Water reaction type asphalt cold patch material and preparation method thereof

Abstract

The application discloses a water reaction type asphalt cold patching material and a preparation method thereof, and belongs to the technical field of road engineering materials. The asphalt cold patching material comprises the following components in parts by weight: 500-600 parts of aggregate, 40-60 parts of mineral powder, 65-120 parts of base asphalt, 0.5-8 parts of a composite initiator and 1-10 parts of a superabsorbent resin; wherein the composite initiator is a combination of an iron salt or a copper salt and maleic acid modified by ethylenediamine or alanine. The acid effect of maleic acid and the metal ion coordination effect of the iron salt or the copper salt are mutually synergistic, and the degree of chemical bond rupture and recombination of asphalt molecules is accurately controlled; the chemical bonding force between the maleic acid modified by ethylenediamine or alanine and the asphalt is increased, so that the early strength, the water stability and the durability are improved; the superabsorbent resin is added, so that the asphalt cold patching material is better in rapid curing and initial strength enhancement under wet conditions.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of road engineering materials, in particular to a water-reactive asphalt cold patch material and a preparation method thereof. BACKGROUND

[0002] Asphalt pavement is widely used in highway construction around the world due to its significant advantages such as effectively reducing driving noise, providing a more comfortable driving experience, and facilitating maintenance and repair. However, over time, asphalt pavement not only bears traffic load but also faces challenges brought by changes in the natural environment. Asphalt pavement is prone to diseases such as rutting, loosening, cracking, and potholing, which are random, sudden, and spreading. These diseases seriously affect the flatness, comfort, and safety of driving and greatly reduce the service life of asphalt pavement. Therefore, it is crucial to implement timely and effective repair and maintenance work on damaged roads.

[0003] For a long time, pavement repair technology mainly relies on two methods. One is the traditional hot patch method using hot-mixed hot-laid asphalt mixture, and the other is the cold patch method using cold-mixed asphalt mixture directly at room temperature. The traditional hot patch method requires special mechanical equipment and experienced operators, and is not suitable for small or scattered pavement repair projects. In addition, the application of hot-mixed asphalt mixture is also limited in low temperature, rainy weather, or wet pavement conditions. In contrast, the cold patch technology overcomes the limitations of the traditional hot patch method. The mixture used is pre-prepared, and no heating is required during on-site pavement repair work. It only needs to be simply stirred, spread, and compacted, greatly simplifying the operation process, and can be used immediately even in poor temperature or environmental conditions.

[0004] The various components used in the cold patch method are collectively referred to as cold patch asphalt mixture, simply referred to as cold patch material. At present, the most widely used in China is solvent type asphalt cold patch material, which is usually composed of base asphalt, diluent and additives. After construction is completed, the cementing material in the cold patch material continuously solidifies with the slow evaporation of the diluent, and is further compacted through the rolling of vehicles after the traffic is opened. However, the slow evaporation speed of the diluent leads to the fact that the initial strength of the solvent type asphalt cold patch material cannot reach the ideal effect, and it is prone to peeling and falling off. If it is in a rainy and humid environment, it is more likely to be taken away by the vehicles running, thereby greatly reducing the repair effect and shortening the service life. Secondly, the diluent often uses petroleum products such as gasoline, kerosene and oil, which also pollutes the environment. For example, the Chinese patent application with the publication number CN112851174A provides a preparation method of chemical reaction type cold patch asphalt mixture, which uses the hydration of calcined material and the generation of fatty acid salt to improve the strength of the cold patch material, but the water resistance and solvent resistance of the fatty acid salt cannot be guaranteed. In view of the shortcomings of the current asphalt cold patch material, it is necessary to propose an asphalt cold patch material with good water stability, high strength, long service life and green environmental protection. SUMMARY

[0005] In view of the above-mentioned deficiencies in the prior art, the purpose of the present application is to provide a water reaction type asphalt cold patch material and a preparation method thereof.

[0006] In order to solve the above technical problems, the present application provides the following technical scheme:

[0007] A water reaction type asphalt cold patch material, comprising the following components by weight: 500-600 parts of aggregate, 40-60 parts of mineral powder, 65-120 parts of base asphalt, 0.5-8 parts of composite initiator and 1-10 parts of superabsorbent resin.

[0008] The composite initiator is a combination of iron salt or copper salt and maleic acid modified by ethylenediamine or alanine.

[0009] Preferably, the aggregate is limestone aggregate, and the aggregate has a gradation type of LB-10. The mineral powder is basalt mineral powder.

