Blended modified asphalt and preparation method thereof

Abstract

The invention relates to blended modified asphalt and a preparation method thereof, and belongs to the technical field of asphalt material compositions. The blended modified asphalt is prepared from 90 # heavy traffic road petroleum asphalt, 70 # road petroleum asphalt, natural rock asphalt, an emulsifier op-10, an HDI-trihydroxymethyl hexyl lactone cross-linked polymer, phenylpropyl dimethyl siloxy silicate ester, vinyl-terminated polydimethylsiloxane, thermoplastic styrene-butadiene rubber, nanoscale calcium carbonate, organobentonite and diatomite according to a specific proportion. Polyethylene wax, an anti-rut agent, an antioxidant and the like. Wherein the natural rock asphalt is pre-modified by the HDI-trihydroxymethyl hexyl lactone cross-linked polymer, the 70 # road petroleum asphalt is pre-modified by the phenylpropyl dimethyl siloxy silicate ester, and the thermoplastic styrene-butadiene rubber is pre-modified by the vinyl terminated polydimethylsiloxane. The modified components are better in compatibility and good in blending homogeneity, the components are not easy to reject, and the blended modified asphalt is excellent in use performance.

Description

Technical Field

[0001] The invention belongs to the technical field of asphalt material compositions, and in particular relates to a blended modified asphalt and a preparation method thereof. Background Art

[0002] As an important part of modern transportation infrastructure, highways have extremely high requirements for pavement materials. Asphalt has become a key material for highway pavement due to its good adhesion, waterproofness and durability.

[0003] Traditional asphalt is mainly sourced from petroleum asphalt, and its performance is limited to a certain extent by the properties of crude oil and the refining process. With the rapid development of highway construction, the demand for asphalt has not only increased significantly in quantity, but also put forward more stringent standards in terms of quality and performance. For example, the climatic conditions in different regions vary greatly. High-temperature areas require asphalt to have good high-temperature stability to prevent damage such as rutting and shifting of the road surface during high temperatures in summer; while cold areas require asphalt to have excellent low-temperature crack resistance to avoid cracks in the road surface under low-temperature conditions. It is often difficult for a single type of petroleum asphalt to meet these diverse performance requirements at the same time.

[0004] In this context, blended asphalt technology came into being. By blending asphalts from different sources and properties, the various performance indicators of asphalt can be optimized to better meet the special requirements of highway construction in different regions. Blended asphalt can combine the advantages of multiple asphalts and make up for the shortcomings of single asphalt in certain properties. For example, blending high softening point asphalt with low softening point asphalt in a certain proportion can improve the low temperature performance of asphalt while ensuring a certain high temperature stability.

[0005] The heavy-load trend of modern highway traffic is becoming more and more obvious, and the vehicle load is constantly increasing, which also prompts the continuous innovation and improvement of blended asphalt technology. Through the blending process, suitable modifiers or other additives can be added to the asphalt to further improve the key performance indicators of asphalt such as fatigue resistance, anti-aging performance and adhesion to aggregates, thereby ensuring that the highway pavement can still maintain good performance and a long service life under heavy-load traffic conditions, ensuring the safety and smoothness of highway traffic.

[0006] There are many kinds of blended asphalt available now, but there are still some shortcomings in highway blended asphalt:

[0007] The first is the problem of blending uniformity. During the blending process, it is difficult to mix different asphalt raw materials evenly due to differences in physical properties such as viscosity and density. If the blending is not uniform, the asphalt performance will be inconsistent and the quality of the paved road will be uneven. For example, some areas have good high-temperature stability, while some areas have poor low-temperature crack resistance, which affects the overall performance and service life of the road.

[0008] The second is the compatibility of additives. In order to improve the performance of asphalt, various modifiers and additives are often added. However, some additives are not compatible with asphalt, and will agglomerate and precipitate. For example, if some polymer modifiers cannot be well dispersed in asphalt, they will not be able to effectively play their role in enhancing the performance of asphalt, and may even become a hidden danger of road disease.

[0009] The third is the applicability of the blending process parameters. Additive compatibility and blending uniformity will be affected by the blending process parameters. Inappropriate blending sequence and parameters will affect the final adjustment quality.

[0010] Therefore, it is necessary to combine multiple factors and continuously improve the asphalt blending technology to ensure that asphalt can adapt to the complex use environment of highways and provide better protection for traffic safety. Summary of the invention

[0011] The existing highway blended asphalt has deficiencies in blending uniformity, additive compatibility, blending process parameters, etc., which lead to the problems of poor quality and poor environmental adaptability of the blended asphalt. The present invention provides a blended modified asphalt and a preparation method thereof, wherein the blended modified asphalt contains No. 90 heavy traffic road petroleum asphalt, No. 70 road petroleum asphalt, natural rock asphalt, thermoplastic styrene-butadiene rubber and other ingredients; wherein the natural rock asphalt is pre-modified by HDI-trimethylol hexyl lactone cross-linked polymer, the No. 70 road petroleum asphalt is pre-modified by phenylpropyl dimethylsiloxysilicate, and the thermoplastic styrene-butadiene rubber is pre-modified by vinyl-terminated polydimethylsiloxane; after modification, the compatibility of the components is better, the blending homogeneity is good, the components are not easily rejected, and the blended modified asphalt has excellent performance. The specific technical scheme is as follows:

[0012] A blended modified asphalt comprises the following raw materials in parts by mass: 30 to 50 parts of No. 90 heavy traffic road petroleum asphalt, 20 to 40 parts of No. 70 road petroleum asphalt, 5 to 15 parts of natural rock asphalt, 0.3 to 0.5 parts of emulsifier OP-10, 2 to 5 parts of HDI-trimethylol hexyl lactone crosslinked polymer, 2 to 5 parts of phenylpropyl dimethyl siloxy silicate, 0.1 to 0.3 parts of vinyl-terminated polydimethylsiloxane, 1.5 to 3 parts of thermoplastic styrene-butadiene rubber, 2 to 6 parts of nano-scale calcium carbonate, 1 to 4 parts of organic bentonite, 2 to 5 parts of diatomaceous earth, 0.5 to 1.5 parts of polyethylene wax, 0.3 to 0.5 parts of anti-rutting agent and 0.1 to 0.3 parts of antioxidant.

