Steel slag aggregate asphalt mixture and preparation method thereof

Abstract

The invention relates to the field of road building materials, and particularly discloses a steel slag aggregate asphalt mixture and a preparation method thereof. The steel slag aggregate asphalt mixture is prepared from the following raw materials in parts by weight: 60-80 parts of steel slag aggregate, 10-20 parts of matrix asphalt, 1-2 parts of an anti-aging agent, 1-2 parts of a waterproof damage agent and 1-2.5 parts of an anti-skid aid, the steel slag aggregate is subjected to organic-inorganic hybrid modification through a modified material in advance, and the modified material comprises polyvinyl alcohol, phosphoric acid and sodium citrate; the steel slag aggregate is modified by using polyvinyl alcohol, phosphoric acid and sodium citrate, so that the expansion rate of the steel slag aggregate can be reduced, the calcium oxide content of the steel slag aggregate is reduced, the cracking phenomenon of the steel slag asphalt mixture is reduced, and meanwhile, the binding force of the steel slag aggregate and an asphalt matrix is enhanced.

Description

Technical Field

[0001] The present application relates to the field of road construction materials, and in particular to a steel slag aggregate asphalt mixture and a preparation method thereof. Background Art

[0002] At present, although the traditional asphalt mixture widely used in road construction has good driving comfort and noise reduction effect, in the face of the increasing vehicle flow and the traffic pressure of heavy vehicles, there are generally problems such as early fatigue cracking and rutting deformation. Especially in high-temperature environments, the road surface is prone to softening and deformation, resulting in frequent repairs and increasing the cost of road maintenance. In recent years, the research on using industrial waste such as steel slag as aggregate to replace natural stone has gradually increased, which not only helps resource recycling but also improves the mechanical properties of asphalt mixtures.

[0003] However, due to the complex mineral composition of the steel slag aggregate produced by domestic steel mills at present, there are many substances such as free calcium oxide, which will cause the steel slag to expand and then cause cracking and damage. At the same time, the adhesion between the steel slag aggregate and asphalt is poor, which further leads to the instability of the internal structure of the mixture and reduces the durability of the asphalt mixture. Summary of the Invention

[0004] In order to improve the structural stability and durability of the steel slag asphalt mixture, the present application provides a steel slag aggregate asphalt mixture and a preparation method thereof.

[0005] In a first aspect, the present application provides a steel slag aggregate asphalt mixture, adopting the following technical solution: A steel slag aggregate asphalt mixture, comprising the following raw materials in parts by weight: 60-80 parts of steel slag aggregate, 10-20 parts of matrix asphalt, 1-2 parts of anti-aging agent, 1-2 parts of waterproof damage agent, 1-2.5 parts of anti-slip aid; the steel slag aggregate is pre-modified by an organic-inorganic hybridization modification with a modification material, and the modification material includes polyvinyl alcohol, phosphoric acid and sodium citrate.

[0006] By adopting the above technical solutions, phosphoric acid can chemically react with calcium oxide in the steel slag aggregate to generate phosphate with strong binding force, which covers the surface, eliminates substances such as calcium oxide in the steel slag, hinders and delays the expansion of the steel slag aggregate, and improves the density and durability of the steel slag asphalt mixture. Sodium citrate can synergistically act with phosphoric acid to chelate the steel slag aggregate, adsorb metal ions and hydration products in the steel slag on the surface of the steel slag aggregate. A large number of metal ions such as calcium ions are adsorbed to form a buffer film, thereby reducing the calcium oxide content in the steel slag aggregate, inhibiting the expansibility of the steel slag, reducing the cracking phenomenon of the steel slag asphalt mixture, and improving the durability and structural stability of the steel slag asphalt mixture. Polyvinyl alcohol can penetrate into the pores of the steel slag aggregate and form a polymer film inside the steel slag aggregate through a polymerization reaction, enhancing the bond between the steel slag aggregate and the matrix asphalt, thereby improving the density and durability of the steel slag asphalt mixture.

