A reactive anti-skid wear layer mixture and construction method thereof

Abstract

The present invention discloses a reactive anti-skid wear layer mixture and a construction method thereof, and relates to the technical field of preventive maintenance of asphalt pavements. A reactive anti-skid wear layer mixture comprises a premix, a thickening emulsified asphalt, and water in a mass ratio of 100:8 to 15:1 to 10, the premix comprising mixed stone and phosphogypsum, the mixed stone comprising steel slag and basalt stone, the premix further comprising a curing agent accounting for 0.1% to 1% of the mass ratio of the mixed stone, and the thickening emulsified asphalt comprising base asphalt and a thickening agent accounting for 2% to 15% of the mass ratio of the base asphalt. The construction method comprises: pre-treating the original pavement, paving the anti-skid wear layer mixture, performing preliminary curing, and rolling. The present application utilizes two major mineral wastes, steel slag and phosphogypsum, to produce a reactive anti-skid wear layer with strength and service life not lower than that of natural stone, meeting the needs of preventive maintenance of asphalt pavements and providing a new approach for the recycling of mineral wastes.

Description

Technical Field

[0001] The present application relates to the technical field of preventive maintenance of asphalt pavements, and in particular to a reactive anti-skid wear layer mixture and a construction method thereof. Background Art

[0002] As we all know, as a means of preventive road maintenance, wearing course is applied above the asphalt road surface to solve problems such as minor cracks in the road surface, water seepage, rutting, and reduced anti-skid performance.

[0003] Currently, steel slag, due to its high hardness and wear resistance, is often incorporated solely into asphalt mixtures for pavement construction. Phosphogypsum, on the other hand, is often used as a construction and roadbed improvement material due to its gelling properties. However, these applications have significant limitations: residual alkaline substances such as magnesium oxide and calcium oxide in steel slag react with water, causing volume expansion and cracking in the pavement. Unreacted sulfates and free acids in phosphogypsum can cause chemical corrosion over long periods of service, loosening the pavement structure and reducing its service life.

[0004] Therefore, technicians have tried to compound steel slag and phosphogypsum and add them to the wearing layer mixture, expecting that the impurities in the two can neutralize each other and circumvent the above-mentioned defects. If the slag and phosphogypsum are compounded and used in the hot mix asphalt process, the two will react to generate water and salt substances. The presence of water will seriously affect the control of the material temperature during the production of the asphalt mixture. More importantly, water and salt substances will corrode the production equipment under high temperature conditions, posing a huge hidden danger to production safety. In addition, the high energy consumption and carbon emissions of the hot mix process are also not in line with the trend of green construction, and the hot mix process is mostly used for new pavement and major and medium repair projects, and its application scenarios are limited. If steel slag and phosphogypsum are simply compounded and used in the cold mix process, the active impurities in the steel slag and phosphogypsum will greatly affect the strength of the mixture, making it difficult to form a dense structure. As a result, the resulting cold-constructed wearing layer has the defects of low strength and poor durability.

[0005] In summary, how to achieve efficient synergistic utilization of steel slag and phosphogypsum, while avoiding the defects of the hot mix process and improving the performance of cold mix mixtures has become a technical problem that urgently needs to be broken through in the field of road maintenance. Summary of the Invention

[0006] In order to improve the problem of low strength and poor durability of the wear layer obtained by adding steel slag and phosphogypsum to cold mix asphalt, the present application provides a reactive anti-skid wear layer mixture and a construction method thereof.

[0007] In a first aspect, the present application provides a reactive anti-skid wear layer mixture, which adopts the following technical solution:

[0008] A reactive anti-skid wear layer mixture includes a premix, thickening emulsified asphalt and water in a mass ratio of 100:8 to 15:1 to 10, the premix includes mixed stone and phosphogypsum in a mass ratio of 100:3 to 5, the mixed stone includes steel slag and basalt stone, the premix also includes a curing agent accounting for 0.1% to 1% of the mass ratio of the mixed stone, and the thickening emulsified asphalt includes base asphalt and a thickening agent accounting for 2% to 15% of the mass ratio of the base asphalt.