[0010] The aggregate, as one of the main components of the cold patch material, provides structural strength and volume basis for the asphalt cold patch material. The limestone aggregate is hard in texture and is an excellent supporting framework in the water reaction type asphalt cold patch material. Its good wear resistance makes the cold patch material not easy to deform when bearing the load of vehicles, and the gradation of LB-10 type forms a close interlocking structure between the limestone aggregates, which helps to maintain the flatness and stability of the repaired road surface. The basalt mineral powder belongs to alkaline rock mineral powder and has good adhesion with asphalt, thereby improving the water stability of the asphalt cold patch material. The basalt mineral powder is stable in chemical properties and is not prone to adverse reactions with other components, which is beneficial to the long-term storage of the cold patch material.

[0011] Preferably, the base asphalt is any one of No. 70 base asphalt, No. 90 base asphalt, No. 110 base asphalt.

[0012] As a binder, the base asphalt binds the aggregate and other components in the cold patch material to form a solid whole, and the base asphalt has a proper viscosity, so that the cold patch material is easy to spread and compact during subsequent construction.

[0013] Preferably, the iron salt is ferric chloride; the copper salt is selected from copper sulfate; the ethylenediamine or alanine is 10-50% of the mass of the maleic acid; the ferric chloride or copper sulfate is 20-80% of the mass of the maleic acid.

[0014] Maleic acid (chemical formula C4H4O4) is an unsaturated dibasic organic acid containing two carboxyl groups (-COOH). Its molecular structure contains a carbon-carbon double bond, which makes it have special chemical properties and wide industrial applications. Maleic acid is a relatively strong organic acid that can ionize hydrogen ions (H + ) in water, showing acidic properties. Due to the carbon-carbon double bond in its molecule, maleic acid is prone to addition reactions, polymerization reactions and other types of chemical transformations. The carboxyl groups in maleic acid can ionize hydrogen ions in aqueous solution, providing an acidic environment for subsequent reactions with metal salts, and interacting with active groups in asphalt molecules through carboxyl groups, initially weakening the chemical bonds in asphalt and improving the performance of cold patch materials.

[0015] Ethylenediamine (EDA) and alanine are amino-based small organic molecules. The chemical structure of ethylenediamine is NH2-CH2-CH2-NH2, and the chemical structure of alanine is CH3-CH(NH2)-COOH. The amino groups can be grafted onto the maleic acid molecules to achieve modification. Maleic acid modified by ethylenediamine or alanine contains both carboxyl and amino groups on its molecular chain. The amino groups can undergo amidation reactions with the carboxyl groups in asphalt to form covalent bonds, enhancing the chemical bonding force between the initiator and asphalt and improving the stability of the reaction. In addition, the molecular structure of ethylenediamine is relatively flexible, and after reacting with maleic acid, the introduced flexible segments can improve the flexibility of asphalt cold patch materials. This allows the cold patch material to better adapt to the deformation of the road under different temperature and stress conditions, reducing the occurrence of cracks. Alanine is a naturally occurring amino acid that can impart better biocompatibility to asphalt cold patch materials.

[0016] The application selects copper sulfate (CuSO4) or ferric chloride (FeCl3), wherein the copper ion in the copper sulfate has strong coordination ability, can effectively coordinate with groups such as carboxyl and amino, and form a stable cross-linking structure, thereby significantly improving the strength and stability of the asphalt cold patch material, and making it better resist the influence of vehicle load and environmental factors. The iron ion in the ferric chloride has strong catalytic activity, can accelerate the reaction between maleic acid and asphalt molecules, promote the breaking and recombination of chemical bonds, make the cold patch material form a high early strength in a short time, shorten the maintenance time after construction, and improve the efficiency of road repair.

[0017] Preferably, the high water-absorbing resin is a polyacrylate with a number average molecular weight of 1000-8000.

[0018] The high molecular resin is a functional molecular material with a three-dimensional space network structure, and a large number of strong water-absorbing groups such as carboxyl, hydroxyl, sulfo, and amide groups exist on the molecular chain. When in contact with water, the external free water diffuses into the resin polymer network to form hydrated polymer chains, so that the water absorption of the resin reaches several hundred times or even thousands of times of its own weight. The macromolecules of the resin are connected by hydrogen bonds to form a three-dimensional network structure, which can effectively lock water and rapidly expand to form a gel structure, which helps the asphalt cold patch material to rapidly solidify and improve the early strength under humid conditions.