[0007] Preferably, the mass ratio of the sodium citrate to the steel slag aggregate is (0.005 - 0.015):1, the mass ratio of the phosphoric acid to the steel slag aggregate is (0.01 - 0.02):1, and the mass ratio of the polyvinyl alcohol to the steel slag aggregate is (0.01 - 0.03):1.

[0008] Preferably, the anti-aging agent is at least one of naphthenic acid and oil-soluble tea polyphenols, and the anti-slip aid is at least one of silica sand, quartz sand, and rubber powder.

[0009] By adopting the above technical solutions, naphthenic acid and oil-soluble tea polyphenols as anti-aging agents can maintain the viscoelasticity and ductility of the asphalt mixture, improve the density and durability of the steel slag asphalt mixture, and reduce the cracking phenomenon caused by long-term use. Silica sand, quartz sand, and rubber powder as anti-slip aids can increase the friction coefficient on the surface of the steel slag asphalt mixture and improve the anti-slip performance of the road surface. The addition of the anti-slip aid can improve the wear resistance and abrasion resistance of the asphalt mixture and extend the service life of the asphalt mixture.

[0010] Preferably, the waterproof damage agent is at least one of silicone resin and styrene-butadiene-styrene block copolymer.

[0011] By adopting the above technical solutions, silicone resin has good waterproof and oxidation resistance properties, can form a waterproof film, reduce water penetration, prevent water from accumulating at the interface between the aggregate and the asphalt, thereby reducing the peeling between the steel slag aggregate and the asphalt caused by water, and improving the durability and density of the steel slag asphalt mixture. Styrene-butadiene-styrene block copolymer can improve the elasticity and toughness of the steel slag asphalt mixture, reduce the cracking phenomenon of the asphalt mixture at low temperatures, thereby reducing water penetration, and at the same time improve the fatigue resistance and crack resistance of the steel slag asphalt mixture.

[0012] Preferably, the silicone resin is modified with epoxy acrylic acid. The modification method includes the following specific steps: Mix acrylic monomers, epoxy resin, and silicone resin, then add an emulsifier and stir evenly to form a pre-emulsion. Then, add an initiator dropwise and raise the temperature to 80-90 °C for reaction. Adjust the pH of the reaction system to neutral, and filter to obtain the modified silicone resin.

[0013] By adopting the above technical solution, using epoxy resin and acrylic monomers to modify the silicone resin can improve the thermal stability and bonding performance of the silicone resin, further promote the adhesion between the steel slag aggregate and the asphalt matrix, and improve the density and crack resistance of the steel slag asphalt mixture. At the same time, the combination of epoxy resin and acrylic acid can enhance the bonding force between the silicone resin and each component in the asphalt mixture system, improve the corrosion resistance and moisture resistance of the silicone resin, and thus improve the waterproof damage effect and crack resistance of the steel slag asphalt mixture.

[0014] Preferably, the acrylic monomers include acrylic acid, methyl methacrylate, and n-butyl acrylate. The mass ratio of acrylic acid, methyl methacrylate, and n-butyl acrylate is 1:(10-15):(8-10). The silicone resin is at least one of octamethyltetrasiloxane and vinyltriethoxysilane.

[0015] Preferably, the mass ratio of the acrylic monomers, epoxy resin, silicone resin, and initiator is (1-1.5):(0.8-1):1:(0.05-0.1).

[0016] In a second aspect, the present application provides a method for preparing a steel slag aggregate asphalt mixture, adopting the following technical solution: A method for preparing a steel slag aggregate asphalt mixture includes the following specific steps: First, crush the steel slag aggregate, mix polyvinyl alcohol with the steel slag, stir evenly, soak it, take out the steel slag and dry it. Then, soak the steel slag in a mixed solution of phosphoric acid and sodium citrate, stir evenly, take out the steel slag, and dry it to obtain an organic-inorganic hybrid modified steel slag aggregate. Mix the organic-inorganic hybrid modified steel slag aggregate with molten matrix asphalt, anti-aging agent, waterproof damage agent, and anti-slip aid to prepare the steel slag aggregate asphalt mixture.

