A device for simulating low-temperature shrinkage of asphalt pavement in an in-situ environment

Abstract

The present invention provides a device for simulating low-temperature shrinkage of asphalt pavement in an in-situ environment, comprising a bottom heating layer, a lower insulation layer and an upper detachable layer; a heating device is arranged in the bottom heating layer, and the bottom heating layer is a closed space; the lower insulation layer is a space closed on all sides, and the bottom of the lower insulation layer is connected to the top of the bottom heating layer, and the lower insulation layer is used to fill the roadbed soil material; the upper detachable layer is a space closed on all sides, which is installed on the top of the lower insulation layer, and its bottom is connected to the top of the lower insulation layer, and the upper detachable layer is used to fill the semi-rigid base material of the road surface. Insulation measures are taken around the lower insulation layer of the present invention to prevent heat exchange, while the upper detachable layer can freely exchange heat with the outside world, which is consistent with the actual road surface conditions, and the bottom heating layer is provided with a heating device, simulating the low surface temperature and slightly higher lower temperature of the actual asphalt pavement in winter, producing the effect of shrinkage due to upper and lower temperature differences.

Description

Technical Field

[0001] The present invention relates to the technical field of observing low-temperature shrinkage of asphalt pavements, and more specifically, to a device for simulating low-temperature shrinkage of asphalt pavements in an in-situ environment. Background Art

[0002] Low-temperature shrinkage cracking of asphalt pavements is the main damage to asphalt pavements in cold regions in winter, which has a great impact on the service life of asphalt pavements. Currently, when studying the low-temperature shrinkage of asphalt pavements, only beam specimen materials made by molds as shown in Figure 2 can be used, and then a temperature environment chamber as shown in Figure 1 is used to simulate the temperature environment.

[0003] However Figure 1 the temperature environment chamber shown can only simulate a fixed temperature environment to study the temperature shrinkage coefficient and temperature shrinkage performance of materials, and cannot simulate the low-temperature shrinkage cracking phenomenon of asphalt pavements. Due to the influence of temperature transfer from top to bottom of asphalt pavements, during the cooling process in cold winter weather, the temperature of the surface of the asphalt pavement is relatively low, while the influence of low temperature on the lower layer structure is relatively small because the temperature of the base layer is relatively high, resulting in a temperature difference between the upper and lower structures. Therefore, low-temperature shrinkage occurs in the pavement base layer. However, the existing temperature shrinkage measurement devices can only simulate a constant temperature environment, making the entire specimen in the same temperature environment and unable to simulate the influence of temperature difference in actual engineering. Although there have been many years of research on low-temperature shrinkage cracking at home and abroad, there is still no corresponding experimental equipment or method to simulate the low-temperature shrinkage cracking phenomenon of asphalt pavements. Summary of the Invention

[0004] In view of the above technical problems, a device for simulating low-temperature shrinkage of asphalt pavements in an in-situ environment is provided.

[0005] The technical means adopted by the present invention are as follows:

[0006] A device for simulating low-temperature shrinkage of asphalt pavements in an in-situ environment, comprising a bottom heating layer, a lower insulation layer, and an upper detachable layer;

[0007] A heating device is arranged in the bottom heating layer, and the bottom heating layer is a closed space;

[0008] The lower insulation layer is a space closed on all sides, and the bottom of the lower insulation layer is connected to the top of the bottom heating layer. The lower insulation layer is used to fill subgrade soil materials;

[0009] The upper detachable layer is a space closed on all sides. It is installed on the top of the lower insulation layer, and its bottom is communicated with the top of the lower insulation layer. The upper detachable layer is used to fill semi-rigid base materials of the pavement.

[0010] Preferably, the lower thermal insulation layer is a space surrounded by multi-layer boards vertically arranged on all sides. The multi-layer boards are, from the inside to the outside, a first wooden board layer, a first steel plate, a thermal insulation layer, and a second steel plate in sequence.

[0011] Preferably, the bottom heating layer includes a horizontally arranged bottom steel plate and a top steel plate. The top steel plate is supported by multiple I-beams, and the second steel plate extends downward to enclose the space around the bottom steel plate and the top steel plate; the upper surface of the top steel plate has a horizontally arranged second wooden board layer; the heating device is a thermocouple, and the thermocouples are distributed all over the bottom heating layer.

[0012] Preferably, the upper detachable layer is a space surrounded by multiple L-shaped steel plates. The horizontal part of the L-shaped steel plate is detachably connected to the top of the lower thermal insulation layer by bolts.

