A pavement structure for cooling in summer and keeping warm in winter in areas with large temperature differences

Abstract

The utility model belongs to the technical field of road engineering, and specifically relates to a pavement structure used for cooling in summer and keeping warm in winter in areas with large temperature differences, including a phase-change asphalt mixture insulation layer from top to bottom, a porous refractory crushed stone asphalt mixture heat-resistant layer, an ordinary asphalt concrete lower layer, an aerogel insulation layer, a cement stabilized base layer and a cushion layer. The phase-change asphalt mixture insulation layer is arranged at the topmost layer of the pavement structure, and absorbs / releases heat by transforming the phase change state, thereby achieving the purpose of regulating the pavement temperature. The porous refractory crushed stone asphalt mixture heat-resistant layer has a low thermal conductivity coefficient, which reduces the heat transfer from the pavement to the depth of the pavement structure in high temperature seasons and prevents the internal heat of the pavement from dissipating outward in low temperature seasons; the aerogel insulation layer isolates the heat transfer between the base layer and the surface layer, which has the effect of cooling in summer and keeping warm in winter, and slowing down the heating and cooling speed of the pavement structure.

Description

Technical Field

[0001] The utility model belongs to the technical field of road engineering, and in particular relates to a road surface structure used for cooling in summer and keeping warm in winter in areas with large temperature differences. Background Art

[0002] Due to the long-term influence of high and low temperatures, the pavement structure has suffered a large number of diseases during its service. Especially under the influence of high temperatures, the high-temperature stability of the pavement is insufficient, and rutting is very easy to occur. Under the influence of low-temperature environments, a large number of cracks will appear on the pavement, which, together with the traffic load, will breed various pavement diseases. At the same time, in the process of frequent high and low temperature cycles, fatigue cracks are very likely to occur on the pavement, causing the pavement service condition to further deteriorate, which is not conducive to the driving comfort and safety of vehicles. With the further development of highway construction, the highway network has been extended to a large number of areas with large temperature differences, and this problem has gradually become impossible to ignore.

[0003] In order to cope with the unique working conditions in areas with large temperature differences, the engineering projects often adopt methods to improve the performance of pavement materials or improve the pavement structure, such as using modified asphalt with better high and low temperature performance, high modulus asphalt, laying anti-cracking geotechnical materials, etc. However, such methods do not fundamentally solve the impact of the temperature field in areas with large temperature differences on the pavement, and can only delay the occurrence of pavement-related diseases to a limited extent, without changing the large temperature difference working conditions themselves, so that the problem has not been effectively solved.

[0004] In recent years, active temperature control technology has become the main research direction for suppressing pavement diseases in areas with large temperature differences. Through methods such as phase change technology and heat reflective coating technology, the temperature inside the pavement structure is actively regulated to reduce the temperature change inside the pavement structure, thereby achieving the ultimate goal of improving the durability of the pavement structure in areas with large temperature differences and suppressing its pavement diseases. However, due to the limitations of materials and technology itself, active temperature control technology can often only adjust the temperature in one direction, and cannot fully adapt to the unique working conditions of high temperature, low temperature, large temperature difference, and extremely fast temperature changes in areas with large temperature differences. Therefore, combining the previous modification technology with active temperature control technology, it is urgent to develop a pavement structure that can adjust the temperature of the pavement structure in both directions, suitable for summer cooling and winter insulation in areas with large temperature differences. Utility Model Content

[0005] The purpose of the utility model is to provide a pavement structure for cooling in summer and keeping warm in winter in areas with large temperature differences, which solves the problem that the existing pavement structure cannot fully adapt to the unique working conditions of areas with large temperature differences, such as high temperature, low temperature, large temperature difference and extremely fast temperature changes.

[0006] The utility model is realized by the following technical solutions:

[0007] A pavement structure used for cooling in summer and keeping warm in winter in areas with large temperature differences, including a top-down phase-change asphalt mixture insulation layer, a porous refractory crushed stone asphalt mixture heat-resistant layer, an ordinary asphalt concrete lower layer, an aerogel insulation layer, a cement stabilized base layer and a cushion layer.

