Dilution asphalt tack coat additive, dilution asphalt tack coat material and preparation method thereof

Abstract

The present application relates to a kind of dilution asphalt tack coat with additive, the additive includes by mass percentage: high temperature viscosity reducer 20-40%, low temperature tackifier 20-40%, curing agent 10-20%, curing catalyst 5-10%.The present application also relates to a kind of dilution asphalt tack coat material comprising the foregoing additive and a preparation method thereof.Using the dilution asphalt tack coat material, the interlayer bonding strength of asphalt pavement is improved by more than 30% compared to ordinary dilution asphalt, the interlayer shear capacity of asphalt pavement is significantly improved, so that the interlayer bonding strength of large longitudinal slope, small radius curve segment asphalt pavement structure meets the demand of pavement paving.

Description

Technical Field

[0001] This invention relates to the field of road paving materials, specifically to admixtures for diluting asphalt tack coats, asphalt tack coat materials, and their preparation methods. Background Technology

[0002] Asphalt mixture pavement is a widely used road structure, generally composed of asphalt concrete wearing course, asphalt concrete bonding course, and asphalt concrete base course. According to design specifications, the asphalt concrete layers are continuous, requiring a tack coat to bond the upper and lower asphalt concrete layers together to form a continuous structure.

[0003] Commonly used tack coat materials are generally divided into two categories: ordinary diluted asphalt and ordinary emulsified asphalt. Ordinary diluted asphalt is diluted with organic solvents, while ordinary emulsified asphalt is mixed with emulsifiers and water, and processed into an oil-in-water liquid asphalt using specialized equipment. Modified emulsified asphalt is also used to improve the adhesion of the tack coat material to meet design requirements. In some economically underdeveloped countries and regions, modified emulsification equipment is lacking, making ordinary emulsified asphalt unsuitable. Commonly used diluted asphalt tack coat materials are usually obtained by diluting asphalt with kerosene or gasoline. While the construction process for this type of tack coat material is simple, it also presents some problems, mainly: using gasoline as a diluent increases the risk of fire during construction; using kerosene as a diluent results in slow solvent evaporation and slow viscosity increase; and the tack coat structure formed after spreading diluted asphalt tack coat materials prepared with both gasoline and kerosene has relatively low bonding strength. Some road sections require high strength in the interlayer bonding of asphalt pavement structures, such as sections with large longitudinal slopes, where the asphalt pavement structure needs to resist longitudinal shear stress, and sections with small-radius horizontal curves, where the asphalt pavement structure needs to resist large transverse shear forces.

[0004] Therefore, it is necessary to develop a diluted asphalt tack coat material so that the interlayer bond strength of asphalt pavement structure on steep longitudinal slopes and small-radius curves meets the pavement paving requirements. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of existing technologies and provide an admixture for diluted asphalt tack coats, diluted asphalt tack coat materials, and their preparation methods. The diluted asphalt tack coat materials prepared using the admixture of this invention exhibit a more than 30% increase in interlayer bond strength compared to ordinary diluted asphalt, and a significant improvement in the interlayer shear strength of the asphalt pavement, ensuring that the interlayer bond strength of asphalt pavement structures on steep longitudinal slopes and small-radius curves meets the requirements for pavement installation.

[0006] To achieve the above objectives, the present invention provides the following technical solution.

[0007] The first aspect of the present invention provides an admixture for diluting asphalt tack coat, the admixture comprising, by weight percentage: 20-30% high-temperature viscosity reducer, 40-50% low-temperature viscosity increaser, 10-20% curing agent, and 5-10% curing catalyst.

[0008] Preferably, the mass percentage of the high-temperature viscosity reducer can be any one of 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, or 30%, or any value that meets the above range.

[0009] Preferably, the mass percentage of the low-temperature tackifier can be any one of 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, or 50%, or any value that satisfies the above range.

[0010] Preferably, the 10-20% mass percentage of the curing agent can be any one of 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, or any value that satisfies the above range.

[0011] Preferably, the mass percentage of the curing agent catalyst can be any one of 5%, 6%, 7%, 8%, 9%, 10%, or any value that meets the above range.