[0019] As a general technical concept, the application also provides a preparation method of the water reaction type asphalt cold patch material, as shown in Figure 2 , comprising the following steps:

[0020] Step (1), maleic acid and ethylenediamine or alanine are added to a reactor containing deionized water, and the temperature is increased to the reaction temperature while stirring, and then the reaction is cooled to room temperature after the reaction to obtain maleic acid modified by ethylenediamine or alanine;

[0021] Step (2), copper sulfate or ferric chloride is added dropwise to step (1) under stirring, and then distilled under reduced pressure after sufficient reaction to obtain a composite initiator;

[0022] Step (3), the base asphalt is preheated, and then aggregate and mineral powder are added and uniformly stirred;

[0023] Step (4), the high water-absorbing resin and the composite initiator prepared in step (2) are continuously added to step (3), and then uniformly stirred to obtain the water reaction type asphalt cold patch material.

[0024] Preferably, in step (1), the reaction temperature is 80-150℃, and the reaction time is 5-10h.

[0025] The equation for the reaction of ethylenediamine with maleic acid is:

[0026]

[0027] The equation of the reaction of alanine with maleic acid is as follows:

[0028]

[0029] Preferably, in the step (2), the reaction time is 1-3 h, the pressure of the reduced pressure distillation is 1.5-4 kPa, and the time of the reduced pressure distillation is 0.5-2 h.

[0030] Preferably, in the step (3), the preheating temperature is 85-100 ℃, the preheating time is 2-4 h, and the stirring time is 2-5 min.

[0031] Preferably, in the step (4), the stirring time is 3-12 min.

[0032] Compared with the prior art, the present application has the following advantages:

[0033] (1) The composite initiator is used in the present application. When the composite initiator contacts water, maleic acid is first dissolved and ionized to produce hydrogen ions: The hydrogen ions make the aqueous solution acidic, and promote the hydrolysis and rupture of relatively weak chemical bonds such as ester bonds and carbon-hydrogen bonds in the asphalt to form free radicals and functional groups with reactivity, for example Meanwhile, the iron salt or copper salt is dissociated into metal ions in water: The metal ions can further react with the hydrolyzed carboxyl groups in the asphalt: and to form cross-linking and constitute a more stable and complex three-dimensional network structure. In the whole reaction process, the acidic action of maleic acid and the coordination action of the metal ions of the iron salt or copper salt are mutually synergistic to control the rupture and recombination of the chemical bonds of the asphalt molecules, further enhancing the strength, water stability and durability of the asphalt cold patching material. The maleic acid modified by ethylenediamine or alanine further adds amino groups to the original molecular chain, and the amino groups can further react with the carboxyl groups in the asphalt to form amide reaction and form covalent bonds, further enhancing the chemical bonding force between the initiator and the asphalt, thereby further improving the overall performance of the asphalt cold patching material.

[0034] (2) The high water-absorbing resin is used in the present application. The high water-absorbing resin has a large number of strong water-absorbing groups such as carboxyl, hydroxyl, sulfo, and amido on the molecular chain, and can quickly solidify after absorbing water to form early strength, which is conducive to rapid traffic.

[0035] (3) The components used in the present application are green and environmentally friendly, and have no volatile solvents, which are friendly to the environment. The asphalt cold patching material prepared has fast curing speed, high strength, and good water stability, and is conducive to popularization and application. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 is the effect diagram of repairing road potholes by using the asphalt cold patch material prepared in Example 1.

[0037] Figure 2 is a flow chart for preparing the water-reactive asphalt cold patch material. DETAILED DESCRIPTION

[0038] The technical solutions in the embodiments of the present application will be described in detail below. The described embodiments are only part of the embodiments of the present application. All other embodiments obtained by those skilled in the art based on the embodiments in the present application belong to the scope of protection of the present application. The present application will be further described below in combination with specific embodiments.

[0039] Unless otherwise specified, the various components and chemical reagents used in the embodiments of the present application are obtained through conventional commercial channels:

[0040] Limestone aggregate and basalt powder are from Hui Xin Mining Processing Factory in Lingshou County.

[0041] 70# and 90# and 110# base asphalt are purchased from Hengshui Zehao Chemical Co., Ltd.

[0042] Maleic acid is from Shandong Hui'an Chemical Co., Ltd.

[0043] Ethylene diamine and alanine are purchased from Jinan Liyan Chemical Co., Ltd.

