A modified polyarylate fiber asphalt mixture and a method for preparing the same

Abstract

The application discloses a modified polyarylate fiber asphalt mixture and a preparation method thereof, and the preparation method comprises the following steps: (1) fiber pretreatment; (2) configuration of silane coupling agent; (3) coupling agent treatment of the fiber; (4) weighing and shortening of the modified fiber; (5) dry mixing of aggregate and fiber; and (6) preparation of the asphalt mixture. The surface of the polyarylate fiber is treated by using a detergent to remove a previous oil agent, and then the fiber is treated by using a silane coupling agent to increase the surface activity, so that the compatibility of the polyarylate fiber as a fiber stabilizer in the asphalt mixture is improved. The length of the polyarylate short fiber and the mixing amount of the polyarylate short fiber in the base asphalt are controlled, and a preparation process of dry mixing first, wet mixing later and multiple times of short fiber addition is combined, so that the polyarylate short fiber asphalt mixture is prepared, and the defects of the traditional asphalt mixture, such as insufficient anti-rutting capacity and poor water damage resistance, are solved.

Description

Technical Field

[0001] This invention relates to the field of asphalt pavement materials technology, specifically to a modified polyarylate fiber asphalt mixture and its preparation method. Background Technology

[0002] Traditional asphalt mixtures are widely used in the construction of highways, airport runways, and parking lots due to their advantages such as simple construction and low cost. With the rapid development of the national economy and the increasingly sophisticated urban road network, asphalt pavements, as the "cornerstone" of this network, are undergoing high-frequency, heavy-load compaction and erosion from various environments. The poor durability and temperature resistance of traditional asphalt mixtures are gradually becoming apparent, leading to pavement defects such as rutting and cracking. These problems result in premature pavement damage, shortening road lifespan and increasing maintenance costs. Therefore, modifying conventional asphalt mixtures to improve their overall performance and meet the requirements of various environments is becoming increasingly important.

[0003] Asphalt mixtures mainly consist of coarse aggregates, fine aggregates, base asphalt, mineral powder, and additives. In existing technologies, polymer-modified asphalt (PMB) can be used, which involves incorporating polymers into asphalt through mechanical mixing or chemical reactions to improve the performance of the asphalt mixture. Commonly used polymers in polymer-modified asphalt include SBS (styrene-butadiene-styrene block copolymer), SBR (styrene-butadiene rubber), EVA (ethylene-vinyl acetate copolymer), and PE. However, existing asphalt mixtures still suffer from insufficient rutting resistance and poor water damage resistance. Summary of the Invention

[0004] The technical problem to be solved by this invention is to overcome the technical defects of the prior art and provide a modified polyaryl ester fiber asphalt mixture and its preparation method. The purpose of this invention is to provide a modified polyaryl ester fiber asphalt mixture and its preparation method that have low manufacturing cost and excellent resistance to water damage and rutting. This invention uses a detergent to treat the surface of the polyaryl ester fibers to remove the preceding oiling agent, and then uses a silane coupling agent to treat the fibers to increase their surface activity, thereby improving the compatibility of polyaryl ester fibers as a fiber stabilizer in asphalt mixtures. This invention, by controlling the length of the polyaryl ester short fibers and their dosage in the base asphalt, combined with a manufacturing process of dry mixing followed by wet mixing and multiple additions of short fibers, produces a polyaryl ester short fiber asphalt mixture, solving the defects of insufficient rutting resistance and poor water damage resistance in traditional asphalt mixtures.

[0005] The technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows:

[0006] A method for preparing a modified polyarylate fiber asphalt mixture includes the following steps:

[0007] (1) Fiber pretreatment: Prepare a washing solution by mixing detergent and deionized water, then soak the polyarylate fiber in the washing solution, then ultrasonically wash it in the same concentration of washing solution, and finally dry it.

[0008] (2) Preparation of silane coupling agent: Prepare an ethanol solution by mixing anhydrous ethanol and water in a certain proportion; then add the silane coupling agent to the above ethanol solution, the amount of which is 5wt% to 10wt% of the ethanol solution; stir thoroughly and let stand to allow the silane coupling agent to be fully hydrolyzed;

[0009] (3) Coupling agent treatment of fibers: The fibers obtained in step (1) are immersed in the silane coupling agent prepared in step (2) to allow the two to react fully; then they are dried in an oven to obtain modified polyarylate fibers.

[0010] (4) Weighing and cutting the modified fiber: Weigh the modified polyarylate fiber obtained in step (3) at 0.5% to 1% of the weight of the asphalt, and cut it to 1 to 4 mm.

