Waterproof modified asphalt and preparation method thereof

Abstract

The invention provides waterproof modified asphalt and a preparation method thereof, and belongs to the technical field of modified asphalt. The waterproof modified asphalt comprises matrix asphalt, a biomass viscosity reducer, maleic anhydride, a modifier and a filler, the biomass viscosity reducer comprises a combination of cardanol and grease, and the grease is palm oil byproduct grease. According to the invention, a mode of compounding cardanol and grease is used for replacing a petroleum softening agent in the modified asphalt, so that the viscosity of the waterproof modified asphalt can be obviously reduced on the premise of ensuring the performance of the waterproof modified asphalt; the biomass viscosity reducer used in the method is environment-friendly and renewable, and resource waste is avoided.

Description

Technical Field

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

[0002] Modified asphalt has good high-temperature stability, low-temperature crack resistance and durability, and is widely used in building waterproofing, road engineering, and dam repair.

[0003] Modified asphalt typically has a high viscosity, making construction more difficult, especially in low-temperature environments. High-viscosity modified asphalt also makes it difficult to fully wet the substrate surface, resulting in reduced interfacial bond strength. This can lead to the risk of peeling or shedding during use due to stress or temperature fluctuations.

[0004] In the related art, petroleum-based softeners are usually used as viscosity improvers for modified asphalt. However, petroleum-based softeners require the use of non-renewable resources, resulting in a waste of resources, and the effect of petroleum-based softeners on improving the viscosity of modified asphalt is relatively limited. Summary of the Invention

[0005] In view of this, in order to at least partially solve at least one of the above-mentioned technical problems, the present invention provides a waterproof modified asphalt and a preparation method thereof.

[0006] According to an embodiment of one aspect of the present invention, a waterproof modified asphalt is provided, comprising: base asphalt, a biomass viscosity reducer, maleic anhydride, a modifier, and a filler; the biomass viscosity reducer comprises a combination of cardanol and oil, and the oil is a palm oil by-product oil.

[0007] In some embodiments, the mass ratio of cardanol to oil is 3:7 to 1:1.

[0008] In some embodiments, the oil has a freezing point of 0-10°C, a flash point ≥200°C, and an acid value ≤10.

[0009] In some embodiments, the modifier is a combination of styrene-butadiene-styrene thermoplastic elastomer, solution-polymerized styrene-butadiene rubber, and rubber powder.

[0010] In some embodiments, the mass ratio of styrene-butadiene-styrene thermoplastic elastomer, solution-polymerized styrene-butadiene rubber, and rubber powder is (1-1.5): (1-1.5): (13-17); and cardanol includes crude or refined cardanol.

[0011] In some embodiments, the matrix asphalt includes a first matrix asphalt and a second matrix asphalt; the second matrix asphalt has a higher softening point than the first matrix asphalt, and the second matrix asphalt has a lower needle penetration than the first matrix asphalt.

[0012] In some embodiments, based on 100 parts by total weight, the base asphalt is 39 to 45 parts, the biomass viscosity reducer is 6 to 12 parts, the maleic anhydride is 0.1 to 0.5 parts, the modifier is 15 to 20 parts, and the filler is 28 to 32 parts.

[0013] According to an embodiment of another aspect of the present invention, a method for preparing the waterproof modified asphalt as described above is provided, comprising: mixing and melting base asphalt and a biomass viscosity reducer to obtain a mixture; adding maleic anhydride and a modifier to the mixture respectively, heating and mixing, to obtain an initial waterproof modified asphalt; adding a filler to the initial waterproof modified asphalt and mixing and stirring to obtain a waterproof modified asphalt.

[0014] In some embodiments, the matrix asphalt and the biomass viscosity reducer are mixed and melted to obtain a mixture, which includes: melting the first matrix asphalt between 130 and 150° C., adding the second matrix asphalt to the first matrix asphalt, and heating the temperature to 160 to 180° C. to obtain molten matrix asphalt; adding the biomass viscosity reducer to the molten matrix asphalt at 160 to 180° C. and stirring to obtain a mixture.