[0013] In the above blended modified asphalt, the particle size range of the nano-scale calcium carbonate is below 200 nm.

[0014] In the above blended modified asphalt, the median particle size of the organic bentonite is 1 μm to 10 μm.

[0015] In the above blended modified asphalt, the median particle size of the diatomaceous earth is 10 μm to 50 μm.

[0016] In the above blended modified asphalt, the median particle size of the polyethylene wax is 1 μm to 10 μm.

[0017] In the above-mentioned blended modified asphalt, the HDI-trimethylol hexyl lactone cross-linked polymer is pre-modified on natural rock asphalt, and the modification method comprises the following steps: heating the natural rock asphalt to a molten state, controlling the temperature at 150°C to 180°C, adding HDI-trimethylol hexyl lactone cross-linked polymer under stirring conditions of 80r / min to 150r / min, raising the temperature to 180°C to 190°C, and continuously stirring at 200r / min to 300r / min for 30min to 60min to obtain modified rock asphalt.

[0018] In the above-mentioned blended modified asphalt, the phenylpropyl dimethylsiloxysilicate is used to pre-modify the No. 70 road petroleum asphalt, and the modification method includes the following steps: heating the No. 70 road petroleum asphalt to a molten state, controlling the temperature at 140°C to 160°C, adding phenylpropyl dimethylsiloxysilicate under stirring conditions of 80r / min to 150r / min, raising the temperature to 160°C to 180°C, and continuously stirring at 200r / min to 300r / min for 30min to 60min to obtain modified No. 70 asphalt.

[0019] In the above-mentioned blended modified asphalt, the vinyl-terminated polydimethylsiloxane is pre-modified on the thermoplastic styrene-butadiene rubber, and the modification method includes the following steps: cutting the thermoplastic styrene-butadiene rubber into small pieces, placing them in a reaction kettle, heating them to 130°C to 150°C, and after the thermoplastic styrene-butadiene rubber is softened, adding the vinyl-terminated polydimethylsiloxane, and continuously stirring at 80r / min to 120r / min for 60min to 90min to maintain the softened state to obtain the modified rubber.

[0020] The above-mentioned method for preparing a blended modified asphalt comprises the following steps:

[0021] S1: According to the mass fraction, heat No. 90 heavy traffic road petroleum asphalt to 140℃~160℃ to melt, then add the molten modified No. 70 asphalt, stir at 200r / min~300r / min for 30min~50min, then add the molten modified rock asphalt, control the temperature at 150℃~170℃, stir at 300r / min~500r / min for 30min~50min, then add the softened modified rubber, control the temperature at 160℃~180℃, stir at 300r / min~500r / min for 40min~60min, and obtain the mixture A;

[0022] S2: Keep the temperature at 160℃~180℃, add nano-calcium carbonate, organic bentonite, diatomaceous earth, polyethylene wax and antioxidant to mixture A in sequence, and stir at 300r / min~500r / min for 20min~30min each time adding one ingredient; then raise the temperature to 180℃~185℃, add anti-rutting agent, and stir at 300r / min~500r / min for 30s~60s; then cool down to 150℃~160℃, add emulsifier OP-10, and stir at 300r / min~500r / min for 5min~10min to obtain blended modified asphalt.

[0023] In S1 of the above preparation method, the modified No. 70 asphalt in the molten state is in the molten state at 150°C to 170°C, the modified rock asphalt in the molten state is in the molten state at 150°C to 170°C, and the modified rubber in the softened state is in the molten state at 130°C to 150°C.

[0024] In S2 of the above preparation method, the anti-rutting agent is preheated and melted at 180° C. to 185° C.

[0025] The present invention provides a blended modified asphalt and a preparation method thereof, and the beneficial effects are as follows:

[0026] 1. The blended modified asphalt of the present invention contains a specific proportion of No. 90 heavy road petroleum asphalt, No. 70 road petroleum asphalt, natural rock asphalt, emulsifier OP-10, HDI-trimethylol hexyl lactone cross-linked polymer, phenylpropyl dimethyl siloxy silicate, vinyl-terminated polydimethyl siloxane, thermoplastic styrene-butadiene rubber, nano-scale calcium carbonate, organic bentonite, diatomaceous earth, polyethylene wax, anti-rutting agent and antioxidant, etc. Among them, HDI-trimethylol hexyl lactone cross-linked polymer pre-modifies natural rock asphalt, phenylpropyl dimethyl siloxy silicate pre-modifies No. 70 road petroleum asphalt, and vinyl-terminated polydimethyl siloxane pre-modifies thermoplastic styrene-butadiene rubber. After modification, the compatibility of each component is better, the blending homogeneity is good, the components are not easily rejected, and the blended modified asphalt has excellent performance.

[0027] 2. When HDI-trimethylol hexyl lactone cross-linked polymer modifies natural rock asphalt, the isocyanate group (-NCO) will react with the active hydrogen (such as hydroxyl, carboxyl, etc.) in the rock asphalt. These reactions can form chemical bonds between the rock asphalt molecules, transforming the molecular structure of the rock asphalt from the original loose state to a three-dimensional network structure, enhancing the cohesion and stability of the rock asphalt, and also reducing the agglomeration phenomenon when mixed with other asphalts and additives, thereby improving the blending uniformity.

[0028] The chemical and physical compatibility of the modified natural rock asphalt with other ingredients such as No. 90 heavy road petroleum asphalt, modified No. 70 road petroleum asphalt and modified rubber is enhanced. Because the cross-linked polymer improves the surface properties of natural rock asphalt, it makes its interaction with other ingredients at the molecular level more friendly, reducing the phase separation caused by ingredient differences. The modified natural rock asphalt can effectively improve the high temperature stability of the blended modified asphalt, enhance the ability to resist rutting deformation at 60°C, and improve the dynamic stability. During the stretching process, the modified natural rock asphalt synergizes with other ingredients to make the overall structure of the blended asphalt stronger and improve the tensile strength ratio. The modified natural rock asphalt gives the blended modified asphalt better elastic memory to a certain extent, and can better restore its original shape after being deformed by external force, so that the elastic recovery rate at 25°C is improved. During the asphalt molding process, the modified natural rock asphalt participates in the construction of a denser structure, interweaving with other ingredients, and enhancing the strength after molding.

