Wide-temperature-range multistage phase-change temperature-adjusting asphalt mixture and preparation method thereof

Abstract

The invention discloses a preparation method of a wide-temperature-range multistage phase-change temperature-adjusting asphalt mixture. The preparation method comprises the following steps: respectively preparing a plurality of different composite organic eutectic phase-change materials; a plurality of different composite organic eutectic phase-change materials are compounded according to different proportions to obtain the wide-temperature-range multistage phase-change material. The wide-temperature-range multi-stage phase-change material is doped into an asphalt mixture according to the mass ratio of 3%-5%, and the wide-temperature-range multi-stage phase-change temperature-adjusting asphalt mixture is formed. The wide-temperature-range multi-stage phase-change temperature-adjusting asphalt mixture disclosed by the invention can continuously play a phase-change heat storage function in a high-temperature environment in summer, and achieves the effects of delaying the pavement temperature change rate, reducing the pavement maximum temperature, delaying the daily maximum appearance time, reducing the pavement surface temperature and improving the pavement temperature. Therefore, the urban heat island effect can be relieved, and the pavement durability is prolonged.

Description

Technical Field

[0001] The present invention belongs to the technical field of road engineering, and in particular relates to a wide-temperature-range multi-stage phase-change temperature-regulating asphalt mixture and a preparation method thereof. Background Art

[0002] Asphalt pavement is widely used in urban road and highway construction due to its high durability, low noise, excellent wear resistance and comfort. However, the heat absorption coefficient of black asphalt pavement is as high as 0.82-0.92, which can absorb up to 90% of solar radiation. In the context of global warming, high temperature weather occurs frequently in summer. Asphalt pavement can convert solar energy into thermal energy, resulting in heat accumulation and temperature rise inside the pavement structure. The average maximum temperature in July in most parts of the country exceeded 35°C, making the surface temperature of asphalt road as high as 60°C, and the temperature at the bottom of the upper layer as high as 56°C.

[0003] On the one hand, high temperature softens asphalt pavement and causes it to lose stiffness, causing deformation, dents and wear under the stress imposed by vehicle loads and traffic flow. When the temperature of the asphalt pavement is below 55°C, rutting can be controlled within a few millimeters, but when the pavement temperature exceeds 55°C, rutting will develop at a centimeter-level speed, greatly reducing the durability of the pavement. On the other hand, the accelerated urbanization process has brought about a sharp increase in human activities, leading to the urban heat island effect. The direct impact of the urban heat island effect on urban livability is mainly reflected in the decline of environmental quality, the intensification of heat stress and the acceleration of heat-related public health problems; extreme urban heat island events can significantly aggravate global warming and high mortality rates. This phenomenon can be attributed to several factors, including the use of highly thermally inert materials and dark surface building materials, complex urban landscape geometry, reduced vegetation cover and significantly increased human energy consumption. Among these factors, black paved asphalt pavements occupy more than 30% of the total urban area, making the increased pavement temperature one of the main factors causing the heat island effect. Therefore, it is urgent to adopt effective strategies to reduce the temperature of asphalt pavement in high temperature environments in summer to improve the durability of the pavement and alleviate the urban heat island effect. Summary of the invention

[0004] In order to solve the above problems existing in the prior art, the present invention provides a wide temperature range multi-stage phase change temperature regulating asphalt mixture and a preparation method thereof. The technical problem to be solved by the present invention is achieved by the following technical solutions:

[0005] One aspect of the present invention provides a method for preparing a wide temperature range multi-stage phase change temperature regulating asphalt mixture, comprising:

[0006] S1: Prepare a variety of different composite organic eutectic phase change materials respectively;

[0007] S2: Compounding the plurality of different composite organic eutectic phase change materials in different proportions to obtain a wide temperature range multi-level phase change material;

[0008] S3: Adding the wide temperature range multi-stage phase change material into the asphalt mixture at a mass ratio of 3% to 5% to form the wide temperature range multi-stage phase change temperature regulating asphalt mixture.

[0009] In one embodiment of the present invention, the plurality of different composite organic eutectic phase change materials include CPCM1 composite organic eutectic phase change material, CPCM2 composite organic eutectic phase change material, CPCM3 composite organic eutectic phase change material, CPCM4 composite organic eutectic phase change material, CPCM5 composite organic eutectic phase change material, CPCM6 composite organic eutectic phase change material and CPCM7 composite organic eutectic phase change material, wherein:

[0010] The raw materials of the CPCM1 composite organic eutectic phase change material are 133-173 parts by mass of palmitic acid, 223-263 parts by mass of myristic acid, 584-624 parts by mass of methyl stearate and 90-110 parts by mass of expanded graphite;

[0011] The raw materials of the CPCM2 composite organic eutectic phase change material are 128 to 168 parts by mass of palmitic acid, 832 to 872 parts by mass of methyl stearate and 90 to 110 parts by mass of expanded graphite;