[0044] Ferric chloride and copper sulfate are purchased from Jiangsu Mu Hong Environmental Protection Technology Co., Ltd.

[0045] Polyacrylate is from Jining Sanyuan Chemical Technology Co., Ltd.

[0046] Example 1

[0047] A water-reactive asphalt cold patch material comprises the following components by weight: 600 parts of LB-10 type limestone aggregate, 60 parts of basalt powder, 110 parts of 70# base asphalt, 5 parts of composite initiator and 2 parts of polyacrylate. The LB-10 type gradation of limestone is shown in Table 1.

[0048] Table 1 LB-10 type gradation

[0049]

[0050] The preparation method of the above water-reactive asphalt cold patch material is as follows:

[0051] (1) Maleic acid and alanine are added to a reactor containing deionized water, and the temperature is raised to 120℃ while stirring, and the reaction is carried out for 8h. After the reaction is completed, it is cooled to room temperature to obtain alanine-modified maleic acid, wherein the mass of alanine is 30% of the mass of maleic acid;

[0052] (2) The copper sulfate accounting for 60% of the mass of the maleic acid is added dropwise into step (1) under stirring, and after fully reacting for 3 h, it is distilled under reduced pressure with a pressure of 3 kPa and a distillation time of 1 h to obtain the composite initiator;

[0053] (3) 110 parts of the No. 70 base asphalt are preheated at 100°C for 2 h, and then 600 parts of the limestone aggregate and 60 parts of the basalt aggregate are added and fully stirred for 5 min;

[0054] (4) 2 parts of the polyacrylate and 5 parts of the composite initiator obtained in step (2) are further added into step (3), and fully stirred for 10 min to obtain the water-reactive asphalt cold patching material.

[0055] The effect diagram of the asphalt cold patching material prepared in Example 1 for repairing the road pit is shown in FIG. 1. Figure 1

[0056] Example 2

[0057] A water-reactive asphalt cold patching material, comprising the following components in parts by weight: 580 parts of LB-10 type limestone aggregate, 50 parts of basalt aggregate, 120 parts of No. 70 base asphalt, 8 parts of composite initiator, and 1 part of polyacrylate.

[0058] The preparation method of the water-reactive asphalt cold patching material is as follows:

[0059] (1) The maleic acid and ethylenediamine are added into a reactor containing deionized water, and while stirring, the temperature is increased to 150°C, and the reaction is carried out for 5 h. After the reaction is completed, the temperature is cooled to room temperature to obtain the ethylenediamine-modified maleic acid, wherein the mass of the ethylenediamine is 50% of the mass of the maleic acid;

[0060] (2) The copper sulfate accounting for 80% of the mass of the maleic acid is added dropwise into step (1) under stirring, and after fully reacting for 1 h, it is distilled under reduced pressure with a pressure of 4 kPa and a distillation time of 2 h to obtain the composite initiator;

[0061] (3) 120 parts of the No. 70 base asphalt are preheated at 90°C for 4 h, and then 580 parts of the limestone aggregate and 50 parts of the basalt aggregate are added and fully stirred for 4 min;

[0062] (4) 1 part of the polyacrylate and 8 parts of the composite initiator obtained in step (2) are further added into step (3), and fully stirred for 12 min to obtain the water-reactive asphalt cold patching material.

[0063] Example 3

[0064] A water-reactive asphalt cold patching material, comprising the following components in parts by weight: 550 parts of LB-10 type limestone aggregate, 40 parts of basalt aggregate, 80 parts of No. 70 base asphalt, 7 parts of composite initiator, and 3 parts of polyacrylate.​

[0065] The preparation method of the water reaction type asphalt cold patching material is as follows:

[0066] (1) maleic acid and ethylenediamine are added into a reactor containing deionized water, and heated to 100°C while stirring, reacted for 6h, and then cooled to room temperature to obtain ethylenediamine modified maleic acid, wherein the mass of ethylenediamine is 20% of the mass of maleic acid;

[0067] (2) 70% of the mass of maleic acid is iron chloride, which is added dropwise into step (1) under stirring, fully reacted for 2h, and then distilled under reduced pressure, with a pressure of 1.5kPa and a distillation time of 0.5h to obtain a composite initiator;

[0068] (3) 80 parts of No. 70 base asphalt are preheated at 85°C for 3h, and then 550 parts of limestone aggregate and 40 parts of basalt aggregate are added, and fully stirred for 2min;

[0069] (4) 3 parts of polyacrylate and 7 parts of the composite initiator obtained in step (2) are further added into step (3), and fully stirred for 3min to obtain the water reaction type asphalt cold patching material.