[0011] (5) Dry mixing of aggregates and fibers: After the aggregates are dried, weigh them according to the gradation, preheat the aggregates and mixing pot, then mix the aggregates in the pot, and then add the short-cut modified polyarylate fibers from step (4) and stir. The short fibers are added in multiple batches to make the fibers evenly mixed.

[0012] (6) Preparation of asphalt mixture (wet mixing): Add preheated asphalt to the dry mixture obtained in step (5), wherein the amount of asphalt added is 71% to 83% of the weight of the aggregate, and stir; then add dried and preheated mineral powder to the mixing pot, wherein the amount of mineral powder added is 7% to 11% of the weight of the aggregate, and stir; then keep warm to obtain modified polyarylate fiber asphalt mixture.

[0013] Preferably, in step (1), the detergent is any one or both of ethanol solution and acetone solution.

[0014] Preferably, in step (1), the volume concentration of the washing liquid is 10% to 20%.

[0015] Preferably, in step (1), the soaking time is 20 to 30 minutes.

[0016] Preferably, in step (1), the washing time is 10 to 20 minutes.

[0017] Preferably, in step (1), the drying temperature is 100-150°C and the drying time is 1-2 hours.

[0018] Preferably, in step (2), the volume ratio of anhydrous ethanol to water is 4:6.

[0019] Preferably, in step (2), the silane coupling agent is any one or more of KH-550, KH-560, and KH-570.

[0020] Preferably, in step (2), the settling time is 20 to 40 minutes.

[0021] Preferably, in step (3), the soaking time is 1 to 2 hours.

[0022] Preferably, in step (3), the drying temperature is 80-100°C and the time is 2-3 hours.

[0023] Preferably, in step (4), the diameter of the monofilament of the modified polyaryl ester fiber is 22-30 μm, and the multifilament strength of the modified polyaryl ester fiber is 22-25 cN / dtex.

[0024] Preferably, in step (5), the aggregate consists of coarse aggregate and fine aggregate, wherein the coarse aggregate is any one or more of limestone, basalt, and granite, and the fine aggregate is any one or more of stone chips, natural sand, and manufactured sand.

[0025] Preferably, in step (5), the preheating temperature is 170-180°C.

[0026] Preferably, in step (5), the mixing time is 90 to 200 seconds.

[0027] Preferably, in step (5), the stirring time is 20 to 30 seconds.

[0028] Preferably, in step (6), the asphalt is No. 90 base asphalt.

[0029] Preferably, in step (6), the preheating temperature of the asphalt is 150-170°C.

[0030] Preferably, in step (6), the stirring time is 70 to 190 seconds.

[0031] Preferably, in step (6), the mineral powder is shale mineral powder.

[0032] Preferably, in step (6), the preheating temperature of the mineral powder is 180-200°C.

[0033] Preferably, in step (6), the temperature for heat preservation is 155-185°C and the time is 60-110 min.

[0034] The basic principle of this invention:

[0035] Polyaryl ester fibers have excellent physical and chemical properties, such as low water absorption, low creep, lightweight and high strength, and resistance to chemical corrosion, making them ideal reinforcing materials. However, they have disadvantages such as a very smooth surface, lack of active groups, and poor adhesion to the matrix material. Therefore, surface treatment is required to increase their bonding strength with the matrix material.

[0036] This invention treats polyaryl ester fibers with a detergent to remove the initial oiling agent from the fiber surface. Then, a silane coupling agent is applied to the fibers. These organosilane compounds can form hydrogen bonds with the base asphalt. The silanols generated after hydrolysis can react and bond with the hydroxyl groups on the polyaryl ester fiber surface, thus coupling two materials with different properties together, thereby improving interfacial adhesion and increasing the strength of the composite material. Simultaneously, the silane coupling agent forms a coating on the fiber surface, making the originally smooth polyaryl ester fiber surface relatively rough, increasing the compatibility between the fiber and the asphalt binder. The polyaryl ester fiber surface is smooth, with almost no polar groups and poor hydrophilicity. Due to the action of the silane coupling agent, the surface energy of the fiber is reduced, making it more difficult to be wetted by water, further enhancing the water damage resistance of the asphalt mixture.

[0037] Polyaryl ester fibers are dispersed in asphalt, and the large surface area forms a contact interface layer. In the interface layer, some asphalt binder adheres to the fiber surface to form a structural asphalt layer, which has better adhesion than the free asphalt outside the interface layer, thus improving the adhesion performance of the asphalt and enabling the pavement to maintain good shape stability at high temperatures.

