High-storability high-content SBS modified emulsified asphalt and preparation method thereof

Abstract

The application provides a high-storage-stability high-content SBS modified emulsified asphalt and a preparation method thereof, and belongs to the technical field of road building materials.The emulsified asphalt comprises, in mass parts, base asphalt 56-65 parts, SBS modifier 3.5-4.5 parts, resin 1-2 parts, cationic emulsifier 1-2.5 parts and weinan glue 0.03-0.10 parts, and water is supplemented to 100 parts.The weinan glue is dissolved in the water phase soap solution in advance, the pseudoplastic rheological characteristics and thickening suspension effect are utilized, no organic solvent is added, no chloride ion is introduced, and the stable emulsification of 5.38%-8.04% high-content SBS modified asphalt is realized.The 5-day storage stability of the obtained product is less than 0.8%, the 30-day storage stability is less than 2%, and the long-term storage requirements such as long-distance transportation and seasonal construction are met.The preparation process is simple, the cost is moderate, the environment is friendly, and the application prospect in engineering is remarkable.

Description

Technical Field

[0001] This invention relates to the field of road construction materials technology, specifically to a high-storage-stability, high-content SBS-modified emulsified asphalt and its preparation method. The emulsified asphalt can be used in construction scenarios such as tack coats for new highway pavements, tack coats for ultra-thin wearing courses, waterproof tack coats for bridge decks, micro-surfacing, and cold recycled mixtures. Background Technology

[0002] With the continuous increase in highway traffic load levels and the frequent occurrence of extreme weather, pavement tack coats and maintenance materials face more stringent performance requirements. SBS-modified emulsified asphalt combines environmental protection and energy saving with excellent high and low temperature performance, making it a key binder material for the maintenance of high-grade pavements. However, current products generally suffer from an inherent contradiction between performance and stability: at low SBS content (SBS modifier dosage is 3%~4.5% of the base asphalt mass), the emulsion storage state is stable, but the bond strength and deformation resistance are insufficient, making it difficult to adapt to heavy traffic and extreme temperature conditions; increasing the SBS content can significantly enhance road performance, but it will directly lead to a decrease in emulsifability and a sharp deterioration in storage stability.

[0003] Specifically, existing technologies for preparing SBS-modified emulsified asphalt typically limit the SBS content to below 5% (i.e., the SBS modifier dosage is less than 5% of the base asphalt mass). Further increasing the modifier dosage leads to a significant increase in the viscosity of the modified asphalt, making it difficult to shear and disperse into uniform emulsion particles, and causing a sharp decline in the storage stability of the finished product. SBS-modified emulsified asphalt is inherently a thermodynamically unstable system; during storage, asphalt droplets containing the SBS phase are prone to buoyancy and aggregation due to density differences, causing system segregation. Current industry standards only use 5-day storage stability as an assessment indicator, and there is a lack of systematic research on the long-term storage stability of emulsified asphalt for 30 days and beyond. Existing products are insufficient to cover the performance requirements of long-term storage conditions such as long-distance transportation and seasonal construction.

[0004] Existing improvement schemes all have significant limitations: while adding inorganic salt stabilizers such as calcium chloride and ammonium chloride can improve short-term stability by enhancing the double-layer repulsion, it will deteriorate the adhesion between asphalt and aggregates and the asphalt's ductility; while organic polymer stabilizers such as polyvinyl alcohol can delay sedimentation by increasing the viscosity of the aqueous phase, they can easily lead to excessively high system viscosity, affecting workability and demulsification rhythm; the technical route of post-incorporation of SBS latex also fails to fundamentally solve the problem of long-term storage stability under high dosage. For example, Chinese patent CN121517928A uses kerlan gum as an emulsified asphalt reinforcing agent, but kerlan gum's core characteristic is its thermogelation property, lacking significant pseudoplastic rheological characteristics, and thus cannot simultaneously ensure long-term storage stability and construction shear thinning performance; the research on kerlan gum-modified asphalt published by Wuhan University of Technology only disperses kerlan gum in thermally modified asphalt to regulate asphalt phase rheology, without involving the emulsified asphalt aqueous phase stabilization system.

