Reaction type anti-skid wearing layer mixture and construction method thereof

Abstract

The invention discloses a reactive anti-skid wearing layer mixture and a construction method thereof, and relates to the technical field of preventive maintenance of asphalt pavements. A reaction type anti-skid wearing layer mixture comprises a premix, tackifying emulsified asphalt and water according to the mass ratio of 100: (8-15): (1-10), the premix comprises mixed stone and ardealite, the mixed stone comprises steel slag and basalt stone, the premix further comprises a curing agent accounting for 0.1%-1% of the mass of the mixed stone, and the curing agent accounts for 0.1%-1% of the mass of the mixed stone. The tackified emulsified asphalt comprises matrix asphalt and a tackifier accounting for 2-15% of the mass of the matrix asphalt. The construction method comprises the following steps: pre-treating an original pavement, paving the anti-skid wearing layer mixture, primarily curing, and rolling. According to the invention, two mineral wastes, namely the steel slag and the ardealite, can be utilized to produce the reactive anti-skid wearing layer with the strength and the service life not shorter than those of natural stones, so that the requirements of preventive maintenance of asphalt pavements are met, and a new way is provided for reutilization of the mineral wastes.

Description

Technical Field

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

[0002] As is well known, the wearing course, as a means of road preventive maintenance, when applied above the asphalt road surface layer, can solve problems such as minor cracks on the road surface, road surface water seepage, rutting, and reduced anti-skid performance.

[0003] Currently, due to its high hardness and wear resistance, steel slag is often separately incorporated into asphalt mixtures for pavement paving; while phosphogypsum, because of its gelling properties, is mostly used as a building and subgrade improvement material. However, the above applications have significant limitations: the residual alkaline substances such as magnesium oxide and calcium oxide in steel slag will react with water, resulting in volume expansion and causing pavement cracking problems; the unreacted sulfates and free acids in phosphogypsum will cause chemical erosion during long-term service, making the road surface structure loose and reducing the service life of the road surface.

[0004] Therefore, technicians have tried to compound and incorporate steel slag and phosphogypsum into the wearing course mixture, expecting that the impurities in the two can neutralize each other and avoid the above defects. If steel slag and phosphogypsum are compounded and used in the hot mix asphalt process, water and salt substances will be generated after their reaction. The presence of water will seriously affect the control of the material temperature during the production process of the asphalt mixture. More importantly, water and salt substances will corrode the production equipment under high-temperature conditions, bringing great potential safety hazards to production. In addition, the high energy consumption and carbon emission problems of the hot mix process do not conform to the trend of green construction, and the hot mix process is mostly used for new pavements and major repair projects, with limited application scenarios. If steel slag and phosphogypsum are simply compounded and used in the cold mix process, the active impurities in steel slag and phosphogypsum will greatly affect the strength of the mixture and it is difficult to form a dense structure. Therefore, the cold-constructed wearing course obtained has defects such as low strength and poor durability.

[0005] In summary, how to achieve the efficient and coordinated utilization of steel slag and phosphogypsum, while avoiding the defects of the hot mix process and improving the performance of the cold mix mixture, 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 problems of low strength and poor durability of the wearing course obtained by incorporating steel slag and phosphogypsum into cold mix asphalt, the present application provides a reactive anti-skid wearing course mixture and a construction method thereof.

[0007] In the first aspect, the present application provides a reactive anti-skid wearing course mixture, adopting the following technical solution: A reactive anti-skid wearing course mixture, comprising a premix, a tackifying emulsified asphalt, and water in a mass ratio of 100:8 - 15:1 - 10. The premix comprises a mixed stone material and phosphogypsum in a mass ratio of 100:3 - 5. The mixed stone material includes steel slag and basalt aggregate. The premix further comprises a curing agent accounting for 0.1% - 1% of the mass of the mixed stone material. The tackifying emulsified asphalt comprises a matrix asphalt and a tackifier accounting for 2% - 15% of the mass of the matrix asphalt.