[0012] Preferably, the additives comprise, by weight percentage: 25-30% high-temperature viscosity reducer, 45-50% low-temperature viscosity increaser, 15-20% curing agent, and 5-8% curing catalyst.

[0013] Preferably, the additive is in powder form with a particle size of 150-200 mesh. For example, it can be 150 mesh, 160 mesh, 170 mesh, 180 mesh, 190 mesh, or 200 mesh.

[0014] Preferably, the ash content of the admixture is less than 5%.

[0015] In some embodiments of the present invention, the viscosity reducer is at least one of paraffin wax and FT wax (methylene polymer, which is an alkane synthesized from natural gas).

[0016] In some embodiments of the present invention, the tackifier is a thermoplastic resin, preferably an ethylene-vinyl acetate resin.

[0017] In some embodiments of the present invention, the curing agent is aluminum naphthenate soap.

[0018] In some embodiments of the present invention, the curing catalyst is 2-hydroxy-2-methyl-1-phenyl-1-propanone.

[0019] The curing catalyst provided by this invention can better promote the curing effect of the curing agent.

[0020] A second aspect of the present invention provides a diluted asphalt tack coat material, the asphalt tack coat material comprising, by weight percentage: 70-90% base asphalt, 5-25% diluent, and 5-10% admixture provided in the first aspect of the present invention.

[0021] Preferably, the diluent is kerosene or a mixture of kerosene and gasoline.

[0022] In this invention, the diluted asphalt tack coat material needs to be spread onto the underlying asphalt structural layer using a spreading device. To ensure uniform spreading of the structural layer, the diluted asphalt tack coat material needs to have a certain viscosity, generally requiring a C25.5 viscosity ≤ 20s. When the diluted asphalt tack coat material is freshly prepared, the temperature is relatively high (130-160℃), resulting in a high viscosity. However, the spreading temperature is around 60-80℃. To meet the required viscosity for application, the viscosity of the diluted asphalt tack coat material needs to be reduced. Therefore, a high-temperature viscosity reducer is used to lower the viscosity of the diluted asphalt tack coat material. After the diluted asphalt tack coat material is spread, a tack coat is formed. The tack coat structure needs to maintain sufficient adhesion within the operating temperature range. Therefore, it is necessary to increase the viscosity at the operating temperature (low temperature 60-80℃). Thus, a low-temperature viscosity increaser is used to increase the viscosity of the diluted asphalt tack coat material. The additive for diluting asphalt tack coat of the present invention contains both a high-temperature viscosity reducer and a low-temperature viscosity increaser. Through the combined effect of the two, the diluting asphalt tack coat material containing the additive for diluting asphalt tack coat can simultaneously achieve the effect of reducing viscosity at high temperatures to meet spreading requirements and increasing viscosity at low temperatures to meet design requirements for adhesion.

[0023] In this invention, aluminum naphthenate soap is prepared by reacting an aqueous solution of sodium naphthenate soap with an aqueous solution of aluminum sulfate. When the diluted asphalt tack coat admixture provided by this invention is added to the base asphalt and a diluent (kerosene or gasoline) is added to obtain a diluted asphalt tack coat material, the physical cross-linking between the gelling molecules in the aluminum naphthenate soap forms a three-dimensional network structure. The interaction between the gelling molecules in this network structure and the liquid kerosene or gasoline molecules, as well as capillary action, causes the kerosene or gasoline to lose its fluidity and thus become fixed. The aluminum naphthenate soap in the admixture acts as a curing agent, solidifying the diluent—liquid kerosene or gasoline—in the diluted asphalt tack coat material into a gel state through gelation, thereby playing the role of curing the diluent.

[0024] Preferably, the mass percentage of the base asphalt can be any one of 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, or 90%, or any value that satisfies the above range.

[0025] Preferably, the mass percentage of the diluent can be any one of 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, or any value that satisfies the above range.

[0026] Preferably, the mass percentage of the admixture provided in the first aspect of the present invention can be any one of 5%, 6%, 7%, 8%, 9%, 10%, or any value that satisfies the above range.

[0027] Preferably, the base asphalt has a penetration of 60-100, where the penetration unit is 1 / 10 mm.

[0028] Preferably, the standard viscosity of the asphalt tack coat material is C25.5≤20s.

