White asphalt mixture for highway tunnel pavement and preparation method and application thereof

Abstract

The application provides a white asphalt mixture for highway and tunnel pavement, a preparation method and application thereof, and the white asphalt mixture comprises the following components in parts by weight: 4-7 parts by weight of light-colored asphalt, 50-58 parts by weight of coarse aggregate, 25-30 parts by weight of fine aggregate, 1-3 parts by weight of titanium dioxide, 2-4 parts by weight of mineral powder and 2.5-3.5 parts by weight of composite flame retardant; the composite flame retardant comprises nano clay, ammonium polyphosphate and aluminum hydroxide in a weight ratio of (50-52):(30-35):(8-10). The white asphalt mixture for highway and tunnel pavement provided by the application is applied to highway and tunnel pavement paving. The application not only improves the flame-retardant and smoke-suppressing performance of the mixed asphalt pavement, but also improves the high and low temperature stability of the pavement.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of road engineering materials, in particular to a white asphalt mixture for highway tunnel pavement, a preparation method and application thereof. BACKGROUND

[0002] With the rapid increase of highway construction mileage in China, the number and mileage of tunnels are also increasing dramatically. At the same time, the frequent safety accidents in tunnels also touch the pain points of highway management personnel and technical personnel. The reason is that, on the one hand, the poor visibility in tunnels due to insufficient lighting makes tunnels become accident-prone sections, which seriously affects the driving safety in tunnels, and this situation is particularly obvious in short tunnels without lighting. On the other hand, the frequency of traffic accidents at the entrance and exit of the tunnel is significantly higher than that in the middle of the tunnel, because the tunnel light environment is composed of the light environment outside the tunnel and the lighting environment inside the tunnel, and the brightness outside the tunnel is usually much higher than that inside the tunnel. When the driver enters or exits the tunnel, the sharp change of light and dark is easy to cause the driver's vision to be difficult to adapt in time, which will cause the "black hole effect" and "white hole effect", and these adverse effects of the tunnel light environment will reduce the visual efficiency of the driver, increase the visual burden of the driver, and even cause the phenomenon of visual illusion of the driver, thereby inducing tunnel traffic accidents, seriously affecting the driving safety of the tunnel, and reducing the driving comfort and energy saving effect. Therefore, it is of great significance to study how to improve the light environment of the tunnel and the visual environment of the driver when driving in the tunnel, and to improve the driving safety in the tunnel.

[0003] In order to improve the tunnel lighting efficiency, improve the driving visual environment of the driver in the tunnel, and improve the driving safety, the project starts from the perspective of high-brightness asphalt pavement, develops a high-performance white asphalt mixture, and lays it in the tunnel pavement to form a high-brightness "white asphalt pavement". This can solve the following problems: when applied to the internal pavement of the tunnel, especially in short tunnels without lighting, the reflectivity of the white pavement is higher than that of the original black asphalt pavement. When the light of the motor vehicle shines on the pavement during driving, the internal brightness of the tunnel can be improved, and the driving comfort of the driver in the tunnel is improved. When applied to the entrance and exit of the tunnel, the strong reflectivity of the white asphalt pavement can reduce the brightness difference of the entrance and exit of the tunnel, thereby reducing the visual blind area of the driver when entering and exiting the tunnel, and improving the driving safety of the driver in the tunnel.

[0004] In addition, in the special section of the tunnel, once a fire occurs, the ordinary asphalt pavement is easy to be ignited and the fire spreads quickly. At present, in the construction of tunnel asphalt pavement, the addition of flame retardant to asphalt is usually adopted, which can reduce the fire hazard in the tunnel, reduce the combustibility of asphalt pavement to self-extinguishing, significantly reduce the possibility of fire, and reduce personnel casualties and property losses caused by asphalt combustion. However, in the prior art, the addition of flame retardant will have a weak influence on each type of additive, although the purpose of flame retardation of asphalt pavement is achieved, but it will have some negative effects on the road performance of asphalt pavement, such as reducing the stability and durability of asphalt pavement. SUMMARY

[0005] The present application provides a white asphalt mixture for highway tunnel pavement and a preparation method and application thereof, to solve the above problems mentioned in the background art.

[0006] The present application provides a white asphalt mixture for highway tunnel pavement, which comprises, by weight: 4-7 parts of light-colored asphalt, 50-58 parts of coarse aggregate, 25-30 parts of fine aggregate, 1-3 parts of titanium dioxide, 2-4 parts of mineral powder, and 2.5-3.5 parts of composite flame retardant.

[0007] The composite flame retardant comprises nano-clay, ammonium polyphosphate and aluminum hydroxide in a weight ratio of (50-52):(30-35):(8-10).

[0008] Optionally, the light-colored asphalt comprises the following components: 30-33.3 parts by weight of naphthenic oil, 62-66.7 parts by weight of petroleum resin, 5-8 parts by weight of EVA resin, 4-33 parts by weight of SBS modifier, 1-1.5 parts by weight of compatibilizer, and 2-22 parts by weight of anti-aging agent.

[0009] Optionally, the anti-aging agent comprises 1076 antioxidant, LDHs and glycerol monooleate polyoxyethylene ether in a weight ratio of 1:2-5.5:0.2-0.4.

[0010] Optionally, the coarse aggregate is classified by particle size into 5-10 mm crushed stone and 10-15 mm crushed stone, and the weight ratio of 5-10 mm crushed stone to 10-15 mm crushed stone is 40-43:20-25.

[0011] Optionally, the fine aggregate is classified by particle size into 0-3 mm machine-made sand and 3-5 mm crushed stone, and the weight ratio of 0-3 mm machine-made sand to 3-5 mm crushed stone is 26-29:5-9.

[0012] Optionally, the titanium dioxide is selected from one of anatase titanium dioxide and rutile titanium dioxide.

[0013] Optionally, the petroleum resin is one or more of a C9 petroleum resin, a C5 petroleum resin, or a coumarone resin.

[0014] In another aspect, the present application provides a method for preparing a white asphalt mixture for highway tunnel pavement, the method being used for preparing the white asphalt mixture described above, the method comprising the following steps:

[0015] (1) Heat the coarse aggregate, fine aggregate, and light-colored asphalt to 160-170°C by weight parts;

[0016] (2) Take a container and preheat the temperature in the container to 160-170°C, add the heated coarse aggregate, fine aggregate, and light-colored asphalt in step (1) above into the preheated container, and stir at a speed of 45-75 r / min for 50-60 s to obtain a mixture A;

[0017] (3) Stir and heat the mineral powder and the composite flame retardant to 160-170°C at a speed of 45-75 rad / min to obtain a mixture B;

[0018] (4) Keep the temperature at 160-170°C, and stir the mixture A, the mixture B, and the unheated titanium white at a speed of 500-700 rad / min for 120-150 min to obtain the white asphalt mixture.