[0009] This application uses steel slag and phosphogypsum as the primary aggregates in the wearing layer, reducing the input of natural stone and lowering construction costs. It also provides a new avenue for the reuse of steel slag and phosphogypsum. By incorporating steel slag and phosphogypsum into cold-applied asphalt concrete and introducing a reactive binder, a reactive anti-skid wearing layer with strength and service life comparable to that of natural stone can be produced. Furthermore, the cold-applied approach avoids the various drawbacks of water and salt exposure to the high temperatures of hot-applied concrete.

[0010] This application adds a thickener to the thickened emulsified asphalt and a curing agent to the premix, so that the thickened emulsified asphalt and the premix come into contact during the mixing process during construction and undergo a curing reaction, thereby greatly improving the strength and wear resistance of the formed asphalt concrete. It can produce road performance comparable to that of traditional slurry mixtures using 100% natural basalt, greatly broadening the application scenarios of steel slag and phosphogypsum.

[0011] Optionally, the mixed stone material includes steel slag and basalt stone material in a mass ratio of 4-6:4-5.

[0012] This application replaces at least 50% of the basalt stone with steel slag, and at the same time utilizes the porous structure of steel slag and the granular structure of basalt stone to form a "skeleton-filling" effect. The two work together to control the porosity of the mixed stone within an appropriate range, thereby ensuring drainage performance and avoiding frost heave caused by water retention.

[0013] Optionally, the steel slag includes a primary steel slag with a particle size of 2.36 to 4.75 mm and a secondary steel slag with a particle size of 4.75 to 9.5 mm, and the mass ratio of the primary steel slag to the secondary steel slag is 4:2 to 5.

[0014] The basalt stone material is fine aggregate, and its particle size is 0-2.36 mm.

[0015] The present application reasonably distributes steel slag according to the particle size range, uses fine-grained steel slag to fill the gaps between coarse particles, and improves the packing density of the stone.

[0016] Optionally, when the premix passes through sieve holes with pore sizes of 9.5, 4.75, 2.36, 1.18, 0.6, 0.3, 0.15, and 0.075 mm, the corresponding passing ratios are 100%, 60% to 90%, 40% to 70%, 28% to 50%, 19% to 34%, 12% to 25%, 7% to 18%, and 5% to 15%, respectively.

[0017] By adopting the above technical solution, not only can the mineral materials of various particle sizes be utilized to the maximum extent, but the density of the premix can also be made more uniform, which is beneficial to improving the strength of the wearing layer.

[0018] Optionally, the curing agent includes at least one of isophoronediamine, diethylenetriamine, triethylenetetramine, and tetraethylenepentamine.

[0019] Optionally, the tackified emulsified asphalt comprises the following raw materials in parts by weight: 100 parts of base asphalt, 3-10 parts of aromatic rubber oil, 3-8 parts of thermoplastic elastomer, 2-15 parts of tackifier, 3-6 parts of emulsifier, and 50-80 parts of water.

[0020] Optionally, the viscosity-enhancing emulsified asphalt further includes 1 to 10 parts of inorganic acid.

[0021] By adding inorganic acid, the emulsifying ability of the emulsifier can be increased and the stability of the emulsion can be improved.

[0022] Optionally, the base asphalt is No. 70 petroleum base asphalt or No. 90 petroleum base asphalt.

[0023] Optionally, the tackifier is an epoxy resin, preferably an E51 type epoxy resin.

[0024] Optionally, the inorganic acid is one or both of industrial hydrochloric acid and 85% phosphoric acid.

[0025] Optionally, the emulsifier is Indulin-MQ65 from Ingevity.

[0026] Optionally, the thermoplastic elastomer includes one or more of styrene-butadiene-styrene copolymer, styrene-isoprene-styrene copolymer, styrene-ethylene-butadiene-styrene copolymer or styrene-ethylene-propylene-styrene copolymer.

[0027] Optionally, the tackified emulsified asphalt is prepared by the following process:

[0028] S1: The temperature of the base asphalt is controlled at 175-185°C, and aromatic rubber oil, thermoplastic elastomer, and tackifier are added in sequence. After high-speed shearing, the primary mixed asphalt is obtained.

