Asphalt regeneration agent and preparation method and application thereof

Abstract

The present invention relates to an asphalt regeneration agent and a preparation method and application thereof, wherein the asphalt regeneration agent comprises 100 parts of low-carbon alcohol esters of high-carbon fatty acids, 10-20 parts of plant wax, 5-10 parts of high-carbon fatty acids, and 10-15 parts of fatty acid amide wax. The present invention compounds low-carbon alcohol esters of high-carbon fatty acids, plant wax, high-carbon fatty acids and fatty acid amide wax to prepare the asphalt regeneration agent, and by designing the system formula, the asphalt regeneration agent has good stability and no stratification, has better compatibility with modified asphalt, and can realize the regeneration of aged modified asphalt, and is suitable for planing and repairing modified asphalt pavement.

Description

Technical Field

[0001] The present invention relates to the technical field of asphalt regeneration, and in particular to an asphalt regeneration agent and a preparation method and application thereof. Background Art

[0002] In recent years, with the rapid development of my country's economy, my country's asphalt road construction has developed rapidly, forming a highway network connecting the whole country, which has played a huge role in China's economic take-off. my country's highway construction mileage ranks among the top in the world. With the upgrading of highway construction technology, the application of modified asphalt in domestic roads has also increased year by year due to its excellent performance. Among them, SBS (styrene-butadiene-styrene block copolymer) modified asphalt is a commonly used polymer modified asphalt with excellent high and low temperature performance. It is widely used in the construction of various grades of pavement, especially highway pavement. However, asphalt pavement is prone to various pavement diseases during use, such as rutting, cracks, potholes and other common problems, so asphalt pavement needs to be regularly repaired and maintained to ensure its service life and road condition stability. Therefore, roads that have been paved for a long time not only need maintenance, but also need to be repaired and repaved. Due to the huge scale of my country's highway mileage, a large amount of waste asphalt mixture (RAP) will be generated during the maintenance process every year, which will have a serious impact on the road and the surrounding environment. One of the current methods of pavement regeneration technology is to regenerate the aged asphalt in RAP, thereby achieving the purpose of regenerating asphalt mixture and restoring road performance. Therefore, choosing excellent regeneration agents to restore the performance of old asphalt is very important for pavement regeneration technology.

[0003] At present, the traditional regeneration agent widely used in China is mainly composed of low-viscosity mineral oil as the base oil, with additives such as plasticizers, anti-aging agents and penetrants, which achieve the purpose of regeneration by making up for the light components lost during the aging process of asphalt. However, there are the following problems with using mineral oil as raw material: First, mineral oil is also a non-renewable resource. Its large-scale use is bound to cause resource loss and waste, which does not meet the national policy requirements of low-carbon environmental protection. Second, due to the serious internal circulation of the asphalt industry, manufacturers have strict cost control. The mineral oil products used by some manufacturers have excessive aromatics and heavy metals, which not only affects the environment but also the health of operators. Third, there are differences in the compatibility of mineral oil with SBS in modified asphalt. To meet the requirements of the regenerated asphalt index, the addition amount is generally high, and the price of mineral oil is greatly affected by the fluctuation of crude oil prices, which is not conducive to the cost control of asphalt users. Therefore, developing an asphalt regeneration agent based on renewable raw materials to achieve the goals of small addition amount, low cost and good effect is conducive to the large-scale promotion of asphalt regeneration applications and meets the technical upgrading needs of the overall industry.

[0004] Chinese patent CN117487371A discloses a bio-based asphalt regeneration cold patching liquid, which is produced by mixing oleic acid monoester, vegetable oil and terpene compounds. The materials used are environmentally friendly bio-based raw materials, but this method is only for base asphalt. The compatibility of vegetable oil with the modifier SBS is general. When it is used for regenerating modified asphalt, especially after supplementing the modified asphalt, it cannot improve the segregation of the modified asphalt. At the same time, oleic acid monoester as a compatibilizer also brings about the problem of increased asphalt penetration and lower softening point, and there is a risk of using asphalt in a high temperature environment.

[0005] Chinese patent CN104761917A discloses an organic composite warm mix asphalt, including base asphalt, fatty acid low carbon alcohol ester and amide surfactant. It mainly uses fatty acid low carbon alcohol ester as the main material of the warm mix agent to reduce the operating temperature. However, amide surfactants are easy to stratify and separate in fatty acid low carbon alcohol ester, and are particularly not suitable for operating conditions where modified asphalt is added.

