Modified polyarylester fiber asphalt mixture and preparation method thereof

Abstract

The invention discloses a modified polyarylester fiber asphalt mixture and a preparation method thereof. The preparation method comprises the following steps: (1) pretreating fibers; (2) preparing a silane coupling agent; (3) treating the fibers with a coupling agent; (4) weighing and chopping the modified fibers; (5) aggregate and fiber dry mixing; and (6) preparing the asphalt mixture. According to the invention, the surface of the polyarylester fiber is treated by using a detergent, a previous oiling agent is removed, and then the fiber is treated by using a silane coupling agent, so that the surface activity of the fiber is improved, and the compatibility of the polyarylester fiber as a fiber stabilizer in an asphalt mixture is improved; the polyarylester short fiber asphalt mixture is prepared by controlling the length of the polyarylester short fibers and the mixing amount of the polyarylester short fibers in the matrix asphalt and combining a manufacturing process of firstly dry mixing, then wet mixing and adding the short fibers for multiple times, and the defects of insufficient rutting resistance and poor water damage resistance of a traditional asphalt mixture are overcome.

Description

Technical Field

[0001] The invention relates to the technical field of asphalt pavement materials, and in particular to a modified polyarylate fiber asphalt mixture and a preparation method thereof. Background Art

[0002] Traditional asphalt mixtures are widely used in the construction of highways, airport runways, and parking lots because of their advantages such as simple construction and low cost. With the increasing development of the national economy, the urban road network is becoming more and more developed. Asphalt pavements, as the "cornerstone" of this network, are undergoing high-frequency, heavy-load rolling and erosion from various environments. Problems such as poor durability and poor temperature tolerance of traditional asphalt mixtures have gradually been exposed, which in turn cause road rutting, cracking and other diseases. These problems lead to early damage to the road surface, shorten the service life of the road, and increase maintenance costs. Therefore, it is becoming increasingly important to modify conventional asphalt mixtures and improve their comprehensive performance to meet the requirements of use in various environments.

[0003] Asphalt mixture is mainly composed of coarse aggregate, fine aggregate, matrix asphalt, mineral powder and additives. In the prior art, polymer modified asphalt (PMB) can be used, that is, polymer is added to asphalt by mechanical mixing or chemical reaction to improve the performance of asphalt mixture. The more commonly used polymers in polymer asphalt modification are SBS (styrene-butadiene-styrene block copolymer), SBR (styrene-butadiene rubber), EVA (ethylene-vinyl acetate copolymer), PE, etc. However, the existing asphalt mixture still has the defects of insufficient rutting resistance and poor water damage resistance. Summary of the invention

[0004] The technical problem to be solved by the present invention is to overcome the technical defects of the background technology and provide a modified polyarylate fiber asphalt mixture and a preparation method thereof. The purpose of the present invention is to provide a modified polyarylate fiber asphalt mixture and a preparation method thereof with low manufacturing cost and excellent water damage resistance and rutting resistance; the present invention uses a detergent to treat the surface of the polyarylate fiber to remove the front oil agent, and then uses a silane coupling agent to treat the fiber to increase its surface activity, thereby improving the compatibility of the polyarylate fiber as a fiber stabilizer in the asphalt mixture; the present invention controls the length of the polyarylate staple fiber and its dosage in the matrix asphalt, combines the production process of dry mixing first, wet mixing later, and adding the staple fiber multiple times, to obtain the polyarylate staple fiber asphalt mixture, which solves the defects of insufficient rutting resistance and poor water damage resistance in the traditional asphalt mixture.

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

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

[0007] (1) Fiber pretreatment: Detergent and deionized water are prepared into a washing solution, and then the polyarylate fiber is placed in the washing solution for immersion, and then ultrasonically washed in the washing solution of the same concentration, and finally dried;

[0008] (2) preparing a silane coupling agent: preparing an ethanol solution by mixing anhydrous ethanol and water in a certain proportion; then adding the silane coupling agent to the ethanol solution in an amount of 5 wt% to 10 wt% of the ethanol solution; stirring the mixture thoroughly and allowing it to stand to allow the silane coupling agent to be fully hydrolyzed;

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

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

[0011] (5) Aggregate and fiber dry mixing: After the aggregate is dried, it is weighed according to the grading, the aggregate and the mixing pot are preheated, and then the aggregate is mixed in the pot, and then the short-cut modified polyarylate fiber of step (4) is added and stirred, and the short fiber is added in multiple times to ensure that the fibers are evenly mixed;

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

[0013] Preferably, in step (1), the detergent is any one or both of an ethanol solution and an 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 standing 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 drying time is 2-3 hours.