[0015] In some embodiments, maleic anhydride and a modifier are separately added to the mixture, and the mixture is heated and mixed to obtain an initial waterproof modified asphalt, which includes: adding maleic anhydride, styrene-butadiene-styrene thermoplastic elastomer, and solution polystyrene-butadiene rubber to the mixture, shearing at 180-200° C. and 4000-6000 rpm for 0.5-1.5 h to obtain a modified mixture; adding rubber powder to the modified mixture in batches, and shearing at 180-200° C. and 1000-2000 rpm for 0.5-1.5 h to obtain an initial waterproof modified asphalt.

[0016] In the waterproof modified asphalt according to the present invention, the biomass viscosity reducer formed by combining cardanol and oil can significantly reduce the viscosity of the waterproof modified asphalt while maintaining performance similar to that of a petroleum-based softener. Furthermore, both of these materials are derived from biomass, which is environmentally friendly and renewable, thus avoiding the waste of non-renewable resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The above and other objects, features and advantages of the present invention will become more apparent through the following description of the embodiments of the present invention with reference to the accompanying drawings, in which:

[0018] Figure 1 A flow chart of a method for preparing waterproof modified asphalt according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0019] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the present invention. In the following detailed description, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of embodiments of the present invention. However, it is apparent that one or more embodiments may also be implemented without these specific details. In addition, in the following description, descriptions of known structures and technologies are omitted to avoid unnecessary confusion of the concept of the present invention.

[0020] The terms used herein are only for describing specific embodiments and are not intended to limit the present invention. The term "comprising" used herein indicates the existence of features, steps, operations, but does not exclude the existence or addition of one or more other features.

[0021] When expressions such as “at least one of A, B, and C, etc.” are used, they should generally be interpreted in accordance with the meaning commonly understood by those skilled in the art (for example, “a system having at least one of A, B, and C” should include but is not limited to systems having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, and C, etc.). When expressions such as “at least one of A, B, or C, etc.” are used, they should generally be interpreted in accordance with the meaning commonly understood by those skilled in the art (for example, “a system having at least one of A, B, or C” should include but is not limited to systems having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, and C, etc.).

[0022] In the related art, petroleum-based softeners are usually used to reduce the viscosity of modified asphalt. However, petroleum-based softeners are derived from petroleum, resulting in excessive consumption of non-renewable resources.

[0023] In the process of realizing the concept of the present invention, it was found that by adding grease to the modified asphalt, the viscosity of the modified asphalt can be reduced to a large extent, but it has a certain impact on the performance of the modified asphalt, especially the flexibility at low temperatures.

[0024] Furthermore, by adding a mixture of oil and cardanol as a biomass viscosity reducer to the modified asphalt, the modified asphalt can be reduced while having better performance, which is helpful to replace petroleum-based softeners for application promotion.

[0025] Specifically, according to an embodiment of one aspect of the present invention, a waterproof modified asphalt is provided, comprising: base asphalt, a biomass viscosity reducer, maleic anhydride, a modifier, and a filler; the biomass viscosity reducer comprises a combination of cardanol and oil, and the oil is a palm oil by-product oil.

[0026] According to an embodiment of the present invention, the cardanol in the biomass viscosity reducer is a polar substance, and the phenolic hydroxyl group in the cardanol has a strong polarity, which can destroy the polar aggregation between the matrix asphalt molecules. The long alkyl chain at one end of the cardanol is dissolved in or has affinity with the non-polar components in grease and asphalt, and the phenolic hydroxyl group at the other end has affinity with polar modifiers and fillers. Grease, especially palm oil by-product grease, can help cardanol to be better dispersed in the matrix asphalt matrix. Its main components are triglycerides and free fatty acids, which are non-polar as a whole and can dilute the colloidal system of the matrix asphalt like a solvent or lubricant, reduce the friction between molecules, and further reduce the overall viscosity.