[0006] Chinese patent CN102448907A discloses that modified regenerated asphalt concrete is obtained by adding a regeneration modifier and a temperature-adjusting additive into waste asphalt concrete. The regeneration modifier is composed of one or more of a binder, an elastic agent, a plasticizer, an anti-stripping agent, an inorganic powder and short fibers, and the binder includes organic acids, vegetable oils, etc.; the temperature-adjusting additive is composed of one or more of a wettable powder, a wax, and a foaming agent, and the wax includes carnauba wax, etc. However, the stability of the wax-oil system is poor, and the patent does not solve the stability problem of the wax-oil system. In addition, the patent does not indicate the proportion of each component, nor does it involve the effect of different proportions on the asphalt regeneration effect. Summary of the invention

[0007] The purpose of the present invention is to provide an asphalt regeneration agent which has good stability, is not easy to delaminate, has good compatibility with modified asphalt and is suitable for regeneration of modified asphalt, and a preparation method thereof.

[0008] In order to achieve the above object, the technical solution adopted by the present invention is:

[0009] An asphalt regeneration agent, comprising the following components in parts by weight:

[0010] 100 parts of low-carbon alcohol esters of high-carbon fatty acids;

[0011] 10-20 parts of vegetable wax;

[0012] 5-10 portions of high-carbon fatty acids;

[0013] 10-15 parts of fatty acid amide wax.

[0014] Low-carbon alcohol esters of high-carbon fatty acids are a good renewable oil derivative product. They have good compatibility with asphalt and SBS, can be used as asphalt functional additives, and have good compatibility with plant-based raw materials; fatty acid amide wax can work synergistically with resin materials such as SBS to reduce the working temperature of asphalt without reducing the penetration of asphalt, and realize the rapid regeneration processing of modified asphalt. However, the two have poor compatibility and are easy to separate by stratification. By adding plant wax and high-carbon fatty acids, high-carbon fatty acids can pre-react with fatty acid amide wax, increase the compatibility of fatty acid amide wax with low-carbon alcohol esters of high-carbon fatty acids, thereby improving the compatibility of regeneration agents and modified asphalt. In addition, it can also reduce the operating temperature of on-site construction, improve efficiency and production safety, and combine plant wax as a cosolvent to further improve the stability of the system, thereby forming a stable and uniform paste solid, which is convenient to use and can avoid the segregation of modified asphalt; In addition, plant wax is a high-carbon alcohol ester of high-carbon fatty acids derived from natural plants, generally has a stable long-chain structure, and after being dispersed in the asphalt system, it can significantly increase the flexibility of asphalt.

[0015] Preferably, the high-carbon fatty acid in the low-carbon alcohol ester of the high-carbon fatty acid is an unsaturated fatty acid having 15 to 20 carbon atoms, and the low-carbon alcohol is a monohydric alcohol having 1 to 4 carbon atoms.

[0016] More preferably, the high-carbon fatty acid in the low-carbon alcohol ester of the high-carbon fatty acid is an unsaturated fatty acid having 16 to 19 carbon atoms, and the low-carbon alcohol is a monohydric alcohol having 1 to 2 carbon atoms.

[0017] In some embodiments, the low-carbon alcohol ester of high-carbon fatty acid is methyl oleate. Methyl oleate has a high flash point, good compatibility with asphalt and SBS, and also has good compatibility with plant-based raw materials, and is a good renewable oil derivative product.

[0018] Preferably, the vegetable wax is selected from one or more of palm wax, rice bran wax and sunflower seed wax.

[0019] Preferably, the high-carbon fatty acid is an unsaturated fatty acid having 15 to 20 carbon atoms.

[0020] More preferably, the high-carbon fatty acid is an unsaturated fatty acid having 16 to 19 carbon atoms.

[0021] In some embodiments, the high carbon fatty acid is oleic acid.

[0022] Furthermore, the high-carbon fatty acid is selected from one or more of palm oil oleic acid, soybean oil oleic acid, and rapeseed oil oleic acid.

[0023] Furthermore, the iodine value of the high carbon fatty acid is less than or equal to 120gI 2 / 100g.