[0070] Example 4

[0071] A water reaction type asphalt cold patching material, comprising the following components by weight: 540 parts of LB-10 type limestone aggregate, 58 parts of basalt aggregate, 105 parts of No. 90 base asphalt, 6 parts of a composite initiator, and 4 parts of polyacrylate.

[0072] The preparation method of the water reaction type asphalt cold patching material is as follows:

[0073] (1) maleic acid and alanine are added into a reactor containing deionized water, and heated to 130°C while stirring, reacted for 7h, and then cooled to room temperature to obtain alanine modified maleic acid, wherein the mass of alanine is 10% of the mass of maleic acid;

[0074] (2) 50% of the mass of maleic acid is copper sulfate, which is added dropwise into step (1) under stirring, fully reacted for 1.5h, and then distilled under reduced pressure, with a pressure of 3.5kPa and a distillation time of 1.5h to obtain a composite initiator;

[0075] (3) 105 parts of No. 90 base asphalt are preheated at 98°C for 2.5h, and then 540 parts of limestone aggregate and 58 parts of basalt aggregate are added, and fully stirred for 4.5min;

[0076] (4) 4 parts of polyacrylate and 6 parts of the composite initiator obtained in step (2) are further added into step (3), and fully stirred for 9min to obtain the water reaction type asphalt cold patching material.

[0077] Example 5

[0078] A water reaction type asphalt cold patching material comprises the following components by weight: 535 parts of LB-10 type limestone aggregate, 56 parts of basalt aggregate, 100 parts of No. 90 base asphalt, 4 parts of a composite initiator and 5 parts of polyacrylate.

[0079] The preparation method of the water reaction type asphalt cold patching material is as follows:

[0080] (1) Maleic acid and ethylenediamine are added into a reactor containing deionized water, and the temperature is increased to 90°C while stirring, and the reaction is carried out for 9 hours. After the reaction is completed, the temperature is cooled to room temperature to obtain ethylenediamine-modified maleic acid, wherein the mass of ethylenediamine is 45% of the mass of maleic acid;

[0081] (2) Copper sulfate accounting for 45% of the mass of maleic acid is added dropwise into step (1) under stirring, and the reaction is carried out for 2.5 hours. After that, vacuum distillation is carried out at a pressure of 2.5 kPa for 1 hour to obtain a composite initiator;

[0082] (3) 90 parts of No. 90 base asphalt are preheated at 96°C for 3.5 hours, and then 535 parts of limestone aggregate and 56 parts of basalt aggregate are added, and the mixture is stirred for 2 minutes;

[0083] (4) 5 parts of polyacrylate and 4 parts of the composite initiator obtained in step (2) are further added into step (3), and the mixture is stirred for 5 minutes to obtain the water reaction type asphalt cold patching material.

[0084] Example 6

[0085] A water reaction type asphalt cold patching material comprises the following components by weight: 530 parts of LB-10 type limestone aggregate, 54 parts of basalt aggregate, 65 parts of No. 90 base asphalt, 3 parts of a composite initiator and 6 parts of polyacrylate.

[0086] The preparation method of the water reaction type asphalt cold patching material is as follows:

[0087] (1) Maleic acid and alanine are added into a reactor containing deionized water, and the temperature is increased to 110°C while stirring, and the reaction is carried out for 5.5 hours. After the reaction is completed, the temperature is cooled to room temperature to obtain alanine-modified maleic acid, wherein the mass of alanine is 25% of the mass of maleic acid;

[0088] (2) Iron chloride accounting for 30% of the mass of maleic acid is added dropwise into step (1) under stirring, and the reaction is carried out for 2.5 hours. After that, vacuum distillation is carried out at a pressure of 2.5 kPa for 1.5 hours to obtain a composite initiator;

[0089] (3) 65 parts of No. 90 base asphalt are preheated at 85°C for 4 hours, and then 530 parts of limestone aggregate and 54 parts of basalt aggregate are added, and the mixture is stirred for 2.5 minutes;

[0090] (4) Continue to add 6 parts of polyacrylate and 3 parts of the composite initiator obtained in step (2) into step (3), and fully stir for 4 min to obtain the water-reactive asphalt cold patch material.

