improved.
Smart Images
Figure CN223361949U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of road engineering detection, in particular to a shear test device for assembled asphalt pavement layers. Background Art
[0002] The interlayer shear test of pavement structures is an important test for measuring the shear resistance of pavement layers. It requires cutting the pavement structure into appropriately sized specimens, which are then placed in a shear device for experimental operation. However, prefabricated asphalt pavement is a new type of pavement structure. Because the surface layer structure includes an upper layer (generally 4 cm), a middle layer (generally 6 cm), and a lower layer (generally 8 cm), their thicknesses vary. Therefore, in shear tests, the specimens made from different surface layers also have different sizes. Before conducting existing shear tests, plug plates are generally installed around the specimens to prevent specimen movement from affecting the experiment. However, the specimens of different surface layers have different sizes, so plug plates of different thicknesses are required to accommodate the different specimens. However, these plug plates are limited to a few different specifications and cannot accommodate most specimens. In view of this, we propose a device for interlayer shear testing of prefabricated asphalt pavements. Utility Model Content
[0003] The purpose of the utility model is to solve the shortcoming of the existing pavement interlayer shear test device having a limited application range, and to propose a shear test device for assembled asphalt pavement interlayer.
[0004] In order to achieve the above purpose, the present invention adopts the following technical solutions:
[0005] A device for interlayer shear testing of assembled asphalt pavement, comprising a placement mold and a specimen placed in the middle of the placement mold, plug plates being provided on both sides of the specimen to limit the specimen's position, a shearing assembly being provided on the placement mold to shear the specimen, an ash discharge chute being provided inside the placement mold to facilitate cleaning of specimen fragments, and an adjustment assembly being provided on the placement mold to adjust the position of the plug plates;
[0006] The adjusting assembly includes an adjusting chute provided on the inner wall of the ash outlet chute, an adjusting slide fixed to the plug plate is slidably installed inside the adjusting chute, and an adjusting space for the adjusting slide to slide is left between the upper part of the adjusting slide and the upper wall of the inner cavity of the adjusting chute, one end of the adjusting chute is provided with a limiting rack 1 and a limiting rack 2 corresponding to each other, and the length of the limiting rack 1 is smaller than the limiting rack 2, and one end of the adjusting slide is rotatably installed with a limiting gear meshing with the limiting rack 1 and the limiting rack 2.
[0007] Preferably, the regulating chute is obliquely opened on the inner wall of the ash discharge chute, and the lowest end is communicated with the ash discharge chute.
[0008] Preferably, the shear assembly includes an MTS arranged in the vertical direction of the specimen and a jack arranged in the horizontal direction, and a control device electrically connected to the MTS and the jack is provided outside the placement mold.
[0009] Preferably, a force-bearing plate is slidably installed inside the placement mold, and one side of the force-bearing plate contacts the outside of the specimen, and the other side contacts the jack or the MTS output end.
[0010] Preferably, a guide groove is provided on the placement mold, and a guide block fixed to the force-bearing plate is slidably installed in the guide groove.
[0011] Preferably, the cross sections of the guide block and the guide groove are both T-shaped.
[0012] Compared with the prior art, the beneficial effects of the present invention are:
[0013] 1. The utility model realizes the adjustment of the plug plate position by setting the adjustment component. Compared with the traditional technology, it replaces the operation of setting plug plates of different specifications and expands the scope of equipment experiment. In addition, by opening the inclined adjustment chute, the fragments generated when the specimen is sheared are not easy to enter the adjustment chute, thereby avoiding the situation where the fragments interfere with the plug plate adjustment.
[0014] 2. The utility model evenly applies the shear force to the side of the specimen through the setting of the force-bearing plate, thereby improving the experimental accuracy of the specimen shearing. The setting of the guide block and the guide groove guides the movement of the force-bearing plate, improves the stability of the movement of the force-bearing plate, and reduces the possibility of its deviation. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Figure 1 This is a schematic diagram of the three-dimensional structure of the utility model;
[0016] Figure 2 for Figure 1 Schematic diagram of the enlarged structure of area A in the middle;
[0017] Figure 3 This is a cross-sectional view of the utility model;
[0018] Figure 4 for Figure 3 Schematic diagram of the enlarged structure of area B in the middle.
[0019] In the figure: 1. Place the mold; 2. Shearing assembly; 21. MTS; 22. Control equipment; 23. Force plate; 24. Guide block; 25. Guide groove; 26. Jack; 3. Test piece; 4. Plug plate; 5. Adjustment assembly; 51. Adjustment slide; 52. Adjustment slide; 53. Limit gear; 54. Limit rack 1; 55. Limit rack 2; 6. Ash discharge chute. DETAILED DESCRIPTION
[0020] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.