[0029] A third aspect of the present invention provides a method for preparing the adhesive layer material provided in the second aspect of the present invention, comprising the following steps:

[0030] Heating the base asphalt;

[0031] The admixture provided in the first aspect of the present invention is added to heated base asphalt and stirred to obtain a mixture;

[0032] Add a diluent to the mixture and stir to obtain a diluted asphalt tack coat material.

[0033] In some embodiments of the present invention, the temperature of the heated matrix asphalt is 120-180°C, for example, any one of 120°C, 125°C, 130°C, 135°C, 140°C, 145°C, 150°C, 155°C, 160°C, 165°C, 170°C, 175°C, 180°C or any value satisfying the above range.

[0034] In some embodiments of the present invention, the stirring time for obtaining the mixture is 15-25 min, for example, any one of 15 min, 16 min, 17 min, 18 min, 19 min, 20 min, 21 min, 22 min, 23 min, 24 min, 25 min or any value satisfying the above range.

[0035] In some embodiments of the present invention, the stirring time for preparing the diluted asphalt tack coat material is 15-25 min, for example, any one of 15 min, 16 min, 17 min, 18 min, 19 min, 20 min, 21 min, 22 min, 23 min, 24 min, 25 min or any value satisfying the above range.

[0036] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0037] The diluted asphalt tack coat material prepared using the additive for diluted asphalt tack coat of the present invention has an interlayer bond strength of more than 30% higher than that of ordinary diluted asphalt, and a significant improvement in the interlayer shear strength of asphalt pavement, so that the interlayer bond strength of asphalt pavement structure on large longitudinal slopes and small radius curves meets the pavement paving requirements.

[0038] The diluted asphalt tack coat material prepared using the additive for diluted asphalt tack coat of the present invention contains a reduced diluent content, by about 20%, which makes it easy to disperse during application and form a uniform application surface. After application, the bonding strength of the diluted asphalt tack coat material increases at least 50% faster than that of ordinary diluted asphalt, which can shorten the construction interval of subsequent processes from 12 hours to 6 hours, a reduction of about 50%. Detailed Implementation

[0039] To facilitate understanding of the present invention, specific embodiments are provided below to further illustrate the technical solutions described herein, but the present invention is not limited thereto. All technologies implemented based on the above-described content of the present invention are covered within the scope of protection intended by the present invention. Unless otherwise stated, the raw materials and reagents used in the embodiments are commercially available products. Reagents, instruments, or operating procedures not described herein are all matters that can be conventionally determined by those skilled in the art.

[0040] Example 1

[0041] 1. Preparation of admixtures for diluting asphalt tack coat:

[0042] A mixture of 21% paraffin wax, 49% ethylene-vinyl acetate resin, 20% aluminum naphthenate soap, and 10% 2-hydroxy-2-methyl-1-phenyl-1-propanone, wherein the mass ratio of paraffin wax to ethylene-vinyl acetate resin is 21:49, is mixed to obtain an additive for diluting asphalt tack coat.

[0043] Tests showed that the particle size of the admixture used to dilute asphalt tack coat was 160 mesh, and the ash content was 4%.

[0044] 2. Preparation of diluted asphalt tack coat material:

[0045] Diluted asphalt tack coat formulation:

[0046] Base asphalt: 85% (penetration 70, unit: 1 / 10 mm); kerosene: 8%; admixtures: 7%.

[0047] 1) In the asphalt spreader, add base asphalt and heat it, measure the asphalt level, and prepare the required mass.

[0048] 2) After heating the base asphalt to 140°C, add the diluted asphalt tack coat admixture prepared in step 1 according to the formula dosage, and circulate and stir for 30 minutes to obtain a mixture;

[0049] 3) Add 7% of the mixture from step 2) according to the formula dosage, and stir continuously for 30 minutes to prepare a diluted asphalt tack coat material.

[0050] The standard viscosity (C25.5) of the prepared asphalt tack coat material was tested and found to be 19 s.