[0029] 3. The phenylpropyl dimethylsiloxysilicate molecule contains a siloxane (Si-O-Si) structure. During the modification of the petroleum asphalt on Route 70, the siloxane can undergo physical adsorption and chemical reaction with the polar components in the asphalt. On the one hand, physical adsorption enhances the interaction between the asphalt molecules and the modifier molecules, making the colloidal structure of the asphalt more stable. On the other hand, the chemical reaction includes the reaction of siloxane with a small amount of active groups such as hydroxyl groups in the asphalt to form covalent bonds and hydrogen bonds, thereby improving the asphalt's flexibility, aging resistance, and water damage resistance.

[0030] Modified No. 70 road asphalt is more compatible with modified natural rock asphalt, No. 90 heavy road asphalt and other additives. The addition of phenylpropyl dimethylsiloxysilicate adjusts the chemical structure of No. 70 road asphalt, reduces the interfacial tension between it and other ingredients, thereby improving compatibility. Modified No. 70 road asphalt can maintain good structural integrity under high temperature environment, enhances the interaction force with other ingredients, and improves the 60℃ dynamic stability. When subjected to tensile force, silicate-modified No. 70 road asphalt can better transmit stress and resist stretching together with other ingredients, thereby increasing the tensile strength ratio. The modification of silicate helps to maintain the elasticity of the blended modified asphalt, which can recover faster and more effectively after deformation, and improve the 25℃ elastic recovery rate. In the asphalt molding stage, the modified No. 70 road asphalt can better fill the gaps and build a tight structure with other ingredients, thereby improving the molding strength.

[0031] 4. Vinyl-terminated polydimethylsiloxane The vinyl groups at both ends of the molecule are active groups. When modifying thermoplastic styrene-butadiene rubber, the vinyl groups can combine with active sites such as double bonds on the styrene-butadiene rubber molecular chain through free radical polymerization or addition reaction. This combination allows the polydimethylsiloxane chain segment to be connected to the styrene-butadiene rubber molecular chain, changing the molecular chain structure of styrene-butadiene rubber. The introduction of siloxane chain segments can reduce the surface energy of rubber, improve the water resistance and weather resistance of rubber, and at the same time improve the flexibility and processing performance of rubber, and improve the blending uniformity.

[0032] The compatibility between the modified thermoplastic styrene butadiene rubber and the asphalt components is enhanced. The addition of siloxane adjusts the surface properties of the rubber, making it more compatible with other components in the asphalt (such as various asphalts and additives) in terms of chemical and physical properties, reducing the phenomenon of stratification caused by incompatibility. The modified thermoplastic styrene butadiene rubber can form a stable network structure in the asphalt, effectively preventing the flow deformation of the asphalt at a high temperature of 60°C and improving the dynamic stability. The modified thermoplastic styrene butadiene rubber can synergize with other components in the asphalt, bear and transfer stress during the stretching process, and increase the tensile strength ratio. Since the thermoplastic styrene butadiene rubber itself is elastic, after modification, it can better play the role of elastic recovery at 25°C, and together with other components of the asphalt, it can improve the elastic recovery rate. During the asphalt molding process, the modified thermoplastic styrene butadiene rubber helps to enhance the overall structural strength of the asphalt.

[0033] 5. Synergistic effect of HDI-trimethylol hexyl lactone cross-linked polymer and phenylpropyl dimethyl siloxysilicate: During the blending process, the two modified asphalts (natural rock asphalt and No. 70 road petroleum asphalt) cooperate with each other to further improve the blending uniformity. They can be mixed together more quickly and thoroughly to form a more stable system. The synergistic effect of the two modifiers significantly improves the dynamic stability of asphalt at 60°C. The modified natural rock asphalt and No. 70 road petroleum asphalt are intertwined to form a more stable high-temperature structure that effectively resists rutting. In terms of tensile strength ratio, the two modifiers synergistically enhance the cohesion of asphalt. The modification of natural rock asphalt and No. 70 road petroleum asphalt respectively provides better tensile resistance from the perspective of different components during the stretching process of asphalt, and improves the tensile strength ratio. The two modified asphalts work together to optimize the elastic structure of asphalt. At room temperature, it can better maintain the elasticity of asphalt, so that it can recover more effectively after being deformed by external forces, and improve the elastic recovery rate. The two modified asphalts work together to build a more compact and stable molding structure. They fill and interweave with each other during the molding process, which improves the overall molding strength of the asphalt.

[0034] 6. In the preparation method of the present invention, the emulsifier OP-10 is added at a later stage. At this time, the main structure of the asphalt has been basically formed. The emulsifier can better play its emulsifying role and can better emulsify the evenly mixed asphalt under a relatively stable temperature and environment. It can avoid the premature failure of the emulsifier or the loss of the best emulsifying performance under high temperature and complex reaction environment, and ensure that the emulsifier can effectively improve the performance of asphalt, such as improving the storage stability, construction and workability of asphalt, and adhesion to aggregates, so as to make the overall performance of the blended modified asphalt better.

[0035] In Comparative Example 6, the emulsifier OP-10 was added together with the modified No. 70 asphalt, which was affected by the high temperature and other ingredients during the early mixing process, resulting in a poor emulsification effect.

[0036] In comparative example 7, the emulsifier OP-10 is added when the nano-calcium carbonate is added. At this time, the system is still at a high temperature (above 170°C) and the components are still being added and mixed. It will also be affected by the high temperature and other components, resulting in a poor emulsification effect, thereby worsening the performance of the blended asphalt.

[0037] 8. Nano-calcium carbonate is used as a filler to increase the density of asphalt and improve the hardness and strength of asphalt. At the same time, nano-calcium carbonate can also improve the high-temperature stability of asphalt, reduce the formation of rutting, and enhance the anti-aging performance of asphalt to a certain extent. Organic bentonite makes asphalt have better deformation resistance and effectively improves the high-temperature performance of asphalt. Organic bentonite can also absorb light components in asphalt, reduce its volatilization at high temperature, and improve the stability of asphalt. Diatomaceous earth has a porous structure, which can absorb some components in asphalt, making the colloidal structure of asphalt more stable, improving the high-temperature stability of asphalt and enhancing the anti-rutting performance; at the same time, the presence of diatomaceous earth can also improve the low-temperature cracking resistance of asphalt to a certain extent, because it can relieve the stress generated inside the asphalt when the temperature changes. Polyethylene wax can improve the rheological properties of asphalt, reduce the brittleness of asphalt at low temperatures, improve its flexibility, and reduce the possibility of low-temperature cracking; and it can also improve the resistance of asphalt to water damage and prevent moisture from invading the interface between asphalt and aggregate. Anti-rutting agents are mainly used to improve the ability of asphalt pavement to resist rutting. Antioxidants are mainly used to prevent the oxidation and aging of asphalt. DETAILED DESCRIPTION

[0038] The present invention is further described below in conjunction with specific implementation cases, but the present invention is not limited to these embodiments.