[0019] Optionally, the method for preparing the light-colored asphalt comprises the following steps:

[0020] Mixing and preheating step: take naphthenic oil, petroleum resin, and EVA resin by weight parts, and preheat and stir at a temperature of 160-170°C for 10-25 min to obtain a molten mixture, the stirring speed being 700-1000 rad / min;

[0021] SBS modifier and compatibilizer adding step: keep the temperature at 160-170°C, add the SBS modifier and the compatibilizer into the molten mixture, and shear at a speed of 4500-5500 rad / min for 30-35 min;

[0022] Anti-aging agent adding step: reduce the temperature to 150-160°C, and sequentially add 1076 antioxidant, LDHs, and tallow amine polyoxyethylene ether, shear at a speed of 2000-2500 rad / min for 15-20 min to obtain a light-colored asphalt preliminary product;

[0023] Development step: place the light-colored asphalt preliminary product into an oven at 160-165°C and develop for 1.5-2 h to obtain the light-colored asphalt.

[0024] In still another aspect, the present application provides an application of the white asphalt mixture for highway tunnel pavement in highway tunnel pavement paving, wherein the white asphalt mixture is the white asphalt mixture described above, or the white asphalt mixture prepared by the method described above.

[0025] The present application provides the white asphalt mixture for highway tunnel pavement, the preparation method and the application thereof, realizes the preparation of the white asphalt mixture for highway tunnel pavement, and has the following beneficial effects compared with the prior art.

[0026] (1) By adding the composite flame retardant to the white asphalt mixture, the combustion performance of the asphalt pavement can be effectively improved, the fire spread can be prevented, the damage of the fire to the pavement can be reduced, and thus the fire resistance of the pavement can be improved. At the same time, it has a certain smoke suppression effect, reduces the emission of harmful smoke gas during the fire, and thus reduces the harm to personnel. By compounding the nano clay, the ammonium polyphosphate and the aluminum hydroxide in a special weight ratio, and by synergistic effect from different flame retardant mechanisms, the flame retardant and smoke suppression performance of the white asphalt mixture is improved. The nano clay in the flame retardant is dispersed in the light-colored asphalt, fills the voids between the asphalt and the coarse aggregate and the fine aggregate, improves the density of the white asphalt mixture, and thus promotes the bearing capacity and the compressive strength of the pavement. The aluminum hydroxide has a certain alkalinity, and after being compounded with the ammonium polyphosphate, it can better interact with and mix with the acidic light-colored asphalt, improve the uniformity of the asphalt mixture, prevent the agglomeration of the components in the asphalt mixture, and thus improve the uniformity and durability of the pavement. By adding the special proportion of the composite flame retardant, not only the flame retardant and smoke suppression performance of the white asphalt mixture is achieved, but also the compressive strength, the bearing capacity and the durability of the asphalt mixture are promoted.

[0027] (2) By adding magnesium silicate to the composite flame retardant, and by using the modified nano clay obtained by modifying the nano clay with N-hydroxy octanamide, the interlayer spacing of the nano clay is increased, and the N-hydroxy octanamide is grafted on the surface and the interlayer of the thin-layer nano clay. Compared with the nano clay, the surface area and the surface adsorption capacity are improved, and the synergistic effect between the ammonium polyphosphate and the aluminum hydroxide is enhanced, the flame retardant and smoke suppression performance for the pavement is improved, and the compatibility between the components is improved, so that the dispersion performance of the nano clay in the asphalt mixture is improved. The modification of N-hydroxy octanamide makes the modified nano clay form a three-dimensional network structure with the components in the asphalt mixture, improves the high-temperature stability and the bearing capacity of the asphalt mixture, and thus improves the pavement performance of the asphalt mixture. The magnesium silicate is also adsorbed in the interlayer and the surface of the modified nano clay, further fills the pores between the modified nano clay and the asphalt, improves the stability of the three-dimensional network structure, and thus improves the integrity of the asphalt pavement, and further improves the flame retardant and smoke suppression performance.

[0028] (3) By paving the white asphalt mixture provided by the present application on the road surface of the highway tunnel, not only the light reflection intensity of the road surface of the highway tunnel is improved, the light environment of the tunnel is improved, and the safety of driving in the tunnel is improved. At the same time, the purpose of flame retardation and smoke suppression of the tunnel road is achieved, and more importantly, the high-temperature stability and durability of the road surface of the tunnel road are further improved, and the road performance of the road surface is improved. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application are described clearly and completely below. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor also belong to the scope of protection of the present application.

[0030] The present application provides a white asphalt mixture for the road surface of a highway tunnel, the white asphalt mixture comprising, by weight: light-colored asphalt 4-7 parts by weight, coarse aggregate 50-58 parts by weight, fine aggregate 25-30 parts by weight, titanium dioxide 1-3 parts by weight, mineral powder 2-4 parts by weight, and composite flame retardant 2.5-3.5 parts by weight.

[0031] The composite flame retardant comprises nano-clay, ammonium polyphosphate and aluminum hydroxide in a weight ratio of (50-52):(30-35):(8-10), respectively.

[0032] Specifically, the light-colored asphalt is mixed with other components to firmly bond various components in the mixture together to form an overall structure, enhancing the mechanical properties and durability of the mixture. At the same time, the light-colored asphalt can fill the voids between the aggregates, reduce the porosity of the mixture, and improve the density and impermeability of the white asphalt mixture, thereby enhancing the durability and road performance of the road surface. The coarse aggregate mainly plays a skeleton role in the asphalt mixture, providing greater bearing capacity and wear resistance to the asphalt mixture, thereby enhancing the bearing capacity and stability of the road, thereby prolonging the service life of the road. The fine aggregate fills the voids between the coarse aggregate, improving the density and stability of the asphalt mixture, thereby enhancing the durability and waterproof performance of the road. By compounding coarse aggregate and fine aggregate with different particle sizes, the strength of the asphalt mixture is improved, and the bearing capacity and stability of the road surface are improved. Titanium dioxide, on the one hand, as a whitening agent, improves the whiteness and gloss of the asphalt mixture, making the asphalt mixture appear white when paved on the road surface, and on the other hand, titanium dioxide has a certain ultraviolet absorption capacity, slowing down the aging process of the asphalt mixture, thereby prolonging the service life of the road surface.

[0033] Preferably, the coarse aggregate and fine aggregate are selected from light-colored stone, i.e., stone with a color of white or off-white, and from the rock group including at least one of silica, granite, dolomitic limestone, dolomite, white quartzite, white marble, and white travertine. In addition to ensuring the color, the key indicators of the crushing value and the polishing value of the coarse aggregate and fine aggregate should meet the relevant requirements in the Technical Specification for Construction of Highway Asphalt Pavement (JTGF40-2004), which is not particularly limited herein.

