A reactive cold-mix asphalt mixture and its preparation method and application

Abstract

The present invention discloses a reactive cold-mix asphalt mixture, a preparation method, and an application thereof, belonging to the technical field of asphalt pavement materials, and is used to solve the problems of low curing strength and heterogeneous curing of cold-mix asphalt mixtures. The cold-mix asphalt mixture is formed by mixing cold-mix asphalt, a curing material, and an aggregate in a certain proportion; the cold-mix asphalt is prepared by shear mixing base asphalt and a reactive diluent; the reactive diluent is formed by shear emulsification of anhydride, a surfactant, and a solvent; and the curing material is prepared by soaking and absorbing a porous mineral material in the curing agent. The composite anhydride reactive diluent of the present invention and the porous structure curing material interact to produce a silica gel precipitate and a carboxylate solid product, thereby improving the curing strength of the cold-mix asphalt mixture and the uniformity of the cured structure.

Description

Technical Field

[0001] The present invention belongs to the technical field of asphalt pavement materials, and in particular relates to a reactive cold-mix asphalt mixture and a preparation method and application thereof. Background Art

[0002] Cold-mix asphalt mixtures are mixed and spread at room temperature, and have the advantages of energy saving, low carbon, green environmental protection, and convenient construction. It is an environmentally friendly asphalt pavement paving material, which is of great significance for building a green transportation system and promoting the national "dual carbon" strategy. At present, commonly used cold-mix asphalt mixtures include solvent-based and emulsified types, but they have engineering application problems such as low initial strength, slow strength improvement, and poor high-temperature stability. In order to improve road performance, researchers have developed composite and reactive cold-mix asphalt mixtures. Patent CN115180875A injects ultra-early-strength cement-based grouting materials with high fluidity into the large-void cold-mix asphalt mixture pavement after rolling and forming, thereby obtaining a high-performance pavement cold patch material with fast traffic opening and good durability. Patent CN113248935A, under the synergistic effect of curing agent and water, releases asphalt viscosity and increases asphalt toughness through reaction, thereby improving the early strength and durability of water-reactive room-temperature asphalt mixtures. The above two methods require grouting after paving and compaction or water spraying before compaction to induce curing and improve strength. The process is complicated and there is the problem of heterogeneous curing of asphalt mixture. Summary of the Invention

[0003] The present invention addresses the technical problems of low curing strength and heterogeneous curing of cold-mix asphalt mixtures, and proposes a reactive cold-mix asphalt mixture, a preparation method, and an application thereof. Through the interaction between a composite anhydride reaction diluent and a porous structure curing material, silicate colloid precipitation and carboxylate solid products are produced, thereby improving the curing strength and uniformity of the cold-mix asphalt mixture.

[0004] In order to achieve the above object, the technical solution of the present invention is achieved as follows:

[0005] A reactive cold-mix asphalt mixture comprises the following components by weight: 5-8 parts cold-mix asphalt, 4-8 parts curing material, and 100 parts aggregate; the cold-mix asphalt comprises base asphalt and a reactive diluent; the reactive diluent comprises an anhydride, a surfactant, and a solvent. A method for preparing the cold-mix asphalt mixture comprises the following steps:

[0006] (1) Shear mixing the base asphalt and the reactive diluent to prepare cold mix asphalt;

[0007] (2) soaking the porous mineral material in a curing agent to prepare a curing material;

[0008] (3) premixing the solidifying material in (2) with the aggregate;

[0009] (4) Add the cold mix asphalt from (1) to the medium mix from (3) to prepare a cold mix asphalt mixture.

[0010] The specific method for preparing cold mix asphalt is: heat the base asphalt to 100-130°C, then add the reaction diluent and shear mix.

[0011] The mass ratio of the matrix asphalt to the reaction diluent is 100:(10-20).

[0012] The preparation method of the reactive diluent comprises the following steps: mixing anhydride, a surfactant and a solvent and then performing shear emulsification; the shear emulsification temperature is 70-90° C., the speed is 2000-5000 rpm and the time is 10-20 min.