[0005] Vilan gum, a microbial metabolic polysaccharide, possesses unique pseudoplastic rheological properties—its viscosity drops sharply under high shear conditions, facilitating pumping and construction. Upon standing, it rapidly recovers to a high-viscosity state, forming a network colloidal structure that effectively suspends particles and inhibits sedimentation. Furthermore, it exhibits excellent temperature and salt resistance. In existing technologies, research on the application of vilan gum in the asphalt field is extremely limited. Only a few publications report its application in hot-melt modified asphalt (such as montmorillonite (MMT) modified asphalt), where the mechanism involves vilan gum being directly dispersed in hot asphalt, improving storage stability through rheological regulation of long-chain molecules in the asphalt phase. However, the hot-modified asphalt system and the emulsified asphalt system described in this invention differ fundamentally in terms of dispersion medium, action phase, and stabilization mechanism: in the former, vilan gum acts on the asphalt phase, while in the latter, it acts on the aqueous phase; in the former, rheological regulation slows down inorganic particle sedimentation, while in the latter, multi-scale synergistic action is required to suspend organic asphalt droplets; the former has a shorter evaluation period, while the latter must balance 30-day long-term storage stability with construction shear thinning characteristics. Therefore, the experience of using V-La rubber in hot-modified asphalt cannot be directly transferred to water-based emulsified asphalt systems. Multiple technical obstacles, such as phase compatibility and compatibility with cationic emulsifiers, need to be overcome. Currently, the application patterns and stabilization effects of V-La rubber in emulsified asphalt systems, especially high-dosage SBS-modified emulsified asphalt systems, have not been systematically studied.

[0006] In summary, existing technologies still face the technical bottleneck of balancing high bonding performance and high storage stability. There is an urgent need to develop a high-content SBS modified emulsified asphalt with excellent emulsification, good long-term storage stability, and environmental friendliness to solve the three major technical problems of emulsification difficulties and easy floating and segregation under high SBS content, the degradation of road performance or workability by traditional stabilizers, and the inability to transfer existing Vilan rubber application technology to emulsified asphalt systems. Summary of the Invention

[0007] To address the aforementioned technical problems, this invention provides a high-storage-stability SBS-modified emulsified asphalt and its preparation method. Through the multi-scale synergistic effect of Weilan rubber, excellent long-term storage stability is achieved under high SBS content conditions, while simultaneously ensuring workability and road performance. The specific solution is as follows:

[0008] A high-storage-stability, high-content SBS-modified emulsified asphalt comprises, by weight, the following components: 56-65 parts base asphalt, 3.5-4.5 parts SBS modifier, 1-2 parts resin, 1-2.5 parts cationic emulsifier, and 0.03-0.10 parts of veneer gum, with water to make up to 100 parts.

[0009] The vesicular gum is an unmodified microbial metabolic polysaccharide powder. It is produced by the fermentation of *Alcaligenes aeruginosa*, and its structural framework consists of a tetrasaccharide repeating unit of D-glucose, D-glucuronic acid, D-glucose, and L-rhamnose. The vesicular gum is dissolved directly in soap solution in powder form without chemical modification.

[0010] The stabilizing mechanism of Weilan rubber stems from its unique polymer structure and the synergistic effect of multi-scale physicochemical processes. First, it provides suspension stabilization: the rigid polysaccharide chains construct a three-dimensional network structure in the aqueous phase, creating a mechanical lifting effect on the emulsified asphalt particles; simultaneously, the macromolecules can adsorb onto the surface of the asphalt particles, forming a thick hydration film, generating strong steric hindrance, preventing particle collision and aggregation, and fundamentally inhibiting upward segregation. Second, it provides rheological regulation: in a static state, the overlapping molecular chains form a high-viscosity gel state, resulting in high system viscosity and good stability; under shear stress, the molecular chains align along the shear direction, causing a sharp drop in viscosity, exhibiting typical shear-thinning characteristics, without affecting pumping, spraying, or other construction processes. Third, it provides water retention: the numerous hydroxyl groups on the Weilan rubber molecular chains convert free water into bound water through hydrogen bonds; simultaneously, the three-dimensional network physically traps water and significantly increases the viscosity of the aqueous phase, increasing resistance to water diffusion, slowing down water evaporation and ion exchange, delaying demulsification, and preventing surface crusting during transportation and storage. Fourthly, it has an interface enhancement effect. After demulsification and film formation, the asphalt-aggregate interface is enriched with the asphalt and aggregates. It can enhance the adhesion to the aggregate surface through hydrogen bonding. At the same time, the continuous polysaccharide film it forms can help improve the anti-flow ability of the asphalt film and will not have a negative impact on the low-temperature ductility of the asphalt matrix.