[0034] The mineral powder has a large surface area, which is conducive to the formation of structural asphalt. The greater the proportion of structural asphalt, the higher the cohesion of the asphalt mixture. Therefore, adding an appropriate amount of mineral powder can significantly improve the adhesion of the asphalt mixture, and can improve the physical and chemical adsorption capacity of the asphalt mixture, reduce the generation of free asphalt, increase the proportion of structural asphalt, thereby improving the cohesion and waterproof performance of the mixture. In addition, the mineral powder can play a filling role in the asphalt mixture, reduce the porosity of the asphalt mixture, increase the density, and further improve the stability and waterproofness of the pavement.

[0035] Preferably, the mineral powder is selected from light-colored limestone, such as white and off-white, and has an alkalinity of 0.97, which can be uniformly mixed with the acid-colored asphalt to enhance the adhesion of the asphalt mixture, thereby improving the density, stability, and compressive strength of the pavement. Preferably, the particle size of the mineral powder is 0.02-0.075 mm.

[0036] By adding a composite flame retardant to the white asphalt mixture, the combustion performance of the asphalt pavement can be effectively improved, the spread of fire can be prevented, and the damage to the pavement caused by fire can be reduced, thereby improving the fire resistance of the pavement. At the same time, it has a certain smoke suppression effect, reduces the emission of harmful smoke during a fire, and further reduces the harm to personnel. The nano-clay has a layered structure, which can form a physical barrier to prevent the spread of flames and effectively prevent the spread of flames. At the same time, the layered structure and surface hydrophilic properties of the nano-clay allow it to undergo a chemical reaction and release water at high temperatures, forming a vacuum effect that prevents the diffusion of air, oxygen, and combustion products, thereby preventing the spread of flames. Ammonium polyphosphate has the advantages of high-efficiency flame retardation and environmental friendliness. Aluminum hydroxide decomposes when heated, absorbing a large amount of heat, thereby reducing the temperature of the material surface and delaying combustion.

[0037] The nano clay, ammonium polyphosphate and aluminum hydroxide are compounded in a weight ratio of (50-52):(30-35):(8-10), and the three synergistically act to improve the flame-retardant and smoke-suppressing performance of the white asphalt mixture from different flame-retardant mechanisms. Meanwhile, the nano clay in the flame retardant is dispersed in the light-colored asphalt and fills the voids between the asphalt and the coarse and fine aggregates, thereby improving the density of the white asphalt mixture and promoting the bearing capacity and stability of the pavement. The aluminum hydroxide has a certain alkalinity, and after being compounded with the ammonium polyphosphate, it can better interact with and mix with the acidic light-colored asphalt, thereby improving the uniformity of the asphalt mixture and preventing the aggregation of components in the asphalt mixture, and further improving the uniformity and durability of the pavement. By adding the special proportion of the composite flame retardant, the application not only achieves the flame-retardant and smoke-suppressing performance of the white asphalt mixture, but also has a good promoting effect on the compressive strength, bearing capacity and durability of the asphalt mixture. Preferably, the particle size of the nano clay is 1-100 nm.

[0038] Optionally, the light-colored asphalt comprises the following components: 30-33.3 parts by weight of naphthenic oil, 62-66.7 parts by weight of petroleum resin, 5-8 parts by weight of EVA resin, 4-33 parts by weight of SBS modifier, 1-1.5 parts by weight of compatibilizer and 2-22 parts by weight of anti-aging agent.

[0039] Specifically, the naphthenic oil and the petroleum resin are the main components of the light-colored asphalt, and the naphthenic oil and the petroleum resin are modified by the EVA resin and the SBS modifier. The modification of the EVA resin can improve the high-temperature strength and stability of the asphalt mixture, and reduce the rutting and permanent deformation. The modification of the SBS can improve the adhesion and elasticity of the asphalt mixture, and improve the adhesion and bonding force between the light-colored asphalt and other component materials, thereby improving the compressive strength and anti-peeling performance of the asphalt mixture. The compatibilizer can improve the compatibility between the naphthenic oil and the petroleum resin and the EVA resin and the SBS modifier by means of intermolecular bonding force, so that the mixed system maintains good stability during the modification process, promotes the modification of the naphthenic oil and the petroleum resin, and further improves the bearing capacity and stability of the light-colored asphalt.

[0040] Preferably, the compatibilizer is furfural extracted oil, which can improve the compatibility of the components in the light-colored asphalt.

[0041] Optionally, the anti-aging agent comprises 1076 antioxidant, LDHs and oleamine polyoxyethylene ether in a weight ratio of 1:2-5.5:0.2-0.4.

[0042] Specifically, the anti-aging agent forms a protective film by reacting with the active ingredients in the light-colored asphalt, preventing the erosion of the asphalt by factors such as ultraviolet light, oxidation, and temperature. The protective film formed can delay the aging process of the asphalt, maintain the softness and elasticity of the asphalt, and thus reduce the cracking and damage of the road surface. The 1076 antioxidant can promote the antioxidant properties of the light-colored asphalt. The LDHs are inorganic layer plates that can shield the effects of ultraviolet light, greatly reducing the excitation effect of ultraviolet light on the asphalt during photo-oxidation. The nitrogen atoms in the oleamine polyoxyethylene ether react with the active ingredients in the light-colored asphalt. At the same time, the oleamine polyoxyethylene ether can be dispersed in the light-colored asphalt with the help of micelles, 1076 antioxidant, and LDHs, improving the stability of the protective film and forming an isolation barrier, which can further reduce the damage of ultraviolet light, oxygen, and other factors to the light-colored asphalt and delay the aging time of the road surface.

[0043] Optionally, the particle size grading of the coarse aggregate is 5-10 mm gravel and 10-15 mm gravel, and the weight ratio of the 5-10 mm gravel to the 10-15 mm gravel is 40-43:20-25.

[0044] Optionally, the particle size grading of the fine aggregate is 0-3 mm machine-made sand and 3-5 mm gravel, and the weight ratio of the 0-3 mm machine-made sand to the 3-5 mm gravel is 26-29:5-9.

[0045] Specifically, by compounding coarse aggregate and fine aggregate with different particle size gradings, the fine aggregate can fill the pores between the coarse aggregate and the asphalt, improving the density and stability of the asphalt mixture, and thus improving the durability of the road surface.

[0046] Optionally, the titanium white powder is selected from one of anatase titanium white powder and rutile titanium white powder.

[0047] Specifically, the particle size of the titanium white powder is selected to be between 120-350 nm. The titanium white powder has a suitable surface area, which helps the uniformity of the mixing of the white asphalt mixture and can effectively scatter light, thereby improving the hiding power and ensuring the color stability of the road surface.