[0013] The mass ratio of the acid anhydride, the surfactant and the solvent is (45-70): (2-5): (5-15).

[0014] The acid anhydride includes liquid acid anhydride and solid acid anhydride, and the mass ratio of the liquid acid anhydride to the solid acid anhydride is (40-60): (5-10).

[0015] The liquid acid anhydride is one or more of methyl nadic anhydride, hydrolyzed polymaleic anhydride and methyltetrahydrophthalic anhydride; the solid acid anhydride is one or more of succinic anhydride, maleic anhydride and phthalic anhydride.

[0016] The surfactant is one or a combination of alkylphenol polyoxyethylene ether, fatty alcohol polyoxyethylene ether nonionic surfactant.

[0017] The solvent is a mixed solvent of a non-polar solvent and a polar solvent, the mass ratio of the non-polar solvent to the polar solvent is 1:(1-2), the non-polar solvent is 200# solvent oil, and the polar solvent is one or a combination of dimethyl sulfoxide and dimethylacetamide.

[0018] The solidified material is prepared by soaking porous mineral materials in a solidifying agent for 1-5 hours, and the mass ratio of the porous mineral materials to the solidifying agent is (1-5):2.

[0019] The porous mineral material is one or more of zeolite, vermiculite and volcanic rock, the particle size of the porous mineral material is 2-5 mm, and the porosity is 40-80%; the water glass is one or a combination of sodium water glass and potassium water glass.

[0020] The cold-mix asphalt mixture is used for municipal road disease repair, pothole cold patching and asphalt road thin surface layer engineering.

[0021] Beneficial effects of the present invention:

[0022] (1) The composite acid anhydride reaction diluent prepared by the present invention generates carboxylic acid active functional groups after hydrolysis, which interact with the water glass curing agent in the curing material to generate carboxylate solid products and silica gel precipitation, thereby improving the curing strength of the cold mix asphalt mixture.

[0023] (2) The porous structure solidifying material prepared by the present invention is pre-mixed and evenly dispersed in the aggregate, which can induce a homogeneous solidification reaction and improve the uniformity of the solidification structure of the cold-mix asphalt mixture.

[0024] (3) The composite acid anhydride reaction diluent of the present invention has a viscosity reduction rate of ≥85% for the base asphalt, and has good viscosity reduction performance. DETAILED DESCRIPTION

[0025] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] Example 1

[0027] A reactive cold mix asphalt mixture, the preparation method is as follows:

[0028] The solvent was prepared by mixing 200# solvent oil and DMSO in a mass ratio of 1:2, and methyl nadic anhydride, phthalic anhydride, alkylphenol polyoxyethylene ether and solvent were shear-emulsified in a mass ratio of 60:10:5:10. The shear emulsification temperature was 90°C, the speed was 5000 rpm and the time was 20 min to prepare a composite anhydride reaction diluent.

[0029] The base asphalt was heated to 130°C and shear-mixed with the reaction diluent at a mass ratio of 100:20 to prepare cold-mix asphalt, with a viscosity reduction rate of 92%.

[0030] Zeolite with a particle size of 2-5 mm and a porosity of 80% is mixed with sodium water glass in a mass ratio of 2:2, and the mixture is immersed and absorbed for 5 hours to prepare a solidified material.

[0031] 8 parts of solidified materials and 100 parts of AC-13 aggregate were pre-mixed, 7 parts of cold mix asphalt were added, and mixed at 60°C to obtain a reactive cold mix asphalt mixture. After compaction, it was cured at room temperature for 2 days, and the Marshall stability was 14.8 kN.

[0032] Example 2

[0033] A reactive cold mix asphalt mixture, the preparation method is as follows:

[0034] A solvent was prepared by mixing 200# solvent oil and DMAC in a mass ratio of 1:2, and methyltetrahydrophthalic anhydride, phthalic anhydride, alkylphenol polyoxyethylene ether and solvent in a mass ratio of 50:9:4:8 by shear emulsification. The shear emulsification temperature was 85°C, the speed was 4000 rpm and the time was 18 min to prepare a composite anhydride reaction diluent.