[0091] Example 7

[0092] A water-reactive asphalt cold patch material comprises the following components by weight: 520 parts of LB-10 type limestone aggregate, 52 parts of basalt aggregate, 92 parts of No. 110 base asphalt, 2 parts of composite initiator, and 8 parts of polyacrylate.

[0093] The preparation method of the above water-reactive asphalt cold patch material is as follows:

[0094] (1) Maleic acid and alanine are added into a reactor containing deionized water, and the temperature is raised to 80°C while stirring, and the reaction is carried out for 6.5 h. After the reaction is completed, the temperature is cooled to room temperature to obtain alanine-modified maleic acid, wherein the mass of alanine is 35% of the mass of maleic acid;

[0095] (2) Iron chloride accounting for 40% of the mass of maleic acid is added dropwise into step (1) under stirring, and fully reacts for 1.5 h. After that, vacuum distillation is carried out at a pressure of 3 kPa for 1 h to obtain the composite initiator;

[0096] (3) 92 parts of No. 110 base asphalt are preheated at 88°C for 3.5 h, and then added into 520 parts of limestone aggregate and 52 parts of basalt aggregate, and fully stirred for 2 min;

[0097] (4) Continue to add 8 parts of polyacrylate and 2 parts of the composite initiator obtained in step (2) into step (3), and fully stir for 3 min to obtain the water-reactive asphalt cold patch material.

[0098] Example 8

[0099] A water-reactive asphalt cold patch material comprises the following components by weight: 510 parts of LB-10 type limestone aggregate, 43 parts of basalt aggregate, 83 parts of No. 110 base asphalt, 1 part of composite initiator, and 9 parts of polyacrylate.

[0100] The preparation method of the above water-reactive asphalt cold patch material is as follows:

[0101] (1) Maleic acid and ethylenediamine are added into a reactor containing deionized water, and the temperature is raised to 80°C while stirring, and the reaction is carried out for 7.5 h. After the reaction is completed, the temperature is cooled to room temperature to obtain ethylenediamine-modified maleic acid, wherein the mass of ethylenediamine is 15% of the mass of maleic acid;

[0102] (2) Iron chloride accounting for 55% of the mass of maleic acid is added dropwise into step (1) under stirring, and fully reacts for 2 h. After that, vacuum distillation is carried out at a pressure of 2 kPa for 2 h to obtain the composite initiator;

[0103] (3) After 83 parts of No. 110 base asphalt is preheated at 94℃ for 2.5h, 510 parts of limestone aggregate and 43 parts of basalt aggregate are added, and stirred thoroughly for 3 min;

[0104] (4) 9 parts of polyacrylate and 1 part of the composite initiator obtained in step (2) are further added into step (3), and stirred thoroughly for 7 min, to obtain the water reactive asphalt cold patch material.

[0105] Example 9

[0106] A water reactive asphalt cold patch material comprises the following components in parts by weight: 500 parts of LB-10 type limestone aggregate, 42 parts of basalt aggregate, 72 parts of No. 110 base asphalt, 0.5 parts of composite initiator and 10 parts of polyacrylate.

[0107] The preparation method of the water reactive asphalt cold patch material is as follows:

[0108] (1) Maleic acid and ethylenediamine are added into a reactor containing deionized water, and stirred while heated to 95℃, and reacted for 8.5h. After the reaction is completed, the reaction system is cooled to room temperature to obtain ethylenediamine-modified maleic acid, wherein the mass of ethylenediamine is 35% of the mass of maleic acid;

[0109] (2) 56% of the mass of maleic acid is copper sulfate, which is added dropwise into step (1) under stirring, and reacted for 2h. After that, the composite initiator is obtained by distillation under reduced pressure, with a pressure of 1.5kPa and a distillation time of 0.5h;

[0110] (3) After 72 parts of No. 110 base asphalt is preheated at 91℃ for 4h, 500 parts of limestone aggregate and 42 parts of basalt aggregate are added, and stirred thoroughly for 5 min;

[0111] (4) 10 parts of polyacrylate and 0.5 parts of the composite initiator obtained in step (2) are further added into step (3), and stirred thoroughly for 8 min, to obtain the water reactive asphalt cold patch material.

[0112] Comparative Example 1

[0113] The preparation method of a water reactive asphalt cold patch material is the same as that of Example 1, except that it does not contain superabsorbent resin.

[0114] Comparative Example 2

[0115] The preparation method of a water reactive asphalt cold patch material is the same as that of Example 1, except that it does not contain composite initiator.