[0017] By adopting the above technical solution, by crushing the steel slag aggregate and then performing ratio modification, steel slag expansion can be reduced, and at the same time, the adhesion between the steel slag and the asphalt matrix can be enhanced, thereby improving the density and structural stability of the steel slag asphalt mixture.

[0018] In summary, the present application has the following beneficial effects: 1. Since this application uses polyvinyl alcohol, phosphoric acid, and sodium citrate to modify steel slag aggregates, on the one hand, it reduces the content of substances such as calcium oxide in the steel slag aggregates, inhibits the expansion of the steel slag aggregates, and reduces the cracking phenomenon of the steel slag asphalt mixture. On the other hand, it can adsorb and generate insoluble salts on the surface of the steel slag aggregates, fill the pores of the asphalt mixture, enhance the adhesion between the steel slag aggregates and the matrix asphalt, and improve the density and durability of the steel slag asphalt mixture.

[0019] 2. In this application, silicone resin and styrene-butadiene-styrene block copolymer are used as waterproof damage agents and added to the steel slag asphalt mixture to reduce the penetration of moisture, inhibit the cracking phenomenon of the asphalt mixture at low temperatures, and improve the durability and crack resistance of the steel slag asphalt mixture. At the same time, epoxy acrylic acid is used to modify the silicone resin, which can improve the thermal stability and bonding performance of the silicone resin, further promote the adhesion between the steel slag aggregates and the asphalt matrix, and improve the density and durability of the steel slag asphalt mixture. Detailed implementation method

[0020] The following further elaborates on this application in combination with examples.

[0021] All raw materials in the examples can be obtained through commercial channels. Example

[0022] Example 1 This example provides a steel slag aggregate asphalt mixture, including the following raw materials in parts by weight: 70 kg of steel slag aggregates, 15 kg of matrix asphalt, 1.5 kg of anti-aging agent, 1.5 kg of waterproof damage agent, and 1.7 kg of anti-skid aid; among them, the matrix asphalt is 70# asphalt produced by PetroChina, the anti-aging agent is naphthenic acid, the CAS number of naphthenic acid is 1338-24-5, the anti-skid aid is quartz sand, the average particle size of the anti-skid aid is 0.5 mm, and the waterproof damage agent is octamethyltetrasiloxane.

[0023] The preparation method of the steel slag aggregate asphalt mixture includes the following specific steps: First, crush the steel slag aggregates, mix polyvinyl alcohol with the steel slag, the mass ratio of polyvinyl alcohol to steel slag aggregates is 0.02:1, stir at a speed of 500 r / min for 2 h, then take out the steel slag and dry it at 105 °C for 2 h, then soak the steel slag in an aqueous solution of phosphoric acid and sodium citrate, the mass ratio of phosphoric acid, sodium citrate, water, and steel slag aggregates is 0.015:0.01:10:1, stir at a speed of 200 r / min for 2 h, then take out the steel slag and dry it at 105 °C for 2 h to obtain organo-inorganic hybrid modified steel slag aggregates, and then mix the organo-inorganic hybrid modified steel slag aggregates with molten matrix asphalt, anti-aging agent, waterproof damage agent, and anti-skid aid, and stir evenly to prepare the steel slag aggregate asphalt mixture.

[0024] Example 2 The difference between Example 2 and Example 1 is that the usage amount of steel slag aggregate in the raw materials of the steel slag aggregate asphalt mixture is 60 kg, the usage amount of matrix asphalt is 20 kg, the usage amount of anti-aging agent is 1 kg, the usage amount of water damage prevention agent is 2 kg, and the usage amount of anti-slip aid is 2.5 kg.