[0024] Preferably, the fatty acid in the fatty acid amide wax is an unsaturated fatty acid having 20 to 25 carbon atoms.

[0025] More preferably, the fatty acid in the fatty acid amide wax is an unsaturated fatty acid having 21 to 24 carbon atoms.

[0026] In some embodiments, the fatty acid amide wax is erucamide wax. Erucamide wax is a high carbon polymer produced in the production of erucamide, which is polymerized erucamide and is a brown to tan wax block with a melting point above 100°C.

[0027] Preferably, the asphalt regeneration agent also includes epoxy fatty acid esters. Due to their natural structural characteristics, bio-based materials have unsaturated bonds such as olefinic bonds. When used alone, they have poor oxidative aging performance, and their service life will be reduced to varying degrees depending on the regional environment. On the one hand, epoxy fatty acid methyl ester can improve the oxidative stability of bio-based materials and increase the gloss and service life of regenerated asphalt products; on the other hand, it can be used in conjunction with plant wax as a cosolvent to further improve the stability of the system.

[0028] More preferably, the epoxy fatty acid ester is epoxy fatty acid methyl ester.

[0029] In some embodiments, the asphalt regeneration agent includes the following components in parts by weight:

[0030] 100 parts of low-carbon alcohol esters of high-carbon fatty acids;

[0031] 10-20 parts of vegetable wax;

[0032] 5-10 portions of high-carbon fatty acids;

[0033] 10-15 parts of fatty acid amide wax;

[0034] 10-15 parts of epoxy fatty acid ester.

[0035] In some specific and preferred embodiments, the asphalt regeneration agent comprises the following components in parts by weight:

[0036] 100 parts of methyl oleate;

[0037] 10-20 parts of vegetable wax;

[0038] Oleic acid 5-10 parts;

[0039] 10-15 parts of erucamide wax;

[0040] Epoxy fatty acid methyl ester 10-15 parts.

[0041] Preferably, the asphalt regeneration agent is a paste solid at room temperature, wherein, unless otherwise specified, the room temperature is 20-30°C.

[0042] The present invention also provides a method for preparing the asphalt regeneration agent as described above, comprising the following steps:

[0043] (1) mixing low-carbon alcohol esters of some high-carbon fatty acids with vegetable wax, and selectively adding epoxy fatty acid esters;

[0044] (2) mixing the high-carbon fatty acid, fatty acid amide wax and the remaining low-carbon alcohol ester of the high-carbon fatty acid;

[0045] (3) Mixing the mixed system of step (1) with the mixed system of step (2).

[0046] Preferably, in step (2), the mixing is performed under stirring, and the mixing temperature is controlled to be 70-90°C.

[0047] Further preferably, the step (2) specifically comprises mixing the high-carbon fatty acid and fatty acid amide wax, then heating to 60-90° C., gradually adding the remaining low-carbon alcohol ester of the high-carbon fatty acid, raising the temperature to 90-100° C. and stirring and mixing.

[0048] Preferably, in step (1), the mixing is performed under stirring, and the mixing temperature is controlled to be 65-85°C.

[0049] More preferably, in step (1), the stirring speed is 40-80 rpm and the stirring time is 20-40 min.

[0050] Preferably, in step (3), the mixing is performed under stirring, and the mixing temperature is controlled to be 110-130°C, more preferably 115-125°C.

[0051] The present invention also provides an application of the asphalt regeneration agent as described above, which includes adding the asphalt regeneration agent into aged modified asphalt.

[0052] Preferably, the asphalt regeneration agent accounts for 1-10% of the total mass of the asphalt regeneration agent and the aged modified asphalt, more preferably 2-8%, further preferably 3-5%, and further preferably 3.5-4.5%.

[0053] Preferably, the modified asphalt comprises base asphalt, a modifier and aromatic oil, and the modifier is styrene-butadiene-styrene block copolymer (SBS).

[0054] In some implementations, based on the total mass of the modified asphalt being 100%, the modified asphalt comprises:

[0055] Base asphalt 85~95%,

[0056] SBS 2~6%,

[0057] Aromatic oil balance.

[0058] The present invention also provides an asphalt mixture composition, comprising the asphalt rejuvenating agent as described above and aged modified asphalt, wherein the modified asphalt is as described above.