[0038] Compared with the prior art, the beneficial effects of the present invention are:

[0039] (1) The modified polyaryl ester fiber asphalt mixture of the present invention, by adding modified polyaryl ester fiber to the mixture, helps to reduce the temperature sensitivity of asphalt; the physical properties of ordinary asphalt change significantly when the temperature changes, such as softening at high temperature and becoming brittle at low temperature; after adding polyaryl ester fiber, due to its low coefficient of thermal expansion over a wide temperature range, the asphalt can maintain relatively stable performance at different temperatures, reducing the impact of temperature changes on the performance of asphalt pavement, making the pavement less prone to cracking in winter and less prone to softening and deformation in summer; in addition, due to the low water absorption of the modified fiber, the asphalt mixture has good resistance to water damage.

[0040] (2) By rationally optimizing the length of polyarylate short-cut fibers, a small amount of short-cut fibers are evenly dispersed inside the matrix asphalt through thorough stirring. This is sufficient to form a dense network structure inside the asphalt, which can further reduce the amount of short fibers used and greatly reduce the cost of asphalt modification. Detailed Implementation

[0041] To better understand the content of this invention, further description is provided below with reference to specific embodiments. It should be understood that these embodiments are only for further illustration of the invention and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the description of this invention, those skilled in the art may make some non-essential modifications or adjustments to the invention, which still fall within the protection scope of this invention.

[0042] The aggregate gradation ranges in Examples 1-8 and Comparative Examples 1-5 adopted SMA-13 ​​in the "Technical Specification for Construction of Highway Asphalt Pavement" (JTG F40-2004), as shown in Table 1.

[0043] Table 1 Overall Gradation Range of Asphalt Mixture Aggregates

[0044]

[0045] A method for preparing a modified polyaryl ester fiber asphalt mixture, comprising the following steps:

[0046] (1) Fiber pretreatment:

[0047] Ethanol solution and deionized water were prepared to form an ethanol solution with a volume concentration of 15%. Polyarylate fiber (Ningbo Haigela New Material Technology Co., Ltd., HT-50D / 10F) was then immersed in the ethanol solution for 30 min, followed by ultrasonic washing in an ethanol solution of the same concentration for 20 min, and finally dried at 130℃ for 1.5 h.

[0048] (2) Preparation of silane coupling agent:

[0049] Anhydrous ethanol and deionized water were mixed in a volume ratio of 4:6 to prepare an ethanol solution; then, silane coupling agent KH-560 was added to the above ethanol solution at a concentration of 5 wt% to 10 wt% of the ethanol solution; the mixture was stirred thoroughly and allowed to stand for 40 minutes to allow the silane coupling agent to be fully hydrolyzed.

[0050] (3) Fibers treated with coupling agents:

[0051] The fiber obtained in step (1) is immersed in the silane coupling agent prepared in step (2) for 1 hour to allow the two to react fully; then it is dried in an oven at 100°C for 2 hours to obtain modified polyarylate fiber.

[0052] (4) Weighing and cutting the modified fibers:

[0053] Weigh the modified polyarylate fiber obtained in step (3) at 0.5% to 1% of the weight of asphalt and cut it to 1 to 4 mm. The monofilament diameter of the modified polyarylate fiber is 22 μm and the multifilament strength of the modified polyarylate fiber is 22 cN / dtex.

[0054] (5) Dry mixing of aggregates and fibers:

[0055] After the aggregate is dried, it is weighed according to the gradation and its weight is 12.1 kg. The aggregate and the mixing pot are preheated to 170°C. Then the aggregate is mixed in the pot for 100 seconds. Then the short-cut modified polyarylate fiber from step (4) is added and stirred for 20 seconds. The short-cut fiber is added in 4 batches to make the fiber evenly mixed. The aggregate is composed of coarse aggregate and fine aggregate, wherein the coarse aggregate is basalt and the fine aggregate is manufactured sand.

[0056] (6) Preparation of asphalt mixture (wet mixing):

[0057] Add No. 90 base asphalt preheated to 150℃ to the dry mix obtained in step (5), the amount of No. 90 base asphalt added is 71% of the aggregate weight, and stir for 170s; then add dried and preheated shale mineral powder at 180℃ to the mixing pot, the amount of shale mineral powder added is 8% of the aggregate weight, and stir for 120s; then keep warm at 180℃ for 90min to obtain modified polyarylate fiber asphalt mixture.

[0058] The values ​​of chopped polyaryl ester fiber length, polyaryl ester fiber content, and coupling agent addition involved in the preparation of asphalt mixtures in Examples 1-8 and Comparative Examples 1-5 are shown in Table 2.