[0048] Optionally, the petroleum resin is one or more of C9 type petroleum resin, C5 type petroleum resin, or coumarone resin.

[0049] On the other hand, the present application provides a preparation method of a white asphalt mixture for highway and tunnel road surfaces. The method is used to prepare the white asphalt mixture described above, and the method comprises the following steps:

[0050] (1) Heat the coarse aggregate, fine aggregate, and light-colored asphalt to 160-170°C respectively according to weight parts;

[0051] (2) take the container, and preheat the temperature in the container to 160-170℃, the above step (1) after heating the coarse aggregate, fine aggregate and light color pitch into the preheated container, and stirring at 45-75r / min speed 50-60s, get the mixture A;

[0052] (3) according to weight parts, the mineral powder, composite flame retardant in 45-75rad / min speed stirring, heated to 160-170℃, get the mixture B;

[0053] (4) keep the temperature 160-170℃, the mixture A, mixture B and unheated titanium dioxide in 500-700rad / min speed stirring 120-150min, prepared white pitch mixture.

[0054] The application realizes the preparation of white pitch mixture for highway tunnel pavement through the above scheme, by heating the coarse aggregate, fine aggregate and light color pitch to 160-170℃ respectively, then stirring and mixing to get mixture A, then keeping the temperature, stirring the mineral powder and composite flame retardant at 45-75rad / min speed to get mixture B, finally stirring and mixing the mixture A, mixture B and unheated titanium dioxide at 500-700rad / min speed to get white pitch mixture. By heating each component of pitch mixture respectively and then mixing, the mixing efficiency of each component can be improved, at the same time, the speed during the preparation of mixture A and mixture B is 45-75rad / min, while the speed after adding titanium dioxide is 500-700rad / min, the different shear rate affects the mixing efficiency and interaction between each component of pitch mixture, and then affects the synergy between each component, and affects the strength and durability of pitch mixture. The increase of shear rate after adding titanium dioxide can improve the uniform dispersion of titanium dioxide in pitch mixture, so that the pitch mixture has uniform color distribution and gloss when paving on the road surface.

[0055] More preferably, the composite flame retardant provided by the application further comprises magnesium silicate, and the nanoclay is modified nanoclay modified by N-hydroxy-n-octanamide. The preparation method of the modified nanoclay comprises the following steps: dispersing nanoclay in anhydrous ethanol at 30-50℃, and activating and intercalating layers by ultrasonic treatment for 30-60s to obtain a first dispersion liquid; then adding N-hydroxy-n-octanamide into the first dispersion liquid, stirring at a rotation speed of 40-60 rad / min, and ultrasonic treatment for 3-7 min to continue intercalating layers and grafting N-hydroxy-n-octanamide on the surface and interlayer of the nanoclay to obtain a second dispersion liquid; and drying the second dispersion liquid at 40-60℃ to constant weight to obtain the modified nanoclay. The weight / volume ratio of nanoclay, anhydrous ethanol and N-hydroxy-n-octanamide is 1g:10-20mL:1.1-1.3g, and the composite flame retardant comprises modified nanoclay, ammonium polyphosphate, aluminum hydroxide and magnesium silicate in a weight ratio of (50-52):(30-35):(8-10):(0.5-1.2).

[0056] The nanoclay is modified by N-hydroxy-n-octanamide, the interlayer spacing of the nanoclay is increased, and N-hydroxy-n-octanamide is grafted on the surface and interlayer of the nanoclay. Compared with the nanoclay, the surface area is increased, the surface adsorption capacity is also increased, the synergistic effect between the nanoclay, ammonium polyphosphate and aluminum hydroxide is enhanced, the flame-retardant and smoke-suppressing performance on the road surface is improved, and the compatibility between the components is improved. The dispersion performance of the nanoclay in the asphalt mixture is improved. The modification of N-hydroxy-n-octanamide enables the modified nanoclay to form a three-dimensional network structure with the components in the asphalt mixture, thereby improving the high-temperature stability and bearing capacity of the asphalt mixture, and further improving the road performance of the asphalt mixture. The magnesium silicate is also adsorbed in the interlayer and surface of the modified nanoclay, further filling the pores between the modified nanoclay and the asphalt, improving the stability of the three-dimensional network structure, and further improving the integrity of the asphalt mixture road surface, and further improving the flame-retardant and smoke-suppressing performance.

[0057] Further, the main component of the titanium white powder is titanium dioxide, and the addition of magnesium silicate can also synergize with the titanium white powder to improve the gloss of the white asphalt mixture road surface, thereby prolonging the service life of the road surface.

[0058] Optionally, the preparation method of the light-colored asphalt comprises the following steps:

[0059] The mixing and preheating step: taking naphthenic oil, petroleum resin and EVA resin by weight parts, and preheating at a temperature of 160-170℃ for 10-25 min with stirring at a stirring speed of 700-1000 rad / min to obtain a molten mixture;

[0060] SBS modifier, compatibilizer adding step: keep the temperature at 160-170℃, add SBS modifier, compatibilizer into the molten mixture, and shear at the speed of 4500-5500 rad / min for 30-35 min;

[0061] Anti-aging agent adding step: reduce the temperature to 150-160℃, and add 1076 antioxidant, LDHs and tallow amine polyoxyethylene ether in sequence, shear at the speed of 2000-2500 rad / min for 15-20 min, to obtain light-colored asphalt primary product;

[0062] Development step: put the light-colored asphalt primary product into an oven at 160-165℃ for 1.5-2 h to obtain light-colored asphalt.

[0063] Specifically, the naphthenic oil, petroleum resin and EVA resin are preheated at the temperature of 160-170℃ to obtain a molten mixture, which helps the EVA resin to modify the naphthenic oil and petroleum resin, and can improve the high-temperature strength and stability of the asphalt mixture, and reduce the rut and permanent deformation. Then the SBS modifier and compatibilizer are added into the molten mixture, the compatibilizer is used to improve the compatibility between the components, so as to facilitate the SBS modifier to modify the naphthenic oil and petroleum resin again, improve the adhesion and elasticity of the asphalt mixture, and improve the adhesion and binding force of the light-colored asphalt and other component materials, thereby improving the high-temperature stability and anti-peeling performance of the asphalt mixture.

[0064] In another aspect, the application provides an application of the white asphalt mixture for highway and tunnel pavement in highway and tunnel pavement paving. The white asphalt mixture is the white asphalt mixture described above, or is prepared by the method described above. The white asphalt mixture provided by the application is paved on the highway and tunnel pavement, which not only improves the light reflection intensity of the highway and tunnel pavement, improves the light environment of the tunnel, and improves the safety of driving in the tunnel. At the same time, the purpose of flame retardation and smoke suppression of the tunnel highway is achieved, and more importantly, the high-temperature stability and durability of the tunnel highway pavement are further improved, and the road performance of the pavement is improved. The paving method can be any method known to those skilled in the art, which is not limited here.