[0059] Preferably, the asphalt regeneration agent accounts for 1-10% of the total mass of the asphalt mixture composition, more preferably 2-8%, further preferably 3-5%, and further preferably 3.5-4.5%.

[0060] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art:

[0061] The present invention compounds low-carbon alcohol esters of high-carbon fatty acids, vegetable waxes, high-carbon fatty acids and fatty acid amide waxes into an asphalt regeneration agent. By designing the system formula, the asphalt regeneration agent has good stability and no stratification, and has better compatibility with modified asphalt. At the same time, it can achieve the regeneration of aged modified asphalt and is suitable for planing and repairing modified asphalt pavements. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1 These are actual photos of the asphalt regeneration agents prepared in Example 1 and Comparative Example 1, wherein the left picture is the asphalt regeneration agent prepared in Comparative Example 1, and the right picture is the asphalt regeneration agent prepared in Example 1. DETAILED DESCRIPTION

[0063] The present invention is further described below in conjunction with the examples. However, the present invention is not limited to the following examples. The implementation conditions used in the examples can be further adjusted according to the different requirements of specific use, and the implementation conditions not specified are conventional conditions in the industry. The technical features involved in each embodiment of the present invention can be combined with each other as long as they do not conflict with each other.

[0064] If not otherwise specified, the reagents and instruments used in the following embodiments and comparative examples are all commercially available products, among which methyl oleate was purchased from Suzhou Fengbei Biotechnology Co., Ltd., methyl oleate 1192; rice bran wax was imported from Suzhou Fengbei Biotechnology Co., Ltd., with a vegetable wax content of more than 50%; palm wax was imported from Suzhou Fengbei Biotechnology Co., Ltd., with a content of 99%; epoxy fatty acid methyl ester was purchased from outside, CAS No.: 6084-76-0, and the control indicator epoxy value was greater than or equal to 2.6; oleic acid was imported from Suzhou Fengbei Biotechnology Co., Ltd., with a content of 99%; erucamide wax was purchased from outside, with a control indicator freezing point of more than 100°C; the modifier SBS was purchased from Baling Petrochemical Branch of China Petrochemical Group Asset Management Co., Ltd., with a brand name of YH-792E; aromatic oil (a by-product of petroleum refining with an aromatic content of more than 70%, also called rubber oil) is the environmentally friendly rubber oil of CNOOC Asphalt.

[0065] Unless otherwise specified, "parts" hereinafter refer to "parts by weight". Example 1

[0066] A method for preparing an asphalt regeneration agent comprises the following steps:

[0067] Step 1: Add 50 parts of methyl oleate, 10 parts of rice bran wax and 10 parts of epoxy fatty acid methyl ester into the first reaction kettle, heat to 70° C., and stir at 60 rpm for 30 minutes.

[0068] Step 2: Add 10 parts of oleic acid and 10 parts of erucamide wax into the second reaction kettle, heat to 60°C, gradually add 50 parts of methyl oleate, continue to heat to 90°C, and stir for 30 minutes.

[0069] Step 3: Transfer the material in the second reaction kettle into the first reaction kettle, slowly heat to 120°C, continue stirring while heating for 1 hour, and then cool to 60°C.

[0070] Step 4: Pack into inner film woven bag / open barrel and cool to room temperature.

[0071] The asphalt regeneration agent prepared in this embodiment is a paste-like solid at room temperature. Figure 1 As shown, after being placed at room temperature for 6 months, it is still a paste solid without separation. Example 2

[0072] A method for preparing an asphalt regeneration agent comprises the following steps:

[0073] Step 1: Add 50 parts of methyl oleate, 20 parts of palm wax and 10 parts of epoxy fatty acid methyl ester into the first reaction kettle, heat to 70°C, and stir at 60 rpm for 30 minutes.

[0074] Step 2: Add 10 parts of oleic acid and 10 parts of erucamide wax into the second reaction kettle, heat to 60°C, gradually add 50 parts of methyl oleate, continue to heat to 90°C, and stir for 30 minutes.

[0075] Step 3: Transfer the material in the second reaction kettle into the first reaction kettle, slowly heat to 120°C, continue stirring while heating for 1 hour, and then cool to 60°C.

[0076] Step 4: Pack into inner film woven bag / open barrel and cool to room temperature.