[0021] Asphalt pavements are widely used in highway and urban road paving due to their excellent mechanical properties and elastic-plastic deformation capacity. Under the long-term effects of high and low temperatures and wheel loads, the combined vertical and horizontal forces caused by wheel loads can generate shear stress within the asphalt pavement layer. If the allowable shear stress of the material is exceeded, the asphalt mixture will become unstable and fail, and its adhesion will decrease, leading to common asphalt pavement defects such as slippage, bulging, and rutting. Therefore, the ability to realistically simulate the stress conditions exerted by actual vehicle loads on asphalt pavement structures is of great engineering significance for evaluating the shear strength of pavement layers.
[0022] Example 1
[0023] The existing pavement interlayer shear test device has a limited scope of application. Figures 1-4 , This embodiment proposes a shear test device for prefabricated asphalt pavement layers, which realizes the adjustment of the position of the plug plate 4. Compared with the traditional technology, it replaces the operation of setting plug plates 4 of different specifications and expands the scope of equipment testing. It mainly consists of a placing mold 1 and a test piece 3 placed in the middle of the placing mold 1. Plug plates 4 for limiting the test piece 3 are provided on both sides of the test piece 3. A shearing component 2 for shearing the test piece 3 is provided on the placing mold 1. An ash outlet 6 for cleaning the fragments of the test piece 3 is opened inside the placing mold 1. An adjusting component 5 for adjusting the position of the plug plate 4 is provided on the placing mold 1. Before the shear test starts, the test piece 3 needs to be placed in the placing mold 1 first, and then the position of the plug plate 4 is adjusted by the adjusting component 5 to make it close to the test piece 3 to prevent the test piece 3 from shifting during the experiment. Then, the shearing operation on the test piece 3 is performed by the shearing component 2 provided on the placing mold 1. After the shearing is completed, the debris generated during the shearing process can be swept into the ash outlet 6 to complete the shear test.
[0024] Prefabricated asphalt pavement is a new type of pavement structure. Different surface layers correspond to different specifications of specimens 3. In existing shear tests, plug plates 4 are generally installed to prevent specimen 3 from shifting. However, this is limited to a few different sizes of plug plates 4 and is not suitable for testing specimens 3 on most road sections. To address this limitation, this embodiment utilizes an adjustment component 5 to adjust the position of the plug plate 4 in the mold 1 as needed, thereby replacing the traditional practice of installing plug plates 4 of different specifications. The detailed implementation is as follows:
[0025] The adjusting assembly 5 includes an adjusting slot 51 provided on the inner wall of the ash outlet chute 6, an adjusting slide 52 fixedly connected to the plug plate 4 is slidably installed inside the adjusting slot 51, and an adjusting space for the adjusting slide 52 to slide is reserved between the upper part of the adjusting slide 52 and the upper wall of the inner cavity of the adjusting slot 51, one end of the adjusting slot 51 is provided with a limiting rack 1 54 and a limiting rack 2 55 corresponding to each other, and the length of the limiting rack 1 54 is smaller than the limiting rack 2 55, and a limiting gear 53 meshing with the limiting rack 1 54 and the limiting rack 2 55 is rotatably installed at one end of the adjusting slot 52, when the limiting rack 1 54 and the limiting rack 2 55 are engaged with the limiting gear 53 at the same time, the limiting gear 53 cannot rotate, and then it will limit the plug by limiting the adjusting slot 52. The movement of the plate 4 is due to the fact that the length of the limit rack 1 54 is less than the limit rack 2 55. Therefore, when adjusting, the plug plate 4 can be pulled upward first, and the limit gear 53 can be disengaged from the limit rack 1 54 by lifting the adjusting slide 52, so that the limit gear 53 can rotate freely at this time, so the plug plate 4 can be slid close to the test piece 3, and then the plug plate 4 can be released so that it can re-engage with the limit rack 1 54 under the action of its own gravity, and the plug plate 4 can be limited again, completing the effect of adjusting the plug plate 4. At the same time, because the limit rack 1 54 and the limit rack 2 55 correspond to each other, and the limit gear 53 is always engaged with the limit rack 2 55, the limit gear 53 will not conflict with the limit rack 1 54 when it falls. In addition, if Figure 3 As shown, the pulling groove provided on one side of the plug plate 4 increases the convenience of adjusting the plug plate 4.
[0026] The adjusting chute 51 is obliquely opened on the inner wall of the ash outlet chute 6, and the lowest end is connected to the ash outlet chute 6. The special setting of the adjusting chute 51 makes it difficult for the fragments generated when the specimen 3 is sheared to enter the adjusting chute 51, thereby avoiding the situation where the fragments interfere with the adjustment of the plug plate 4.