[0011] The amount of SBS modifier used in this invention is 5.38%-8.04% of the mass of the base asphalt; through the combination of Weilan rubber and other raw materials, stable emulsification of high-content SBS modified asphalt is achieved.

[0012] Optionally, the high-content SBS modified emulsified asphalt further includes a pH adjuster for adjusting the pH of the soap solution to 1.5~2.0, wherein the soap solution is prepared from water, a cationic emulsifier, and venereal gum.

[0013] Optionally, the SBS modifier is linear SBS.

[0014] Optionally, the linear SBS is selected from at least one of 791H, 6302H, and 1301; the resin is selected from at least one of petroleum resin, terpene resin, and phenolic resin, used to improve the compatibility of SBS modifier with base asphalt and enhance the high-temperature performance of modified asphalt.

[0015] Optionally, the cationic emulsifier is selected from at least one of quaternary ammonium salt cationic emulsifiers, amide polyamine cationic emulsifiers, and lignoamine cationic emulsifiers.

[0016] This invention also provides a method for preparing the above-mentioned high-storage-stability, high-content SBS-modified emulsified asphalt, specifically including the following steps: (1) Preparation of SBS modified asphalt: The base asphalt is heated to a fluid state, and SBS modifier and petroleum resin are added in sequence. After high-speed shear dispersion, it is swelled and developed at low speed and constant temperature to obtain SBS modified asphalt. (2) Preparation of soap solution: Heat water to 55~65℃, add cationic emulsifier and stir to dissolve, then add Weilan gum powder and continue stirring until completely dissolved, then adjust pH to 1.5~2.0 to obtain soap solution; (3) Emulsification and shearing: The SBS modified asphalt from step (1) is mixed with the soap solution from step (2) and continuously sheared to obtain primary emulsified asphalt. (4) Cooling and storage: Cool the primary emulsified asphalt to below 50°C and store it in a sealed container to obtain the high-content SBS modified emulsified asphalt with high storage stability.

[0017] The preparation method of this invention pre-dissolves SBS in an aqueous soap solution, utilizing its pseudoplastic rheological properties and thickening and suspending effect, without adding organic solvents or introducing chloride ions, to achieve stable emulsification of 5.38%-8.04% high-content SBS modified asphalt. The preparation process of this invention is simple, cost-effective, and environmentally friendly, and has significant engineering application prospects.

[0018] Optionally, in step (1), the high-speed shearing rate is 5000~6000 r / min, the shearing time is 50~60 min, and the shearing temperature is 175~180℃.

[0019] Optionally, in step (1), the constant temperature swelling temperature is 175~180℃, the low-speed shearing rate is 1000~2000r / min, and the swelling time is 10~15 min.

[0020] Optionally, in step (2), the dissolution temperature of the vegan adhesive is 55~65℃, the dissolution time is 10~15 min, and the stirring rate is 300~500 r / min.

[0021] Optionally, in step (3), the temperature of the SBS modified asphalt pump before mixing is 170~185℃, and the temperature of the soap solution before mixing is 55~65℃.

[0022] Optionally, in step (2), a pH adjuster is used to adjust the pH. The pH adjuster is at least one of hydrochloric acid, sulfuric acid, nitric acid, and phosphoric acid, used to adjust the pH of the soap solution to 1.5~2.0 to ensure the charge activity and emulsification efficiency of the cationic emulsifier.

[0023] Optionally, in step (3), a colloid mill is used for continuous shearing.

[0024] Optionally, in step (1), the base asphalt is heated to a fluid state, and then the shear rate is set to 2500-3500 r / min. Under continuous shear, SBS modifier and resin are added in batches, and shear is maintained for 10-20 min after each addition.

[0025] The present invention has the following advantages over the prior art: 1. Significantly improved long-term stability: Through the synergistic effect of the spatial steric hindrance and three-dimensional network suspension of the Weilan rubber, the 30-day storage stability of high-content SBS modified emulsified asphalt can be controlled within 2%, which is far superior to existing products and meets the requirements of long-term storage conditions such as long-distance transportation, seasonal construction, and emergency reserves.