[0029] S2: Heat water to 55-65°C, add emulsifier to water, and stir for 12-18 minutes to obtain soap solution;

[0030] S3: Maintain the temperature of the soap solution and adjust the pH value of the soap solution to between 2 and 3 with inorganic acid;

[0031] S4: Cool the temperature of the primary mixed asphalt to 130-150°C, add the soap solution into the colloid mill, start the colloid mill, and then slowly add the primary mixed asphalt. When the color of the liquid circulating in the colloid mill becomes uniform coffee color or dark brown, close the colloid mill to obtain the thickened emulsified asphalt.

[0032] Optionally, the shearing time in step S1 is 20-30 min, and the shearing rate is 5000-6000 r / min.

[0033] Optionally, the raw materials in the premix are premixed 5 to 7 days before construction.

[0034] The present application mixes the premix 5 to 7 days in advance and leaves it to stand in a dry place. During this period, the residual alkaline impurities such as magnesium oxide and calcium oxide contained in the steel slag and the residual acid contained in the phosphogypsum can fully undergo a neutralization reaction and be converted into salts and water, thereby completing the mutual modification of the two and completing their respective "purification treatments"; and the salts generated by the conversion can become a "delayed break agent" to increase the charge density during the mixing process of the slurry system, extend the mixing time of the system, make the mixture more stable during the construction process, and reduce segregation during the construction process.

[0035] In a second aspect, the present application provides a construction method for a reactive anti-skid wear layer mixture, which adopts the following technical solution:

[0036] A construction method for a reactive anti-skid wear layer mixture comprises the following steps:

[0037] Pre-treat the original road surface;

[0038] Use a slurry sealer to load the tackified emulsified asphalt, premix, and water into separate silos. Start the sealer and open the feed valve. The vehicle's mixing drum mixes the materials evenly. As the paving vehicle moves forward, a layer of wearing course mixture is spread on the road surface.

[0039] After the wearing course mixture is paved, let it stand for initial curing;

[0040] After the initial curing is completed and there is no obvious stickiness on the surface, it will be rolled. After the rolling treatment is completed, traffic can be opened.

[0041] Optionally, in step S3, the standing time is 20 minutes to 180 minutes, and the health-preserving time depends on the weather conditions.

[0042] Optionally, in step S4, the rolling is performed at least three times, and rolling can further remove moisture from the mixture and promote the curing reaction.

[0043] In summary, this application has at least one of the following beneficial effects:

[0044] 1. This application utilizes steel slag and phosphogypsum, two major mineral wastes, to produce a reactive anti-skid wear layer with strength and service life no less than that of natural stone, meeting the needs of preventive maintenance of asphalt pavements and providing a new way to reuse mineral waste.

[0045] 2. This application provides a lightweight preventive highway maintenance solution that has a wider range of application scenarios compared to new construction and major and medium-sized repair projects. DETAILED DESCRIPTION

[0046] This application provides a reactive anti-skid wear layer mixture comprising a premix, thickening emulsified asphalt, and water in a mass ratio of 100:8 to 15:1 to 10. The premix comprises mixed stone and phosphogypsum in a mass ratio of 100:3 to 5, and the mixed stone comprises steel slag and basalt in a mass ratio of 4 to 6:4 to 5. The steel slag comprises primary steel slag with a particle size of 2.36 to 4.75 mm and secondary steel slag with a particle size of 4.75 to 9.5 mm, with the mass ratio of primary steel slag to secondary steel slag being 4:2 to 5. When the premix passes through sieve holes with apertures of 9.5, 4.75, 2.36, 1.18, 0.6, 0.3, 0.15, and 0.075 mm, the corresponding passing ratios are 100%, 60%-90%, 40%-70%, 28%-50%, 19%-34%, 12%-25%, 7%-18%, and 5%-15%, respectively.

[0047] The premix further comprises a curing agent accounting for 0.1% to 1% by mass of the mixed stone, and the curing agent comprises at least one of isophorone diamine, diethylene triamine, triethylene tetramine and tetraethylene pentamine.