[0008] Furthermore, the phase change asphalt mixture insulation layer has a gradation of AC-13 / 16 or SMA-13 / 16 and a thickness of 4 to 6 cm.

[0009] Furthermore, the porous refractory crushed stone asphalt mixture heat-resistant layer has a grading of AC-20 and a thickness of 5 to 7 cm.

[0010] Furthermore, porous refractory crushed stone is mixed into the mineral material used for the porous refractory crushed stone asphalt mixture heat-resistant layer.

[0011] Furthermore, the lower layer of the common asphalt concrete is graded as AC-25 or ATB-25, and has a thickness of 6 to 8 cm.

[0012] Furthermore, the aerogel thermal insulation layer is made of aerogel thermal insulation material toughened by glass fiber and has a thickness of 0.5 to 1 cm.

[0013] Furthermore, the cement stabilized base layer is made of cement stabilized crushed stone or cement stabilized gravel, with a thickness of 30 to 38 cm.

[0014] Furthermore, the cushion layer is made of graded crushed stone, graded gravel or natural gravel material with a thickness of 20 cm.

[0015] Compared with the prior art, the utility model has the following beneficial technical effects:

[0016] The utility model discloses a pavement structure used for cooling in summer and keeping warm in winter in areas with large temperature differences, including a top-down phase-change asphalt mixture insulation layer, a porous refractory crushed stone asphalt mixture heat-resistant layer, a common asphalt concrete lower layer, an aerogel insulation layer, a cement stabilized base layer and a graded crushed stone cushion layer. The phase-change asphalt mixture insulation layer is arranged at the topmost layer of the pavement structure, and absorbs / releases heat by transforming the phase change morphology, thereby achieving the purpose of regulating the pavement temperature. Indoor tests have shown that compared with asphalt mixtures without phase-change temperature regulating materials, the temperature rise curve of the pavement structure can be effectively changed;

[0017] The porous refractory crushed stone asphalt mixture heat barrier layer is mixed with porous refractory crushed stone, which has a low thermal conductivity. It reduces the heat transfer from the road surface to the road surface structure in high temperature seasons and prevents the heat inside the road surface from being lost in low temperature seasons. The porous characteristics of the porous refractory crushed stone can achieve the effect of cooling in summer and keeping warm in winter. Indoor tests have shown that compared with ordinary asphalt concrete, it can effectively change the temperature change curve of the road surface structure;

[0018] The aerogel insulation layer is set between the surface layer and the base layer of the road surface. The aerogel insulation layer partially isolates the heat transfer between the base layer and the surface layer, plays the role of cooling in summer and keeping warm in winter, and slows down the heating and cooling rates of the road surface structure.

[0019] The utility model designs a new pavement structure for cooling in summer and keeping warm in winter in areas with large temperature differences. It can adjust the internal temperature of the pavement structure through active temperature control technologies such as phase change materials and thermal insulation layers, thereby reducing the pavement's requirements for high and low temperature performance without reducing the performance of the pavement itself, thereby improving the pavement's durability and effectively improving the pavement's disease conditions under the same conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram of a pavement structure for cooling in summer and keeping warm in winter in areas with large temperature differences according to the utility model;

[0021] Among them: 1. Phase change asphalt mixture insulation layer; 2. Porous refractory crushed stone asphalt mixture heat barrier layer; 3. Ordinary asphalt concrete bottom layer; 4. Aerogel insulation layer; 5. Cement stabilized base layer; 6. Cushion layer;

[0022] Figure 2 A statistical diagram of the temperature drop of the pavement structure under high temperature environment provided by the example of the utility model;

[0023] Figure 3 A statistical diagram of the thermal insulation range of a pavement structure in a low temperature environment provided by an example of the utility model. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solution and advantages of the utility model clearer, the following is further described in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the utility model, and are not used to limit the utility model, that is, the embodiments described are only part of the embodiments of the utility model, not all of the embodiments.