[0008] In this application, steel slag and phosphogypsum are used as the main materials in the wearing course aggregate, which can reduce the input of natural stone materials, lower the construction cost, and at the same time provide a new treatment channel for the reuse of steel slag and phosphogypsum. By applying steel slag and phosphogypsum to cold - construction asphalt concrete and introducing a reactive binder simultaneously, a reactive anti - skid wearing course with strength and service life not lower than that using natural stone materials can be produced. At the same time, due to the cold - construction scheme, various drawbacks caused by water and salts at high temperatures during hot construction are avoided.

[0009] In this application, by adding a tackifier to the tackifying emulsified asphalt and a curing agent to the premix, the tackifying emulsified asphalt and the premix come into contact during the mixing process during construction and undergo a curing reaction, greatly improving the strength and abrasion resistance of the formed asphalt concrete. The road - using performance comparable to that of traditional slurry mixtures using 100% natural basalt can be produced, greatly broadening the application scenarios of steel slag and phosphogypsum.

[0010] Optionally, the mixed stone material comprises steel slag and basalt aggregate in a mass ratio of 4 - 6:4 - 5.

[0011] In this application, by using steel slag to replace at least 50% of the basalt aggregate, and at the same time using the porous structure of steel slag and the granular structure of basalt aggregate to form a "skeleton - filling" effect, the two cooperate with each other to control the void ratio of the mixed stone material within a suitable range, thus ensuring both drainage performance and avoiding frost heaving caused by water retention.

[0012] Optionally, the steel slag comprises primary steel slag with a particle size of 2.36 - 4.75 mm and secondary steel slag with a particle size of 4.75 - 9.5 mm, and the mass ratio of the primary steel slag to the secondary steel slag is 4:2 - 5.

[0013] The basalt aggregate is fine aggregate with a particle size of 0 - 2.36 mm.

[0014] In this application, by reasonably distributing the steel slag according to the particle size range and using fine - grained steel slag to fill the gaps between coarse grains, the stacking density of the stone material is improved.

[0015] Optionally, when the premix passes through the sieve holes with pore diameters 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.

[0016] By adopting the above technical solution, not only can the mineral materials of various particle sizes be utilized to the maximum extent, but also the density of the premix can be made more uniform, which is conducive to improving the strength of the wearing course.

[0017] Optionally, the curing agent includes at least one of isophorone diamine, diethylenetriamine, triethylenetetramine, and tetraethylenepentamine.

[0018] Optionally, the tackifying emulsified asphalt includes the following raw materials in parts by weight: 100 parts of matrix 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.

[0019] Optionally, the tackifying emulsified asphalt further includes 1 - 10 parts of inorganic acid.

[0020] Adding inorganic acid can increase the emulsifying ability of the emulsifier and improve the stability of the emulsion.

[0021] Optionally, the matrix asphalt is 70# petroleum matrix asphalt or 90# petroleum matrix asphalt.

[0022] Optionally, the tackifier is epoxy resin, preferably E51 type epoxy resin.

[0023] Optionally, the inorganic acid is one or two of industrial hydrochloric acid and 85% phosphoric acid.

[0024] Optionally, the emulsifier is Indulin - MQ65 of Ingevity Corporation.

[0025] 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.

[0026] Optionally, the tackifying emulsified asphalt is prepared by the following process: S1: Control the temperature of the matrix asphalt at 175 - 185°C, and sequentially add aromatic rubber oil, thermoplastic elastomer, and tackifier, and obtain the preliminary mixed asphalt through high - speed shearing; S2: Heat water to 55-65°C, add emulsifier into water, 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 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.

[0027] Optionally, the shearing time in step S1 is 20-30 min, and the shearing rate is 5000-6000 r / min.

[0028] Optionally, the raw materials in the premix are premixed 5 to 7 days before construction.

[0029] 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 can fully react with the residual acid contained in the phosphogypsum 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 "slow-breaking agent" to increase the charge density during the mixing process of the slurry system, prolong the mixing time of the system, make the mixture more stable during the construction process, and reduce the segregation phenomenon during the construction process.

[0030] In a second aspect, the present application provides a construction method of a reactive anti-skid wear layer mixture, which adopts the following technical solution: A construction method for a reactive anti-skid wear layer mixture comprises the following steps: Pre-treat the original road surface; Use a slurry sealer to load the thickened emulsified asphalt, premix and water into their own separate silos, start the sealer, open the feed valve, and the mixing cylinder of the vehicle will mix 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, when there is no obvious stickiness on the surface, rolling treatment is carried out. After the rolling treatment is completed, traffic can be opened.