[0027] Combining polar cardanol with a nonpolar oil significantly improves the compatibility between the polar modifier / filler and the nonpolar asphalt matrix, preventing phase separation and ensuring the uniformity and storage stability of the waterproof modified asphalt system. Without the addition of oil, excessive cardanol, due to its strong polarity, may accumulate in the base asphalt, resulting in higher viscosity and higher energy consumption during subsequent use. Without cardanol, the oil's insufficient affinity for polar additives makes it difficult to effectively improve the performance of the resulting waterproof modified asphalt.

[0028] Furthermore, based on the combination of the two materials in the biomass viscosity reducer, the waterproof modified asphalt maintains good flexibility and deformation ability within a wider temperature range, especially under low temperature conditions, which is particularly important for it to be used as a waterproof material to resist deformation and cracking of the base layer.

[0029] It should be noted that the phenolic hydroxyl groups of cardanol can undergo esterification with maleic anhydride. The introduction of cardanol increases the number of active sites for interaction between the asphalt system and maleic anhydride, helping maleic anhydride more effectively function as a compatibilizer and coupling agent, enhancing the effectiveness of modifiers and fillers in asphalt. Cardanol is derived from cashew nut shell liquid, an agricultural byproduct; oils and fats are derived from palm oil byproducts, both of which are renewable resources. The combination of these two as a biomass viscosity reducer significantly reduces the use of traditional petroleum-based viscosity reducers, meeting the requirements of green chemistry and sustainable development.

[0030] The base asphalt of the present invention serves as a waterproof foundation layer. The addition of maleic anhydride promotes uniform dispersion of fillers and modifiers, maintaining flexibility at low temperatures, preventing brittle cracking, and enhancing waterproofing. The addition of a biomass viscosity reducer strengthens the chemical bond between the asphalt layer and the base layer, further preventing water seepage at the interface and providing a stronger anchoring effect.

[0031] In some embodiments, the filler includes at least one of limestone powder (hereinafter referred to as stone powder), dolomite powder, and natural rock powder. Limestone powder is preferred, and stone powder with a mesh size of 100 to 300 is more preferred, such as 100 mesh, 200 mesh, or 300 mesh.

[0032] In some embodiments, the mass ratio of cardanol to oil is 3:7~1:1. Adjusting cardanol within the above range ensures a sufficient amount of polar phenolic hydroxyl groups, effectively destroying the aggregate structure of asphaltene and reducing viscosity; cardanol can also react with maleic anhydride to generate a compatibilizer, anchoring the filler and the base layer to enhance adhesion. Adjusting the proportion of oil within the above range provides sufficient non-polar grafting, and can dissolve the long alkyl chain of cardanol, reduce its self-aggregation phenomenon, and is highly compatible with the matrix asphalt, further avoiding phase separation. When the ratio of the two is lower than the aforementioned range, the polar phenolic hydroxyl group is insufficient, the filler is easy to agglomerate, and the interfacial bonding is weak; when the ratio is higher than the aforementioned range, the polarity of the asphalt system is too strong, the compatibility with the asphalt is reduced, and stratification is prone to occur.

[0033] Optionally, the mass ratio of cardanol to oil is 3:7, 3.5:6.5, 4:6, 4.5:5.5 or 1.1, or a range consisting of any two of the above values.

[0034] In some embodiments, the grease has a pour point of 0-10°C. A pour point within this range indicates that the grease is liquid at room temperature, facilitating construction. If the pour point is too high, the grease will crystallize and precipitate during low-temperature construction, losing its viscosity-reducing effect. If the pour point is too low, the high-temperature stability of the asphalt decreases. A flash point of ≥200°C ensures the grease is relatively stable at the typical asphalt processing temperature (160-180°C), ensuring production safety. An unstable acid value of ≤10 effectively regulates the corrosion and aging resistance of the asphalt, slowing the aging and hardening of the asphalt and maintaining long-term adhesion and sealing properties.

[0035] In some embodiments, the modifier is a combination of styrene-butadiene-styrene thermoplastic elastomer (SBS), solution-polymerized styrene-butadiene rubber (SSBR), and rubber powder. SBS constructs an elastic network skeleton, which helps improve the overall mechanical properties. When SSBR and SBS are blended, they can form an interpenetrating network structure, improving low-temperature tensile properties. Rubber powder can be understood as waste tire rubber powder, etc., which is a solid waste recycling method that reduces the modified asphalt's dependence on virgin rubber and reduces material costs. As a rigid filler, rubber powder can be dispersed in asphalt to physically hinder crack propagation, further swell and strengthen the structure, and improve impact resistance (for example, during construction).