[0025] The components described and shown in the drawings and embodiments of the present invention can be arranged and designed in various different configurations. Therefore, the detailed description of the embodiments of the present invention provided in the following drawings is not intended to limit the scope of the claimed invention, but merely represents a selected embodiment of the present invention. Based on the drawings and embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0026] It should be noted that the terms "comprises", "includes" or any other variations are intended to cover non-exclusive inclusion, so that a process, element, method, article or equipment that includes a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to the process, element, method, article or equipment.

[0027] The features and performance of the present invention are further described in detail below in conjunction with the embodiments.

[0028] like Figure 1 As shown, the utility model discloses a new pavement structure for cooling in summer and keeping warm in winter in areas with large temperature differences, including a phase-change asphalt mixture insulation layer 1, a porous refractory crushed stone asphalt mixture heat-resistant layer 2, an ordinary asphalt concrete lower layer 3, an aerogel insulation layer 4, a cement stabilized base layer 5, and a cushion layer 6 from top to bottom.

[0029] The phase change asphalt mixture insulation layer 1 is composed of phase change modified asphalt, mineral powder, fine aggregate, coarse aggregate and fiber (if necessary), the mixture types include AC-13, AC-16, SMA-13 ​​and SMA-16, and the thickness of the structural layer is 4 to 6 cm.

[0030] In the phase change AC-13 asphalt mixture, the mass fraction of phase change modified asphalt is 4.3% to 5.0%, the mass fraction of mineral powder is 4% to 8%, the mass fraction of 0-2.36mm fine aggregate is 16% to 46%, the mass fraction of 2.36 to 4.75mm aggregate is 0% to 38%, the mass fraction of 4.75 to 9.5mm aggregate is 0% to 47%, and the mass fraction of 9.5 to 16mm aggregate is 15% to 32%.

[0031] In the phase change AC-16 asphalt mixture, the mass fraction of phase change modified asphalt is 3.7% to 4.4%, the mass fraction of mineral powder is 4% to 8%, the mass fraction of 0-2.36mm fine aggregate is 12% to 44%, the mass fraction of 2.36-4.75mm aggregate is 0% to 42%, the mass fraction of 4.75-9.5mm aggregate is 0% to 46%, and the mass fraction of 9.5-20mm aggregate is 20% to 40%.

[0032] In the phase-change SMA-13 ​​asphalt mixture, the mass fraction of phase-change modified asphalt is 5.3% to 6.0%, the mass fraction of mineral powder is 8% to 12%, the mass fraction of 0-2.36mm fine aggregate is 3% to 18%, the mass fraction of 2.36-4.75mm aggregate is 0% to 19%, the mass fraction of 4.75-9.5mm aggregate is 16% to 55%, the mass fraction of 9.5% to 16mm aggregate is 25% to 50%, and the fiber content is 0.3% to 0.5%

[0033] In the phase change SMA-16 asphalt mixture, the mass fraction of phase change modified asphalt is 5.1% to 5.8%, the mass fraction of mineral powder is 8% to 12%, the mass fraction of 0-2.36mm fine aggregate is 3% to 16%, the mass fraction of 2.36-4.75mm aggregate is 0% to 17%, the mass fraction of 4.75-9.5mm aggregate is 13% to 45%, the mass fraction of 9.5-20mm aggregate is 35% to 55%, and the fiber content is 0.3% to 0.5%.

[0034] The different mineral aggregate gradations of the phase change asphalt mixture mentioned above are already very mature technologies.