[0012] The raw materials of the CPCM3 composite organic eutectic phase change material are 180-220 parts by mass of stearic acid, 270-330 parts by mass of palmitic acid, 440-540 parts by mass of myristic acid and 90-110 parts by mass of expanded graphite;

[0013] The raw materials of the CPCM4 composite organic eutectic phase change material are 105-145 parts by mass of butanamide, 855-895 parts by mass of myristic acid and 90-110 parts by mass of expanded graphite;

[0014] The raw materials of the CPCM5 composite organic eutectic phase change material are 360-440 parts by mass of stearic acid, 540-660 parts by mass of palmitic acid and 90-110 parts by mass of expanded graphite;

[0015] The raw materials of the CPCM6 composite organic eutectic phase change material are 121 to 161 parts by mass of butanamide, 839 to 879 parts by mass of palmitic acid and 90 to 110 parts by mass of expanded graphite;

[0016] The raw materials of the CPCM7 composite organic eutectic phase change material are 134 to 174 parts by mass of butanamide, 826 to 866 parts by mass of stearic acid and 90 to 110 parts by mass of expanded graphite.

[0017] In one embodiment of the present invention, the preparation process of the CPCM1 composite organic eutectic phase change material includes:

[0018] 133-173 parts by mass of palmitic acid, 223-263 parts by mass of myristic acid, and 584-624 parts by mass of methyl stearate are heated until completely melted, and stirred thoroughly to form a blended mixture;

[0019] Adding 90 to 110 parts by weight of expanded expanded graphite to the blended mixture, stirring and adsorbing for 4 to 6 hours in a vacuum environment of 70 to 90° C., and then placing the mixture in a vacuum drying oven to continue adsorbing for 40 to 55 hours;

[0020] The adsorbed mixture was taken out, stirred and rinsed with anhydrous ethanol for multiple times, and placed in an oven for drying to obtain the CPCM1 composite organic eutectic phase change material.

[0021] In one embodiment of the present invention, the preparation process of the CPCM2 composite organic eutectic phase change material includes:

[0022] 128-168 parts by mass of palmitic acid and 832-872 parts by mass of methyl stearate are heated until completely melted, and are fully stirred to form a blended mixture; 90-110 parts by mass of expanded expanded graphite are added to the blended mixture, and the mixture is stirred and adsorbed for 4-6 hours in a vacuum environment of 70-90° C., and then placed in a vacuum drying oven to continue adsorption for 40-55 hours; the adsorbed mixture is taken out, stirred and rinsed with anhydrous ethanol for multiple times, and placed in an oven for drying to obtain the CPCM1 composite organic eutectic phase change material.

[0023] In one embodiment of the present invention, the S2 includes:

[0024] 2-8% by mass of CPCM1 composite organic eutectic phase change material, 17-23% by mass of CPCM2 composite organic eutectic phase change material, 27-33% by mass of CPCM3 composite organic eutectic phase change material, 17-23% by mass of CPCM4 composite organic eutectic phase change material, 7-13% by mass of CPCM5 composite organic eutectic phase change material, 7-13% by mass of CPCM6 composite organic eutectic phase change material and 2-8% by mass of CPCM7 composite organic eutectic phase change material are mixed to obtain a wide temperature range multi-stage phase change material.

[0025] In one embodiment of the present invention, the asphalt mixture comprises mineral aggregate, mineral powder and asphalt, and S3 comprises:

[0026] Dry various specifications of mineral aggregates for later use, melt and heat asphalt to the specified asphalt mixture mixing temperature for later use;

[0027] Preheating an asphalt mixture mixer to a predetermined temperature above a required mixing temperature, placing the mineral aggregates of various specifications in the asphalt mixture mixer for mixing;

[0028] The required asphalt heated to the mixing temperature is added to the asphalt mixture mixer and the mixing is continued. The mixing is then stopped. The mineral powder and the wide temperature range multi-stage phase change material heated to the mixing temperature are added to the asphalt mixture mixer and the mixing is continued until the mixture is uniform, thereby obtaining the wide temperature range multi-stage phase change temperature regulating asphalt mixture.

[0029] In one embodiment of the present invention, the asphalt is SBS polymer modified asphalt.

[0030] In one embodiment of the present invention, the S3 further includes:

[0031] Before use, the prepared wide-temperature-range multi-stage phase-change temperature-regulating asphalt mixture is kept within a predetermined mixing temperature range.

[0032] Another aspect of the present invention provides a wide temperature range multi-stage phase change temperature regulating asphalt mixture, which is prepared using the preparation method described in any one of the above embodiments.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] 1. The wide-temperature range multi-stage phase-change temperature-regulating asphalt mixture prepared by the preparation method of the present invention can rely on the latent heat characteristics of the phase-change material to give the asphalt mixture a heat storage and temperature-regulating function, thereby reducing the maximum temperature of the road surface, delaying the occurrence time of the daily maximum temperature, and reducing the surface temperature of the road surface, thereby alleviating the urban heat island effect and extending the durability of the road surface.