[0027] The shear assembly 2 includes a vertically mounted MTS 21 and a horizontally mounted jack 26 on the specimen 3. A control device 22 electrically connected to the MTS 21 and jack 26 is located outside the mold 1. Currently, direct shear, oblique shear, or different inclination angles are commonly used to test interlayer shear strength. The direct shear method fails to account for compressive stresses in other directions imposed by wheel loads on the pavement structure, and therefore cannot accurately assess the shear strength between pavement layers. The oblique shear method or setting different inclination angles takes into account the horizontal and vertical forces on the pavement structure, but is limited to a few modes of pavement conditions, and different inclination angles require different customized molds to test their shear strength. This method is relatively complex and cannot adapt to all shear stress states of the pavement structure layer. In this embodiment, through the setting of the jack 26 and the MTS21, not only is the specimen 3 sheared in the horizontal and vertical directions at the same time, but the jack 26 and the MTS21 are started to apply pressure by the control device 22, thereby realizing real-time and continuous adjustment of the shear force, truly restoring the more comprehensive shear stress state of the pavement structure layer, and improving the shearing accuracy.
[0028] Example 2
[0029] On the basis of Example 1, the technical solution proposed in Example 1 is used to solve the shortcoming that the existing pavement interlayer shear test device has a limited scope of application. However, the output end action area of the existing jack 26 or MTS21 is limited, and it is not easy to act more comprehensively or concentratedly on the load-bearing surface of the specimen 3, which makes the experimental data not accurate enough.
[0030] Reference Figures 1-4 A force-bearing plate 23 is slidably installed inside the mold 1, and one side of the force-bearing plate 23 contacts the outside of the specimen 3, and the other side contacts the jack 26 or the output end of the MTS 21. In this embodiment, by setting the force-bearing plate 23 between the specimen 3 and the jack 26 or the MTS 21, the force can be applied to the specimen 3 in a more comprehensive or concentrated manner, thereby improving the detection accuracy of the specimen 3.
[0031] A guide groove 25 is provided on the placement mold 1, and a guide block 24 fixed to the force-bearing plate 23 is slidably installed in the guide groove 25. The setting of the guide block 24 and the guide groove 25 guides the movement of the force-bearing plate 23, improves the stability of the movement of the force-bearing plate 23, and reduces the possibility of its deviation.
[0032] The cross-sections of the guide block 24 and the guide groove 25 are both "T"-shaped. The "T"-shaped setting is relatively complicated compared to the "T"-shaped setting, but when the guide block 24 guides and slides, it can avoid its separation from the guide groove 25, further improving the guiding effect on the plug plate 4.
[0033] Although the embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.
Claims
1. A device for shear testing between layers of assembled asphalt pavement, comprising a placement mold (1), and a test piece (3) placed in the middle of the placement mold (1), wherein plug plates (4) are provided on both sides of the test piece (3) for limiting the position of the test piece (3), and a shearing component (2) is provided on the placement mold (1) for shearing the test piece (3), characterized in that: An ash outlet trough (6) for facilitating the cleaning of fragments of the test piece (3) is provided inside the placement mold (1), and an adjustment component (5) for adjusting the position of the plug plate (4) is provided on the placement mold (1); The adjustment assembly (5) includes an adjustment chute (51) provided on the inner wall of the ash outlet chute (6), an adjustment slide (52) fixed to the plug plate (4) is slidably installed inside the adjustment chute (51), and an adjustment space for the adjustment slide (52) to slide is reserved between the upper part of the adjustment slide (52) and the upper wall of the inner cavity of the adjustment chute (51), one end of the adjustment chute (51) is provided with a limiting rack 1 (54) and a limiting rack 2 (55) corresponding to each other, and the length of the limiting rack 1 (54) is smaller than that of the limiting rack 2 (55), and one end of the adjustment slide (52) is rotatably installed with a limiting gear (53) meshing with the limiting rack 1 (54) and the limiting rack 2 (55).
2. The interlayer shear test device for assembled asphalt pavement according to claim 1, characterized in that: The regulating chute (51) is obliquely opened on the inner wall of the ash discharge chute (6), and the lowest end is communicated with the ash discharge chute (6).
3. The interlayer shear test device for assembled asphalt pavement according to claim 1, characterized in that: The shearing assembly (2) includes an MTS (21) arranged in the vertical direction of the test piece (3) and a jack (26) arranged in the horizontal direction. A control device (22) electrically connected to the MTS (21) and the jack (26) is provided outside the placement mold (1).
4. The interlayer shear test device for assembled asphalt pavement according to claim 1, characterized in that: A force-bearing plate (23) is slidably installed inside the placement mold (1), and one side of the force-bearing plate (23) contacts the outside of the test piece (3), and the other side contacts the jack (26) or the output end of the MTS (21).
5. The interlayer shear test device for assembled asphalt pavement according to claim 4, characterized in that: The placement mold (1) is provided with a guide groove (25), and a guide block (24) fixedly connected to the force-bearing plate (23) is slidably installed in the guide groove (25).
6. The interlayer shear test device for assembled asphalt pavement according to claim 5, characterized in that: The cross sections of the guide block (24) and the guide groove (25) are both T-shaped.