[0025] Example 3 The difference between Example 3 and Example 1 is that the usage amount of steel slag aggregate in the raw materials of the steel slag aggregate asphalt mixture is 80 kg, the usage amount of matrix asphalt is 10 kg, the usage amount of anti-aging agent is 2 kg, the usage amount of water damage prevention agent is 1 kg, and the usage amount of anti-slip aid is 1 kg.

[0026] Example 4 The difference between Example 4 and Example 1 is that the mass ratio of phosphoric acid, sodium citrate, water, and steel slag aggregate in the raw materials of the steel slag aggregate asphalt mixture is 0.005:0.02:10:1.

[0027] Example 5 The difference between Example 5 and Example 1 is that the mass ratio of phosphoric acid, sodium citrate, water, and steel slag aggregate in the raw materials of the steel slag aggregate asphalt mixture is 0.015:0.01:10:1.

[0028] Example 6 The difference between Example 6 and Example 1 is that the anti-aging agent in the raw materials of the steel slag aggregate asphalt mixture is a mixture of naphthenic acid and oil-soluble tea polyphenols, and the mass ratio of naphthenic acid to oil-soluble tea polyphenols is 1:1. The oil-soluble tea polyphenols are purchased from Kangyuan.

[0029] Example 7 The difference between Example 7 and Example 6 is that the anti-slip aid in the raw materials of the steel slag aggregate asphalt mixture is a mixture of silica sand, quartz sand, and rubber powder, and the mass ratio of silica sand, quartz sand, and rubber powder is 1:1:1.

[0030] Example 8 The difference between Example 8 and Example 1 is that the water damage prevention agent in the raw materials of the steel slag aggregate asphalt mixture is styrene-butadiene-styrene block copolymer, and the styrene-butadiene-styrene block copolymer is purchased from Guangdong Wengjiang Chemical Reagent Co., Ltd., model PA97663, F875.

[0031] Example 9 The difference between Example 9 and Example 7 is that the water damage prevention agent in the raw materials of the steel slag aggregate asphalt mixture is a mixture of styrene-butadiene-styrene block copolymer and vinyltriethoxysilane, and the mass ratio of styrene-butadiene-styrene block copolymer to vinyltriethoxysilane is 1:1.

[0032] Example 10 The difference between Example 10 and Example 9 is that the silicone resin in the raw materials of the steel slag aggregate asphalt mixture is modified with epoxy acrylic acid.

[0033] The preparation method of the steel slag aggregate asphalt mixture includes the following specific steps: S1: Mix acrylic monomers, epoxy resin, and vinyltriethoxysilane of silicone resin in advance. The acrylic monomers are acrylic acid, methyl methacrylate, and n-butyl acrylate, and the mass ratio of acrylic acid, methyl methacrylate, and n-butyl acrylate is 1:13:9. Then add emulsifier OP-10 and stir evenly to form a pre-emulsion. Then add initiator sodium persulfate dropwise. The mass ratio of acrylic monomers, epoxy resin, silicone resin, and initiator is 1.3:0.9:1:0.08. Heat up to 85 °C and react. Use ammonia water to adjust the pH of the reaction system to neutral. After filtration, the modified silicone resin is obtained. Then mix the modified silicone resin with styrene-butadiene-styrene block copolymer to obtain a waterproof damage agent.

[0034] S2: Crush the steel slag aggregate, mix polyvinyl alcohol with the steel slag. The mass ratio of polyvinyl alcohol to the steel slag aggregate is 0.02:1. Stir at a speed of 500 r / min for 2 h. Then take out the steel slag and dry it at 105 °C for 2 h. Then soak the steel slag in an aqueous solution of phosphoric acid and sodium citrate. The mass ratio of phosphoric acid, sodium citrate, water, and the steel slag aggregate is 0.015:0.01:10:1. Stir at a speed of 200 r / min for 2 h. Then take out the steel slag and dry it at 105 °C for 2 h to obtain an organo-inorganic hybrid modified steel slag aggregate. Then mix the organo-inorganic hybrid modified steel slag aggregate with molten matrix asphalt, anti-aging agent, waterproof damage agent, and anti-slip agent, and stir evenly to prepare the steel slag aggregate asphalt mixture.