[0077] The asphalt regeneration agent prepared in this example is a paste solid at room temperature and remains a paste solid after being left at room temperature for 6 months without any delamination. Example 3

[0078] A method for preparing an asphalt regeneration agent comprises the following steps:

[0079] Step 1: Add 50 parts of methyl oleate, 20 parts of palm wax and 10 parts of epoxy fatty acid methyl ester into the first reaction kettle, heat to 70°C, and stir at 60 rpm for 30 minutes.

[0080] Step 2: Add 10 parts of oleic acid and 15 parts of erucamide wax into the second reaction kettle, heat to 60°C, gradually add 50 parts of methyl oleate, continue to heat to 90°C, and stir for 30 minutes.

[0081] Step 3: Transfer the material in the second reaction kettle into the first reaction kettle, slowly heat to 120°C, continue stirring while heating for 1 hour, and then cool to 60°C.

[0082] Step 4: Pack into inner film woven bag / open barrel and cool to room temperature.

[0083] The asphalt regeneration agent prepared in this example is a paste solid at room temperature and remains a paste solid after being left at room temperature for 6 months without any delamination. Example 4

[0084] A method for preparing an asphalt regeneration agent comprises the following steps:

[0085] Step 1: Add 50 parts of methyl oleate, 20 parts of palm wax and 10 parts of epoxy fatty acid methyl ester into the first reaction kettle, heat to 70°C, and stir at 60 rpm for 30 minutes.

[0086] Step 2: Add 5 parts of oleic acid and 10 parts of erucamide wax into the second reaction kettle, heat to 60°C, gradually add 50 parts of methyl oleate, continue to heat to 90°C, and stir for 30 minutes.

[0087] Step 3: Transfer the material in the second reaction kettle into the first reaction kettle, slowly heat to 120°C, continue stirring while heating for 1 hour, and then cool to 60°C.

[0088] Step 4: Pack into inner film woven bag / open barrel and cool to room temperature.

[0089] The asphalt regeneration agent prepared in this example is a paste solid at room temperature and remains a paste solid after being left at room temperature for 6 months without any delamination. Example 5

[0090] A method for preparing an asphalt regeneration agent comprises the following steps:

[0091] Step 1: Add 50 parts of methyl oleate and 20 parts of palm wax into the first reaction kettle, heat to 70°C, and stir at 60 rpm for 30 minutes.

[0092] Step 2: Add 10 parts of oleic acid and 10 parts of erucamide wax into the second reaction kettle, heat to 60°C, gradually add 50 parts of methyl oleate, continue to heat to 90°C, and stir for 30 minutes.

[0093] Step 3: Transfer the material in the second reaction kettle into the first reaction kettle, slowly heat to 120°C, continue stirring while heating for 1 hour, and then cool to 60°C.

[0094] Step 4: Pack into inner film woven bag / open barrel and cool to room temperature.

[0095] The asphalt regeneration agent prepared in this example is a paste solid at room temperature and remains a paste solid after being left at room temperature for 6 months without any delamination.

[0096] Comparative Example 1

[0097] A method for preparing an asphalt regeneration agent comprises the following steps:

[0098] Step 1: Add 100 parts of methyl oleate and 10 parts of erucamide wax into a reaction kettle, heat to 70°C, and stir at 60 rpm for 30 minutes.

[0099] Step 2: Slowly heat the reactor in step 1 to 120°C and continue stirring for 1 hour while heating.

[0100] Step 3: Cool to 60℃, pack into inner film woven bag / open barrel and cool to room temperature.

[0101] The asphalt regeneration agent prepared in this comparative example is in a stratified state at room temperature, with a small amount of yellow oily liquid in the upper layer, and the product as a whole is a fluid porridge-like liquid. Figure 1 shown.

[0102] Comparative Example 2

[0103] A method for preparing an asphalt regeneration agent comprises the following steps:

[0104] Step 1: Add 50 parts of methyl oleate, 20 parts of palm wax and 10 parts of epoxy fatty acid methyl ester into the first reaction kettle, heat to 70°C, and stir at 60 rpm for 30 minutes.

[0105] Step 2: Add 10 parts of erucamide wax into the second reaction kettle, heat to 60°C, gradually add 50 parts of methyl oleate, continue to heat to 90°C, and stir for 30 minutes.