[0065] The application will be further described in detail below in combination with examples. However, it should be understood that the examples are only for illustrative purposes, and are not intended to limit the scope of the application.

[0066] Example 1

[0067] The preparation method of the white asphalt mixture for highway and tunnel pavement in this example is as follows:

[0068] The method comprises the following steps:

[0069] (1) Preparation of light-colored asphalt:

[0070] Mixing and preheating step: take naphthenic oil, petroleum resin and EVA resin by weight parts, and preheat at 160-170℃ for 10min with stirring, to obtain a molten mixture, the stirring speed is 700-1000rad / min; keep the temperature at 160-170℃, add SBS modifier and compatibilizer to the molten mixture, and shear at a speed of 4500-5500rad / min for 30min; cool to 150-160℃, and add anti-aging agent, shear at a speed of 2000-2500rad / min for 15min, to obtain light-colored asphalt primary product; put the light-colored asphalt primary product into an oven at 160-165℃ for 1.5h, to obtain light-colored asphalt. The petroleum resin is C9 type petroleum resin.

[0071] The light-colored asphalt comprises the following components: 30 parts by weight of naphthenic oil, 62 parts by weight of petroleum resin, 5 parts by weight of EVA resin, 4 parts by weight of SBS modifier, 1 part by weight of compatibilizer and 2 parts by weight of anti-aging agent. The anti-aging agent comprises 1076 antioxidant, LDHs and tallow amine polyoxyethylene ether in a weight ratio of 1:2:0.2.

[0072] (2) Heat the coarse aggregate, fine aggregate and light-colored asphalt to 160-170℃ respectively by weight parts;

[0073] The coarse aggregate comprises 5-10mm gravel and 10-15mm gravel in a weight ratio of 40:20.

[0074] The fine aggregate comprises 0-3mm machine-made sand and 3-5mm gravel in a weight ratio of 26:5.

[0075] (3) Take a container and preheat the temperature in the container to 160-170℃, add the heated coarse aggregate, fine aggregate and light-colored asphalt in step (2) above to the preheated container, and stir at a speed of 45-75r / min for 50-60s, to obtain mixture A;

[0076] (4) Stir and heat the mineral powder and composite flame retardant to 160-170℃ at a speed of 45-75rad / min, to obtain mixture B by weight parts;

[0077] (5) Keep the temperature at 160-170℃, stir mixture A, mixture B and unheated titanium dioxide at a speed of 500-700rad / min for 120min, to prepare white-colored asphalt mixture.

[0078] The white asphalt mixture comprises, by weight, 4 parts of light-colored asphalt, 50 parts of coarse aggregate, 25 parts of fine aggregate, 1 part of titanium dioxide, 2 parts of mineral powder, and 2.5 parts of composite flame retardant; the composite flame retardant comprises, by weight ratio, 50:30:8 of nano-clay, ammonium polyphosphate, and aluminum hydroxide.

[0079] Example 2

[0080] In this embodiment, the preparation method of the white asphalt mixture for highway tunnel pavement comprises the following steps:

[0081] The method comprises the following steps:

[0082] (1) Preparation of light-colored asphalt:

[0083] Mixing and preheating step: take naphthenic oil, petroleum resin, and EVA resin by weight, and preheat at a temperature of 160-170°C for 20 min with stirring at a speed of 700-1000 rad / min; maintain the temperature at 160-170°C, add SBS modifier and compatibilizer to the molten mixture, and shear at a speed of 4500-5500 rad / min for 32 min; cool to 150-160°C, and add anti-aging agent, shear at a speed of 2000-2500 rad / min for 17 min to obtain light-colored asphalt primary product; place the light-colored asphalt primary product in an oven at 160-165°C for 1.8 h to obtain light-colored asphalt.

[0084] The light-colored asphalt comprises the following components: 31 parts by weight of naphthenic oil, 64 parts by weight of petroleum resin, 6.5 parts by weight of EVA resin, 18 parts by weight of SBS modifier, 1.2 parts by weight of compatibilizer, and 12 parts by weight of anti-aging agent. The anti-aging agent comprises 1076 antioxidant, LDHs, and glyceryl oleate polyoxyethylene ether in a weight ratio of 1:3.5:0.3. The petroleum resin is C9 type petroleum resin.

[0085] (2) Heat the coarse aggregate, fine aggregate, and light-colored asphalt to 160-170°C by weight;

[0086] The coarse aggregate comprises 5-10 mm crushed stone and 10-15 mm crushed stone in a weight ratio of 41:22.

[0087] The fine aggregate comprises 0-3 mm machine-made sand and 3-5 mm crushed stone in a weight ratio of 27:7.

[0088] (3) Take a container and preheat the temperature in the container to 160-170°C, add the heated coarse aggregate, fine aggregate, and light-colored asphalt from step (2) above to the preheated container, and stir at a speed of 45-75 r / min for 50-60 s to obtain mixture A;

[0089] (4) by weight, the mineral powder, the composite flame retardant is stirred under the speed of 45-75 rad / min, heated to 160-170℃, to obtain the mixture B;

[0090] (5) keeping the temperature 160-170℃, the mixture A, the mixture B and the unheated titanium white powder are stirred at the speed of 500-700 rad / min for 130 min, to prepare the white asphalt mixture.

[0091] The white asphalt mixture comprises, by weight, 67 parts of the light-colored asphalt, 54 parts of the coarse aggregate, 27 parts of the fine aggregate, 2 parts of the titanium white powder, 3 parts of the mineral powder and 3 parts of the composite flame retardant; the composite flame retardant comprises, by weight, 51:32:9 of the nano-clay, the ammonium polyphosphate and the aluminum hydroxide.

[0092] Example 3

[0093] The preparation method of the white asphalt mixture for the highway tunnel pavement in the example comprises the following steps:

[0094] The method comprises the following steps:

[0095] (1) preparation of the light-colored asphalt:

[0096] The mixing and preheating step: by weight, naphthenic oil, petroleum resin and EVA resin are taken and stirred at the temperature of 160-170℃ for 25 min to obtain a molten mixture, the stirring speed is 700-1000 rad / min; keeping the temperature 160-170℃, the SBS modifier and the compatibilizer are added to the molten mixture and sheared at the speed of 4500-5500 rad / min for 35 min; the temperature is lowered to 150-160℃, and the anti-aging agent is added, and sheared at the speed of 2000-2500 rad / min for 20 min to obtain the light-colored asphalt primary product; the light-colored asphalt primary product is placed in an oven at 160-165℃ for 2 h to obtain the light-colored asphalt. The petroleum resin is C9 type petroleum resin.