[0035] The porous refractory crushed stone asphalt mixture heat-resistant layer 2 is composed of asphalt, mineral powder, coarse and fine aggregates, natural aggregates, and porous refractory crushed stone. The mixture type is AC-20, and the thickness of the structural layer is 5 to 7 cm. The mass fraction of asphalt is 3.9% to 4.3%, the mass fraction of mineral powder is 3% to 7%, the fine aggregate of 0-2.36 mm is 9% to 41%, the coarse aggregate of 2.36 to 4.75 mm is 0% to 40%, and the natural aggregate of 19 to 26.5 mm is

[0036] 0% to 10%, 4.75 to 9.5 mm porous refractory crushed stone is 0% to 39%, 9.5 to 19 mm porous refractory crushed stone is 25% to 55%. The different mineral gradations of the porous refractory crushed stone asphalt mixture heat-resistant layer 2 are already very mature technologies.

[0037] The common asphalt concrete lower layer 3 is composed of asphalt, mineral powder, coarse aggregate and fine aggregate. The mixture type is AC-25 or ATB25. The thickness of the lower layer is generally 6 to 8 cm.

[0038] The aerogel insulation layer 4 placed between the base layer and the surface layer is made of glass fiber reinforced aerogel material with a thickness of 0.5 to 1 cm. As a functional layer outside the traditional pavement structure, it can effectively insulate while maintaining the pavement strength. By comparing the following embodiments, it can be seen that the addition of the aerogel insulation layer 4 can increase the cooling range of the pavement structure in a high temperature environment by 1.4 to 1.7°C, and the insulation range in a low temperature environment by 0.4 to 1.2°C.

[0039] The cement stabilized base layer 5 is made of cement stabilized crushed stone, cement stabilized gravel and other materials, and has a thickness of 30 cm to 38 cm. The thickness is determined according to the traffic level.

[0040] The cushion layer 6 is made of graded crushed stone, graded gravel or natural gravel material, and has a thickness of 20 cm.

[0041] Example 1

[0042] like Figure 1As shown, the pavement structure used in this example is, from top to bottom, a phase change asphalt mixture insulation layer 1, a porous refractory crushed stone asphalt mixture heat-resistant layer 2, an ordinary asphalt concrete lower layer 3, an aerogel insulation layer 4, a cement stabilized base layer 5, and a cushion layer 6.

[0043] The phase change asphalt mixture insulation layer 1 is composed of phase change modified asphalt, mineral powder, coarse aggregate and fine aggregate. The structure layer adopts the grading of SMA-13 ​​and the thickness of the structure layer is 6 cm.

[0044] The porous refractory crushed stone asphalt mixture heat-resistant layer 2 is composed of asphalt, mineral powder, coarse aggregate, fine aggregate, and porous refractory crushed stone. The structural layer adopts a grading of AC-20 and a thickness of 7 cm.

[0045] The 3rd structural layer below the ordinary asphalt concrete adopts the grading of AC-25 and the thickness of the structural layer is 8cm.

[0046] The aerogel thermal insulation layer 4 is made of glass fiber reinforced silica aerogel material, and the thickness of the structural layer is 1 cm.

[0047] The cement stabilized base layer 5 is made of cement stabilized crushed stone material, and the thickness of the structural layer is 36 cm.

[0048] The cushion layer 6 is made of graded crushed stone material, and the thickness of the structural layer is 20 cm.

[0049] The pavement structure specimen and the ordinary pavement specimen were placed in a simulated large temperature difference environment to examine the temperature change amplitude compared with the conventional pavement structure in high temperature environment and low temperature environment. Through actual testing, it can be obtained that Figure 2 As shown in the figure, in a high temperature environment simulating a summer temperature of 35°C, the surface temperature of the road surface dropped by about 8.1°C and the bottom temperature dropped by 3.8°C. Figure 3 As shown, in an environment simulating a winter temperature of -15°C, the surface temperature of the road surface is about 4.6°C higher and the bottom temperature is about 3.5°C higher than that of ordinary roads.

[0050] Example 2

[0051] The structural differences between Example 2 and Example 1 are as follows:

[0052] The thickness of the phase change asphalt mixture insulation layer 1 changes to 4 cm.