[0106] Step 3: Transfer the material in the second reaction kettle into the first reaction kettle, slowly heat to 130°C, continue stirring while heating for 1 hour, and then cool to 60°C.

[0107] Step 4: Pack into inner film woven bag / open barrel and cool to room temperature.

[0108] This comparative example does not use oleic acid, and the erucamide wax does not melt in step 2. After increasing the heating temperature to 130°C in step 3, the erucamide wax can be melted but still cannot be evenly dispersed in the product, and a stringy colloid appears. The possible reason is that the erucamide wax is partially polymerized under high temperature, resulting in the asphalt regeneration agent prepared in this comparative example being a waxy solid at room temperature with obvious colloid clusters at the bottom.

[0109] Comparative Example 3

[0110] A method for preparing an asphalt regeneration agent comprises the following steps:

[0111] Step 1: Add 50 parts of methyl oleate, 20 parts of palm wax and 10 parts of epoxy fatty acid methyl ester into the first reaction kettle, heat to 70°C, and stir at 60 rpm for 30 minutes.

[0112] Step 2: Add 20 parts of oleic acid and 10 parts of erucamide wax into the second reaction kettle, heat to 60°C, gradually add 50 parts of methyl oleate, continue to heat to 90°C, and stir for 30 minutes.

[0113] Step 3: Transfer the material in the second reaction kettle into the first reaction kettle, slowly heat to 120°C, continue stirring while heating for 1 hour, and then cool to 60°C.

[0114] Step 4: Pack into inner film woven bag / open barrel and cool to room temperature.

[0115] The asphalt regeneration agent prepared in this embodiment is a paste-like solid at room temperature.

[0116] Comparative Example 4

[0117] A method for preparing an asphalt regeneration agent comprises the following steps:

[0118] Step 1: Add 50 parts of methyl oleate, 20 parts of palm wax and 10 parts of epoxy fatty acid methyl ester into the first reaction kettle, heat to 70°C, and stir at 60 rpm for 30 minutes.

[0119] Step 2: Add 10 parts of oleic acid and 20 parts of erucamide wax into the second reaction kettle, heat to 60°C, gradually add 50 parts of methyl oleate, continue to heat to 90°C, and stir for 30 minutes.

[0120] Step 3: Transfer the material in the second reaction kettle into the first reaction kettle, slowly heat to 120°C, continue stirring while heating for 1 hour, and then cool to 60°C.

[0121] Step 4: Pack into inner film woven bag / open barrel and cool to room temperature.

[0122] In this comparative example, the amount of erucamide wax used is increased, and the erucamide wax cannot be fully dispersed, resulting in the obtained asphalt regeneration agent being a waxy solid at room temperature with obvious colloidal clusters at the bottom.

[0123] Product performance verification

[0124] 1. Asphalt segregation detection

[0125] The asphalt regeneration agents prepared in the above-mentioned embodiments and comparative examples were respectively mixed with Jingbo Petrochemical National Standard No. 70 asphalt and modifier SBS (a triblock copolymer of styrene and butadiene as monomers) to prepare samples to be tested, wherein the mass proportion of SBS in the samples was 4.5%, and the mass proportion of asphalt regeneration agent was 4%.

[0126] The above samples were respectively poured into separation tubes, placed in an oven at 163±5℃, and left to stand for 48h±1h without any disturbance. After heating, transfer to 0℃ and store for no less than 4h. After cold storage, the separation tube was divided into upper, middle and lower parts, and the upper and lower parts were heated at 163℃, respectively poured into softening point test molds, and the corresponding softening point data were measured. The separation result is the difference between the upper and lower softening points. The difference is ≤2.5℃, which is qualified, otherwise it is unqualified. The results are described in Table 1 below.

[0127]

[0128] According to Table 1, uneven dispersion of asphalt regeneration agent will affect its application in asphalt and lead to failure of segregation test.

[0129] 2. Verification of the effect of asphalt regeneration agent

[0130] 2.1 Modified asphalt: It is composed of base asphalt, modifier SBS and aromatic oil. Among them, the base asphalt adopts Jingbo Petrochemical National Standard No. 70 asphalt, accounting for 91.5% by mass; the modifier SBS accounts for 4.5% by mass; and the aromatic oil accounts for 4% by mass.