[0036] In some embodiments, the mass ratio of styrene-butadiene-styrene thermoplastic elastomer, solution-polymerized styrene-butadiene rubber, and rubber powder is (1-1.5):(1-1.5):(13-17). This arrangement helps balance high- and low-temperature performance. SBS enhances high-temperature stability, while SSBR enhances low-temperature crack resistance. The two rubbers form an interpenetrating network, improving the overall strength and elasticity of the asphalt. The aforementioned rubber powder ratio can improve the stability of the asphalt and enhance its resistance to fatigue cracking.

[0037] In some embodiments, cardanol comprises crude or refined cardanol. Crude cardanol can be understood as having a cardanol content of 60% or more by weight and a specific gravity of 0.98 or less; refined cardanol can be understood as having a cardanol content of 80% or more by weight. It should be noted that a higher cardanol content results in a stronger polar effect, which can improve compatibility and dispersibility, and also provide better stability.

[0038] In some embodiments, the matrix asphalt includes a first matrix asphalt and a second matrix asphalt; wherein the first matrix asphalt may be 70# asphalt, having a softening point of about 45-55°C and a needle penetration of 60-80. The softening point of the second matrix asphalt is higher than that of the first matrix asphalt, and the needle penetration of the second matrix asphalt is lower than that of the first matrix asphalt. The second matrix asphalt may use hard asphalt, having a softening point ≥100°C and a needle penetration <10. In this way, the matrix asphalt is combined using the above-mentioned two asphalts of different hardness, and the rigidity of the second matrix asphalt is used to improve the high-temperature rutting resistance of the mixture, while the flexibility of the first matrix asphalt is used to maintain the low-temperature cracking resistance of the matrix asphalt, making construction easier. By complementing the performance of the two, the asphalt performs more evenly over a wide temperature range and is widely used in common application scenarios of asphalt.

[0039] In some embodiments, based on 100 parts by weight, the base asphalt comprises 39-45 parts, the biomass viscosity reducer comprises 6-12 parts, the maleic anhydride comprises 0.1-0.5 parts, the modifier comprises 15-20 parts, and the filler comprises 28-32 parts. The waterproof modified asphalt formulation of the present invention significantly improves the workability of the asphalt by reducing viscosity while also addressing environmental concerns. The biomass viscosity reducer significantly reduces the viscosity of the modified asphalt system at application temperature, improving workability in all aspects of the process (particularly mixing, pumping, paving, and compacting), resulting in energy conservation and environmental protection.

[0040] More preferably, the biomass viscosity reducer is present in an amount of 9 to 11 parts, for example, 9, 10, or 11 parts, or a range consisting of any two of these values. This further reduces the viscosity of the waterproof modified asphalt while ensuring better performance.

[0041] According to another embodiment of the present invention, a method for preparing the waterproof modified asphalt as described above is provided. Figure 1 A flow chart showing a method for preparing waterproof modified asphalt according to an embodiment of the present invention is shown. Figure 1 As shown, it includes operations S101 to S103.

[0042] In operation S101, base asphalt and biomass viscosity reducer are mixed and melted to obtain a mixture.

[0043] In operation S102, maleic anhydride and a modifier are added to the mixture respectively, and the mixture is heated and mixed to obtain an initial waterproof modified asphalt.

[0044] In operation S103, fillers are added to the initial waterproof modified asphalt and mixed and stirred to obtain waterproof modified asphalt.