[0048] The tackified emulsified asphalt comprises the following raw materials by weight: 100 parts of base asphalt, 3-10 parts of aromatic rubber oil, 3-8 parts of thermoplastic elastomer, 2-15 parts of tackifier, 3-6 parts of emulsifier, 1-10 parts of inorganic acid, and 50-80 parts of water. The tackified emulsified asphalt is prepared using the following process:

[0049] S1: The temperature of the base asphalt is controlled at 175-185°C, and aromatic rubber oil, thermoplastic elastomer, and tackifier are added in sequence. After high-speed shearing, the primary mixed asphalt is obtained.

[0050] S2: Heat water to 55-65°C, add emulsifier to water, and stir for 12-18 minutes to obtain soap solution;

[0051] S3: Maintain the temperature of the soap solution and adjust the pH value of the soap solution to between 2 and 3 with an inorganic acid;

[0052] S4: Cool the temperature of the primary asphalt mix to 130-150° C., add the soap solution into the colloid mill, start the colloid mill, and then slowly add the primary asphalt mix. When the color of the liquid circulating in the colloid mill becomes uniform coffee color or dark brown, close the colloid mill to obtain the thickened emulsified asphalt.

[0053] The present application also provides a construction method of a reactive anti-skid wear layer mixture, comprising the following steps:

[0054] Pre-treat the original road surface;

[0055] Use a slurry sealer to load the tackified emulsified asphalt, premix, and water into separate silos. Start the sealer and open the feed valve. The vehicle's mixing drum mixes the materials evenly. As the paving vehicle moves forward, a layer of wearing course mixture is spread on the road surface.

[0056] After the wearing course mixture is paved, let it stand for initial curing;

[0057] After the initial curing is completed and there is no obvious stickiness on the surface, it will be rolled. After the rolling treatment is completed, traffic can be opened.

[0058] The present application will be further described below with reference to specific examples and comparative examples. The following examples are illustrative rather than restrictive, and the scope of protection of the present application cannot be limited by the following examples.

[0059] The raw materials used in the examples and comparative examples of this application can be obtained commercially, as shown in Table 1.

[0060] Table 1 Source of raw materials

[0061]

[0062] Preparation Example 1: Preparation Example 1 provides a tackified emulsified asphalt, which includes base asphalt, aromatic rubber oil, thermoplastic elastomer, tackifier, emulsifier and water. The specific amounts are shown in Table 2. The preparation method is as follows:

[0063] S1: The temperature of the base asphalt is controlled at 180°C, and aromatic rubber oil, thermoplastic elastomer, and tackifier are added in sequence, and then subjected to high-speed shearing to obtain the primary mixed asphalt;

[0064] S2: Heat water to 60°C, add emulsifier to water, and stir for 15 minutes to obtain soap solution;

[0065] S3: Maintain the temperature of the soap solution and adjust the pH value of the soap solution to between 2 and 3 with inorganic acid;

[0066] S4: Cool the temperature of the primary asphalt mix to 140°C, add the soap solution into the colloid mill, start the colloid mill, and then slowly add the primary asphalt mix. When the color of the liquid circulating in the colloid mill becomes a uniform coffee color or dark brown, close the colloid mill to obtain the thickened emulsified asphalt.

[0067] Preparation Example 2-3: Preparation Example 2-3 is basically the same as Preparation Example 1, except that the amounts of raw materials used in each preparation example are different. For specific amounts, see Table 2.

[0068] Preparation of Comparative Example 1: Preparation of Comparative Example 1 is basically the same as Preparation Example 1, except that the amounts of raw materials used in each preparation example are different. For specific amounts, see Table 2.

[0069] Table 2 Types and amounts of raw materials used in each preparation example (unit: kg)

[0070]

[0071] Example 1: Example 1 provides a reactive anti-skid wear layer mixture, which includes a premix, thickening emulsified asphalt and water. The specific amounts are shown in Table 3. The premix is premixed 7 days before construction and stacked statically for use during construction.