[0035] 2. The wide temperature range multi-stage phase change temperature regulating asphalt mixture prepared by the preparation method of the present invention has the characteristics of step-by-step phase change due to the introduction of a multi-stage phase change system, which enables it to continuously and efficiently exert its latent heat temperature regulating function within the range of 30 to 70°C. The wide temperature range multi-stage phase change temperature regulating asphalt mixture of the present invention changes at a more stable rate during the temperature change process, reducing the damage to the pavement structure caused by drastic temperature fluctuations. Especially during the transition between seasons, the temperature difference varies greatly, and the wide temperature range multi-stage phase change material provided by the present invention can effectively absorb and release heat, reduce the expansion and contraction of the pavement caused by the temperature difference, avoid cracks and surface damage, and improve the overall performance of the pavement.

[0036] 3. The wide temperature range multi-stage phase change temperature regulating asphalt mixture prepared by the preparation method of the present invention can effectively reduce the urban heat island effect by reducing the heat radiation and heat absorption of the road surface during high temperature periods. Especially in summer, by reducing the impact of road surface temperature on the surrounding air temperature, the problem of excessive temperature in the city center can be alleviated, thereby improving the quality of the urban ecological environment. In addition, the reusability and long service life of phase change materials also make this technology highly environmentally friendly and economically beneficial.

[0037] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is a flow chart of a method for preparing a wide temperature range multi-stage phase change temperature regulating asphalt mixture provided by an embodiment of the present invention;

[0039] Figure 2 are heat flow curves of different composite organic eutectic phase change materials provided by embodiments of the present invention;

[0040] Figure 3 It is the temperature rise curve of different asphalt mixtures provided by the embodiments of the present invention and the temperature difference curve between them and ordinary asphalt mixtures.

[0041] Description of reference numerals: DETAILED DESCRIPTION

[0042] In order to further illustrate the technical means and effects adopted by the present invention to achieve the predetermined purpose of the invention, a wide temperature range multi-stage phase change temperature regulating asphalt mixture and a preparation method thereof proposed by the present invention are described in detail below in combination with the accompanying drawings and specific implementation methods.

[0043] The above and other technical contents, features and effects of the present invention are clearly presented in the following detailed description of the specific implementation modes in conjunction with the accompanying drawings. Through the description of the specific implementation modes, the technical means and effects adopted by the present invention to achieve the predetermined purpose can be more deeply and specifically understood. However, the attached drawings are only for reference and explanation purposes and are not used to limit the technical solutions of the present invention.

[0044] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants are intended to cover non-exclusive inclusion, so that an article or device including a series of elements includes not only those elements, but also other elements that are not explicitly listed. In the absence of more restrictions, the elements defined by the statement "including one..." do not exclude the existence of other identical elements in the article or device including the elements.

[0045] Embodiment 1

[0046] In this embodiment, a phase change material with corresponding temperature requirements is obtained by means of eutectic, and this is used as the core unit of phase change temperature regulation. Expanded graphite is used as the encapsulation carrier structure to prepare a variety of composite organic eutectic phase change materials with different phase change temperatures. A wide temperature range multi-stage phase change temperature regulating asphalt mixture is obtained by proportioning the various composite organic eutectic phase change materials and adding them to an asphalt mixture. The wide temperature range multi-stage phase change temperature regulating asphalt mixture has a temperature regulating and cooling effect in the entire temperature range under the high temperature environment of the asphalt pavement in summer, and can continue to exert the phase change heat storage function under the high temperature environment in summer, thereby delaying the temperature change rate of the pavement, reducing the maximum temperature of the pavement, and delaying the occurrence time of the daily maximum temperature, thereby alleviating the urban heat island effect and extending the durability of the pavement.

[0047] In this embodiment, a wide temperature range multi-stage phase change material is obtained by compounding a plurality of different composite organic eutectic phase change materials in different proportions; then, the wide temperature range multi-stage phase change material is added to the asphalt mixture in a predetermined mass ratio. Figure 1 , Figure 1 This is a flow chart of a method for preparing a wide temperature range multi-stage phase change temperature regulating asphalt mixture provided by an embodiment of the present invention. The specific preparation method includes the following steps:

[0048] S1: Prepare a variety of different composite organic eutectic phase change materials respectively.