[0045] According to an embodiment of the present invention, a biomass viscosity reducer is added in operation S101. The cardanol and oil combination in the biomass viscosity reducer forms a polar-nonpolar synergistic weakening of the intermolecular force of asphalt, reduces the viscosity in the molten state, makes feeding and stirring more efficient, and helps to ensure the uniform distribution of raw materials in the mixture. In operation S102, maleic anhydride and a modifier are added to help trigger a cross-linking reaction, promote mild cross-linking between the modifiers, and improve the elasticity, heat resistance and aging resistance of the asphalt. The rubber powder expands by adsorbing the light components in the asphalt to form an elastic network, thereby improving the overall strength of the waterproof modified asphalt. In operation S103, fillers are added. By filling the fillers in the alternating gaps of the asphalt, the volume expansion at high temperature and the contraction at low temperature are suppressed, thereby reducing the risk of cracking during subsequent applications.

[0046] In some embodiments, operation S101 includes sub-operations S1011 - S1012 .

[0047] In sub-operation S1011, the first matrix asphalt is melted at 130-150°C, the second matrix asphalt is added to the first matrix asphalt, and the temperature is raised to 160-180°C to obtain molten matrix asphalt.

[0048] In sub-operation S1012, a biomass viscosity reducer is added to the molten base asphalt at 160-180° C. and stirred to obtain a mixture.

[0049] In some embodiments, melting the two base asphalts using a gradient temperature ramp facilitates uniform miscibility and avoids localized overheating caused by large temperature differences. This temperature range ensures complete asphalt melting while remaining below the critical temperature for thermal oxidative aging (typically >200°C), balancing asphalt melting efficiency with material stability. At higher temperatures, asphalt is in a low-viscosity liquid state. Adding a biomass viscosity reducer facilitates full miscibility with the asphalt, reducing dispersion time and enhancing viscosity reduction effectiveness.

[0050] In some implementations, operation S102 includes sub-operations S1021 - S1022 .

[0051] In sub-operation S1021, maleic anhydride, styrene-butadiene-styrene thermoplastic elastomer, and solution polystyrene-butadiene rubber are added to the mixture, and sheared at 180-200° C. and 4000-6000 rpm for 0.5-1.5 h to obtain a modified mixture.

[0052] In sub-operation S1022, the rubber powder is added to the modified mixture in batches, and sheared at 180-200°C and 1000-2000 rpm for 0.5-1.5 hours to obtain an initial waterproof modified asphalt.

[0053] In some embodiments, at the aforementioned temperature, the viscosity of the asphalt is significantly reduced, allowing molecular motion and polymerization, providing kinetic conditions for the grafting reaction between maleic anhydride and SBS / SSBR, and facilitating the formation of SBS / SSBR agglomerates. When preparing the modified mixture, the SBS / SSBR agglomerates are broken into nano-sized particles by shearing at the aforementioned rotational speed, ensuring that the modifier is evenly dispersed in the asphalt in the form of micron-sized particles to avoid agglomeration. By adding rubber powder, costs can be reduced and it is more environmentally friendly. The added rubber powder can be dispersed in the modified mixture to form physical cross-linking points, thereby improving overall elasticity and fatigue cracking resistance.

[0054] In a specific embodiment, the waterproof modified asphalt can be prepared by the following steps.

[0055] Melt 70# asphalt at 130-150°C, add hard asphalt, and heat to 160-180°C to obtain molten base asphalt. Add biomass viscosity reducer to the molten base asphalt at 160-180°C and stir to obtain a mixture.

[0056] Maleic anhydride, SBS, and SSBR were added to the mixture and sheared at 4000-6000 rpm at 180-200°C for 0.5-1.5 hours to obtain a modified mixture. Rubber powder was added to the modified mixture in batches and sheared at 1000-2000 rpm at 180-200°C for 0.5-1.5 hours to obtain the initial waterproof modified asphalt.

[0057] The filler is added to the initial waterproof modified asphalt and mixed and stirred to obtain the waterproof modified asphalt.

[0058] The present invention will be further described below by way of examples and related test experiments and results thereof. In the detailed description below, for ease of explanation, many specific details have been set forth to provide a comprehensive understanding of the embodiments of the present invention. However, it is apparent that one or more embodiments may be implemented without these specific details. Moreover, in the absence of conflict, the details in the following embodiments may be combined arbitrarily into other feasible embodiments.

[0059] It should be noted that the following specific examples are for illustration only and the scope of protection of the present invention is not limited thereto. The chemicals and raw materials used in the following examples were either commercially available or prepared in-house using recognized processing methods.