[0035] Example 11 The difference between Example 11 and Example 10 is that the mass ratio of acrylic monomers, epoxy resin, silicone resin, and initiator in the raw materials of the steel slag aggregate asphalt mixture is 1.5:1:1:0.05.

[0036] Example 12 The difference between Example 12 and Example 10 is that the mass ratio of acrylic monomers, epoxy resin, silicone resin, and initiator in the raw materials of the steel slag aggregate asphalt mixture is 1:0.8:1:0.1.

[0037] Comparative Example Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that polyvinyl alcohol is not used as the modifying material in the raw materials of the steel slag aggregate asphalt mixture.

[0038] Preparation method of steel slag aggregate asphalt mixture, comprising the following specific steps: Pre-crush the steel slag aggregate, soak the steel slag in an aqueous solution of phosphoric acid and sodium citrate, the mass ratio of phosphoric acid, sodium citrate, water and steel slag aggregate is 0.015:0.01:10:1, stir at a speed of 200 r / min for 2 h, then take out the steel slag and dry it at 105 °C for 2 h to obtain the modified steel slag aggregate, and then mix the modified steel slag aggregate with molten matrix asphalt, anti-aging agent, waterproof damage agent and anti-slip aid, stir evenly to prepare the steel slag aggregate asphalt mixture.

[0039] Comparative Example 2 The difference between Comparative Example 2 and Example 1 is that sodium citrate is not used as the modifying material in the raw materials of the steel slag aggregate asphalt mixture.

[0040] Comparative Example 3 The difference between Comparative Example 3 and Example 1 is that neither sodium citrate nor phosphoric acid is used as the modifying material in the raw materials of the steel slag aggregate asphalt mixture.

[0041] Preparation method of steel slag aggregate asphalt mixture, comprising the following specific steps: Pre-crush the steel slag aggregate, mix polyvinyl alcohol with the steel slag, the mass ratio of polyvinyl alcohol to steel slag aggregate is 0.02:1, stir at a speed of 500 r / min for 2 h, then take out the steel slag and dry it at 105 °C for 2 h to obtain the modified steel slag aggregate, and then mix the modified steel slag aggregate with molten matrix asphalt, anti-aging agent, waterproof damage agent and anti-slip aid, stir evenly to prepare the steel slag aggregate asphalt mixture.

[0042] Performance detection test For the steel slag aggregate asphalt mixtures provided in Examples 1-12 and Comparative Examples 1-3 of the present application, the following performance detections are carried out, and the specific detection results are shown in Table 1.

[0043] Detection method I. Steel slag expansion rate Detect according to the standard of GB / T 24175-2009 "Test Method for Steel Slag Stability", and detect the immersion expansion rate of the steel slag aggregate asphalt mixture prepared in the present application for 3 d.

[0044] II. Adhesion performance Detect the adhesion between the components of the steel slag aggregate asphalt mixture system prepared in the present application, as well as the freeze-thaw splitting test and the rutting dynamic stability test, according to the standard of JTG E20-2011 "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering".

[0045] Table 1: Data table of performance detection results It can be seen from the performance test results that the steel slag aggregate asphalt mixture prepared in this application has good stability, the components in the steel slag asphalt mixture system have good adhesion, and at the same time, the expansion rate of the steel slag is reduced. By comparing Comparative Examples 1-3 with Example 1, it can be seen that using polyvinyl alcohol, phosphoric acid, and sodium citrate to modify the steel slag aggregate can perform multiple modifications on the steel slag aggregate, reduce the expansibility of the steel slag aggregate, and enhance the adhesion between the steel slag aggregate and the asphalt mixture. The lack of any component will affect the durability and structural stability of the steel slag asphalt mixture.