[0031] Optionally, in step S3, the standing time is 20 min to 180 min, and the health-preserving time depends on weather conditions.

[0032] 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.

[0033] In summary, the present application includes at least one of the following beneficial effects: 1. By using two major mineral wastes, namely steel slag and phosphogypsum, the present application can produce a reactive anti-skid wearing course with strength and service life not lower than that of natural stone materials, meeting the needs of preventive maintenance of asphalt pavements and providing a new way for the reuse of mineral wastes.

[0034] 2. The present application provides a lightweight preventive highway maintenance solution, which has a wider application scenario compared with new construction and major and medium repairs. Specific Embodiments

[0035] The present application provides a reactive anti-skid wearing course mixture, which includes a premix, a tackifying emulsified asphalt, and water with a mass ratio of 100:8 - 15:1 - 10. The premix includes a mixed stone material and phosphogypsum with a mass ratio of 100:3 - 5, and the mixed stone material includes steel slag and basalt aggregate with a mass ratio of 4 - 6:4 - 5. The steel slag includes primary steel slag with a particle size of 2.36 - 4.75 mm and secondary steel slag with a particle size of 4.75 - 9.5 mm, and the mass ratio of the primary steel slag to the secondary steel slag is 4:2 - 5. When the premix passes through the 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.

[0036] The premix further includes a curing agent accounting for 0.1% - 1% of the mass of the mixed stone material, and the curing agent includes at least one of isophorone diamine, diethylenetriamine, triethylenetetramine, and tetraethylenepentamine.

[0037] The tackifying emulsified asphalt includes the following raw materials in parts by weight: 100 parts of matrix 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 tackifying emulsified asphalt is prepared by the following process: S1: Control the temperature of the matrix asphalt at 175 - 185°C, and successively add aromatic rubber oil, thermoplastic elastomer, and tackifier, and obtain a preliminary mixed asphalt through high-speed shearing; S2: Heat the water to 55 - 65°C, add the emulsifier to the water, and stir for 12 - 18 minutes to obtain a soap solution; S3: Keep 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 preliminarily mixed asphalt to 130 - 150°C, add the soap solution into the colloid mill, start the colloid mill, and then slowly add the preliminarily mixed asphalt. When the color of the liquid circulating in the colloid mill presents uniform coffee color or dark brown, turn off the colloid mill to obtain the viscosity-increasing emulsified asphalt.

[0038] This application also provides a construction method for a reactive anti-skid wearing course mixture, including the following steps: Pre-treat the original road surface; Using a slurry seal truck, load the viscosity-increasing emulsified asphalt, premix, and water into their respective independent bins, start the seal truck, open the feed valve, and the mixing cylinder of the truck will mix the materials evenly. As the paving truck moves forward, pave a layer of wearing course mixture on the road surface; After the paving of the wearing course mixture is completed, let it stand for preliminary curing; After the preliminary curing is completed, when there is no obvious viscosity on the surface, carry out rolling treatment. After the rolling treatment is completed, the traffic can be opened.

[0039] The following will further illustrate this application in combination with specific examples and comparative examples. The following examples are illustrative and not restrictive, and the protection scope of this application cannot be limited by the following examples.

[0040] The raw materials used in the examples and comparative examples of this application can all be obtained commercially. Specifically, see Table 1.

[0041] Table 1 Raw material sources

[0042] Preparation Example 1: Preparation Example 1 provides a viscosity-increasing emulsified asphalt, which includes matrix asphalt, aromatic rubber oil, thermoplastic elastomer, tackifier, emulsifier, and water. The specific dosages are shown in Table 2. Its preparation method is as follows: S1: Control the temperature of the matrix asphalt at 180°C, and successively add aromatic rubber oil, thermoplastic elastomer, and tackifier, and obtain the preliminarily mixed asphalt through high-speed shearing; S2: Heat the water to 60°C, add the emulsifier into the water, and stir for 15 minutes to obtain the soap solution; S3: Keep the temperature of the soap solution and adjust the pH value of the soap solution to between 2 - 3 with inorganic acid; S4: Cool the temperature of the preliminarily mixed asphalt to 140°C, add the soap solution into the colloid mill, start the colloid mill, and then slowly add the preliminarily mixed asphalt. When the color of the liquid circulating in the colloid mill presents uniform coffee color or dark brown, turn off the colloid mill to obtain the viscosity-increasing emulsified asphalt.