[0059] The rutting resistance and water damage resistance of the asphalt mixtures prepared in Examples 1-8 and Comparative Examples 1-5 were tested. The dynamic stability and water immersion residual stability of the samples were determined according to the standard JTG E20-2011 "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering". The specific test results are shown in Table 2.

[0060] Table 2 shows the values ​​of relevant parameters involved in the preparation of asphalt mixtures in Examples 1-8 and Comparative Examples 1-5, and the performance test results of the prepared asphalt mixtures.

[0061]

[0062] The foregoing description is not intended to limit the invention, nor is the invention limited to the examples given. Any changes, modifications, additions, or substitutions made by those skilled in the art within the scope of the invention should also be considered within the protection scope of the invention.

Claims

1. A method for preparing a modified polyarylate fiber asphalt mixture, characterized in that, Includes the following steps: (1) Fiber pretreatment: Prepare a washing solution by mixing detergent and deionized water, then soak the polyarylate fiber in the washing solution, then ultrasonically wash it in the same concentration of washing solution, and finally dry it. (2) Preparation of silane coupling agent: Prepare an ethanol solution by mixing anhydrous ethanol and water in a certain proportion; then add the silane coupling agent to the above ethanol solution, the amount of which is 5wt% to 10wt% of the ethanol solution; stir thoroughly and let stand to allow the silane coupling agent to be fully hydrolyzed; (3) Coupling agent treatment of fibers: The fibers obtained in step (1) are immersed in the silane coupling agent prepared in step (2) to allow the two to react fully; then they are dried in an oven to obtain modified polyarylate fibers. (4) Weighing and cutting the modified fiber: Weigh the modified polyarylate fiber obtained in step (3) at 0.5% to 1% of the weight of the asphalt, and cut it to 1 to 4 mm. (5) Dry mixing of aggregates and fibers: After the aggregates are dried, weigh them according to the gradation, preheat the aggregates and mixing pot, then mix the aggregates in the pot, and then add the short-cut modified polyarylate fibers from step (4) and stir. The short fibers are added in multiple batches to make the fibers evenly mixed. (6) Preparation of asphalt mixture: Add preheated asphalt to the dry mixture obtained in step (5), wherein the amount of asphalt added is 71% to 83% of the weight of the aggregate, and stir; then add dried and preheated mineral powder to the mixing pot, wherein the amount of mineral powder added is 7% to 11% of the weight of the aggregate, and stir. Then, heat preservation is performed to obtain modified polyarylate fiber asphalt mixture.

2. The method for preparing a modified polyarylate fiber asphalt mixture as described in claim 1, characterized in that, In step (1), the detergent is any one or both of ethanol solution and acetone solution.

3. The method for preparing a modified polyarylate fiber asphalt mixture as described in claim 1, characterized in that, In step (2), the volume ratio of anhydrous ethanol to water is 4:

6.

4. The method for preparing a modified polyarylate fiber asphalt mixture as described in claim 1, characterized in that, In step (2), the silane coupling agent is any one or more of KH-550, KH-560, and KH-570.

5. The method for preparing a modified polyarylate fiber asphalt mixture as described in claim 1, characterized in that, In step (4), the diameter of the monofilament of the modified polyaryl ester fiber is 22-30 μm, and the multifilament strength of the modified polyaryl ester fiber is 22-25 cN / dtex.

6. The method for preparing a modified polyarylate fiber asphalt mixture as described in claim 1, characterized in that, In step (5), the aggregate consists of coarse aggregate and fine aggregate, wherein the coarse aggregate is any one or more of limestone, basalt, and granite, and the fine aggregate is any one or more of stone chips, natural sand, and manufactured sand.

7. The method for preparing a modified polyarylate fiber asphalt mixture as described in claim 1, characterized in that, In step (5), the preheating temperature is 170-180℃; the mixing time is 90-200s; and the stirring time is 20-30s.

8. The method for preparing a modified polyarylate fiber asphalt mixture as described in claim 1, characterized in that, In step (6), the asphalt is No. 90 base asphalt; the preheating temperature of the asphalt is 150-170℃; and the stirring time is 70-190s.

9. The method for preparing a modified polyarylate fiber asphalt mixture as described in claim 1, characterized in that, In step (6), the mineral powder is shale mineral powder; the preheating temperature of the mineral powder is 180-200℃.

10. A modified polyarylate fiber asphalt mixture, characterized in that, It is prepared by the preparation method of the modified polyaryl ester fiber asphalt mixture as described in any one of claims 1 to 9.

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