[0131] The preparation method of modified asphalt includes: heating the base asphalt to 160°C, adding a specified proportion of modifier SBS, high-speed shearing for 30 minutes (5000r / min), during which the temperature is controlled at 180°C. Then, it is transferred to a mixer and a specified proportion of aromatic oil is added, and low-speed stirring is performed for 2.5 hours (700r / min), during which the temperature is controlled at 180°C.

[0132] The modified asphalt indicators are shown in Table 2.

[0133]

[0134] Among them, the 5℃ ductility test method is based on GB / T 4508-2010 asphalt ductility determination method; the softening point test method is based on GB / T 4507-2014 asphalt softening point determination method ring and ball method; the 25℃ needle penetration test method is based on GB / T 4509-2010 asphalt needle penetration determination method.

[0135] 2.2 The modified asphalt was aged in a rotary thin film oven at 163°C for 80 minutes. The indicators of the modified asphalt after aging are shown in Table 3.

[0136]

[0137] 2.3 Asphalt recycling test

[0138] The asphalt regeneration agents prepared in the above-mentioned embodiments and comparative examples and the aged modified asphalt were used for verification: the aged modified asphalt was heated to 165°C and kept warm for 30 minutes, divided into several portions, one of which was used as a control, and the remaining aged modified asphalt was added with the asphalt regeneration agents prepared in the comparative examples and embodiments, with an addition ratio of 4wt%. After continued keeping warm and stirring for 1 hour, the regenerated asphalt samples were obtained, and the indicators were tested. The results are shown in Table 4 below.

[0139]

[0140] Ductility is an indicator of asphalt plasticity. If the ductility is unqualified, the adhesion between asphalt and aggregate will decrease, which will affect the stability and durability in the subsequent use process. Softening point is an indicator of asphalt heat resistance. If the softening point is unqualified, it will affect the stability and safety in the subsequent use process. Penetration is an indicator of asphalt consistency. If the penetration is unqualified, it will affect the durability and crack resistance of the road surface. Generally, the standard for modified asphalt is: 5℃ ductility ≥15cm, softening point ≥60℃, 25℃ penetration 40-60μm, according to industry practice.

[0141] 2.4 Asphalt regeneration aging test

[0142] Some of the regenerated asphalt samples and their control samples in the above-mentioned asphalt regeneration test 2.3 were aged in a rotary thin film oven at 163°C for 80 minutes. The indicators of the regenerated asphalt samples and the control samples after aging are shown in Table 5.

[0143]

[0144] After aging of the modified asphalt, the ductility decreases, the softening point increases, and the penetration decreases. Although the asphalt regeneration agent (methyl oleate and erucamide wax composite system) prepared in Comparative Example 1 is added to the aged modified asphalt, the ductility can be increased, the softening point can be reduced, and the penetration can be improved to a certain extent, its compatibility with the aged modified asphalt is poor, the segregation test fails, and the improvement in ductility is not good.

[0145] Adding vegetable wax and epoxy fatty acid methyl ester (see Comparative Example 2) to the compound system of Comparative Example 1 can effectively improve the ductility. However, the presence of gum groups in the product not only leads to uneven dispersion of the product and difficulty in stirring, but also a high freezing point of the product, which is not conducive to on-site construction and increases the difficulty of subsequent construction. In addition, the product has poor compatibility with modified asphalt and fails the segregation test.

[0146] The present invention uses methyl oleate as the base material, uses oleic acid and erucamide to react to pre-dissolve erucamide, and then compound plant wax and environmentally friendly plasticizer epoxy fatty acid methyl ester to produce a regeneration agent suitable for modified asphalt. First, it solves the segregation phenomenon of modified asphalt after adding the regeneration agent; second, it accelerates the swelling and dispersion of erucamide wax in methyl oleate, reduces the operating temperature of erucamide wax swelling, and reduces the difficulty of on-site construction; third, it improves the performance of regenerated asphalt, and improves the oxidation stability of regenerated modified asphalt while meeting the requirements of modified asphalt indicators. The inventor also found in the process of exploration that the addition amount of each component in the compounding system is very important. For example, if the addition amount of oleic acid, plant wax, erucamide wax, etc. is not appropriate, it may cause unqualified segregation detection, and also lead to poor regeneration improvement effect on modified asphalt after aging (for example, Comparative Examples 3 and 4).