[0039] Example 1

[0040] A blended modified asphalt comprises the following raw materials in parts by mass: 40 parts of No. 90 heavy traffic road petroleum asphalt, 30 parts of No. 70 road petroleum asphalt, 10 parts of natural rock asphalt, 0.4 parts of emulsifier OP-10, 3.5 parts of HDI-trimethylol hexyl lactone crosslinked polymer, 3.5 parts of phenylpropyl dimethyl siloxy silicate, 0.2 parts of vinyl-terminated polydimethylsiloxane, 2.2 parts of thermoplastic styrene-butadiene rubber, 4 parts of nano-scale calcium carbonate, 2.5 parts of organic bentonite, 3.5 parts of diatomaceous earth, 1 part of polyethylene wax, 0.4 parts of anti-rutting agent and 0.2 parts of antioxidant.

[0041] Among them, the particle size range of nano calcium carbonate is below 200nm. The median particle size of organic bentonite is 5μm. The median particle size of diatomaceous earth is 23μm. The median particle size of polyethylene wax is 7μm.

[0042] Among them, HDI-trimethylol hexyl lactone cross-linked polymer is used to pre-modify natural rock asphalt, and the modification method includes the following steps: heating the natural rock asphalt to a molten state, controlling the temperature at 160°C, adding HDI-trimethylol hexyl lactone cross-linked polymer under stirring conditions of 120r / min, heating to 185°C, and continuously stirring at 250r / min for 45 minutes to obtain modified rock asphalt.

[0043] Among them, phenylpropyl dimethylsiloxysilicate is used to pre-modify No. 70 road petroleum asphalt, and the modification method includes the following steps: heating No. 70 road petroleum asphalt to a molten state, controlling the temperature at 150°C, adding phenylpropyl dimethylsiloxysilicate under stirring conditions of 120r / min, raising the temperature to 170°C, and continuously stirring at 250r / min for 45 minutes to obtain modified No. 70 asphalt.

[0044] Among them, vinyl-terminated polydimethylsiloxane is pre-modified on thermoplastic styrene-butadiene rubber, and the modification method includes the following steps: cutting the thermoplastic styrene-butadiene rubber into small pieces with a side length of less than 3 cm, placing them in a reactor, heating them to 140°C, and after the thermoplastic styrene-butadiene rubber is softened, adding vinyl-terminated polydimethylsiloxane, and continuously stirring at 100 r / min for 80 minutes to maintain the softened state to obtain modified rubber.

[0045] The above-mentioned method for preparing a blended modified asphalt comprises the following steps:

[0046] S1: According to the mass fraction, No. 90 heavy road petroleum asphalt was heated to 150°C to melt, then the modified No. 70 asphalt in a molten state at 160°C was added, and stirred at 250r / min for 40min, then the modified rock asphalt in a molten state at 160°C was added, the temperature was controlled at 160°C, and stirred at 400r / min for 40min, then the modified rubber in a softened state at 140°C was added, the temperature was controlled at 170°C, and stirred at 400r / min for 50min, to obtain mixture A;

[0047] S2: Keep the temperature at 170℃, add nano-calcium carbonate, organic bentonite, diatomaceous earth, polyethylene wax and antioxidant to mixture A in sequence, stirring at 400r / min for 25min each time each ingredient is added; then raise the temperature to 182℃, add anti-rutting agent, and stir at 400r / min for 45s; then cool down to 155℃, add emulsifier OP-10, and stir at 400r / min for 8min to obtain blended modified asphalt.

[0048] Example 2

[0049] A blended modified asphalt comprises the following raw materials in parts by mass: 30 parts of No. 90 heavy traffic road petroleum asphalt, 20 parts of No. 70 road petroleum asphalt, 5 parts of natural rock asphalt, 0.3 parts of emulsifier OP-10, 2 parts of HDI-trimethylol hexyl lactone crosslinked polymer, 2 parts of phenylpropyl dimethyl siloxy silicate, 0.1 parts of vinyl-terminated polydimethylsiloxane, 1.5 parts of thermoplastic styrene-butadiene rubber, 2 parts of nano-scale calcium carbonate, 1 part of organic bentonite, 2 parts of diatomaceous earth, 0.5 parts of polyethylene wax, 0.3 parts of anti-rutting agent and 0.1 parts of antioxidant.

[0050] Among them, the particle size range of nano calcium carbonate is below 200nm. The median particle size of organic bentonite is 3μm. The median particle size of diatomaceous earth is 10μm. The median particle size of polyethylene wax is 2μm.

[0051] Among them, HDI-trimethylol hexyl lactone cross-linked polymer is used to pre-modify natural rock asphalt, and the modification method includes the following steps: heating the natural rock asphalt to a molten state, controlling the temperature at 150°C, adding HDI-trimethylol hexyl lactone cross-linked polymer under stirring conditions of 80r / min, heating to 180°C, and continuously stirring at 200r / min for 30 minutes to obtain modified rock asphalt.

[0052] Among them, phenylpropyl dimethylsiloxysilicate is used to pre-modify No. 70 road petroleum asphalt, and the modification method includes the following steps: heating No. 70 road petroleum asphalt to a molten state, controlling the temperature at 140°C, adding phenylpropyl dimethylsiloxysilicate under stirring conditions of 80r / min, raising the temperature to 160°C, and continuously stirring at 200r / min for 30 minutes to obtain modified No. 70 asphalt.