[0026] 2. Construction performance is unaffected. Weilan adhesive imparts excellent shear-thinning properties to emulsified asphalt. After stirring and pumping at room temperature, the viscosity is significantly reduced, allowing for smooth spraying and completely eliminating the problems of high construction viscosity and uneven spraying caused by conventional thickening stabilizers.

[0027] 3. Environmentally friendly and without side effects, Weilan adhesive is a non-toxic bio-based polymer. The preparation process does not introduce chloride ions or use organic solvents, so it will not deteriorate the adhesion between asphalt and aggregates, nor will it reduce the low-temperature ductility of asphalt. It overcomes the inherent defects of traditional inorganic salts and organic polymer stabilizers.

[0028] 4. The process is simple and easy to promote. It does not require modification of existing emulsified asphalt production equipment. Only the addition of a Weilan gum dissolution step in the soap solution preparation process is needed to achieve large-scale production. The cost is controllable and the prospects for engineering applications are significant. Attached Figure Description

[0029] Figure 1 The original infrared spectra of the evaporation residues of Example 1 and Comparative Example 1 are shown below. Figure 2 The internal standard normalized difference spectra of the evaporation residues of Example 1 and Comparative Example 1 are shown. Figure 3 Comparison of the appearance of emulsified asphalt in Example 1 and Comparative Example 1 after 30 days of storage; the left image is the sample of Comparative Example 1, and the right image is the sample of Example 1. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention are within the scope of protection of the present invention.

[0031] The raw materials used in the embodiments of the present invention are sourced from the following sources: 70# base bitumen was purchased from Shell; the SBS modifier was 791H linear SBS, purchased from Baling Petrochemical; the petroleum resin was purchased from Shenzhen Yoshida Chemical; the hydrochloric acid was purchased from Sinopharm Chemical Reagent Co., Ltd.; the cationic emulsifier was CMK-600 quaternary ammonium salt emulsifier, purchased from Tianlong Chemical; the Weilan gum was purchased from Henan Cunbing Food Co., Ltd.; and the commercially available bio-based emulsified bitumen stabilizer was purchased from a chemical materials company.

[0032] Performance tests were conducted in accordance with JTG 3410-2025 "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering".

[0033] Example 1 A high-storage-stability, high-content SBS-modified emulsified asphalt, comprising the following components by weight: 56 parts of No. 70 base asphalt, 4 parts of SBS modifier, 1 part of petroleum resin, 2 parts of cationic emulsifier, and 0.06 parts of Weilan rubber, with water to make up to 100 parts.

[0034] A method for preparing high-content SBS-modified emulsified asphalt includes the following steps: (1) Preparation of SBS modified asphalt: The base asphalt of No. 70 was heated to 160℃. A high-speed shearing machine was used, and the shearing rate was set to 3000 r / min. SBS modifier and petroleum resin were added in small amounts and multiple times under continuous shearing. Shearing was maintained for 15 min after each addition. Then (after the addition was completed), the shearing rate was adjusted to 5500 r / min, and the temperature was raised to 180℃. Shearing was carried out for 60 min. Finally, the swelling and development stage was entered. The shearing rate was reduced to 2000 r / min, the temperature was maintained at 180℃, and development was carried out for 120 min to obtain SBS modified asphalt. (2) Preparation of soap solution: Heat water to 60°C, add cationic emulsifier and stir to dissolve, stirring at 400 r / min for 15 min; then add Weilan gum powder and continue stirring until completely dissolved, stirring at 400 r / min for 15 min; add hydrochloric acid to adjust pH to 2.0 to obtain soap solution. (3) Emulsification and shearing: SBS modified asphalt maintained at 180°C in step (1) and soap solution maintained at 60°C in step (2) are pumped into a colloid mill at a mass ratio of 60:40 and continuously sheared and emulsified to obtain primary emulsified asphalt. (4) Cooling and storage: Cool the pre-emulsified asphalt to below 50°C, seal and store it to obtain the finished product.

[0035] Example 2 The difference from Example 1 is that the amount of Weilan glue is 0.03 parts, while the other components and preparation methods are the same as in Example 1.

[0036] Example 3 The difference from Example 1 is that the amount of Weilan glue is 0.10 parts, while the other components and preparation methods are the same as in Example 1.