[0097] The light-colored asphalt comprises the following components: 33.3 parts by weight of naphthenic oil, 66.7 parts by weight of petroleum resin, 8 parts by weight of EVA resin, 33 parts by weight of SBS modifier, 1.5 parts by weight of compatibilizer and 22 parts by weight of anti-aging agent. The anti-aging agent comprises 1:5.5:0.4 of 1076 antioxidant, LDHs and oleamine polyoxyethylene ether by weight.

[0098] (2) by weight, the coarse aggregate, the fine aggregate and the light-colored asphalt are heated to 160-170℃ respectively;

[0099] The coarse aggregate comprises 43:25 of 5-10 mm gravel and 10-15 mm gravel by weight.

[0100] The fine aggregate comprises 0-3 mm machine-made sand and 3-5 mm crushed stone in a weight ratio of 29:9.

[0101] (3) Take a container and preheat the temperature in the container to 160-170°C, add the coarse aggregate, fine aggregate and light-colored asphalt heated in the above step (2) into the preheated container, and stir at a speed of 45-75 r / min for 60 s to obtain a mixture A;

[0102] (4) According to the weight parts, the mineral powder and the composite flame retardant are stirred and heated to 160-170°C at a speed of 45-75 rad / min to obtain a mixture B;

[0103] (5) Keep the temperature at 160-170°C, and stir the mixture A, the mixture B and the unheated titanium white powder at a speed of 500-700 rad / min for 150 min to prepare a white asphalt mixture.

[0104] The white asphalt mixture comprises, by weight parts, light-colored asphalt 7 parts, coarse aggregate 58 parts, fine aggregate 30 parts, titanium white powder 3 parts, mineral powder 4 parts and composite flame retardant 3.5 parts; the composite flame retardant comprises nano-clay, ammonium polyphosphate and aluminum hydroxide in a weight ratio of 52:35:10.

[0105] Comparative Example 1

[0106] The difference from Example 2 is that:

[0107] (5) Keep the temperature at 160-170°C, and stir the mixture A, the mixture B and the unheated titanium white powder at a speed of 500-700 rad / min for 120-150 min to prepare a white asphalt mixture.

[0108] The white asphalt mixture comprises, by weight parts, light-colored asphalt 67 parts, coarse aggregate 54 parts, fine aggregate 27 parts, titanium white powder 2 parts, mineral powder 3 parts and composite flame retardant 3.7 parts.

[0109] Comparative Example 2

[0110] The difference from Example 2 is that:

[0111] (5) Keep the temperature at 160-170°C, and stir the mixture A, the mixture B and the unheated titanium white powder at a speed of 500-700 rad / min for 120-150 min to prepare a white asphalt mixture.

[0112] The white asphalt mixture comprises, by weight parts: 67 parts by weight of light-colored asphalt, 54 parts by weight of coarse aggregate, 27 parts by weight of fine aggregate, 2 parts by weight of titanium dioxide, 3 parts by weight of mineral powder, and 3 parts by weight of composite flame retardant.2.3.

[0113] Experimental Example 1

[0114] The flame-retardant and smoke-suppressing properties of the white asphalt mixtures provided in Examples 1 to 3 and Comparative Examples 1 and 2 were detected. The limiting oxygen index (LOI) test was performed in accordance with the standard NB / SH / T 0815-2010 "Determination of Combustion Performance of Asphalt - Oxygen Index Method", and the smoke density test was performed in accordance with the standard GB / T 8627-2007 "Determination of Smoke Density of Building Materials by Combustion or Decomposition". Each test group had 3 parallel tests, and the average value was taken. The detection results are shown in Table 1:

[0115] Table 1

[0116] Limiting oxygen index / % Smoke density / % Example 1 28 40 Example 2 29 42 Example 3 28 41 Comparative Example 1 22 43 Comparative Example 2 18 66

[0117] Experimental Example 2

[0118] The road performance of the white asphalt mixtures provided in Examples 1 to 3 and Comparative Examples 1 and 2 was detected by the method provided in JTG F40-2004 "Technical Specification for Construction of Highway Asphalt Pavement". Each test group had 3 parallel tests, and the average value was taken. The detection results are shown in Table 2:

[0119] Table 2

[0120]

[0121] From Tables 1 and 2, it can be seen that the white asphalt mixtures provided in the present application have excellent flame-retardant and smoke-suppressing properties. At the same time, the dynamic stability can reflect the high-temperature stability of the asphalt mixture, the failure strain can reflect the low-temperature crack resistance of the asphalt material, and the splitting strength ratio reflects the water stability of the asphalt material. Referring to Table 2, it can be seen that the dynamic stability, failure strain, and splitting strength of Examples 1 to 3 are significantly enhanced compared to those of Comparative Examples 1 and 2, indicating that the white asphalt mixture provided in the present application not only has good effects in terms of flame retardation and smoke suppression, but also significantly improves the high-temperature, low-temperature, and water stability of the mixed asphalt. And according to Table 1, when the addition amount of the composite flame retardant increases, the limiting oxygen index of the mixed asphalt mixture does not correspondingly increase, but the smoke density slightly increases, indicating that the composite flame retardant is not better in terms of flame retardation and smoke suppression with a larger addition amount.

[0122] Example 4

[0123] The difference from Example 2 is that:

[0124] (4) by weight parts, the mineral powder, composite flame retardant stirring, heating to 160-170℃ under the speed of 45-75 rad / min, get mixed B;

[0125] (5) keep temperature 160-170℃, the mixture A, mixed B and unheated titanium dioxide in the speed of 500-700 rad / min under the stirring 130 min, prepared white asphalt mixture.

[0126] The preparation method of the modified nanoclay comprises: dispersing the nanoclay in anhydrous ethanol at 30-50℃, ultrasonic treatment for 30s for activation and interlayer exfoliation to obtain a first dispersion liquid, then adding N-hydroxy octanamide to the first dispersion liquid, stirring at a speed of 40-60 rad / min, and ultrasonic treatment for 3min, continuing to exfoliate and grafting N-hydroxy octanamide on the surface and interlayer of the thin-layer nanoclay to obtain a second dispersion liquid, drying the second dispersion liquid at 40-60℃ to constant weight to obtain the modified nanoclay. The weight-volume ratio of the nanoclay, anhydrous ethanol and N-hydroxy octanamide is 1g:10mL:1.1g.

[0127] The white asphalt mixture comprises, by weight parts: 67 parts by weight of light-colored asphalt, 54 parts by weight of coarse aggregate, 27 parts by weight of fine aggregate, 2 parts by weight of titanium dioxide, 3 parts by weight of mineral powder and 3 parts by weight of composite flame retardant; the composite flame retardant comprises modified nanoclay, ammonium polyphosphate, aluminum hydroxide and magnesium silicate in a weight ratio of 51:32:9:0.5.