[0060] It should be noted that the 70# asphalt used in the present invention is a commercial product with a softening point of 45~55℃ and a needle penetration of 60~80. The hard asphalt is a commercial product with a softening point of >100℃ and a needle penetration of <10. The crude cardanol index requires a cardanol content of ≥60% and a specific gravity of ≤0.98. The cardanol content in the crude cardanol used in the present invention is 63%. The refined cardanol index requires a cardanol content of ≥80%. The refined cardanol content used in the present invention is 85% and 93%. Both the crude cardanol and the refined cardanol used in the present invention are commercial products. Palm oil by-product oil is a commercial product with a solidification point of 0~10℃, a flash point of ≥220, and an acid value of ≤10. The maleic anhydride index requires a melting point of 51~56℃. The present invention uses commercially available maleic anhydride. SBS uses a commercially available 4402 model product with a melt index of 0.1g / 10min. The SSBR used was the commercially available 1901H model. The modified powder (rubber powder) required an ash content of ≤30%. The commercially available 40 / 60 mesh modified rubber powder was used, and the filler was 200 mesh stone powder.

[0061] Example 1:

[0062] Formula of waterproof modified asphalt:

[0063] Based on 100 parts by total weight, 35 to 40 parts of 70# asphalt, 4 to 5 parts of hard asphalt, 9 to 11 parts of biomass viscosity reducer, 0.1 to 0.5 parts of maleic anhydride, 1 to 1.5 parts of SBS, 1 to 1.5 parts of SSBR, 13 to 17 parts of modified rubber powder, and 28 to 32 parts of stone powder (it should be noted that the formula of this Example 1 is the formula of Type I waterproof modified asphalt).

[0064] Among them, the mass ratio of cardanol and oil in the biomass viscosity reducer is 1:1. It should be noted that the cardanol used here is crude cardanol, and the cardanol mass content in the crude cardanol is 63%; the oil used is palm oil by-product oil.

[0065] Preparation process of waterproof modified asphalt:

[0066] After adding 70# asphalt, heat the mixture to 140°C. Add the aforementioned hard asphalt and heat it to 170°C to melt it. Add the oil and cardanol, stir evenly, add maleic anhydride, SBS, and SSBR, and quickly heat the mixture to 185°C. Shear the mixture at 5000 rpm for 1 hour until no visible particles remain.

[0067] The modified rubber powder was added in two batches. At a rotation speed of 1500 rpm, shear development was carried out for 1 hour to allow the rubber powder to fully swell. The stone powder was added to the mixer at 500 rpm and then stirred for 30 minutes. After stirring evenly, the prepared waterproof modified asphalt was obtained. Sampling tests were carried out at 180°C. The measured results are shown in Table 1 below.

[0068] Example 2:

[0069] The formula of Example 2 is substantially the same as that of Example 1, except that the mass ratio of cardanol to oil in the biomass viscosity reducer is 4:6.

[0070] The same preparation process as in Example 1 was used to prepare waterproof modified asphalt, which was sampled and tested at 180° C. The measured results are shown in Table 1 below.

[0071] Example 3:

[0072] The formulation of Example 3 is substantially the same as that of Example 1, except that the mass ratio of cardanol to oil in the biomass viscosity reducer is 3:7.

[0073] The same preparation process as in Example 1 was used to prepare waterproof modified asphalt, which was sampled and tested at 180° C. The measured results are shown in Table 1 below.

[0074] Comparative Example 1:

[0075] The formulation of Comparative Example 1 is substantially the same as that of Example 1, except that 9 to 11 parts of base oil (petroleum-based softener) are used in place of the biomass viscosity reducer in Comparative Example 1; the base oil has a pour point of -20 to 30°C and a density of 0.8 to 1.0 g / cm 3 , saturated content is 50~70%, and aromatic content is 20~30%.

[0076] The same preparation process as in Example 1 was used to prepare waterproof modified asphalt, which was sampled and tested at 180° C. The measured results are shown in Table 1 below.