[0053] Among them, vinyl-terminated polydimethylsiloxane is pre-modified on thermoplastic styrene-butadiene rubber, and the modification method includes the following steps: cutting the thermoplastic styrene-butadiene rubber into small pieces with a side length of less than 3 cm, placing them in a reactor, heating them to 130°C, and after the thermoplastic styrene-butadiene rubber is softened, adding vinyl-terminated polydimethylsiloxane, and continuously stirring at 80r / min for 60 minutes to maintain the softened state to obtain modified rubber.

[0054] The above-mentioned method for preparing a blended modified asphalt comprises the following steps:

[0055] S1: According to the mass fraction, No. 90 heavy road petroleum asphalt was heated to 140°C for melting, then the modified No. 70 asphalt in a molten state at 150°C was added, and stirred at 200 r / min for 30 min, then the modified rock asphalt in a molten state at 150°C was added, the temperature was controlled at 150°C, and stirred at 300 r / min for 30 min, then the modified rubber in a softened state at 130°C was added, the temperature was controlled at 160°C, and stirred at 300 r / min for 40 min, to obtain mixture A;

[0056] S2: Keep the temperature at 160℃, add nano-calcium carbonate, organic bentonite, diatomaceous earth, polyethylene wax and antioxidant to mixture A in sequence, stirring at 300r / min for 20min each time each ingredient is added; then raise the temperature to 180℃, add anti-rutting agent, and stir at 300r / min for 30s; then cool down to 150℃, add emulsifier OP-10, and stir at 300r / min for 5min to obtain blended modified asphalt.

[0057] Example 3

[0058] A blended modified asphalt comprises the following raw materials in parts by mass: 35 parts of No. 90 heavy traffic road petroleum asphalt, 25 parts of No. 70 road petroleum asphalt, 8 parts of natural rock asphalt, 0.35 parts of emulsifier OP-10, 3 parts of HDI-trimethylol hexyl lactone crosslinked polymer, 3 parts of phenylpropyl dimethyl siloxy silicate, 0.15 parts of vinyl-terminated polydimethylsiloxane, 2 parts of thermoplastic styrene-butadiene rubber, 3 parts of nano-scale calcium carbonate, 2 parts of organic bentonite, 3 parts of diatomaceous earth, 0.6 parts of polyethylene wax, 0.35 parts of anti-rutting agent and 0.15 parts of antioxidant.

[0059] Among them, the particle size range of nano calcium carbonate is below 200nm. The median particle size of organic bentonite is 1μm. The median particle size of diatomaceous earth is 16μm. The median particle size of polyethylene wax is 10μm.

[0060] Among them, HDI-trimethylol hexyl lactone cross-linked polymer is used to pre-modify natural rock asphalt, and the modification method includes the following steps: heating the natural rock asphalt to a molten state, controlling the temperature at 150°C, adding HDI-trimethylol hexyl lactone cross-linked polymer under stirring conditions of 150r / min, heating to 180°C, and continuously stirring at 300r / min for 60 minutes to obtain modified rock asphalt.

[0061] Among them, phenylpropyl dimethylsiloxysilicate is used to pre-modify No. 70 road petroleum asphalt, and the modification method includes the following steps: heating No. 70 road petroleum asphalt to a molten state, controlling the temperature at 140°C, adding phenylpropyl dimethylsiloxysilicate under stirring conditions of 150r / min, raising the temperature to 160°C, and continuously stirring at 300r / min for 60 minutes to obtain modified No. 70 asphalt.

[0062] Among them, vinyl-terminated polydimethylsiloxane is pre-modified on thermoplastic styrene-butadiene rubber, and the modification method includes the following steps: cutting the thermoplastic styrene-butadiene rubber into small pieces with a side length of less than 3 cm, placing them in a reactor, heating them to 130°C, and after the thermoplastic styrene-butadiene rubber is softened, adding vinyl-terminated polydimethylsiloxane, and continuously stirring at 120r / min for 90 minutes to maintain the softened state to obtain modified rubber.

[0063] The above-mentioned method for preparing a blended modified asphalt comprises the following steps:

[0064] S1: According to the mass fraction, No. 90 heavy road petroleum asphalt was heated to 140°C for melting, and then the modified No. 70 asphalt in a molten state at 150°C was added, and stirred at 300 r / min for 50 min, and then the modified rock asphalt in a molten state at 150°C was added, the temperature was controlled at 150°C, and stirred at 500 r / min for 50 min, and then the modified rubber in a softened state at 130°C was added, the temperature was controlled at 160°C, and stirred at 500 r / min for 60 min to obtain mixture A;

[0065] S2: Keep the temperature at 160℃, add nano-calcium carbonate, organic bentonite, diatomaceous earth, polyethylene wax and antioxidant to mixture A in sequence, stirring at 500r / min for 30min each time each ingredient is added; then raise the temperature to 180℃, add the anti-rutting agent preheated to 180℃, and stir at 500r / min for 60s; then cool down to 150℃, add emulsifier OP-10, and stir at 500r / min for 10min to obtain blended modified asphalt.

[0066] Example 4

[0067] A blended modified asphalt comprises the following raw materials in parts by mass: 50 parts of No. 90 heavy traffic road petroleum asphalt, 40 parts of No. 70 road petroleum asphalt, 15 parts of natural rock asphalt, 0.5 parts of emulsifier OP-10, 5 parts of HDI-trimethylol hexyl lactone crosslinked polymer, 5 parts of phenylpropyl dimethyl siloxy silicate, 0.3 parts of vinyl-terminated polydimethylsiloxane, 3 parts of thermoplastic styrene-butadiene rubber, 6 parts of nano-scale calcium carbonate, 4 parts of organic bentonite, 5 parts of diatomaceous earth, 1.5 parts of polyethylene wax, 0.5 parts of anti-rutting agent and 0.3 parts of antioxidant.

[0068] Among them, the particle size range of nano calcium carbonate is below 200nm. The median particle size of organic bentonite is 10μm. The median particle size of diatomaceous earth is 42μm. The median particle size of polyethylene wax is 1μm.

[0069] Among them, HDI-trimethylol hexyl lactone cross-linked polymer is used to pre-modify natural rock asphalt, and the modification method includes the following steps: heating the natural rock asphalt to a molten state, controlling the temperature at 180°C, adding HDI-trimethylol hexyl lactone cross-linked polymer under stirring conditions of 150r / min, heating to 190°C, and continuously stirring at 300r / min for 60 minutes to obtain modified rock asphalt.