[0051] Example 2

[0052] 1. Preparation of admixtures for diluting asphalt tack coat:

[0053] A mixture of 23% paraffin wax, 49% ethylene-vinyl acetate resin, 19% aluminum naphthenate soap, and 9% 2-hydroxy-2-methyl-1-phenyl-1-propanone, wherein the mass ratio of paraffin wax to ethylene-vinyl acetate resin is 23:49, is used to obtain an additive for diluting asphalt tack coat.

[0054] Tests showed that the particle size of the admixture used to dilute asphalt tack coat was 165 mesh, and the ash content was 4.5%.

[0055] 2. Preparation of diluted asphalt tack coat material:

[0056] Diluted asphalt tack coat formulation:

[0057] Base asphalt: 85% (penetration 70, unit: 1 / 10 mm); kerosene: 8%; admixtures: 7%.

[0058] 1) In the asphalt spreader, add base asphalt and heat it, measure the asphalt level, and prepare the required mass.

[0059] 2) After heating the base asphalt to 140°C, add the diluted asphalt tack coat admixture prepared in step 1 according to the formula dosage, and circulate and stir for 30 minutes to obtain a mixture;

[0060] 3) Add kerosene to the mixture in step 2) according to the formula dosage, and stir continuously for 30 minutes to prepare diluted asphalt tack coat material.

[0061] The standard viscosity (C25.5) of the prepared asphalt tack coat material was tested and found to be 18 s.

[0062] Example 3

[0063] 1. Preparation of admixtures for diluting asphalt tack coat:

[0064] A mixture of 26% paraffin wax, 48% ethylene-vinyl acetate resin, 18% aluminum naphthenate soap, and 8% 2-hydroxy-2-methyl-1-phenyl-1-propanone, wherein the mass ratio of paraffin wax to ethylene-vinyl acetate resin is 26:48, is used to obtain an additive for diluting asphalt tack coat.

[0065] Tests showed that the particle size of the admixture used to dilute asphalt tack coat was 166 mesh, and the ash content was 4.6%.

[0066] 2. Preparation of diluted asphalt tack coat material:

[0067] Diluted asphalt tack coat formulation:

[0068] Base asphalt: 85% (penetration 70, unit: 1 / 10 mm); kerosene: 8%; admixtures: 7%.

[0069] 1) In the asphalt spreader, add base asphalt and heat it, measure the asphalt level, and prepare the required mass.

[0070] 2) After heating the base asphalt to 140°C, add the diluted asphalt tack coat admixture prepared in step 1 according to the formula dosage, and circulate and stir for 30 minutes to obtain a mixture;

[0071] 3) Add kerosene to the mixture in step 2) according to the formula dosage, and stir continuously for 30 minutes to prepare diluted asphalt tack coat material.

[0072] The standard viscosity (C25.5) of the prepared asphalt tack coat material was tested and found to be 17 s.

[0073] Example 4

[0074] 1. Preparation of admixtures for diluting asphalt tack coat:

[0075] A mixture of 29% paraffin wax, 47% ethylene-vinyl acetate resin, 17% aluminum naphthenate soap, and 7% 2-hydroxy-2-methyl-1-phenyl-1-propanone, wherein the mass ratio of paraffin wax to ethylene-vinyl acetate resin is 29:47, is used to obtain an additive for diluting asphalt tack coat.

[0076] Testing revealed that the particle size of the admixture used to dilute asphalt tack coat was 170 mesh, and the ash content was 4.8%.

[0077] 2. Preparation of diluted asphalt tack coat material:

[0078] Diluted asphalt tack coat formulation:

[0079] Base asphalt: 85% (penetration 70, unit: 1 / 10 mm); kerosene: 8%; admixtures: 7%.

[0080] 1) In the asphalt spreader, add base asphalt and heat it, measure the asphalt level, and prepare the required mass.

[0081] 2) After heating the base asphalt to 140°C, add the diluted asphalt tack coat admixture prepared in step 1 according to the formula dosage, and circulate and stir for 30 minutes to obtain a mixture;

[0082] 3) Add kerosene to the mixture in step 2) according to the formula dosage, and stir continuously for 30 minutes to prepare diluted asphalt tack coat material.

[0083] The standard viscosity (C25.5) of the prepared asphalt tack coat material was tested and found to be 16 s.