[0037] Example 4 The difference from Example 1 is that: the base asphalt No. 70 is 65 parts, the SBS modifier is 3.5 parts, and the remaining components and preparation method are the same as in Example 1.

[0038] Example 5 The difference from Example 1 is that the amount of SBS modifier is 4.5 parts, while the other components and preparation methods are the same as in Example 1.

[0039] Comparative Example 1 The difference from Example 1 is that no velan gum is added, and the remaining components and preparation methods are the same as in Example 1, which is used as a blank control.

[0040] Comparative Example 2 The difference from Example 1 is that: no velan gum is added, and ammonium chloride is used instead of velan gum as a stabilizer. The remaining components and preparation methods are the same as in Example 1, which is used to compare the effect of inorganic salt stabilizers.

[0041] Comparative Example 3 The difference from Example 1 is that: no velan gum is added, and a commercially available bio-based stabilizer is used instead. The remaining components and preparation methods are the same as in Example 1, and it is used to compare the effects of similar commercially available products.

[0042] Comparative Example 4 The difference from Example 1 is that: the Weilan rubber is directly added to the hot SBS modified asphalt in step (1) for dispersion, without being added to the soap solution. The remaining components and preparation methods are the same as in Example 1, which is used to simulate the existing Weilan rubber addition method.

[0043] A method for preparing high-content SBS-modified emulsified asphalt includes the following steps: (1) Preparation of SBS modified asphalt: The base asphalt of No. 70 was heated to 160℃. A high-speed shearing machine was used, and the shearing rate was set to 3000 r / min. Under continuous shearing, SBS modifier and petroleum resin were added in small amounts and multiple times. After each addition, shearing was maintained for 15 min. Then the shearing rate was adjusted to 5500 r / min, and the temperature was raised to 180℃. Shearing was carried out for 60 min. Finally, the swelling and development stage was entered. The shearing rate was reduced to 2000 r / min, and then Weilan rubber powder was added. The temperature was maintained at 180℃ and the development was carried out for 120 min to obtain SBS modified asphalt. (2) Preparation of soap solution: Heat water to 60°C, add cationic emulsifier and stir to dissolve, stirring at a rate of 400 r / min for 15 min; add hydrochloric acid to adjust pH to 2.0 to obtain soap solution; (3) Emulsification and shearing: SBS modified asphalt maintained at 180°C in step (1) and soap solution maintained at 60°C in step (2) are pumped into a colloid mill at a mass ratio of 60:40 and continuously sheared and emulsified to obtain primary emulsified asphalt. (4) Cooling and storage: Cool the pre-emulsified asphalt to below 50°C, seal and store it to obtain the finished product.

[0044] Comparative Example 5 The difference from Example 1 is that petroleum resin is not added, while the remaining components and preparation method are the same as in Example 1.

[0045] Comparative Example 6 The difference from Example 1 is that the amount of Weilan glue is 0.2 parts, and the other components and preparation methods are the same as in Example 1.

[0046] The emulsified asphalt prepared in Examples 1-5 and Comparative Examples 1-5 were subjected to performance tests. The test indicators included 5-day storage stability, 30-day storage stability, standard viscosity, softening point of evaporation residue, ductility at 5°C, and penetration. The test results are shown in Table 1.

[0047] Table 1. Performance test results of the emulsified asphalt prepared in Examples 1-5

[0048] Table 2. Performance test results of emulsified asphalt prepared in Comparative Examples 1-5

[0049] As shown in Table 1, the high-content SBS modified emulsified asphalt of this invention exhibits excellent comprehensive performance. Under the same SBS formulation conditions (Examples 1-3), the evaporation residue penetration and softening point of the examples with added Weilan rubber are basically consistent with those of the blank comparative example (Comparative Example 1), and the differences are within the allowable error range of the test. This indicates that Weilan rubber only acts on the aqueous phase system and does not change the intrinsic high and low temperature performance of the modified asphalt. Compared with inorganic salt stabilizers (Example 1 and Comparative Example 2), the system of this invention does not degrade the ductility of asphalt at 5℃, and has a better low-temperature crack resistance.

[0050] Regarding storage stability, the 5-day storage stability of all embodiments was less than 0.8%, and the 30-day long-term storage stability was less than 2%. The improvement effect was significant compared with the blank system (Comparative Example 1) and the commercially available conventional stabilizer (Comparative Example 2 and Comparative Example 3). This fundamentally improved the technical defects of high-content SBS modified emulsified asphalt, such as easy floating and segregation and poor long-term storage performance.