[0070] Among them, phenylpropyl dimethylsiloxysilicate is used to pre-modify No. 70 road petroleum asphalt, and the modification method includes the following steps: heating No. 70 road petroleum asphalt to a molten state, controlling the temperature at 160°C, adding phenylpropyl dimethylsiloxysilicate under stirring conditions of 150r / min, raising the temperature to 180°C, and continuously stirring at 300r / min for 60 minutes to obtain modified No. 70 asphalt.

[0071] Among them, vinyl-terminated polydimethylsiloxane is pre-modified on thermoplastic styrene-butadiene rubber, and the modification method includes the following steps: cutting the thermoplastic styrene-butadiene rubber into small pieces with a side length of less than 3 cm, placing them in a reactor, heating them to 150°C, and after the thermoplastic styrene-butadiene rubber is softened, adding vinyl-terminated polydimethylsiloxane, and continuously stirring at 120r / min for 90 minutes to maintain the softened state to obtain modified rubber.

[0072] The above-mentioned method for preparing a blended modified asphalt comprises the following steps:

[0073] S1: According to the mass fraction, No. 90 heavy road petroleum asphalt was heated to 160°C for melting, then the modified No. 70 asphalt in a molten state at 170°C was added, and stirred at 300 r / min for 50 min, then the modified rock asphalt in a molten state at 170°C was added, the temperature was controlled at 170°C, and stirred at 500 r / min for 50 min, then the modified rubber in a softened state at 150°C was added, the temperature was controlled at 180°C, and stirred at 500 r / min for 60 min, to obtain mixture A;

[0074] S2: Keep the temperature at 180℃, add nano-calcium carbonate, organic bentonite, diatomaceous earth, polyethylene wax and antioxidant to mixture A in sequence, and stir at 500r / min for 30min each time each ingredient is added; then raise the temperature to 185℃, add the anti-rutting agent preheated to 185℃, and stir at 500r / min for 60s; then cool down to 160℃, add emulsifier OP-10, and stir at 500r / min for 10min to obtain blended modified asphalt.

[0075] Example 5

[0076] A blended modified asphalt comprises the following raw materials in parts by mass: 45 parts of No. 90 heavy traffic road petroleum asphalt, 35 parts of No. 70 road petroleum asphalt, 12 parts of natural rock asphalt, 0.45 parts of emulsifier OP-10, 4 parts of HDI-trimethylol hexyl lactone crosslinked polymer, 4 parts of phenylpropyl dimethyl siloxy silicate, 0.25 parts of vinyl-terminated polydimethylsiloxane, 2.5 parts of thermoplastic styrene-butadiene rubber, 5 parts of nano-scale calcium carbonate, 3 parts of organic bentonite, 4 parts of diatomaceous earth, 1.2 parts of polyethylene wax, 0.45 parts of anti-rutting agent and 0.25 parts of antioxidant.

[0077] Among them, the particle size range of nano calcium carbonate is below 200nm. The median particle size of organic bentonite is 8μm. The median particle size of diatomaceous earth is 50μm. The median particle size of polyethylene wax is 7μm.

[0078] Among them, HDI-trimethylol hexyl lactone cross-linked polymer is used to pre-modify natural rock asphalt, and the modification method includes the following steps: heating the natural rock asphalt to a molten state, controlling the temperature at 180°C, adding HDI-trimethylol hexyl lactone cross-linked polymer under stirring conditions of 80r / min, heating to 190°C, and continuously stirring at 200r / min for 30 minutes to obtain modified rock asphalt.

[0079] Among them, phenylpropyl dimethylsiloxysilicate is used to pre-modify No. 70 road petroleum asphalt, and the modification method includes the following steps: heating No. 70 road petroleum asphalt to a molten state, controlling the temperature at 160°C, adding phenylpropyl dimethylsiloxysilicate under stirring conditions of 80r / min, raising the temperature to 180°C, and continuously stirring at 200r / min for 30 minutes to obtain modified No. 70 asphalt.

[0080] Among them, vinyl-terminated polydimethylsiloxane is pre-modified on thermoplastic styrene butadiene rubber, and the modification method includes the following steps: cutting the thermoplastic styrene butadiene rubber into small pieces with a side length of less than 3 cm, placing them in a reactor, heating them to 150°C, and after the thermoplastic styrene butadiene rubber is softened, adding vinyl-terminated polydimethylsiloxane, and continuously stirring at 80r / min for 60 minutes to maintain the softened state to obtain modified rubber.

[0081] The above-mentioned method for preparing a blended modified asphalt comprises the following steps:

[0082] S1: According to the mass fraction, No. 90 heavy road petroleum asphalt was heated to 160°C for melting, then the modified No. 70 asphalt in a molten state at 170°C was added, and stirred at 200 r / min for 30 min, then the modified rock asphalt in a molten state at 170°C was added, the temperature was controlled at 170°C, and stirred at 300 r / min for 30 min, then the modified rubber in a softened state at 150°C was added, the temperature was controlled at 180°C, and stirred at 300 r / min for 40 min, to obtain mixture A;

[0083] S2: Keep the temperature at 180℃, add nano-calcium carbonate, organic bentonite, diatomaceous earth, polyethylene wax and antioxidant to mixture A in sequence, stirring at 300r / min for 20min each time each ingredient is added; then raise the temperature to 185℃, add the anti-rutting agent preheated to 185℃, and stir at 300r / min for 30s; then cool down to 160℃, add emulsifier OP-10, and stir at 300r / min for 5min to obtain blended modified asphalt.