[0077] Table 1

[0078]

[0079] As shown in Table 1, the materials from Examples 1-3 exhibit lower viscosity and better low-temperature performance than Comparative Example 1, demonstrating that the addition of a biomass viscosity reducer can significantly reduce the viscosity of waterproof modified asphalt. While the high-temperature tolerance of Examples 1-3 is slightly weaker than that of Comparative Example 1, they still meet practical requirements (GB18242-2008 requires a heat resistance of 90°C for Type I waterproof modified asphalt membranes, and the products prepared in these examples still have a significant high-temperature tolerance). These results demonstrate the feasibility of the biomass viscosity reducer.

[0080] Example 4:

[0081] The formula of Example 4 is substantially the same as that of Example 1, except that refined cardanol is used in the biomass viscosity reducer, and the cardanol content in the refined cardanol is 85% by mass.

[0082] The same preparation process as in Example 1 was used to prepare waterproof modified asphalt, which was sampled and tested at 180° C. The measured results are shown in Table 2 below.

[0083] Example 5:

[0084] The formula of Example 5 is substantially the same as that of Example 2, except that refined cardanol is used in the biomass viscosity reducer, and the cardanol content in the refined cardanol is 85% by mass.

[0085] The same preparation process as in Example 1 was used to prepare waterproof modified asphalt, which was sampled and tested at 180° C. The measured results are shown in Table 2 below.

[0086] Example 6:

[0087] The formula of Example 6 is substantially the same as that of Example 3, except that refined cardanol is used in the biomass viscosity reducer, and the cardanol content in the refined cardanol is 85% by mass.

[0088] The same preparation process as in Example 1 was used to prepare waterproof modified asphalt, which was sampled and tested at 180° C. The measured results are shown in Table 2 below.

[0089] Table 2

[0090]

[0091] As shown in Table 2, the materials in Examples 4-6 have lower viscosities and better low-temperature performance than Comparative Example 1, demonstrating that the addition of a biomass viscosity reducer can significantly reduce the viscosity of waterproof modified asphalt. Further comparisons between Examples 4-6 and corresponding Examples 1-3 show that higher cardanol purity improves viscosity reduction, albeit at the expense of high-temperature performance. However, these materials still demonstrate high feasibility for application.

[0092] Example 7:

[0093] The formula of Example 7 is substantially the same as that of Example 1, except that refined cardanol is used in the biomass viscosity reducer, and the cardanol content in the refined cardanol is 93% by mass.

[0094] The same preparation process as in Example 1 was used to prepare waterproof modified asphalt, which was sampled and tested at 180° C. The measured results are shown in Table 3 below.

[0095] Example 8:

[0096] The formula of Example 8 is substantially the same as that of Example 2, except that refined cardanol is used in the biomass viscosity reducer, and the cardanol content in the refined cardanol is 93% by mass.

[0097] The same preparation process as in Example 1 was used to prepare waterproof modified asphalt, which was sampled and tested at 180° C. The measured results are shown in Table 3 below.

[0098] Example 9:

[0099] The formula of Example 9 is substantially the same as that of Example 3, except that refined cardanol is used in the biomass viscosity reducer, and the cardanol content in the refined cardanol is 93% by mass.

[0100] The same preparation process as in Example 1 was used to prepare waterproof modified asphalt, which was sampled and tested at 180° C. The measured results are shown in Table 3 below.

[0101] Table 3

[0102]

[0103] As shown in Table 3, the materials from Examples 7-9 exhibit lower viscosity and better low-temperature performance than Comparative Example 1, demonstrating that the addition of a biomass viscosity reducer can significantly reduce the viscosity of waterproof modified asphalt. Further comparisons between Examples 7-9 and the previous examples show that higher cardanol purity improves viscosity reduction, albeit at the expense of high-temperature performance. However, these materials still demonstrate high feasibility.

[0104] Comparative Example 2:

[0105] The formula of this comparative example 2 is substantially the same as that of Example 1, except that this comparative example 2 uses 10 parts of crude cardanol (cardanol mass fraction is 63%) instead of the biomass viscosity reducer.