[0046] By comparing Example 9 with Examples 8 and 1, it can be seen that using silicone resin and styrene-butadiene-styrene block copolymer as waterproof damage agents in the steel slag asphalt mixture. It can be seen from the performance test results that the comprehensive performance of the steel slag asphalt mixture prepared in Example 9 is better. From Examples 10-12, it can be seen that using epoxy resin and acrylic monomers to modify the silicone resin. It can be seen from the performance test results that the stability of the prepared steel slag asphalt mixture is further improved.

[0047] This specific embodiment is only an explanation of this application and does not limit this application. Those skilled in the art can make modifications without creative contributions to this embodiment according to needs after reading this specification, but as long as it is within the scope of the claims of this application, it is protected by the patent law.

Claims

1. A steel slag aggregate asphalt mixture, characterized in that: The invention comprises the following raw materials in parts by weight: 60-80 parts of steel slag aggregate, 10-20 parts of matrix asphalt, 1-2 parts of anti-aging agent, 1-2 parts of waterproof damage agent and 1-2.5 parts of anti-skid agent; the steel slag aggregate is preliminarily subjected to organic-inorganic hybrid modification by a modifying material, and the modifying material comprises polyvinyl alcohol, phosphoric acid and sodium citrate.

2. The steel slag aggregate asphalt mixture according to claim 1, characterized in that: The mass ratio of the sodium citrate to the steel slag aggregate is (0.005-0.015):1, the mass ratio of the phosphoric acid to the steel slag aggregate is (0.01-0.02):1, and the mass ratio of the polyvinyl alcohol to the steel slag aggregate is (0.01-0.03):

1.

3. The steel slag aggregate asphalt mixture according to claim 1, characterized in that: The anti-aging agent is at least one of cyclohexane acid and oil-soluble tea polyphenols, and the anti-slip agent is at least one of silica sand, quartz sand and rubber powder.

4. The steel slag aggregate asphalt mixture according to claim 1, characterized in that: The waterproof damage agent is one of organic silicone resin and styrene-butadiene-styrene block copolymer.

5. The steel slag aggregate asphalt mixture according to claim 4, characterized in that: The silicone resin is modified by epoxy acrylic acid, and the modification method comprises the following specific steps: acrylic monomer, epoxy resin and silicone resin are mixed, and then an emulsifier is added and stirred evenly to form a pre-emulsion, and then an initiator is added dropwise, the temperature is raised to 80-90° C. for reaction, the pH of the reaction system is adjusted to neutral, and the modified silicone resin is obtained after filtering.

6. The steel slag aggregate asphalt mixture according to claim 5, characterized in that: The acrylic monomer includes acrylic acid, methyl methacrylate and n-butyl acrylate, wherein the mass ratio of acrylic acid, methyl methacrylate and n-butyl acrylate is 1:(10-15):(8-10), and the silicone resin is at least one of octamethyltetrasiloxane and vinyltriethoxysiloxane.

7. The steel slag aggregate asphalt mixture according to claim 6, characterized in that: The mass ratio of the acrylic monomer, epoxy resin, silicone resin and initiator is: (1-1.5): (0.8-1): 1: (0.05-0.1).

8. A method for preparing a steel slag aggregate asphalt mixture according to any one of claims 1 to 7, characterized in that: The specific steps include: The steel slag aggregate is crushed in advance, polyvinyl alcohol is mixed with the steel slag, stirred evenly, the steel slag is taken out and dried, and then the steel slag is soaked in a mixture of phosphoric acid and sodium citrate, stirred evenly, the steel slag is taken out and dried to obtain organic-inorganic hybrid modified steel slag aggregate, and the organic-inorganic hybrid modified steel slag aggregate is mixed with molten matrix asphalt, anti-aging agent, waterproof damage agent and anti-skid agent to obtain steel slag aggregate asphalt mixture.

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