[0116] Comparative Example 3

[0117] A preparation method of a solvent type asphalt cold patching material, comprising the following components by weight: 100 parts of No. 70 base asphalt, 10 parts of No. 10 diesel oil, 10 parts of heavy oil, 1 part of coumarone resin, 10 parts of C1 aromatic hydrocarbon solvent oil, 1 part of lignin, 0.2 parts of fatty alcohol polyoxyethylene ether, and 0.5 parts of PA-1 type anti-stripping agent. The specific preparation process comprises the following steps:

[0118] (1) 100 parts of No. 70 base asphalt is heated to a molten state, then 10 parts of No. 10 diesel oil is added, and the asphalt is diluted by using a high-speed shearing machine with a rotation speed of 2000 r / min for about 10 min to prepare a prepolymer A;

[0119] (2) 10 parts of heavy oil is heated to 80℃ in a reaction kettle, 1 part of coumarone resin is added, and uniformly stirred to prepare a prepolymer B, and the shearing time is about 10 min;

[0120] (3) 10 parts of C1 aromatic hydrocarbon solvent oil is heated to 50℃ in a reaction kettle, and 1 part of lignocellulose, 0.2 parts of fatty alcohol polyoxyethylene ether, and 0.5 parts of PA-1 type anti-stripping agent are sequentially added, and uniformly stirred to prepare a prepolymer C, and the shearing time is about 15 min;

[0121] (4) The mixture of the above prepolymers A, B and C is uniformly stirred in a reaction kettle for about 10 min to prepare a cold patching asphalt liquid; then, the cold patching asphalt liquid is uniformly stirred with aggregate to obtain a solvent type asphalt cold patching material.

[0122] Performance test:

[0123] The water reactive asphalt cold patching materials prepared in Examples 1-9 and the asphalt cold patching materials prepared in Comparative Examples 1-3 are subjected to performance tests, wherein the cold patching materials prepared in Examples 1-9 and Comparative Examples 1-2 need to be added with 2% of water by weight and stirred for 30 s before testing. The Marshall test, the beam bending test, and the freeze-thaw splitting test method refer to JTG E20-2011 “Highway Engineering Asphalt and Asphalt Mixture Test Procedures”, and the cohesion test refers to JTG F40-2004 “Highway Asphalt Pavement Construction Technical Specifications”, and the performance test results are shown in Table 2:

[0124] Table 2 Performance test results of the water reactive asphalt cold patching materials prepared in Examples 1-9 and the asphalt cold patching materials prepared in Comparative Examples 1-3

[0125]

[0126] The initial Marshall stability and the molded Marshall stability can well show the strength of the prepared asphalt cold patch material. According to the technical requirements in JTG E20-2011 “Highway Engineering Asphalt and Asphalt Mixture Test Procedures”, the molded Marshall stability needs to be ≥3kN, and the technical requirements of examples 1-9 are all met, and the minimum molded Marshall stability is 5.23kN, which is higher than the comparative example 1 without high water-absorbing resin, the comparative example 2 without composite initiator and the solvent type asphalt cold patch comparative example 3, because the asphalt cold patch material containing polyacrylate can rapidly undergo a curing reaction after reacting with water, thereby enhancing the bonding effect, and the addition of the composite initiator can effectively form a crosslinked network, which can also enhance the bonding performance of the asphalt cold patch material. Combined with Table 2, with the increase of the content of polyacrylate, the initial Marshall stability and the molded Marshall stability of the water reaction type asphalt cold patch material first increase and then decrease.

[0127] The cold patch material needs to have good crack resistance under low temperature conditions, and good low temperature performance is the premise of the cold patch material applied to the pit and groove repair. According to the technical requirements in the specification, in the beam bending test, the maximum bending strain value of the cold patch material in the winter cold area should be greater than 2500με, and examples 1-9 all meet the requirements, while comparative example 1, comparative example 2 and comparative example 3 all fail to meet the requirements, especially comparative example 2 and comparative example 3, the maximum bending strain value of the beam bending is only about 1500με, because the modified maleic acid and metal salt in the composite initiator are crosslinked with asphalt, and the three-dimensional multidirectional distribution in the asphalt cold patch material can effectively improve the low temperature deformation resistance of the cold patch material.