[0072] The viscosified emulsified asphalt used in Example 1 was prepared according to the formulation of Preparation Example 1. The premix gradation was as follows: the corresponding pass ratios for sieves with apertures of 9.5, 4.75, 2.36, 1.18, 0.6, 0.3, 0.15, and 0.075 mm were 100%, 75%, 55%, 39%, 26.5%, 18.5%, 12.5%, and 10%, respectively. The mass ratio of primary steel slag to secondary steel slag was 4:5.

[0073] The construction method of the reactive anti-skid wear layer mixture of Example 1 is as follows:

[0074] Pre-treat the original road surface;

[0075] Use a slurry sealer to load the tackified emulsified asphalt, premix, and water into separate silos. Start the sealer and open the feed valve. The vehicle's mixing drum mixes the materials evenly. As the paving vehicle moves forward, a layer of wearing course mixture is spread on the road surface.

[0076] After the wearing course mixture is paved, let it stand for initial curing;

[0077] After the initial curing is completed and there is no obvious stickiness on the surface, it will be rolled. After the rolling treatment is completed, traffic can be opened.

[0078] Example 2-3: Example 2-3 is basically the same as Example 1, except that the amounts of raw materials used in each example are different. For specific amounts, see Table 3.

[0079] Table 3 Types and amounts of raw materials used in various examples (unit: kg)

[0080]

[0081] Example 4: Example 4 is essentially the same as Example 1, differing only in the gradation of the premix. Specifically, the gradation of the premix in Example 4 is as follows: 100%, 90%, 70%, 50%, 34%, 25%, 18%, and 15% of the premix pass through sieves with apertures of 9.5, 4.75, 2.36, 1.18, 0.6, 0.3, 0.15, and 0.075 mm, respectively. The mass ratio of primary steel slag to secondary steel slag is 2:1.

[0082] Example 5: Example 5 is essentially the same as Example 1, differing only in the gradation of the premix. Specifically, the gradation of the premix in Example 5 is as follows: 100%, 60%, 40%, 28%, 19%, 12%, 7%, and 5% of the premix pass through sieves with apertures of 9.5, 4.75, 2.36, 1.18, 0.6, 0.3, 0.15, and 0.075 mm, respectively. The mass ratio of primary steel slag to secondary steel slag is 1:2.

[0083] Example 6: Example 6 is substantially the same as Example 1, except that the source of the viscosified emulsified asphalt is different. Specifically, the viscosified emulsified asphalt of Example 6 is from Preparation Example 2.

[0084] Example 7: Example 7 is substantially the same as Example 1, except that the source of the viscosified emulsified asphalt is different. Specifically, the viscosified emulsified asphalt of Example 7 is from Preparation Example 3.

[0085] Comparative Example 1: Comparative Example 1 is substantially the same as Example 1, except that the source of the viscosified emulsified asphalt is different. Specifically, the viscosified emulsified asphalt of Comparative Example 1 is obtained from the preparation of Comparative Example 1.

[0086] Comparative Example 2: Comparative Example 2 is substantially the same as Example 1, except that no curing agent is added to the premix in Comparative Example 2.

[0087] Comparative Example 3: Comparative Example 3 is substantially the same as Example 1, except that the raw materials in the premix are not premixed 7 days in advance and are used immediately after preparation.

[0088] Comparative Example 4: Comparative Example 4 is essentially the same as Example 1, except that the premix and the viscosified emulsified asphalt are derived from different sources. The premix is entirely composed of basalt stone, and its gradation is the same as that of Example 1, while the viscosified emulsified asphalt is derived from the preparation of Comparative Example 1.

[0089] Performance testing: According to the "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering (JTGE20-2011)", the reactive anti-skid wear layer mixtures obtained in the above Examples 1-7 and Comparative Examples 1-4 were subjected to mixing tests, cohesion tests, 1h wet wheel wear tests, and wheel rutting deformation tests, and the specific results are as follows.

[0090] Table 4 Test results of various embodiments and comparative examples

[0091]

[0092] From the results in Table 4, it can be seen that no tackifier was added in the preparation of Comparative Example 1, resulting in the cohesion test result of Comparative Example 1 being "loose", and the wet wheel wear loss and rutting deformation being significantly deteriorated; Comparative Example 2 lacks a curing agent, and its cohesion test result is "loose", and the performance of wet wheel wear loss and rutting deformation are both substandard, indicating that both the tackifier and the curing agent are indispensable.