[0084] In the above embodiments: No. 90 heavy traffic road petroleum asphalt comes from Maoming Zhengcheng Petrochemical Co., Ltd., 90# asphalt; the batch indicators of No. 90 heavy traffic road petroleum asphalt are: softening point 44°C, 15°C elongation 112cm, flash point 258°C. No. 70 road petroleum asphalt comes from Maoming Zhengcheng Petrochemical Co., Ltd., 70# asphalt; the batch indicators of No. 70 road petroleum asphalt are: softening point 47°C, 15°C elongation 147cm, flash point 264°C, 60°C dynamic viscosity 193Pa·s. Natural rock asphalt comes from Hebei Haizuan Petrochemical Co., Ltd., model 0011. Emulsifier op-10 is alkylphenol polyoxyethylene ether, which comes from Hai'an Petrochemical Plant in Jiangsu Province. HDI-trimethylol hexyl lactone crosslinked polymer comes from Wuhan Huaxiang Kejie Biotechnology Co., Ltd. Phenylpropyl dimethylsiloxysilicate comes from Shanghai Pu'en Biochemical Technology Co., Ltd. Vinyl-terminated polydimethylsiloxane comes from Huangshan Qiangli Chemical Co., Ltd., model QL-2311VDV70. Thermoplastic styrene-butadiene rubber comes from Sinopec Baling Petrochemical Co., Ltd., model YH-815. Organic bentonite comes from Lingshou County Jinyuan Mining Processing Plant. Polyethylene wax comes from Dongguan Shanyi Plastic Co., Ltd., specification WL-95. Anti-rutting agent comes from Jinan Shengquan Group Co., Ltd., model SQBIO R2. Antioxidant is antioxidant 1010, which comes from Dongguan Shanyi Plastic Co., Ltd. Emulsifier op-10 is added,

[0085] Comparative Example 1

[0086] No HDI-trimethylol hexyllactone crosslinked polymer is added to the blended modified asphalt, and the mass fraction of HDI-trimethylol hexyllactone crosslinked polymer is replaced by No. 90 heavy road petroleum asphalt; the natural rock asphalt is not pre-modified; in the preparation method, the modified rock asphalt in the molten state is replaced by the natural rock asphalt in the molten state; other parameters and methods are the same as in Example 1.

[0087] Comparative Example 2

[0088] No phenylpropyl dimethylsiloxysilicate is added to the blended modified asphalt, and the mass fraction of phenylpropyl dimethylsiloxysilicate is replaced by No. 90 heavy traffic road petroleum asphalt; No. 70 road petroleum asphalt is not pre-modified; in the preparation method, the modified No. 70 asphalt in the molten state is replaced by the No. 70 road petroleum asphalt in the molten state; other parameters and methods are the same as in Example 1.

[0089] Comparative Example 3

[0090] No vinyl-terminated polydimethylsiloxane is added to the blended modified asphalt, and the mass fraction of vinyl-terminated polydimethylsiloxane is replaced by No. 90 heavy-duty road petroleum asphalt; the thermoplastic styrene-butadiene rubber is not pre-modified; in the preparation method, the modified rubber in a softened state is replaced by the thermoplastic styrene-butadiene rubber in a softened state; other parameters and methods are the same as in Example 1.

[0091] Comparative Example 4

[0092] No HDI-trimethylol hexyl lactone crosslinked polymer and no phenylpropyl dimethyl siloxy silicate are added to the blended modified asphalt; the mass fractions of each component are replaced by No. 90 heavy traffic road petroleum asphalt; neither natural rock asphalt nor No. 70 road petroleum asphalt is modified; in the preparation method, the modified rock asphalt in the molten state is replaced by the natural rock asphalt in the molten state, and the modified No. 70 asphalt in the molten state is replaced by the No. 70 road petroleum asphalt in the molten state; other parameters and methods are the same as in Example 1.

[0093] Comparative Example 5

[0094] No HDI-trimethylol hexyl lactone crosslinked polymer, phenylpropyl dimethylsiloxysilicate, or vinyl-terminated polydimethylsiloxane is added to the blended modified asphalt; the mass fraction of each component is replaced by No. 90 heavy traffic road petroleum asphalt; natural rock asphalt, No. 70 road petroleum asphalt, and thermoplastic styrene-butadiene rubber are not modified; in the preparation method, the modified rock asphalt in a molten state is replaced by natural rock asphalt in a molten state, the modified No. 70 asphalt in a molten state is replaced by No. 70 road petroleum asphalt in a molten state, and the modified rubber in a softened state is replaced by thermoplastic styrene-butadiene rubber in a softened state; other parameters and methods are the same as in Example 1.

[0095] Comparative Example 6

[0096] In the preparation method, the time of adding the emulsifier OP-10 was changed: in S1, the emulsifier OP-10 was added together with the modified No. 70 asphalt; other parameters and methods were the same as in Example 1.

[0097] Comparative Example 7

[0098] In the preparation method, the time of adding the emulsifier OP-10 was changed: when the nano-calcium carbonate was added, the emulsifier OP-10 was added together; other parameters and methods were the same as in Example 1.

[0099] The performance of the blended modified asphalt prepared in the above embodiments and comparative examples was tested.

[0100] Asphalt samples: various blended modified asphalts mentioned above. Asphalt mixture samples: AC-13 type asphalt concrete containing 6 wt% of various blended modified asphalts mentioned above.

[0101] According to the testing methods of JTG E20 "Testing Procedures for Asphalt and Asphalt Mixtures in Highway Engineering" and DG / TJ 08-87 "Construction and Acceptance Procedures for Finished and Semi-finished Products of Roads and Drainage Pipelines", various blended modified asphalt samples and asphalt concrete samples were tested for the following indicators: residual stability was tested by the immersion Marshall test method (asphalt concrete); 60°C dynamic stability was tested by the high temperature stability test method (asphalt concrete); 25°C elastic recovery was tested by the ductility tester (asphalt concrete), and the middle part of the test mold was replaced with a straight side mold; initial strength and molding strength were tested by the Marshall strength test method (asphalt concrete); tensile strength ratio was tested by the freeze-thaw splitting test method (asphalt concrete); 163°C mass loss rate was tested by the cohesiveness test method (asphalt). The test results are shown in Table 1 below:

[0102] Table 1 Performance index test results

[0103]

[0104]

[0105] It can be seen from the above results that the blended modified asphalts of Examples 1 to 5 have good performance. It can be seen from the comparison of the results of Comparative Examples 1 to 3 that the modified asphalt and rubber can improve the blending uniformity when mixed with other asphalts and additives, and the chemical and physical compatibility is enhanced. The modified asphalt and rubber can effectively improve the high temperature stability and residual stability of the blended asphalt mixture, enhance the cohesion of the blended asphalt, help maintain the elastic recovery performance of the blended asphalt, help build a denser structure, and improve the strength of use.