[0013] Preferably, multiple steel plate wing plates are installed at intervals on the vertical part of the L-shaped steel plate. The bottom of the steel plate wing plate is connected to the horizontal part of the L-shaped steel plate by bolts, and the connection part between two adjacent L-shaped steel plates is connected by bolts.

[0014] Preferably, a temperature controller electrically connected to the heating device is installed on the outer wall of the upper detachable layer. The temperature controller is used to regulate the heating temperature of the heating device.

[0015] Compared with the prior art, the present invention has the following advantages:

[0016] The present invention simulates the low-temperature shrinkage of the semi-rigid base of the asphalt pavement. By using a large-scale device, heat insulation measures are taken around the lower thermal insulation layer to prevent heat exchange, while the upper detachable layer can freely exchange heat with the outside, which is in line with the actual road surface situation. The bottom heating layer is equipped with a heating device, which can heat and keep warm through the temperature controller, so that the bottom temperature is maintained at about the set temperature. It can simulate the situation that the surface temperature of the actual asphalt pavement is low in winter and the lower temperature is slightly higher, resulting in the effect of up and down temperature difference shrinkage. It not only meets the large-scale mold but also greatly simulates the low-temperature shrinkage phenomenon of the actual asphalt pavement. Compared with the traditional indoor test, it is very close to the actual project and makes the experimental phenomenon more obvious, which has a certain guiding significance for the construction of the actual project. The upper detachable layer is a detachable structure, and the steel plate wing plates are arranged at intervals, which not only increases the bearing capacity but also serves as a disassembly device. The size of the device can be compared with the thickness of the actual road surface structure, and the length is also sufficient to produce an obvious shrinkage effect.

[0017] Based on the above reasons, the present invention can be widely promoted in the fields such as the observation of low-temperature shrinkage of asphalt pavements. Description of the Drawings

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0019] Figure 1 It is a schematic diagram of a temperature environment chamber in the background art of the present invention.

[0020] Figure 2 It is a schematic diagram of a mold in the background art of the present invention.

[0021] Figure 3 It is a three-dimensional external view of a device for simulating the low-temperature shrinkage of an asphalt pavement in-situ in the specific embodiment of the present invention.

[0022] Figure 4 For Figure 3 The sectional view taken along the A-A direction in

[0023] Figure 5 It is the front view of a device for simulating the low-temperature shrinkage of an asphalt pavement in-situ in the specific embodiment of the present invention.

[0024] Figure 6 It is the top view of a device for simulating the low-temperature shrinkage of an asphalt pavement in-situ in the specific embodiment of the present invention. Specific Embodiment

[0025] It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other. The following will detail the present invention with reference to the drawings and in combination with the embodiments.

[0026] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all the embodiments. The description of at least one exemplary embodiment below is actually only illustrative and in no way restricts the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

[0027] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they specify the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0028] Unless otherwise specifically stated, the relative arrangements of components and steps, numerical expressions, and numerical values set forth in these embodiments do not limit the scope of the present invention. At the same time, it should be clear that, for the sake of convenience of description, the dimensions of the various parts shown in the drawings are not drawn in actual proportional relationships. Technologies, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, such technologies, methods, and devices should be regarded as part of the authorized specification. In all the examples shown and discussed here, any specific value should be construed as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that like reference numerals and letters denote like items in the following drawings, and thus, once an item is defined in one drawing, it does not require further discussion in subsequent drawings.

[0029] In the description of the present invention, it should be understood that the orientation or positional relationships indicated by orientation words such as "front, rear, upper, lower, left, right", "lateral, vertical, perpendicular, horizontal", and "top, bottom" are generally based on the orientation or positional relationships shown in the drawings. These orientation words are only for the convenience of describing the present invention and simplifying the description. Without contrary description, these orientation words do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the protection scope of the present invention. The orientation words "inner, outer" refer to the inside and outside relative to the contour of each component itself.

[0030] For ease of description, spatial relative terms such as "above", "over", "on the upper surface", "upper", etc. can be used here to describe the spatial positional relationship between a device or feature shown in the figure and other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation in addition to the orientation depicted in the figure for the device. For example, if the device in the attached drawing is inverted, a device described as "above" or "over" other devices or structures will then be positioned "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both the orientations of "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and corresponding interpretations are made for the spatial relative descriptions used here.

[0031] In addition, it should be noted that the use of terms such as "first", "second", etc. to define components is merely for the convenience of differentiating the corresponding components. Without additional statements, the above terms have no special meanings, and thus should not be construed as limiting the protection scope of the present invention.