[0035] The base asphalt was heated to 120°C and shear-mixed with the reaction diluent at a mass ratio of 100:18 to prepare cold-mix asphalt, with a viscosity reduction rate of 90%.

[0036] Zeolite with a particle size of 2-5 mm and a porosity of 70% was mixed with sodium water glass in a mass ratio of 5:2, and the mixture was immersed and absorbed for 4 hours to prepare a solidified material.

[0037] 7 parts of solidified materials and 100 parts of AC-13 aggregate were pre-mixed, 8 parts of cold mix asphalt were added, and mixed at 50°C to obtain a reactive cold mix asphalt mixture. After compaction, it was cured at room temperature for 2 days, and the Marshall stability was 12.9N.

[0038] Example 3

[0039] A reactive cold mix asphalt mixture, the preparation method is as follows:

[0040] The solvent was prepared by mixing 200# solvent oil and DMSO in a mass ratio of 1:1, and methyl nadic anhydride, maleic anhydride, fatty alcohol polyoxyethylene ether and solvent were shear-emulsified in a mass ratio of 50:7:3:5. The shear emulsification temperature was 80°C, the speed was 3000 rpm and the time was 15 min to prepare a composite anhydride reaction diluent.

[0041] The base asphalt was heated to 110°C and shear-mixed with the reaction diluent at a mass ratio of 100:14 to prepare cold-mix asphalt, with a viscosity reduction rate of 87%.

[0042] Vermiculite with a particle size of 2-5 mm and a porosity of 60% was mixed with potassium water glass in a mass ratio of 1:2, and the mixture was immersed and absorbed for 3 hours to prepare a solidified material.

[0043] 6 parts of solidified materials and 100 parts of AC-13 aggregate were pre-mixed, 8 parts of cold mix asphalt were added, and mixed at 45°C to obtain a reactive cold mix asphalt mixture. After compaction, it was cured at room temperature for 2 days, and the Marshall stability was 11.4 kN.

[0044] Example 4

[0045] A reactive cold mix asphalt mixture, the preparation method is as follows:

[0046] A solvent was prepared by mixing 200# solvent oil and DMAC in a mass ratio of 1:1, and hydrolyzed polymaleic anhydride, succinic anhydride, fatty alcohol polyoxyethylene ether and solvent in a mass ratio of 55:6:3:12 by shear emulsification. The shear emulsification temperature was 75°C, the speed was 2500 rpm and the time was 15 min to prepare a composite anhydride reaction diluent.

[0047] The base asphalt was heated to 100°C and shear-mixed with the reaction diluent at a mass ratio of 100:12 to prepare cold-mix asphalt, with a viscosity reduction rate of 86%.

[0048] Volcanic rock with a particle size of 2-5 mm and a porosity of 50% is mixed with potassium water glass in a mass ratio of 3:2, and the mixture is immersed and absorbed for 3 hours to prepare a solidified material.

[0049] 5 parts of solidified materials and 100 parts of AC-13 aggregate were pre-mixed, 6 parts of cold mix asphalt were added, and mixed at 40°C to obtain a reactive cold mix asphalt mixture. After compaction, it was cured at room temperature for 2 days, and the Marshall stability was 10.7 kN.

[0050] Example 5

[0051] A reactive cold mix asphalt mixture, the preparation method is as follows:

[0052] The solvent was prepared by mixing 200# solvent oil and DMAC in a mass ratio of 1:2, and hydrolyzed polymaleic anhydride, succinic anhydride, fatty alcohol polyoxyethylene ether and solvent in a mass ratio of 40:5:2:15 by shear emulsification. The shear emulsification temperature was 70°C, the speed was 2000 rpm and the time was 10 min to prepare an emulsified composite anhydride reaction diluent.

[0053] The base asphalt was heated to 100°C and shear-mixed with the reaction diluent at a mass ratio of 100:10 to prepare cold-mix asphalt, with a viscosity reduction rate of 85%.

[0054] Volcanic rock with a particle size of 2-5 mm and a porosity of 40% is mixed with potassium water glass in a mass ratio of 4:2, and the mixture is immersed and absorbed for 1 hour to prepare a solidified material.