[0043] Preparation Examples 2 - 3: Preparation Examples 2 - 3 are basically the same as Preparation Example 1, except that the dosages of the raw materials in each preparation example are different. The specific dosages are shown in Table 2.

[0044] Preparation of Comparative Example 1: The preparation of Comparative Example 1 is basically the same as that of Preparation Example 1, except that the amounts of raw materials in each preparation example are different. For specific amounts, see Table 2.

[0045] Table 2 Types and amounts of raw materials in each preparation example (unit: kg)

[0046] Example 1: Example 1 provides a reactive anti-skid wear-resistant layer mixture, which includes a premix, tackifying emulsified asphalt, and water. For specific amounts, see Table 3. Seven days before construction, the premix is pre-mixed and then stacked and left standing for use during construction.

[0047] The tackifying emulsified asphalt used in Example 1 is the tackifying emulsified asphalt prepared according to the formula of Preparation Example 1. The gradation of the premix is as follows: when passing through the 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%, 75%, 55%, 39%, 26.5%, 18.5%, 12.5%, and 10% respectively. Among them, the mass ratio of primary steel slag to secondary steel slag is 4:5.

[0048] The construction method of the reactive anti-skid wear-resistant layer mixture in Example 1 is as follows: Pre-treat the original road surface; Using a slurry seal truck, load the tackifying emulsified asphalt, premix, and water into their respective independent bins. Start the seal truck, open the feed valve, and the mixing cylinder of the truck will mix the materials evenly. As the paving truck moves forward, pave a layer of wear-resistant layer mixture on the road surface; After the paving of the wear-resistant layer mixture is completed, let it stand for initial curing; After the initial curing is completed, when there is no obvious viscosity on the surface, carry out rolling treatment. After the rolling treatment is completed, the traffic can be opened.

[0049] Examples 2 - 3: Examples 2 - 3 are basically the same as Example 1, except that the amounts of raw materials in each example are different. For specific amounts, see Table 3.

[0050] Table 3 Types and amounts of raw materials in each example (unit: kg)

[0051] Example 4: Example 4 is basically the same as Example 1, except that the gradation of the premix is different. Specifically, the gradation of the premix in Example 4 is as follows: when passing through the sieve holes with pore diameters 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%, 90%, 70%, 50%, 34%, 25%, 18%, and 15% respectively. Among them, the mass ratio of primary steel slag to secondary steel slag is 2:1.

[0052] Example 5: Example 5 is basically the same as Example 1, except that the gradation of the premix is different. Specifically, the gradation of the premix in Example 5 is as follows: when passing through the sieve holes with pore diameters 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%, 40%, 28%, 19%, 12%, 7%, and 5% respectively. Among them, the mass ratio of primary steel slag to secondary steel slag is 1:2.

[0053] Example 6: Example 6 is basically the same as Example 1, except that the source of the tackifier emulsified asphalt is different. Specifically, the tackifier emulsified asphalt in Example 6 is from Preparation Example 2.

[0054] Example 7: Example 7 is basically the same as Example 1, except that the source of the tackifier emulsified asphalt is different. Specifically, the tackifier emulsified asphalt in Example 7 is from Preparation Example 3.

[0055] Comparative Example 1: Comparative Example 1 is basically the same as Example 1, except that the source of the tackifier emulsified asphalt is different. Specifically, the tackifier emulsified asphalt in Comparative Example 1 is from Comparative Preparation Example 1.

[0056] Comparative Example 2: Comparative Example 2 is basically the same as Example 1, except that no curing agent is added to the premix in Comparative Example 2.

[0057] Comparative Example 3: Comparative Example 3 is basically 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 mixing.

[0058] Comparative Example 4: Comparative Example 4 is basically the same as Example 1, except that the sources of the premix and the tackifier emulsified asphalt are different. Among them, the premix is entirely composed of basalt aggregate, and its gradation is the same as that of Example 1. The tackifier emulsified asphalt is from Comparative Preparation Example 1.