[0053] like Figure 2 As shown in the figure, under the high temperature environment of 35℃ in simulated summer, the surface temperature of the road surface drops by about 6.7℃ and the bottom temperature drops by 3.2℃. Figure 3 As shown, in an environment simulating a winter temperature of -15°C, the surface temperature of the road surface is about 4.2°C higher and the bottom temperature is about 3.1°C higher than that of ordinary roads.

[0054] Example 3

[0055] The structural differences between Example 3 and Example 1 are as follows:

[0056] The thickness of the phase-change asphalt mixture insulation layer 1 becomes 4 cm, and the thickness of the porous refractory crushed stone asphalt mixture becomes 5 cm.

[0057] like Figure 2 As shown in the figure, under the high temperature environment of 35℃ in simulated summer, the surface temperature of the road surface drops by about 6.5℃ and the bottom temperature drops by 2.8℃. Figure 3 As shown, in an environment simulating a winter temperature of -15°C, the surface temperature of the road surface is about 3.5°C higher and the bottom temperature is about 2.3°C higher than that of ordinary roads.

[0058] Example 4

[0059] The differences between Example 4 and Example 1 are as follows:

[0060] The thickness of the phase-change asphalt mixture insulation layer 1 becomes 4 cm, the thickness of the porous refractory crushed stone asphalt mixture becomes 5 cm, and the thickness of the aerogel insulation layer 4 becomes 0 cm.

[0061] like Figure 2 As shown in the figure, under the high temperature environment of 35℃ in simulated summer, the surface temperature of the road surface drops by about 6.4℃ and the bottom temperature drops by 1.9℃. Figure 3 As shown, in an environment simulating a winter temperature of -15°C, the surface temperature of the road surface is about 2.9°C higher and the bottom temperature is about 1.5°C higher than that of ordinary roads.

[0062] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model rather than to limit it. Although the utility model is described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the utility model can still be modified or replaced by equivalents, and any modification or equivalent replacement that does not depart from the spirit and scope of the utility model should be included in the scope of protection of the claims of the utility model.

Claims

1. A pavement structure for cooling in summer and keeping warm in winter in areas with large temperature differences, characterized in that: It comprises a phase-change asphalt mixture insulation layer (1) from top to bottom, a porous fire-resistant crushed stone asphalt mixture heat-resistant layer (2), a common asphalt concrete lower layer (3), an aerogel insulation layer (4), a cement stabilized base layer (5) and a cushion layer (6).

2. A pavement structure for cooling in summer and keeping warm in winter in areas with large temperature differences according to claim 1, characterized in that: The phase-change asphalt mixture thermal insulation layer (1) has a grading of AC-13 / 16 or SMA-13 / 16 and a thickness of 4 to 6 cm.

3. The pavement structure for cooling in summer and keeping warm in winter in areas with large temperature differences according to claim 1, characterized in that: The porous refractory crushed stone asphalt mixture heat-resistant layer (2) has a grading of AC-20 and a thickness of 5 to 7 cm.

4. The pavement structure for cooling in summer and keeping warm in winter in areas with large temperature differences according to claim 1, characterized in that: The common asphalt concrete lower layer (3) is graded to be AC-25 or ATB-25, and has a thickness of 6 to 8 cm.

5. The pavement structure for cooling in summer and keeping warm in winter in areas with large temperature differences according to claim 1, characterized in that: The aerogel thermal insulation layer (4) is made of a glass fiber reinforced aerogel thermal insulation material and has a thickness of 0.5 to 1 cm.

6. The pavement structure for cooling in summer and keeping warm in winter in areas with large temperature differences according to claim 1, characterized in that: The cement stabilized base layer (5) is made of cement stabilized crushed stone or cement stabilized gravel, and has a thickness of 30 to 38 cm.

7. The pavement structure for cooling in summer and keeping warm in winter in areas with large temperature differences according to claim 1, characterized in that: The cushion layer (6) is made of graded crushed stone, graded gravel or natural sand and gravel, and has a thickness of 20 cm.

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