[0049] In this embodiment, a variety of different composite organic eutectic phase change materials include CPCM1 composite organic eutectic phase change material, CPCM2 composite organic eutectic phase change material, CPCM3 composite organic eutectic phase change material, CPCM4 composite organic eutectic phase change material, CPCM5 composite organic eutectic phase change material, CPCM6 composite organic eutectic phase change material and CPCM7 composite organic eutectic phase change material, wherein the raw materials of CPCM1 composite organic eutectic phase change material are 133-173 parts by mass of palmitic acid, 223-263 parts by mass of myristic acid, 584-624 parts by mass of methyl stearate and 90-110 parts by mass of expanded graphite; the raw materials of CPCM2 composite organic eutectic phase change material are 128-168 parts by mass of palmitic acid, 832-872 parts by mass of methyl stearate and 90-110 parts by mass of expanded graphite; the raw materials of CPCM3 composite organic eutectic phase change material are 180-220 parts by mass of stearic acid. The raw materials of CPCM4 composite organic eutectic phase change material are 105-145 parts by mass of butanamide, 855-895 parts by mass of myristic acid and 90-110 parts by mass of expanded graphite; the raw materials of CPCM5 composite organic eutectic phase change material are 360-440 parts by mass of stearic acid, 540-660 parts by mass of stearic acid, 100-140 parts by mass of butanamide, 270-330 parts by mass of palmitic acid, 440-540 parts by mass of myristic acid and 90-110 parts by mass of expanded graphite. The raw materials of CPCM6 composite organic eutectic phase change material are 121-161 parts by mass of butanamide, 839-879 parts by mass of palmitic acid and 90-110 parts by mass of expanded graphite; the raw materials of CPCM7 composite organic eutectic phase change material are 134-174 parts by mass of butanamide, 826-866 parts by mass of stearic acid and 90-110 parts by mass of expanded graphite.

[0050] In other embodiments, other types of appropriate composite organic eutectic phase change materials may also be included, which will not be described in detail here.

[0051] The above 7 composite organic eutectic phase change materials all use organic eutectic phase change materials as phase change core energy storage units and expanded graphite as encapsulation carriers, and are compounded by vacuum impregnation adsorption method. Specifically, the preparation process of CPCM1 composite organic eutectic phase change material includes:

[0052] 133-173 parts by mass of palmitic acid, 223-263 parts by mass of myristic acid, and 584-624 parts by mass of methyl stearate are heated until completely melted, and are fully stirred to form a blended mixture; 90-110 parts by mass of expanded expanded graphite are added to the blended mixture, and the mixture is stirred and adsorbed for 4-6 hours in a vacuum environment of 70-90° C., and then placed in a vacuum drying oven to continue adsorption for 40-55 hours; the adsorbed mixture is taken out, stirred and rinsed with anhydrous ethanol for multiple times, and placed in an oven for drying to obtain a CPCM1 composite organic eutectic phase change material.

[0053] Similar to the preparation process of the CPCM1 composite organic eutectic phase change material described above, the preparation of CPCM2 composite organic eutectic phase change material to CPCM7 composite organic eutectic phase change material only requires replacing different organic phase change materials in corresponding proportions. Exemplarily, the preparation process of CPCM2 composite organic eutectic phase change material includes:

[0054] 128-168 parts by mass of palmitic acid and 832-872 parts by mass of methyl stearate are heated until completely melted, and are fully stirred to form a blended mixture; 90-110 parts by mass of expanded expanded graphite are added to the blended mixture, and the mixture is stirred and adsorbed for 4-6 hours in a vacuum environment of 70-90° C., and then placed in a vacuum drying oven to continue adsorption for 40-55 hours; the adsorbed mixture is taken out, stirred and rinsed with anhydrous ethanol for multiple times, and placed in an oven for drying to obtain a CPCM1 composite organic eutectic phase change material.

[0055] The preparation process of CPCM3 composite organic eutectic phase change material to CPCM7 composite organic eutectic phase change material is the same as the above preparation process, which will not be repeated here.

[0056] See also Figure 2 , Figure 2 It is the heat flow curve of different composite organic eutectic phase change materials provided by the embodiments of the present invention. It can be seen from the figure that the seven composite organic eutectic phase change materials have obvious phase change latent heat peaks, the latent heat peak range is 30-70°C, and the phase difference between the peak values ​​of two adjacent composite organic eutectic phase change materials is about 4-7°C, and they gradually change from 30°C to 70°C; these effects mean that the composite organic eutectic phase change material prepared by the preparation method of the present invention can completely cover the complete high temperature environment of the asphalt pavement in summer, thereby realizing step-by-step phase change in a wide temperature range (30-70°C), and continuously and efficiently exerting its latent heat characteristics.

[0057] S2: Compounding a variety of different composite organic eutectic phase change materials in different proportions to obtain a wide temperature range multi-level phase change material.

[0058] In this embodiment, 2-8% by mass of CPCM1 composite organic eutectic phase change material, 17-23% by mass of CPCM2 composite organic eutectic phase change material, 27-33% by mass of CPCM3 composite organic eutectic phase change material, 17-23% by mass of CPCM4 composite organic eutectic phase change material, 7-13% by mass of CPCM5 composite organic eutectic phase change material, 7-13% by mass of CPCM6 composite organic eutectic phase change material and 2-8% by mass of CPCM7 composite organic eutectic phase change material are mixed to obtain a wide temperature range multi-stage phase change material.