[0128] Example 5

[0129] The difference from example 2 is that:

[0130] (4) by weight parts, the mineral powder, composite flame retardant stirring, heating to 160-170℃ under the speed of 45-75 rad / min, get mixed B;

[0131] (5) keep temperature 160-170℃, the mixture A, mixed B and unheated titanium dioxide in the speed of 500-700 rad / min under the stirring 130 min, prepared white asphalt mixture.

[0132] The preparation method of modified nanoclay includes: dispersing nanoclay in anhydrous ethanol at 30-50℃, activating and exfoliating the layers by ultrasonic treatment for 45s to obtain a first dispersion; then adding N-hydroxyoctanoamide to the first dispersion, stirring at 40-60 rad / min while ultrasonic treatment for 5min, continuing exfoliation, and grafting N-hydroxyoctanoamide onto the surface and interlayer of the thin-layer nanoclay to obtain a second dispersion; drying the second dispersion at 40-60℃ to constant weight to obtain modified nanoclay. The weight-to-volume ratio of nanoclay, anhydrous ethanol, and N-hydroxyoctanoamide is 1g:15mL:1.2g.

[0133] The white asphalt mixture by weight comprises: 67 parts by weight of light-colored asphalt, 54 parts by weight of coarse aggregate, 27 parts by weight of fine aggregate, 2 parts by weight of titanium dioxide, 3 parts by weight of mineral powder, and 3 parts by weight of composite flame retardant; the composite flame retardant comprises modified nano clay, ammonium polyphosphate, aluminum hydroxide, and magnesium silicate in a weight ratio of 51:32:9:0.9.

[0134] Example 6

[0135] The difference from Example 2 is that:

[0136] (4) According to the weight parts, the mineral powder and composite flame retardant are stirred and heated to 160-170℃ at a speed of 45-75 rad / min to obtain mixture B;

[0137] (5) Keep the temperature at 160-170℃, and stir the mixture A, mixture B and unheated titanium dioxide at a speed of 500-700 rad / min for 130 min to obtain white asphalt mixture.

[0138] The preparation method of modified nanoclay includes: dispersing nanoclay in anhydrous ethanol at 30-50℃, activating and exfoliating the layers by ultrasonic treatment for 60s to obtain a first dispersion; then adding N-hydroxyoctanoamide to the first dispersion, stirring at 40-60 rad / min while ultrasonic treatment for 7min, continuing exfoliation, and grafting N-hydroxyoctanoamide onto the surface and interlayer of the thin-layer nanoclay to obtain a second dispersion; drying the second dispersion at 40-60℃ to constant weight to obtain modified nanoclay. The weight-to-volume ratio of nanoclay, anhydrous ethanol, and N-hydroxyoctanoamide is 1g:20mL:1.3g.

[0139] The white asphalt mixture by weight comprises: 67 parts by weight of light-colored asphalt, 54 parts by weight of coarse aggregate, 27 parts by weight of fine aggregate, 2 parts by weight of titanium dioxide, 3 parts by weight of mineral powder, and 3 parts by weight of composite flame retardant; the composite flame retardant comprises modified nano clay, ammonium polyphosphate, aluminum hydroxide, and magnesium silicate in a weight ratio of 51:32:9:1.2.

[0140] Comparative Example 3

[0141] The difference from Example 5 is that:

[0142] The white asphalt mixture comprises, by weight parts: light-colored asphalt 67 parts by weight, coarse aggregate 54 parts by weight, fine aggregate 27 parts by weight, titanium dioxide 2 parts by weight, mineral powder 3 parts by weight, and composite flame retardant 3 parts by weight; the composite flame retardant comprises nano-clay, ammonium polyphosphate, aluminum hydroxide, and magnesium silicate in a weight ratio of 51:32:9:0.9, respectively.

[0143] Comparative Example 4

[0144] The difference from Example 5 is that:

[0145] The white asphalt mixture comprises, by weight parts: light-colored asphalt 67 parts by weight, coarse aggregate 54 parts by weight, fine aggregate 27 parts by weight, titanium dioxide 2 parts by weight, mineral powder 3 parts by weight, and composite flame retardant 3 parts by weight; the composite flame retardant comprises modified nano-clay, ammonium polyphosphate, and aluminum hydroxide in a weight ratio of 51:32:9, respectively.

[0146] Comparative Example 5

[0147] The difference from Example 5 is that:

[0148] (No composite flame retardant is added to the mixed asphalt)

[0149] (4) The mineral powder is stirred at a rotational speed of 45-75 rad / min and heated to 160-170°C to obtain a mixture B, by weight parts;

[0150] (5) The temperature is maintained at 160-170°C, and the mixture A, the mixture B, and the unheated titanium dioxide are stirred at a rotational speed of 500-700 rad / min for 130 min to prepare a white asphalt mixture.

[0151] The white asphalt mixture comprises, by weight parts: light-colored asphalt 67 parts by weight, coarse aggregate 54 parts by weight, fine aggregate 27 parts by weight, titanium dioxide 2 parts by weight, mineral powder 3 parts by weight.

[0152] Experimental Example 3

[0153] The flame-retardant and smoke-suppressing properties of the white asphalt mixtures provided in Examples 4-6 and Comparative Examples 3-5 were tested. The limiting oxygen index (LOI) test was performed in accordance with the standard NB / SH / T 0815-2010 "Determination of Combustion Performance of Asphalt by Oxygen Index Method", and the smoke density test was performed in accordance with the standard GB / T 8627-2007 "Smoke Density Test Method for Combustion or Decomposition of Building Materials". Each test group had 3 parallel tests, and the average value was taken. The test results are shown in Table 3:

[0154] Table 3

[0155] Limiting oxygen index / % Smoke density / % Example 4 35 28 Example 5 36 28 Example 6 36 30 Comparative Example 3 24 39 Comparative Example 4 25 40 Comparative Example 5 17.5 89

[0156] Experimental Example 4

[0157] The road performance of the white asphalt mixture material provided by Examples 4 to 6 and Comparative Examples 3 to 5 was detected by the method provided in JTG F40-2004 "Technical Specification for Construction of Highway Asphalt Pavement". Three parallel tests were set for each test group, and the average value was taken. The detection results are shown in Table 4:

[0158] Table 4

[0159] Dynamical stability (cycles / mm) Breaking strain (με) Splitting strength ratio (%) Example 4 8642 2785 86.03 Example 5 8056 2838 87.08 Example 6 8879 2744 86.29 Comparative Example 3 7401 2365 82.1 Comparative Example 4 7123 2405 82.9 Comparative Example 5 2804 2196 80.06

[0160] As can be seen from Table 3 and Table 4, the modified nanoclay and magnesium silicate in the composite flame retardant can further improve the flame-retardant and smoke-suppressing performance of the white asphalt mixture, and the modified nanoclay and magnesium silicate can have a synergistic effect, which can improve the high-temperature stability and load-bearing capacity of the asphalt mixture, and further improve the road performance of the asphalt mixture.