[0106] From the comparison of the results of Comparative Example 4, it can be seen that the two modified asphalts (natural rock asphalt and No. 70 road petroleum asphalt) cooperate with each other to further improve the blending uniformity; the synergistic effect of the two makes the blended asphalt have significant improvements in dynamic stability, residual stability and elastic recovery rate at 60°C, forming a more stable high-temperature structure that effectively resists rutting; the two synergistically enhance the cohesion of asphalt and improve the tensile strength ratio.

[0107] From the comparison of the results of Comparative Example 5, it can be seen that the three modified components (natural rock asphalt, No. 70 road petroleum asphalt and thermoplastic styrene-butadiene rubber) work together to make the asphalt reach a highly uniform state during the mixing process, better blend with each other, form a homogeneous system, and construct an efficient high-temperature deformation resistance network, which greatly improves the dynamic stability and residual stability; the modified components each play their elastic advantages to achieve a higher level of elastic recovery rate; they complement and fill each other during the molding process, reduce the porosity of the asphalt, and make the overall structure more compact and firm, thereby greatly improving the molding strength; they bear and transmit stress from different angles to form a tough overall structure, which significantly improves the tensile strength ratio.

[0108] In Comparative Example 6, the emulsifier OP-10 is added together with the modified No. 70 asphalt, which will be affected by the high temperature and other ingredients in the early mixing process, resulting in a poor emulsification effect, thereby worsening the performance of the blended asphalt.

[0109] In Comparative Example 7, the emulsifier OP-10 is added when the nano-calcium carbonate is added, which is also affected by the high temperature and other ingredients, resulting in a poor emulsification effect, thereby deteriorating the performance of the blended asphalt.

Claims

1. A blended modified asphalt, characterized in that: The blended modified asphalt includes the following raw materials in parts by mass: 30 to 50 parts of No. 90 heavy traffic road petroleum asphalt, 20 to 40 parts of No. 70 road petroleum asphalt, 5 to 15 parts of natural rock asphalt, 0.3 to 0.5 parts of emulsifier OP-10, 2 to 5 parts of HDI-trimethylol hexyl lactone cross-linked polymer, 2 to 5 parts of phenylpropyl dimethylsiloxy silicate, 0.1 to 0.3 parts of vinyl-terminated polydimethylsiloxane, 1.5 to 3 parts of thermoplastic styrene-butadiene rubber, 2 to 6 parts of nano-calcium carbonate, 1 to 4 parts of organic bentonite, 2 to 5 parts of diatomaceous earth, 0.5 to 1.5 parts of polyethylene wax, 0.3 to 0.5 parts of anti-rutting agent and 0.1 to 0.3 parts of antioxidant.

2. The blended modified asphalt according to claim 1, characterized in that: The particle size range of the nano-scale calcium carbonate is below 200 nm.

3. The blended modified asphalt according to claim 1, characterized in that: The median particle size of the organic bentonite is 1 μm to 10 μm.

4. The blended modified asphalt according to claim 1, characterized in that: The median particle size of the diatomaceous earth is 10 μm to 50 μm.

5. The blended modified asphalt according to claim 1, characterized in that: The median particle size of the polyethylene wax is 1 μm to 10 μm.

6. The blended modified asphalt according to claim 1, characterized in that: The HDI-trimethylol hexyl lactone cross-linked polymer is used to pre-modify natural rock asphalt, and the modification method includes the following steps: heating the natural rock asphalt to a molten state, controlling the temperature at 150°C to 180°C, adding the HDI-trimethylol hexyl lactone cross-linked polymer under stirring conditions of 80r / min to 150r / min, raising the temperature to 180°C to 190°C, and continuously stirring at 200r / min to 300r / min for 30min to 60min to obtain modified rock asphalt.

7. The blended modified asphalt according to claim 6, characterized in that: The phenylpropyl dimethylsiloxysilicate is used to pre-modify No. 70 road petroleum asphalt, and the modification method comprises the following steps: heating No. 70 road petroleum asphalt to a molten state, controlling the temperature at 140°C to 160°C, adding phenylpropyl dimethylsiloxysilicate under stirring conditions of 80r / min to 150r / min, raising the temperature to 160°C to 180°C, and continuously stirring at 200r / min to 300r / min for 30min to 60min to obtain modified No. 70 asphalt.

8. The blended modified asphalt according to claim 7, characterized in that: The vinyl-terminated polydimethylsiloxane is used to pre-modify the thermoplastic styrene-butadiene rubber. The modification method comprises the following steps: cutting the thermoplastic styrene-butadiene rubber into small pieces, placing the pieces in a reaction kettle, heating the pieces to 130° C. to 150° C., adding the vinyl-terminated polydimethylsiloxane after the thermoplastic styrene-butadiene rubber is softened, continuously stirring the pieces at 80 r / min to 120 r / min for 60 min to 90 min, and maintaining the softened state to obtain the modified rubber.

9. A method for preparing a blended modified asphalt, used for preparing the blended modified asphalt according to claim 8, characterized in that: The steps include: S1: According to the mass fraction, heat No. 90 heavy traffic road petroleum asphalt to 140℃~160℃ to melt, then add the molten modified No. 70 asphalt, stir at 200r / min~300r / min for 30min~50min, then add the molten modified rock asphalt, control the temperature at 150℃~170℃, stir at 300r / min~500r / min for 30min~50min, then add the softened modified rubber, control the temperature at 160℃~180℃, stir at 300r / min~500r / min for 40min~60min, and obtain the mixture A; S2: Keep the temperature at 160℃~180℃, add nano calcium carbonate, organic bentonite, diatomaceous earth, polyethylene wax and antioxidant to the mixture A in sequence, stir at 300r / min~500r / min for 20min~30min each time adding one ingredient; then raise the temperature to 180℃~185℃, add anti-rutting agent, and stir at 300r / min~500r / min for 30s~60s; Then the temperature is lowered to 150°C to 160°C, emulsifier OP-10 is added, and stirring is carried out at a speed of 300r / min to 500r / min for 5min to 10min to obtain blended modified asphalt.

10. The method for preparing a blended modified asphalt according to claim 9, characterized in that: In S1, the modified No. 70 asphalt in the molten state is in the molten state at 150°C to 170°C, the modified rock asphalt in the molten state is in the molten state at 150°C to 170°C, and the modified rubber in the softened state is in the molten state at 130°C to 150°C; in S2, the anti-rutting agent is preheated and melted at 180°C to 185°C.

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