[0051] In terms of workability, compared with Comparative Examples 1-2, in Examples 1-5, although the viscosity of the emulsion was slightly increased by the presence of Weilan rubber, its pseudoplastic rheological properties allowed the viscosity to decrease rapidly under shear conditions such as pumping and spraying, without affecting workability. This achieved a synergistic optimization of storage stability and workability. Furthermore, this system maintained excellent stability even with increased SBS content, making it suitable for preparing a wide range of high-content SBS-modified emulsified asphalts and meeting the requirements of various working conditions such as long-distance transportation, seasonal construction, and emergency storage.

[0052] Comparative Example 4 uses the existing hot asphalt phase feeding method to disperse the hot SBS modified asphalt added in step (1). The emulsified asphalt prepared has storage stability comparable to that of Comparative Example 1, and both have poor storage stability. This result proves that there is an essential difference between the patent system and the literature system: the rheological regulation effect of Weilan gum in the hot melt asphalt phase in the literature cannot be transferred to the emulsified asphalt system. In this patent, Weilan gum is added to the soap solution in step (2), and the stabilization effect achieved through the multi-scale synergistic effect of the aqueous phase is something that cannot be expected in the comparative literature.

[0053] After removing the petroleum resin component in Comparative Example 5, the compatibility between the SBS modifier and the No. 70 base asphalt decreased, the emulsifability of the modified asphalt deteriorated, and the storage stability decreased. This demonstrates that there is a synergistic effect between petroleum resin and Weilan gum—the resin improves the compatibility and emulsifability of the asphalt phase, providing a basis for homogeneous emulsification; Weilan gum enhances the suspension stability of the aqueous phase and inhibits particle segregation. Together, they achieve a synergistic improvement in the performance and stability of high-dosage SBS-modified emulsified asphalt.

[0054] Comparative Example 6 increased the amount of Vilan gum to 0.2 parts and found that the viscosity of the soap solution increased and flocculation and precipitation occurred during the preparation of the soap solution. This is because excessive Vilan gum reacts with the cationic emulsifier to form an insoluble polyelectrolyte complex, which reduces the stability and emulsifurability of the emulsified asphalt. This proves that 0.03~0.10 parts is the reasonable dosage range for this system.

[0055] from Figure 1 It can be seen that the spectral profiles of the emulsified asphalt evaporation residue without vesile gum (Comparative Example 1) and the emulsified asphalt evaporation residue with vesile gum (Example 1) are highly similar, both exhibiting typical modified asphalt characteristics. This indicates that the addition of vesile gum did not change the chemical composition of the evaporation residue, which is predominantly asphalt; asphalt remains the absolute main phase, and vesile gum exists only as a trace additive in the system. Pure vesile gum has a low overall absorbance, but at 1068 cm⁻¹... -1 The COC glycosidic bond vibration peak can be clearly identified at this point.

[0056] Because the amount of veneer added is very small, its characteristic peaks contribute very little to the absolute absorbance and are masked by the strong absorption of the asphalt matrix in the original spectrum, making them impossible to observe directly. Therefore, this invention employs an internal standard normalized difference spectral analysis method: using 2920 cm⁻¹... -1 Using the asymmetric stretching vibration peak of the adipose-derived CH4 (the main peak of asphalt) as a reference, each spectrum is divided by the absorbance of this reference peak to ensure that all spectra have the same "equivalent asphalt content" before difference calculation, thereby eliminating the overall absorbance decrease effect caused by the dilution of the asphalt matrix. Figure 2 As shown, the normalized difference spectrum at 1068 cm⁻¹ -1 (COC glycosidic bond), 1408cm -1 (COO) - The characteristic peaks of vesicular gum (symmetric stretching) all showed positive values, precisely corresponding to the characteristic peaks of pure vesicular gum, while these positive peaks were absent in Comparative Example 1 without vesicular gum. This result directly proves the presence of vesicular gum in the evaporation residue at the molecular level, and that its polysaccharide skeleton is still retained after demulsification and film formation, providing a material basis for vesicular gum to exert multi-scale stabilizing effects such as steric hindrance, three-dimensional network suspension, and interface reinforcement. Meanwhile, the asphalt main peak region (2800~3000 cm⁻¹) -1 After normalization, the difference is close to zero, which further confirms that Weilan rubber does not change the chemical composition of the asphalt itself, but only acts on the aqueous system and the interface region. This is consistent with the test results of the evaporation residue penetration and softening point of Example 1 and Comparative Example 1 in Table 1, indicating that Weilan rubber has achieved a significant improvement in the storage stability of the emulsion system without deteriorating the intrinsic high and low temperature performance of the modified asphalt.