[0093] The premix in Example 3 was used immediately after preparation, but the performance of the resulting mixture still did not meet the standards, indicating that the premix and standing for 7 days ensured that the steel slag and phosphogypsum could fully react and improve the performance.

[0094] Compared with Comparative Example 4, Example 1 uses steel slag to replace 50% of basalt stone, and the road performance of the anti-skid wear layer mixture is not reduced, and may even be better in some indicators. Therefore, this application can achieve high-value utilization of industrial solid waste without reducing road performance.

[0095] The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A reactive anti-skid wear layer mixture, characterized in that: The invention comprises a premix, a tackifying emulsified asphalt and water in a mass ratio of 100:8-15:1-10, the premix comprising mixed stone and phosphogypsum in a mass ratio of 100:3-5, the mixed stone comprising steel slag and basalt stone, the premix further comprising a curing agent accounting for 0.1%-1% by mass of the mixed stone, and the tackifying emulsified asphalt comprising the following raw materials in parts by weight: 100 parts of base asphalt, 3-10 parts of aromatic rubber oil, 3-8 parts of thermoplastic elastomer, 2-15 parts of tackifier, 3-6 parts of emulsifier, and 50-80 parts of water; The raw materials in the premix are premixed 5 to 7 days before construction.

2. The reactive anti-skid wear layer mixture according to claim 1, characterized in that: The mixed stone material comprises steel slag and basalt stone material in a mass ratio of 4-6:4-5.

3. The reactive anti-skid wear layer mixture according to claim 1, characterized in that: The steel slag includes primary steel slag with a particle size of 2.36 to 4.75 mm and secondary steel slag with a particle size of 4.75 to 9.5 mm. The mass ratio of the primary steel slag to the secondary steel slag is 4:2 to 5.

4. The reactive anti-skid wear layer mixture according to claim 1, characterized in that: When the premix passes through the sieve holes of 9.5, 4.75, 2.36, 1.18, 0.6, 0.3, 0.15, and 0.075 mm in diameter, the corresponding passing ratios are 100%, 60%～90%、40%～70%、28%～50%、19%～34%、12%～25%、7%～18%、5%～15%。 5. The reactive anti-skid wear layer mixture according to claim 1, characterized in that: The curing agent includes at least one of isophoronediamine, diethylenetriamine, triethylenetetramine, and tetraethylenepentamine.

6. The reactive anti-skid wear layer mixture according to claim 1, characterized in that: The viscosity-enhancing emulsified asphalt also includes 1 to 10 parts of inorganic acid.

7. The reactive anti-skid wear layer mixture according to claim 6, characterized in that: The tackified emulsified asphalt is prepared by the following process: S1: The temperature of the base asphalt is controlled at 175-185°C, and aromatic rubber oil, thermoplastic elastomer, and tackifier are added in sequence. After high-speed shearing, the primary mixed asphalt is obtained. S2: Heat water to 55-65°C, add emulsifier to water, and stir for 12-18 minutes to obtain soap solution; S3: Maintain the temperature of the soap solution and adjust the pH value of the soap solution to between 2 and 3 with inorganic acid; S4: Cool the temperature of the primary asphalt mix to 130-150° C., add the soap solution into the colloid mill, start the colloid mill, and then slowly add the primary asphalt mix. When the color of the liquid circulating in the colloid mill becomes uniform coffee color or dark brown, close the colloid mill to obtain the thickened emulsified asphalt.

8. The construction method of the reactive anti-skid wear layer mixture according to any one of claims 1 to 7, characterized in that: The steps include: Pre-treat the original road surface; Use a slurry sealer to load the tackified emulsified asphalt, premix, and water into separate silos. Start the sealer and open the feed valve. The vehicle's mixing drum mixes the materials evenly. As the paving vehicle moves forward, a layer of wearing course mixture is spread on the road surface. After the wearing course mixture is paved, let it stand for initial curing; After the initial curing is completed and there is no obvious stickiness on the surface, it will be rolled. After the rolling treatment is completed, traffic can be opened.

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