[0161] Experimental Example 5

[0162] The flame-retardant performance of the asphalt mixture obtained by Examples 2, 5 and Comparative Examples 3 to 5 was further analyzed by direct combustion test. The specific method is as follows: considering that the asphalt material is difficult to ignite in air, the method of igniting the test piece with gasoline was adopted. In order to control the consistency of test conditions, 100-110g of test piece was taken, and the test piece was placed in an iron plate, 40mL of gasoline was poured on each test piece, in order to avoid the error caused by the volatilization of gasoline, the test piece was ignited immediately after the gasoline was poured, and the test piece was extinguished. The flame-retardant performance of the white asphalt mixture was analyzed from the two indexes of combustion time and mass loss rate. Three parallel tests were set for each test group, and the average value was taken. The test results are shown in Table 5:

[0163] Table 5

[0164] Burning time / s Mass loss / % Example 2 232 4.5 Example 5 220 2.6 Comparative Example 3 259 3.6 Comparative Example 4 251 3.2 Comparative Example 5 266 7.3

[0165] The results show that the flame-retardant performance of Example 5 is the best, and it is obviously improved compared with Example 2, and the mass loss of the asphalt mixture obtained by Comparative Examples 3 to 5 is greatly reduced. Combined with the data in Table 3, it is shown that the modified nanoclay and magnesium silicate can effectively improve the flame-retardant and smoke-suppressing performance and road performance of the asphalt concrete under the synergistic effect.

[0166] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and are not limited thereto; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand; it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A white asphalt mixture for highway tunnel pavement, characterized in that, The white asphalt mixture comprises, by weight, 4-7 parts light-colored asphalt, 50-58 parts coarse aggregate, 25-30 parts fine aggregate, 1-3 parts titanium dioxide, 2-4 parts mineral powder, and 2.5-3.5 parts composite flame retardant. The composite flame retardant is composed of modified nano-clay, ammonium polyphosphate, aluminum hydroxide and magnesium silicate in a weight ratio of (50-52):(30-35):(8-10):(0.5-1.2); The method for preparing the modified nanoclay includes: dispersing nanoclay in anhydrous ethanol at 30-50℃, activating and exfoliating the layers by ultrasonic treatment for 30-60s to obtain a first dispersion, adding N-hydroxyoctanoamide to the first dispersion, stirring at 40-60 rad / min, and simultaneously ultrasonicating for 3-7 min, continuing to exfoliate and grafting N-hydroxyoctanoamide onto the surface and interlayer of the thin-layer nanoclay to obtain a second dispersion, and drying the second dispersion at 40-60℃ to constant weight to obtain the modified nanoclay.

2. The white asphalt mixture for highway tunnel pavement according to claim 1, characterized in that, The light-colored asphalt comprises the following components: 30-33.3 parts by weight of naphthenic oil, 62-66.7 parts by weight of petroleum resin, 5-8 parts by weight of EVA resin, 4-33 parts by weight of SBS modifier, 1-1.5 parts by weight of compatibilizer, and 2-22 parts by weight of anti-aging agent.

3. The white asphalt mixture for highway tunnel pavement according to claim 2, characterized in that, The anti-aging agent comprises 1076 antioxidant, LDHs, and tallow amine polyoxyethylene ether in a weight ratio of 1:2-5.5:0.2-0.

4.

4. The white asphalt mixture for highway tunnel pavement according to claim 1, characterized in that, The coarse aggregate is classified into 5-10mm crushed stone and 10-15mm crushed stone, wherein the weight ratio of 5-10mm crushed stone to 10-15mm crushed stone is 40-43:20-25.

5. The white asphalt mixture for highway tunnel pavement according to claim 1, characterized in that, The fine aggregate is classified into 0-3mm manufactured sand and 3-5mm crushed stone, wherein the weight ratio of 0-3mm manufactured sand to 3-5mm crushed stone is 26-29:5-9.

6. The white asphalt mixture for highway tunnel pavement according to claim 1, characterized in that, The titanium dioxide is selected from either anatase titanium dioxide or rutile titanium dioxide.

7. The white asphalt mixture for highway tunnel pavement according to claim 2, characterized in that, The petroleum resin is one or more of C9 type petroleum resin, C5 type petroleum resin, or coumarone resin.

8. A method for preparing a white asphalt mixture for highway tunnel pavement, characterized in that, This method is used to prepare the white asphalt mixture according to any one of claims 1-7, and the method includes the following steps: (1) Heat the coarse aggregate, the fine aggregate, and the light-colored asphalt to 160-170°C respectively according to the weight parts; (2) Take a container and preheat the temperature inside the container to 160-170℃. Add the coarse aggregate, fine aggregate and light-colored asphalt heated in step (1) to the preheated container and stir at a speed of 45-75r / min for 50-60s to obtain mixture A. (3) According to the weight parts, the mineral powder and the composite flame retardant are stirred at a speed of 45-75 rad / min and heated to 160-170℃ to obtain mixture B; (4) Keep the temperature at 160-170℃, and stir the mixture A, the mixture B and the unheated titanium dioxide at a speed of 500-700 rad / min for 120-150 min to obtain the white asphalt mixture.

9. The method for preparing white asphalt mixture for highway tunnel pavement according to claim 8, characterized in that, The preparation method of the light-colored asphalt includes the following steps: Mixing and preheating step: Take the naphthenic oil, the petroleum resin and the EVA resin according to the weight parts, and stir and preheat at 160-170℃ for 10-25min to obtain a molten mixture. The stirring speed is 700-1000rad / min. SBS modifier and compatibilizer addition steps: Maintain the temperature at 160-170℃, add the SBS modifier and compatibilizer to the melt mixture, and shear at a speed of 4500-5500 rad / min for 30-35 min; Anti-aging agent addition steps: Cool down to 150-160℃, and add the 1076 antioxidant, the LDHs and the tallow amine polyoxyethylene ether in sequence. Shear at a speed of 2000-2500 rad / min for 15-20 min to obtain the light-colored asphalt primary product. Development steps: Place the light-colored asphalt precursor in an oven at 160-165℃ for 1.5-2 hours to develop, and obtain light-colored asphalt.

10. The application of a white asphalt mixture for highway tunnel pavement in highway tunnel pavement paving, characterized in that, The white asphalt mixture is the white asphalt mixture according to any one of claims 1-7, or the white asphalt mixture prepared by the method of claim 8 or 9.

Images