[0059] S3: Adding the wide temperature range multi-stage phase change material into the asphalt mixture at a mass ratio of 3% to 5% to form a wide temperature range multi-stage phase change temperature regulating asphalt mixture.

[0060] The asphalt mixture of this embodiment includes mineral aggregate, mineral powder and asphalt, and step S3 specifically includes:

[0061] The mineral aggregates of various specifications are dried for use, and the asphalt is melted and heated to the specified asphalt mixture mixing temperature for use; the asphalt mixture mixer is preheated to a predetermined temperature above the required mixing temperature, and the mineral aggregates of various specifications are placed in the asphalt mixture mixer for mixing; the required asphalt heated to the mixing temperature is added to the asphalt mixture mixer and the mixing is continued, and then the mixing is stopped, and the mineral powder and the wide temperature range multi-stage phase change material heated to the mixing temperature are added to the asphalt mixture mixer, and the mixing is continued until the mixture is uniform, so as to obtain a wide temperature range multi-stage phase change temperature regulating asphalt mixture.

[0062] In addition, step S3 also includes: before use (for example, before pavement paving), keeping the prepared wide temperature range multi-stage phase change temperature regulating asphalt mixture within a predetermined mixing temperature range.

[0063] Preferably, the asphalt of this embodiment is SBS polymer modified asphalt.

[0064] Embodiment 2

[0065] Based on the first embodiment, this embodiment provides another method for preparing a wide temperature range multi-stage phase change temperature regulating asphalt mixture, the preparation method comprising:

[0066] Step 1: Prepare 7 different composite organic eutectic phase change materials respectively.

[0067] The seven different composite organic eutectic phase change materials include CPCM1 composite organic eutectic phase change material, CPCM2 composite organic eutectic phase change material, CPCM3 composite organic eutectic phase change material, CPCM4 composite organic eutectic phase change material, CPCM5 composite organic eutectic phase change material, CPCM6 composite organic eutectic phase change material and CPCM7 composite organic eutectic phase change material, wherein the raw materials of CPCM1 composite organic eutectic phase change material are 153 parts by mass of palmitic acid, 243 parts by mass of myristic acid, 604 parts by mass of methyl stearate and 100 parts by mass of expanded graphite; the raw materials of CPCM2 composite organic eutectic phase change material are 148 parts by mass of palmitic acid, 852 parts by mass of methyl stearate and 100 parts by mass of expanded graphite; the raw materials of CPCM3 composite organic eutectic phase change material are The raw materials of CPCM4 composite organic eutectic phase change material are 125 parts by mass of butanamide, 875 parts by mass of myristic acid and 100 parts by mass of expanded graphite; the raw materials of CPCM5 composite organic eutectic phase change material are 400 parts by mass of stearic acid, 610 parts by mass of palmitic acid and 100 parts by mass of expanded graphite; the raw materials of CPCM6 composite organic eutectic phase change material are 141 parts by mass of butanamide, 859 parts by mass of palmitic acid and 100 parts by mass of expanded graphite; the raw materials of CPCM7 composite organic eutectic phase change material are 154 parts by mass of butanamide, 846 parts by mass of stearic acid and 100 parts by mass of expanded graphite.

[0068] Specifically, the preparation process of CPCM1 composite organic eutectic phase change material includes:

[0069] 153 parts by mass of palmitic acid, 243 parts by mass of myristic acid, and 604 parts by mass of methyl stearate were heated until completely melted, mixed at 300 rad / min for 4 hours, and fully stirred to form a blended mixture; 100 parts by mass of 50-mesh expanded graphite was added to the blended mixture, stirred and adsorbed for 5 hours in a vacuum environment of 80°C, and then placed in a vacuum drying oven to continue adsorption for 48 hours; the adsorbed mixture was taken out, stirred and rinsed with anhydrous ethanol for 5 times, and placed in an oven at 80°C for 24 hours to obtain CPCM1 composite organic eutectic phase change material.

[0070] Similar to the preparation process of the CPCM1 composite organic eutectic phase change material described above, the preparation of CPCM2 composite organic eutectic phase change material to CPCM7 composite organic eutectic phase change material only requires replacing different organic phase change materials in corresponding proportions. Exemplarily, the preparation process of CPCM2 composite organic eutectic phase change material includes:

[0071] 153 parts by mass of palmitic acid, 243 parts by mass of myristic acid, and 604 parts by mass of methyl stearate were heated until completely melted, mixed at 300 rad / min for 4 hours, and fully stirred to form a blended mixture; 100 parts by mass of 50-mesh expanded graphite was added to the blended mixture, stirred and adsorbed for 5 hours in a vacuum environment of 80°C, and then placed in a vacuum drying oven to continue adsorption for 48 hours; the adsorbed mixture was taken out, stirred and rinsed with anhydrous ethanol for 5 times, and placed in an oven at 80°C for 24 hours to obtain CPCM1 composite organic eutectic phase change material.