[0055] 4 parts of solidified materials and 100 parts of AC-13 aggregate were pre-mixed, 5 parts of cold mix asphalt were added, and mixed at 40°C to obtain a reactive cold mix asphalt mixture. After compaction, it was cured at room temperature for 2 days, and the Marshall stability was 10.2 kN.

[0056] Comparative Example 1

[0057] The composite anhydride reaction diluent in Example 1 was replaced with 200# solvent oil, and the other conditions remained unchanged. After compaction, the mixture was cured at room temperature for 2 days, and the Marshall stability was 5.2 kN.

[0058] Comparative Example 2

[0059] The solidifying material in Example 1 was replaced with mineral powder, and the other conditions remained unchanged. After compaction, the mixture was cured at room temperature for 2 days, and the Marshall stability was 8.6 kN.

[0060] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A reactive cold mix asphalt mixture, characterized in that: The invention comprises the following components in parts by mass: 5-8 parts of cold mix asphalt, 4-8 parts of curing material and 100 parts of aggregate; the cold mix asphalt comprises base asphalt and a reactive diluent; the reactive diluent comprises an acid anhydride, a surfactant and a solvent; the curing material comprises a porous mineral carrier and a curing agent, wherein the curing agent is water glass; the mass ratio of the acid anhydride, the surfactant and the solvent is (45-70): (2-5): (5-15); The preparation method of the solidified material is to soak the porous mineral material in a solidifying agent for 1-5 hours, wherein the mass ratio of the porous mineral material to the solidifying agent is (1-5):

2.

2. The reactive cold mix asphalt mixture according to claim 1, characterized in that: The mass ratio of the matrix asphalt to the reaction diluent is 100:(10-20).

3. The reactive cold mix asphalt mixture according to claim 1, characterized in that: The preparation method of the reactive diluent comprises the following steps: mixing anhydride, a surfactant and a solvent and then performing shear emulsification; the shear emulsification temperature is 70-90° C., the speed is 2000-5000 rpm and the time is 10-20 min.

4. The reactive cold mix asphalt mixture according to claim 3, characterized in that: The acid anhydride includes liquid acid anhydride and solid acid anhydride, and the mass ratio of the liquid acid anhydride to the solid acid anhydride is (40-60): (5-10); the liquid acid anhydride is one or more of methylnadic anhydride, hydrolyzed polymaleic anhydride and methyltetrahydrophthalic anhydride; and the solid acid anhydride is one or more of succinic anhydride, maleic anhydride and phthalic anhydride.

5. The reactive cold mix asphalt mixture according to claim 3, characterized in that: The surfactant is one or a combination of alkylphenol polyoxyethylene ether, fatty alcohol polyoxyethylene ether nonionic surfactant.

6. The reactive cold mix asphalt mixture according to claim 3, characterized in that: The solvent is a mixed solvent of a non-polar solvent and a polar solvent, the mass ratio of the non-polar solvent to the polar solvent is 1:(1-2), the non-polar solvent is 200# solvent oil, and the polar solvent is one or a combination of dimethyl sulfoxide and dimethylacetamide.

7. The reactive cold mix asphalt mixture according to claim 6, characterized in that: The porous mineral material is one or more of zeolite, vermiculite and volcanic rock, the particle size of the porous mineral material is 2-5 mm, and the porosity is 40-80%; the water glass is one or a combination of sodium water glass and potassium water glass.

8. The method for preparing cold mix asphalt mixture according to claim 1, characterized in that: The following steps are involved: (1) Shear mixing the base asphalt and the reactive diluent to prepare cold mix asphalt; (2) soaking the porous mineral material in a curing agent to prepare a curing material; (3) premixing the solidifying material in (2) with the aggregate; (4) Add the cold mix asphalt from (1) to the medium mix from (3) to prepare a cold mix asphalt mixture.

9. The use of the cold mix asphalt mixture according to any one of claims 1 to 7, characterized in that: The cold-mix asphalt mixture is used in municipal road disease repair and asphalt road thin surface layer engineering fields.