[0128] The initial splitting tensile strength of examples 1-9 is all ≥0.32MPa, and the molded splitting tensile strength is ≥0.52MPa, indicating that the prepared asphalt cold patch material can withstand the load after repair, and meet the demand of rapid traffic, and when polyacrylate and ethylenediamine or alanine modified maleic acid and iron salt or copper salt are added, the splitting tensile strength is improved to different degrees. With the increase of the content of ethylenediamine or alanine modified maleic acid and iron salt or copper salt, the splitting tensile strength shows a trend of first increasing and then decreasing, because the ethylenediamine or alanine modified maleic acid and iron salt or copper salt can synergize with each other to form more stable crosslinked structures, thereby optimizing the internal structure of the asphalt cold patch material, so that the asphalt cold patch material can better resist the splitting load, and thus has stronger splitting tensile strength. Then when the content of ethylenediamine or alanine modified maleic acid and iron salt or copper salt is too high, the excessive crosslinking leads to the brittleness of the cold patch material, and the excessive crosslinked structure cannot effectively disperse stress by deformation when subjected to splitting load, and is prone to brittle failure, so the splitting tensile strength shows a trend of first increasing and then decreasing.

[0129] The pit slot repaired by the cold patch material needs to ensure that it will not be loose or shed due to the action of driving load or natural conditions, which requires the cold patch material to have good cohesiveness. As can be seen from Table 2, the cohesiveness of Examples 1-9 is all ≥70%, indicating that the water-reactive asphalt cold patch material prepared by the application has good cohesiveness and can effectively avoid problems such as looseness and shedding.

[0130] The above only describes the preferred embodiments of the present application, and it should be noted that those skilled in the art can make several improvements and modifications without departing from the technical principles of the present application, and these improvements and modifications should also be considered as the protection scope of the present application.

Claims

1. A water reactive asphalt cold patch material, characterized by, The components include the following weight parts: 500-600 parts of aggregate, 40-60 parts of mineral powder, 65-120 parts of base pitch, 0.5-8 parts of composite initiator and 1-10 parts of super absorbent resin; The composite initiator is a combination of iron salt or copper salt and maleic acid modified by ethylenediamine or alanine; the preparation method of the composite initiator is: copper sulfate or ferric chloride is added dropwise into maleic acid modified by ethylenediamine or alanine under stirring, and after sufficient reaction, vacuum distillation is performed to obtain the composite initiator; the preparation method of the maleic acid modified by ethylenediamine or alanine is: maleic acid and ethylenediamine or alanine are added into a reactor containing deionized water, and the temperature is increased to the reaction temperature while stirring, and after the reaction is completed, the temperature is cooled to room temperature to obtain the maleic acid modified by ethylenediamine or alanine.

2. The water reactive asphalt cold patch material of claim 1, wherein, In the preparation method of the maleic acid modified by ethylenediamine or alanine, the reaction temperature is 80-150°C, and the reaction time is 5-10h; in the preparation method of the composite initiator, the reaction time is 1-3h, the vacuum distillation pressure is 1.5-4kPa, and the vacuum distillation time is 0.5-2h.

3. The water reactive asphalt cold patch material of claim 1, wherein, The aggregate is limestone aggregate, and the aggregate has a gradation type of LB-10 type.

4. The water reactive asphalt patching material of claim 1, wherein, The base pitch is any one of No. 70 base pitch, No. 90 base pitch and No. 110 base pitch.

5. The water reactive asphalt patching material of claim 1, wherein, The iron salt is ferric chloride, and the copper salt is selected from copper sulfate; the mass of ethylenediamine or alanine is 10-50% of the mass of maleic acid; the mass of ferric chloride or copper sulfate is 20-80% of the mass of maleic acid.

6. The water reactive asphalt patching material of claim 1, wherein, The super absorbent resin is polyacrylate with a number average molecular weight of 1000-8000.

7. A method for preparing a water reactive asphalt cold patch material according to any one of claims 1 to 6, characterized in that, The method comprises the following steps: Step (1): after the base pitch is preheated, the aggregate and the mineral powder are added and uniformly stirred; Step (2): the super absorbent resin and the composite initiator are continuously added to step (1), and uniformly stirred to obtain the water reaction type pitch cold patching material.

8. The method of claim 7, wherein the water reactive asphalt cold patch is prepared by mixing the asphalt, the aggregate, the water reactive additive, and the water. In step (1), the preheating temperature is 85-100°C, and the preheating time is 2-4h; the stirring time is 2-5min.

9. The method of claim 7, wherein the water reactive asphalt cold patch is prepared by mixing the asphalt, the aggregate, the water reactive additive, and the water. In step (2), the stirring time is 3-12min.

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