[0072] The preparation process of CPCM3 composite organic eutectic phase change material to CPCM7 composite organic eutectic phase change material is the same as the above preparation process, which will not be repeated here.

[0073] Step 2: Compound 7 different composite organic eutectic phase change materials in different proportions to obtain a wide temperature range multi-level phase change material.

[0074] Specifically, 5% by mass of CPCM1 composite organic eutectic phase change material, 20% by mass of CPCM2 composite organic eutectic phase change material, 30% by mass of CPCM3 composite organic eutectic phase change material, 20% by mass of CPCM4 composite organic eutectic phase change material, 10% by mass of CPCM5 composite organic eutectic phase change material, 10% by mass of CPCM6 composite organic eutectic phase change material and 5% by mass of CPCM7 composite organic eutectic phase change material are compounded to obtain a wide temperature range multi-level phase change material.

[0075] S3: Adding the wide temperature range multi-stage phase change material into the asphalt mixture at a mass ratio of 3% to 5% to form a wide temperature range multi-stage phase change temperature regulating asphalt mixture.

[0076] The effect of the wide temperature range multi-stage phase change temperature regulating asphalt mixture prepared in this embodiment is further described by experiments below, wherein the asphalt mixture includes mineral aggregate, mineral powder and SBS polymer modified asphalt, and the proportion of the asphalt mixture is shown in Table 1. The raw materials required for the wide temperature range multi-stage phase change temperature regulating asphalt mixture include: mineral aggregate, mineral powder, SBS polymer modified asphalt and wide temperature range multi-stage phase change material. The gradation of the mineral aggregate adopts the median value of the mineral aggregate gradation range required in the "Technical Specifications for Highway Asphalt Pavement Construction" (JTG F40-2004).

[0077] Specifically, various specifications (different coarseness and fineness) of mineral aggregates are dried for use, and at the same time, asphalt is melted and heated to the specified asphalt mixture mixing temperature for use; the asphalt mixture mixer is preheated to about 10°C above the mixing temperature for use, the preheated coarse and fine mineral aggregates are placed in the mixer, and mixed for 90 seconds, and then the required amount of asphalt heated to the mixing temperature is added, and the mixer is started to mix for 60 seconds; then the mixing is stopped, and the mineral powder and wide temperature range multi-stage phase change material heated to the mixing temperature are added, and the mixing is continued until it is uniform, so as to obtain a wide temperature range multi-stage phase change temperature regulating asphalt mixture and keep the prepared wide temperature range multi-stage phase change temperature regulating asphalt mixture within the required mixing temperature range.

[0078] Subsequently, the specimens required for the experiment were prepared using the mixed wide temperature range multi-stage phase change temperature regulating asphalt mixture. Specifically, the mixed wide temperature range multi-stage phase change temperature regulating asphalt mixture was evenly weighed to obtain the required amount for each specimen, and then molded into the required specimen type according to the test requirements. After the specimen was compacted, the sleeve and base were removed, and the test mold containing the specimen was placed horizontally and cooled to room temperature, and then placed on a demoulding machine to remove the specimen. The specimen was carefully placed on a dry and clean surface and left to stand overnight at room temperature for testing.

[0079] Implementation Case 1: 3% of the wide temperature range multi-stage phase change material prepared in Example 2 (accounting for the total mass ratio of the asphalt mixture) was added to the AC-13 asphalt mixture. The formulation of the asphalt mixture is shown in Table 1.

[0080] Table 1 Asphalt mixture ratio

[0081]

[0082] Implementation Case 2: 4% of the wide temperature range multi-stage phase change material prepared in Example 2 (accounting for the total mass ratio of the asphalt mixture) was added to the AC-13 asphalt mixture. The formulation of the asphalt mixture is shown in Table 1.

[0083] Implementation Case 3: 5% of the wide temperature range multi-stage phase change material prepared in Example 2 (accounting for the total mass ratio of the asphalt mixture) is added to the AC-13 asphalt mixture. The formulation of the asphalt mixture is shown in Table 1.

[0084] The samples without adding wide temperature range multi-stage phase change material were used as the control group. It should be noted that the sizes of the specimens prepared using the materials of Implementation Case 1, Implementation Case 2, Implementation Case 3 and the reference group were exactly the same.

[0085] The performance of different implementation cases is shown in Table 2. The temperature adjustment effect was tested through indoor temperature adjustment test. The temperature rise curves of different asphalt mixtures and the temperature difference curves between them and ordinary asphalt mixtures are shown in Table 2. Figure 3 shown.