[0057] from Figure 3It can be observed that, in Comparative Example 1 ( Figure 3 The emulsified asphalt in Example 1 (left) exhibited significant segregation, which worsened with prolonged storage. In contrast, Example 1 (left) showed better segregation. Figure 3 The emulsified asphalt on the right maintained a uniform and stable darker emulsion state throughout the entire 30-day storage period, without any visible layering, crusting, or sedimentation. Figure 3 The results are consistent with the storage stability data in Table 1, which fully demonstrates that Weilan rubber can effectively ensure the long-term storage stability of high-dosage SBS modified emulsified asphalt within the dosage range, meeting the actual needs of long-term storage conditions such as long-distance transportation, seasonal construction and emergency reserves.

[0058] The above are preferred embodiments of the present invention. For those skilled in the art, any improvements and modifications made without departing from the principle of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A high-storage-stability, high-content SBS-modified emulsified asphalt, characterized in that, By weight, it comprises the following components: 56-65 parts base bitumen, 3.5-4.5 parts SBS modifier, 1-2 parts resin, 1-2.5 parts cationic emulsifier, and 0.03-0.10 parts Weilan rubber, with water to make up to 100 parts.

2. The high-storage-stability, high-content SBS-modified emulsified asphalt according to claim 1, characterized in that, The SBS modifier is linear SBS.

3. The high-storage-stability, high-content SBS-modified emulsified asphalt according to claim 1, characterized in that, The resin is selected from at least one of petroleum resin, terpene resin, and phenolic resin.

4. The high-storage-stability, high-content SBS-modified emulsified asphalt according to claim 1, characterized in that, The cationic emulsifier is selected from at least one of quaternary ammonium salt cationic emulsifiers, amide polyamine cationic emulsifiers, and lignoamine cationic emulsifiers.

5. A method for preparing high-storage-stability, high-content SBS-modified emulsified asphalt as described in any one of claims 1 to 4, characterized in that, Includes the following steps: (1) Preparation of SBS modified asphalt: The base asphalt is heated to a fluid state, and SBS modifier and resin are added in sequence. After high-speed shear dispersion, it is swelled and developed at low speed and constant temperature to obtain SBS modified asphalt. (2) Preparation of soap solution: Heat water to 55~65℃, add cationic emulsifier and stir to dissolve, then add Weilan gum powder and continue stirring until dissolved, then adjust pH to 1.5~2.0 to obtain soap solution; (3) Emulsified shearing: The SBS modified asphalt from step (1) is mixed with the soap solution from step (2) and continuously sheared to obtain primary emulsified asphalt. (4) Cooling and storage: Cool the primary emulsified asphalt to below 50°C and store it in a sealed container to obtain the high-content SBS modified emulsified asphalt with high storage stability.

6. The preparation method according to claim 5, characterized in that, In step (1), the high-speed shearing rate is 5000~6000 r / min, the shearing time is 50~60 min, and the shearing temperature is 175~180℃.

7. The preparation method according to claim 5 or 6, characterized in that, In step (1), the isothermal swelling temperature is 175~180℃, the low-speed shearing rate is 1000~2000r / min, and the swelling time is 10~15 min.

8. The preparation method according to claim 5, characterized in that, In step (2), the dissolution temperature of the Weilan adhesive is 55~65℃, the dissolution time is 10~15 min, and the stirring rate is 300~500 r / min.

9. The preparation method according to claim 5 or 8, characterized in that, In step (3), the temperature of the SBS modified asphalt before mixing is 170~185℃, and the temperature of the soap solution before mixing is 55~65℃.

10. The preparation method according to claim 5 or 6, characterized in that, In step (1), the base asphalt is heated to a fluid state, and then the shear rate is set to 2500-3500 r / min. Under continuous shear, SBS modifier and resin are added in batches, and shear is maintained for 10-20 min after each addition.

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