[0084] Comparative Example 1

[0085] Preparation of diluted asphalt tack coat material:

[0086] Unlike Example 1, the base bitumen was 85% (penetration 70, unit: 1 / 10 mm); kerosene was 15%.

[0087] The standard viscosity (C25.5) of the prepared asphalt tack coat material was tested and found to be 30 s.

[0088] Experimental Example

[0089] The diluted asphalt tack coat materials prepared in Examples 1-3 and Comparative Example 1 were used to pave roads, and tests were conducted on asphalt roads with large longitudinal slopes and asphalt roads with small radius curves.

[0090] 1) Shear strength (bond strength) improvement rate test: The diluted asphalt tack coat material prepared in Comparative Example 1, at an interface temperature of 30℃, had a shear strength of 0.22 MPa after 6 hours of application and 0.3 MPa after 12 hours. Under the same conditions, the diluted asphalt tack coat materials prepared in Examples 1-4 had shear strengths of 0.3 MPa, 0.33 MPa, 0.34 MPa, and 0.36 MPa after 6 hours, respectively. These significantly improved the interlayer shear strength compared to tack coat materials prepared with base asphalt without diluted asphalt tack coat admixtures, with an average improvement of over 1.5 times. Their 12-hour shear strengths were 0.45 MPa, 0.47 MPa, 0.5 MPa, and 0.52 MPa, respectively, also significantly improving the interlayer shear strength compared to tack coat materials prepared with base asphalt without diluted asphalt tack coat admixtures, with an average improvement of over 1.6 times.

[0091] 2) Fifteen days after the construction of the asphalt pavement structure, the interlayer bond shear test was conducted. The results showed that the shear strength of the diluted asphalt tack coat material prepared in Comparative Example 1 was 0.35 MPa at an interface temperature of 30℃. Under the same conditions, the shear strengths of the diluted asphalt tack coat materials prepared in Examples 1-4 were 0.7 MPa, 0.69 MPa, 0.68 MPa, and 0.66 MPa, respectively. These values ​​were significantly higher than the interlayer shear strength of the tack coat material prepared with base asphalt without the diluent for the asphalt tack coat, with an average increase of more than 1.88 times.

[0092] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. An admixture for diluting asphalt tack coat, characterized in that, The additives, by weight percentage, include: 20-30% high-temperature viscosity reducer, 40-50% low-temperature viscosity improver, 10-20% curing agent, and 5-10% curing catalyst; The high-temperature viscosity reducer is at least one of paraffin wax and FT wax; The low-temperature tackifier is ethylene-vinyl acetate resin; The curing agent is aluminum naphthenate soap; The curing catalyst is 2-hydroxy-2-methyl-1-phenyl-1-propanone.

2. The admixture according to claim 1, characterized in that, The additives, by weight percentage, include: 25-30% high-temperature viscosity reducer, 45-50% low-temperature viscosity increaser, 15-20% curing agent, and 5-8% curing catalyst.

3. The admixture according to claim 1 or 2, characterized in that, The additive is in powder form with a particle size of 150-200 mesh.

4. The admixture according to claim 1, characterized in that, The ash content of the additive is less than 5%.

5. A diluted asphalt tack coat material, characterized in that, The asphalt tack coat material comprises, by weight percentage: 70-90% base asphalt, 5-25% diluent, and 5-10% of the admixture as described in any one of claims 1-4; The diluent is kerosene or a mixture of kerosene and gasoline.

6. The adhesive layer material according to claim 5, characterized in that, The penetration of the base asphalt is 60-100, and the penetration unit is 1 / 10 mm; The standard viscosity of the asphalt tack coat material is C25.5≤20s.

7. The method for preparing the adhesive layer material according to claim 5 or 6, characterized in that, Includes the following steps: Heating the base asphalt; Add the admixture according to any one of claims 1-4 to the heated base asphalt and stir to obtain a mixture; Add a diluent to the mixture and stir to obtain a diluted asphalt tack coat material.

8. The preparation method according to claim 7, characterized in that, The temperature of the heated base asphalt is 120-180℃.

9. The preparation method according to claim 7, characterized in that, The stirring time for obtaining the mixture is 15-35 minutes; The stirring time for preparing the diluted asphalt tack coat material is 15-35 minutes.