[0086] The experimental results show that the wide temperature range multi-stage phase change temperature regulating asphalt mixture prepared by the preparation method of the present invention greatly improves the anti-rutting performance of the asphalt mixture, and the improvement effect under different implementation cases is roughly the same. Furthermore, the temperature adjustment test results show that compared with ordinary asphalt mixtures, the wide temperature range multi-stage phase change temperature regulating asphalt mixture prepared by the preparation method of the present invention has a slower heating rate, while effectively delaying the occurrence of the highest temperature, and showing a significant temperature difference, with the maximum temperature difference recorded as -16°C (Example 3), -15°C (Example 2) and -14°C (Example 1). The large temperature difference can intuitively reflect its cooling effect, thereby effectively reducing the road surface temperature. The lower the road surface temperature, the better its bearing capacity and anti-deformation ability. At the same time, a lower road surface temperature is beneficial to alleviating the urban heat island effect.

[0087] Table 2 Hamburger rutting test results of different samples

[0088] Sample Rutting depth (mm) AC-13 asphalt mixture 14.55 Implementation Case 1 3.24 Implementation Case 2 3.43 Implementation Case 3 3.54

[0089] Through the above experiments, it can be known that the wide temperature range multi-stage phase change temperature regulating asphalt mixture prepared by introducing the above wide temperature range multi-stage phase change material into the asphalt mixture using the method of the present invention can buffer the temperature rise of the road surface in summer, prolong the time of the highest daily temperature, and reduce the surface temperature of the road surface.

[0090] The wide temperature range multi-stage phase change temperature regulating asphalt mixture prepared by the preparation method of the present invention has the characteristic of step-by-step phase change due to the introduction of a multi-stage phase change system, so that it can continuously and efficiently exert the latent heat temperature regulating function in the range of 30 to 70°C. The wide temperature range multi-stage phase change temperature regulating asphalt mixture of the present invention changes at a more stable rate during the temperature change process, reducing the damage to the pavement structure caused by drastic temperature fluctuations. Especially during the transition between seasons, the temperature difference varies greatly, and the wide temperature range multi-stage phase change material provided by the present invention can effectively absorb and release heat, reduce the expansion and contraction of the pavement caused by the temperature difference, avoid cracks and surface damage, and improve the overall performance of the pavement.

[0091] The wide temperature range multi-stage phase change temperature regulating asphalt mixture of the present invention can effectively reduce the urban heat island effect by reducing the heat radiation and heat absorption of the road surface during high temperature periods. Especially in summer, by reducing the impact of road surface temperature on the surrounding air temperature, the problem of excessive temperature in the city center can be alleviated, thereby improving the quality of the urban ecological environment. In addition, the reusability and long service life of phase change materials also make this technology highly environmentally friendly and economically beneficial.

[0092] The present invention can improve the performance of asphalt pavement in many aspects through the technical application of wide temperature range multi-stage phase change temperature regulating asphalt mixture, which can not only improve the temperature control effect and extend the life of the pavement, but also effectively solve the urban heat island effect, improve road safety, reduce maintenance costs and other problems. These advantages make this technology have broad application prospects and significant economic benefits in modern transportation infrastructure.

[0093] In the several embodiments provided by the present invention, it should be understood that the apparatus and method disclosed by the present invention can be implemented in other ways. For example, the apparatus embodiments described above are only illustrative, for example, the division of the modules is only a logical function division, and there may be other division methods in actual implementation, for example, multiple modules or components can be combined or integrated into another system, or some features can be ignored or not executed.

[0094] In addition, each functional module in each embodiment of the present invention may be integrated into one processing module, or each module may exist physically separately, or two or more modules may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of hardware plus software functional modules.

[0095] The above contents are further detailed descriptions of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as falling within the scope of protection of the present invention.

Claims

1. A method for preparing a wide temperature range multi-stage phase change temperature regulating asphalt mixture, characterized in that: include: S1: Prepare a variety of different composite organic eutectic phase change materials respectively; S2: Compounding the plurality of different composite organic eutectic phase change materials in different proportions to obtain a wide temperature range multi-level phase change material; S3: Adding the wide temperature range multi-stage phase change material into the asphalt mixture at a mass ratio of 3% to 5% to form the wide temperature range multi-stage phase change temperature regulating asphalt mixture.