[0032] As Figures 3 to 6 shown, a device for simulating the low-temperature shrinkage of an asphalt pavement in an in-situ environment includes a bottom heating layer, a lower insulation layer, and an upper detachable layer;

[0033] The upper detachable layer is a rectangular space surrounded by four L-shaped steel plates 1, which has no top plate and bottom plate. The upper detachable layer is used to fill the semi-rigid base material of the road surface. A plurality of steel plate wings 2 are installed at intervals on the vertical part of the L-shaped steel plate 1. The bottom of the steel plate wing 2 is bolted to the horizontal part of the L-shaped steel plate 1, and the connection between two adjacent L-shaped steel plates 1 is bolted. The vertical part of the L-shaped steel plate 1 is 450 mm high, and the width of the horizontal part is 130 mm; the spacing distance of the steel plate wings 2 is 400 mm, and the thickness is 5 mm;

[0034] The lower insulation layer is a rectangular space surrounded by four multi-layer boards, which has no top plate and bottom plate. It forms a large rectangular space with the rectangular space of the upper detachable layer. The multi-layer board consists of a first wooden board layer 3, a first steel plate 4, an insulation layer 5, and a second steel plate 6 from the inside to the outside in sequence. The lower insulation layer is filled with subgrade soil material; the horizontal part of the L-shaped steel plate 1 of the upper detachable layer is bolted to the second steel plate 6 of the lower insulation layer. The insulation layer 5 is composed of insulation boards, and its thickness is 50 mm, which prevents the influence of external low temperature on the material and improves the insulation ability of the lower layer; the thickness of the first wooden board layer 3 is 18 mm, which plays a role in heat insulation and prevents heat dissipation.

[0035] The bottom heating layer includes a bottom steel plate 7 and a top steel plate 8 which are arranged horizontally. The top steel plate 8 is supported by a plurality of I-beams 9. The top steel plate 8 forms the bottom plate of the lower insulation layer. The second steel plate 6 extends downward to close the space around the bottom steel plate 7 and the top steel plate 8. The upper surface of the top steel plate 8 has a second wooden board layer 10 which is arranged horizontally. A heating device 11 is arranged in the bottom heating layer. The heating device 11 is a thermocouple, and the thermocouples are distributed throughout the bottom heating layer.

[0036] A temperature controller 12 electrically connected to the heating device 11 is installed on the outer wall of the vertical portion of the L-shaped steel plate 1. The temperature controller 12 is used to adjust the heating temperature of the heating device 11.

[0037] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein by equivalents. However, these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A device for simulating low-temperature shrinkage of asphalt pavement in an in-situ environment, characterized in that: It includes a bottom heating layer, a lower insulation layer and an upper removable layer; A heating device is arranged in the bottom heating layer, and the bottom heating layer is a closed space; The lower insulation layer is a closed space on all sides, which has no top plate and bottom plate, and the bottom of the lower insulation layer is connected to the top of the bottom heating layer, and the lower insulation layer is used to fill the roadbed soil material; The upper detachable layer is a space enclosed on all sides, which has no top plate and bottom plate, is installed on the top of the lower insulation layer, and its bottom is connected to the top of the lower insulation layer. The upper detachable layer is used to fill the semi-rigid base material of the road surface; The lower insulation layer is a space surrounded by vertically arranged multi-layer boards, wherein the multi-layer boards are, from the inside to the outside, a first wood board layer, a first steel plate, an insulation layer, and a second steel plate; The bottom heating layer comprises a bottom steel plate and a top steel plate arranged horizontally, the top steel plate is supported by a plurality of I-beams, and the second steel plate extends downward to close the space around the bottom steel plate and the top steel plate; The upper surface of the top steel plate is provided with a second wooden board layer which is arranged horizontally; the heating device is a thermocouple, and the thermocouple is distributed throughout the bottom heating layer.

2. The device for simulating low-temperature shrinkage of asphalt pavement in an in-situ environment according to claim 1, characterized in that: The upper detachable layer is a space surrounded by a plurality of L-shaped steel plates, and the horizontal portion of the L-shaped steel plate is detachably connected to the top of the lower insulation layer by bolts.

3. The device for simulating low-temperature shrinkage of asphalt pavement in an in-situ environment according to claim 2, characterized in that: A plurality of steel plate wing plates are installed at intervals on the vertical portion of the L-shaped steel plate, the bottom of the steel plate wing plate is connected to the horizontal portion of the L-shaped steel plate by bolts, and the connection points of two adjacent L-shaped steel plates are connected by bolts.

4. The device for simulating low-temperature shrinkage of asphalt pavement in an in-situ environment according to claim 1, characterized in that: A temperature controller electrically connected to the heating device is installed on the outer wall of the upper detachable layer, and the temperature controller is used to adjust the heating temperature of the heating device.

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