[0147] In addition, referring to Table 5, compared with Example 5 in which epoxy fatty acid methyl ester is not added, the regenerated asphalt sample prepared by Example 2 in which epoxy fatty acid methyl ester is added has a smaller decrease in ductility in the aging test, indicating that epoxy fatty acid methyl ester can slow down the aging of the regenerated asphalt sample. The inventors speculate that asphalt oxidation will produce oxygen free radicals, and the addition of epoxy fatty acid methyl ester can effectively eliminate this effect, thereby improving the stability of the regenerated asphalt.

[0148] The above detailed description of the present invention is intended to enable persons familiar with the art to understand the contents of the present invention and implement them. It does not limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. An asphalt regeneration agent, characterized in that: In parts by weight, the asphalt regeneration agent is a paste-like solid, which includes the following components: 100 parts of low-carbon alcohol esters of high-carbon fatty acids, wherein the high-carbon fatty acids in the low-carbon alcohol esters of high-carbon fatty acids are unsaturated fatty acids having 15 to 20 carbon atoms, and the low-carbon alcohols are monohydric alcohols having 1 to 4 carbon atoms; 10-20 parts of vegetable wax, wherein the vegetable wax is selected from one or more of palm wax, rice bran wax and sunflower seed wax; 5-10 parts of high-carbon fatty acids, wherein the high-carbon fatty acids are unsaturated fatty acids having 15-20 carbon atoms; 10-15 parts of fatty acid amide wax, wherein the fatty acid in the fatty acid amide wax is an unsaturated fatty acid having 20-25 carbon atoms, The preparation method of the asphalt regeneration agent comprises the following steps: (1) mixing a portion of the low-carbon alcohol esters of the high-carbon fatty acids and the plant wax; (2) mixing the high-carbon fatty acid, the fatty acid amide wax and the remaining low-carbon alcohol ester of the high-carbon fatty acid; (3) Mixing the mixed system of step (1) with the mixed system of step (2).

2. The asphalt regeneration agent according to claim 1, characterized in that: The low-carbon alcohol ester of the high-carbon fatty acid is methyl oleate; and / or, The high carbon fatty acid is oleic acid; and / or, The fatty acid amide wax is erucamide wax.

3. The asphalt regeneration agent according to claim 1, characterized in that: The asphalt rejuvenating agent also includes epoxy fatty acid ester.

4. The asphalt regeneration agent according to claim 3, characterized in that: In parts by weight, the asphalt regeneration agent includes the following components: 100 parts of low-carbon alcohol esters of high-carbon fatty acids; 10-20 parts of vegetable wax; 5-10 portions of high-carbon fatty acids; 10-15 parts of fatty acid amide wax; 10-15 parts of epoxy fatty acid ester, The epoxy fatty acid ester is epoxy fatty acid methyl ester.

5. A method for preparing an asphalt regeneration agent as claimed in any one of claims 1 to 4, characterized in that: The step (2) specifically comprises mixing the high-carbon fatty acid and fatty acid amide wax, then heating to 70-90° C., gradually adding the remaining low-carbon alcohol ester of the high-carbon fatty acid, raising the temperature to 90-100° C. and stirring and mixing.

6. The method for preparing the asphalt regeneration agent according to claim 5, characterized in that: In the step (1), the mixture is mixed under stirring and the mixing temperature is controlled to be 65-85° C.; and / or, In the step (3), the mixture is mixed under stirring and the mixing temperature is controlled to be 110-130°C.

7. The use of the asphalt regeneration agent according to any one of claims 1 to 4, characterized in that: The application includes adding the asphalt rejuvenating agent into aged modified asphalt.

8. The use of the asphalt regeneration agent according to claim 7, characterized in that: The asphalt regeneration agent accounts for 1-10% of the total mass of the asphalt regeneration agent and the aged modified asphalt.

9. The use of the asphalt regeneration agent according to claim 7, characterized in that: The modified asphalt comprises base asphalt, a modifier and aromatic oil, and the modifier is a styrene-butadiene-styrene block copolymer.

10. An asphalt mixture composition, characterized in that: The invention comprises the asphalt regeneration agent as described in any one of claims 1 to 4 and the aged modified asphalt.

11. The asphalt mixture composition according to claim 10, wherein the asphalt regeneration agent accounts for 1-10% of the total mass of the asphalt mixture composition.

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