2. The method for preparing a wide temperature range multi-stage phase change temperature regulating asphalt mixture according to claim 1, characterized in that: The plurality of different composite organic eutectic phase change materials include CPCM1 composite organic eutectic phase change material, CPCM2 composite organic eutectic phase change material, CPCM3 composite organic eutectic phase change material, CPCM4 composite organic eutectic phase change material, CPCM5 composite organic eutectic phase change material, CPCM6 composite organic eutectic phase change material and CPCM7 composite organic eutectic phase change material, wherein: The raw materials of the CPCM1 composite organic eutectic phase change material are 133-173 parts by mass of palmitic acid, 223-263 parts by mass of myristic acid, 584-624 parts by mass of methyl stearate and 90-110 parts by mass of expanded graphite; The raw materials of the CPCM2 composite organic eutectic phase change material are 128 to 168 parts by mass of palmitic acid, 832 to 872 parts by mass of methyl stearate and 90 to 110 parts by mass of expanded graphite; The raw materials of the CPCM3 composite organic eutectic phase change material are 180-220 parts by mass of stearic acid, 270-330 parts by mass of palmitic acid, 440-540 parts by mass of myristic acid and 90-110 parts by mass of expanded graphite; The raw materials of the CPCM4 composite organic eutectic phase change material are 105-145 parts by mass of butanamide, 855-895 parts by mass of myristic acid and 90-110 parts by mass of expanded graphite; The raw materials of the CPCM5 composite organic eutectic phase change material are 360-440 parts by mass of stearic acid, 540-660 parts by mass of palmitic acid and 90-110 parts by mass of expanded graphite; The raw materials of the CPCM6 composite organic eutectic phase change material are 121 to 161 parts by mass of butanamide, 839 to 879 parts by mass of palmitic acid and 90 to 110 parts by mass of expanded graphite; The raw materials of the CPCM7 composite organic eutectic phase change material are 134 to 174 parts by mass of butanamide, 826 to 866 parts by mass of stearic acid and 90 to 110 parts by mass of expanded graphite.

3. The method for preparing a wide temperature range multi-stage phase change temperature regulating asphalt mixture according to claim 2, characterized in that: The preparation process of the CPCM1 composite organic eutectic phase change material comprises: 133-173 parts by mass of palmitic acid, 223-263 parts by mass of myristic acid, and 584-624 parts by mass of methyl stearate are heated until completely melted, and stirred thoroughly to form a blended mixture; Adding 90 to 110 parts by weight of expanded expanded graphite to the blended mixture, stirring and adsorbing for 4 to 6 hours in a vacuum environment of 70 to 90° C., and then placing the mixture in a vacuum drying oven to continue adsorbing for 40 to 55 hours; The adsorbed mixture was taken out, stirred and rinsed with anhydrous ethanol for multiple times, and placed in an oven for drying to obtain the CPCM1 composite organic eutectic phase change material.

4. The method for preparing a wide temperature range multi-stage phase change temperature regulating asphalt mixture according to claim 2, characterized in that: The preparation process of the CPCM2 composite organic eutectic phase change material comprises: 128-168 parts by mass of palmitic acid and 832-872 parts by mass of methyl stearate are heated until completely melted, and are fully stirred to form a blended mixture; 90-110 parts by mass of expanded expanded graphite are added to the blended mixture, and the mixture is stirred and adsorbed for 4-6 hours in a vacuum environment of 70-90° C., and then placed in a vacuum drying oven to continue adsorption for 40-55 hours; the adsorbed mixture is taken out, stirred and rinsed with anhydrous ethanol for multiple times, and placed in an oven for drying to obtain the CPCM1 composite organic eutectic phase change material.

5. The method for preparing a wide temperature range multi-stage phase change temperature regulating asphalt mixture according to claim 2, characterized in that: The S2 includes: 2-8% by mass of CPCM1 composite organic eutectic phase change material, 17-23% by mass of CPCM2 composite organic eutectic phase change material, 27-33% by mass of CPCM3 composite organic eutectic phase change material, 17-23% by mass of CPCM4 composite organic eutectic phase change material, 7-13% by mass of CPCM5 composite organic eutectic phase change material, 7-13% by mass of CPCM6 composite organic eutectic phase change material and 2-8% by mass of CPCM7 composite organic eutectic phase change material are mixed to obtain a wide temperature range multi-stage phase change material.

6. The method for preparing a wide temperature range multi-stage phase change temperature regulating asphalt mixture according to claim 1, characterized in that: The asphalt mixture comprises mineral aggregate, mineral powder and asphalt, and S3 comprises: Dry various specifications of mineral aggregates for later use, melt and heat asphalt to the specified asphalt mixture mixing temperature for later use; Preheating an asphalt mixture mixer to a predetermined temperature above a required mixing temperature, placing the mineral aggregates of various specifications in the asphalt mixture mixer for mixing; The required asphalt heated to the mixing temperature is added to the asphalt mixture mixer and the mixing is continued. The mixing is then stopped. The mineral powder and the wide temperature range multi-stage phase change material heated to the mixing temperature are added to the asphalt mixture mixer and the mixing is continued until the mixture is uniform, thereby obtaining the wide temperature range multi-stage phase change temperature regulating asphalt mixture.

7. The method for preparing a wide temperature range multi-stage phase change temperature regulating asphalt mixture according to claim 6, characterized in that: The asphalt is SBS polymer modified asphalt.

8. The method for preparing a wide temperature range multi-stage phase change temperature regulating asphalt mixture according to claim 6, characterized in that: The S3 further includes: Before use, the prepared wide-temperature-range multi-stage phase-change temperature-regulating asphalt mixture is kept within a predetermined mixing temperature range.

9. A wide temperature range multi-stage phase change temperature regulating asphalt mixture, characterized in that: Prepared by the preparation method according to any one of claims 1 to 8.

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