[0059] Performance testing: According to the "Test Procedures for Bitumen and Bituminous Mixtures in Highway Engineering (JTGE20 - 2011)", the reactive anti-skid wear-resistant layer mixtures obtained from the above Examples 1 - 7 and Comparative Examples 1 - 4 were respectively subjected to mixing tests, cohesion tests, 1h wet wheel abrasion tests, and rutting deformation tests. The specific results are as follows.

[0060] Table 4 Detection Results of Each Example and Comparative Example

[0061] It can be seen from the results in Table 4 that no tackifier was added in Comparative Example 1 during preparation, resulting in the cohesion test result of Comparative Example 1 being "loose", and the wet wheel abrasion loss and rutting deformation being significantly deteriorated; the curing agent was missing in Comparative Example 2, and its cohesion test result was "loose", and the performance of both the wet wheel abrasion loss and rutting deformation did not meet the standards, indicating that neither the tackifier nor the curing agent can be missing.

[0062] The premix in Comparative Example 3 was used immediately after preparation, and the performance of the obtained mixture still did not meet the standards, indicating that premixing and standing for 7 days ensured that the steel slag and phosphogypsum could fully react and improve the performance.

[0063] Compared with Comparative Example 4, in Example 1, 50% of the basalt aggregate was replaced with steel slag, and the road performance of the anti-skid wear-resistant layer mixture did not decrease, and even may be better in some indicators. Therefore, the present application can realize the high-value utilization of industrial solid waste without reducing the road performance.

[0064] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereby. Therefore, all equivalent changes made according to the structure, shape, and principle of the present application should be covered within the protection scope of the present application.

Claims

1. A reactive anti-skid wearing course mixture, characterized in that, The invention comprises a premix, thickening emulsified asphalt and water in a mass ratio of 100:8-15:1-10, wherein the premix comprises mixed stone and phosphogypsum in a mass ratio of 100:3-5, wherein the mixed stone comprises steel slag and basalt stone, and the premix further comprises a curing agent accounting for 0.1%-1% of the mixed stone by mass. The thickening 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 thickener, 3-6 parts of emulsifier and 50-80 parts of water.

2. The reactive anti-skid wearing course mixture according to claim 1, wherein 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 wearing course mixture according to claim 1, wherein The steel slag includes primary steel slag with a particle size of 2.36-4.75 mm and secondary steel slag with a particle size of 4.75-9.5 mm, and the mass ratio of the primary steel slag to the secondary steel slag is 4:2-5.

4. The reactive anti-skid wearing course mixture according to claim 1, wherein 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% to 90%, 40% to 70%, 28% to 50%, 19% to 34%, 12% to 25%, 7% to 18%, and 5% to 15%, respectively.

5. The reactive anti-skid wearing course 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 wearing course mixture according to claim 1, characterized in that, The thickened emulsified asphalt also includes 1 to 10 parts of inorganic acid.

7. The reactive anti-skid wearing course mixture according to claim 6, characterized in that, The viscosity-enhanced 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, and the primary mixed asphalt is obtained through high-speed shearing; S2: Heat water to 55-65°C, add emulsifier into water, 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 an inorganic acid; S4: Cooling the temperature of the primary mixed asphalt to 130-150° C., adding soap solution into the colloid mill, starting the colloid mill, and then slowly adding the primary mixed asphalt, and when the color of the liquid circulating in the colloid mill becomes uniform coffee color or dark brown, closing the colloid mill to obtain the thickened emulsified asphalt.

8. The reactive anti-skid wearing course mixture according to claim 1, characterized in that, The raw materials in the premix are premixed 5 to 7 days before construction.

9. The construction method of the reactive anti-skid wearing course mixture according to any one of claims 1-8, characterized in that, The steps include: Pre-treat the original road surface; Use a slurry sealer to load the thickened emulsified asphalt, premix and water into their own separate silos, start the sealer, open the feed valve, and the mixing cylinder of the vehicle will mix 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, when there is no obvious stickiness on the surface, rolling treatment is carried out. After the rolling treatment is completed, traffic can be opened.

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