[0106] The same preparation process as in Example 1 was used to prepare waterproof modified asphalt, which was sampled and tested at 180° C. The measured results are shown in Table 3 below.

[0107] Comparative Example 3:

[0108] The formulation of Comparative Example 3 is substantially the same as that of Example 1, except that 10 parts of oil (palm oil by-product oil) is used in this Comparative Example 3 instead of the biomass viscosity reducer.

[0109] The same preparation process as in Example 1 was used to prepare waterproof modified asphalt, which was sampled and tested at 180° C. The measured results are shown in Table 4 below.

[0110] Table 4

[0111]

[0112] As shown in Table 4, it can be seen that in Comparative Example 2, only cardanol was added, which failed to reduce the viscosity of the waterproof modified asphalt and had limited effect on improving the low-temperature performance; in Comparative Example 3, only grease was added, which reduced the viscosity, but did not significantly improve the overall performance of the waterproof modified asphalt.

[0113] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A waterproof modified asphalt comprising: Base asphalt, biomass viscosity reducer, maleic anhydride, modifier, filler; The biomass viscosity reducer comprises a combination of cardanol and oil, and the oil is palm oil by-product oil.

2. The waterproof modified asphalt according to claim 1, wherein The mass ratio of cardanol to oil is 3:7~1:

1.

3. The waterproof modified asphalt according to claim 1 or 2, wherein: The solidification point of oil is 0~10℃, the flash point is ≥200, and the acid value is ≤10.

4. The waterproof modified asphalt according to claim 1 or 2, wherein: The modifier is a combination of styrene-butadiene-styrene thermoplastic elastomer, solution-polymerized styrene-butadiene rubber and rubber powder.

5. The waterproof modified asphalt according to claim 4, wherein: The mass ratio of styrene-butadiene-styrene thermoplastic elastomer, solution-polymerized styrene-butadiene rubber, and rubber powder is (1-1.5): (1-1.5): (13-17); The cardanol includes crude or refined cardanol.

6. The waterproof modified asphalt according to claim 1 or 2, wherein: The matrix asphalt includes a first matrix asphalt and a second matrix asphalt; The softening point of the second matrix asphalt is higher than that of the first matrix asphalt, and the needle penetration of the second matrix asphalt is lower than that of the first matrix asphalt.

7. The waterproof modified asphalt according to any one of claims 1 or 2, wherein Based on 100 parts by total weight, the base asphalt is 39 to 45 parts, the biomass viscosity reducer is 6 to 12 parts, maleic anhydride is 0.1 to 0.5 parts, the modifier is 15 to 20 parts, and the filler is 28 to 32 parts.

8. A method for preparing the waterproof modified asphalt according to any one of claims 1 to 7, comprising: Mixing and melting the base asphalt and the biomass viscosity reducer to obtain a mixture; adding maleic anhydride and a modifier to the mixture respectively, heating and mixing, and obtaining an initial waterproof modified asphalt; The filler is added to the initial waterproof modified asphalt and mixed and stirred to obtain the waterproof modified asphalt.

9. The preparation method according to claim 8, wherein The mixing and melting of the matrix asphalt and the biomass viscosity reducer to obtain a mixture comprises: Melting the first matrix asphalt at 130-150° C., adding the second matrix asphalt to the first matrix asphalt, and heating the mixture to 160-180° C. to obtain molten matrix asphalt; The biomass viscosity reducer is added to the molten base asphalt at 160-180° C. and stirred to obtain the mixture.

10. The preparation method according to claim 8, wherein The step of adding maleic anhydride and a modifier to the mixture, heating and mixing the mixture to obtain an initial waterproof modified asphalt comprises: adding maleic anhydride, styrene-butadiene-styrene thermoplastic elastomer, and solution-polymerized styrene-butadiene rubber to the mixture, and shearing the mixture at 180-200° C. and 4000-6000 rpm for 0.5-1.5 h to obtain a modified mixture; The rubber powder is added to the modified mixture in batches, and the mixture is sheared at 180-200° C. and 1000-2000 rpm for 0.5-1.5 hours to obtain the initial waterproof modified asphalt.

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