[0023] Preferably, in step (4), the monofilament diameter of the modified polyarylate fiber is 22 to 30 μm, and the multifilament strength of the modified polyarylate fiber is 22 to 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 machine-made 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 insulation temperature is 155-185° C. and the insulation time is 60-110 min.

[0034] Basic principles of the present invention:

[0035] Polyarylate fiber has excellent physical and chemical properties, such as low water absorption, low creep, light weight, high strength, and chemical corrosion resistance. It is an ideal reinforcing material. However, it has the disadvantages of a very smooth surface, lack of active groups, and poor adhesion to the matrix material. Therefore, it needs to be surface treated to increase its bonding strength with the matrix material.

[0036] The present invention treats polyarylate fiber with detergent, removes the front oil agent on the fiber surface, and then uses silane coupling agent to act on the fiber, and hydrogen bonds can be formed between this type of organic silane compound and matrix asphalt, and the silanol generated after its hydrolysis can react and bond with the hydroxyl group on the surface of the polyarylate fiber, so that two materials of different properties are coupled together, thereby improving the interfacial adhesion performance and improving the strength of the composite material. At the same time, the silane coupling agent forms a coating on the fiber surface, so that the originally smooth polyarylate fiber surface becomes relatively rough, and the compatibility of the fiber and the asphalt binder is increased. The surface of the polyarylate fiber is smooth, there is almost no polar group, and the hydrophilicity is poor. Due to the effect of the silane coupling agent, the fiber surface energy is reduced, and it is more difficult to be wetted by water, which further enhances the water damage resistance of the asphalt mixture.

[0037] Polyarylate fibers are dispersed in asphalt, and a large amount of surface area forms a contact interface layer. In the interface layer, part of the 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, improving the adhesion of asphalt and allowing the road surface to maintain good shape stability at high temperatures.

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] (1) The modified polyarylate fiber asphalt mixture of the present invention, by adding the modified polyarylate fiber to the mixture, helps to reduce the temperature sensitivity of asphalt; the physical properties of ordinary asphalt will change greatly when the temperature changes, such as becoming soft at high temperature and becoming brittle at low temperature; after adding the polyarylate fiber, due to its low thermal expansion coefficient in 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 brittle cracking in winter and less prone to softening and deformation in summer; in addition, due to the low water absorption rate of the modified fiber, the prepared asphalt mixture has good water damage resistance;

[0040] (2) The present invention rationally optimizes the length of polyarylate chopped fibers, and a small amount of chopped fibers are fully stirred to be uniformly dispersed in the matrix asphalt, which is sufficient to form a dense network structure in the asphalt, further reducing the amount of short fibers used and greatly reducing the cost of asphalt modification. DETAILED DESCRIPTION

[0041] In order to better understand the content of the present invention, further description is given below in conjunction with specific embodiments. It should be understood that these embodiments are only used to further illustrate the present invention, and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content described in the present invention, those skilled in the art make some non-essential changes or adjustments to the present invention, which still belong to the protection scope of the present invention.

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

[0043] Table 1 Overall gradation range of asphalt mixture aggregate

[0044]

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

[0046] (1) Fiber pretreatment:

[0047] The ethanol solution and deionized water were prepared into an ethanol solution with a volume concentration of 15%, and then the polyarylate fiber (Ningbo Haigla New Material Technology Co., Ltd., HT-50D / 10F) was placed in the ethanol solution and soaked for 30 minutes, and then ultrasonically washed in the ethanol solution of the same concentration for 20 minutes, and finally dried at 130°C for 1.5 hours;

[0048] (2) Prepare silane coupling agent:

[0049] Anhydrous ethanol and deionized water are prepared into an ethanol solution in a volume ratio of 4:6; then the silane coupling agent KH-560 is added to the above ethanol solution in an amount of 5wt% to 10wt% of the ethanol solution; the mixture is stirred fully and allowed to stand for 40 minutes to allow the silane coupling agent to be fully hydrolyzed;

[0050] (3) Coupling agent treated fibers:

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

[0052] (4) Weighing and chopping of modified fibers:

[0053] Weighing the modified polyarylate fiber obtained in step (3) at 0.5% to 1% of the weight of the asphalt, and chopping it into 1 to 4 mm, wherein 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) Aggregate and fiber dry mix:

[0055] After the aggregate is dried, it is weighed according to the grading, and its weight is 12.1 kg. The aggregate and the mixing pot are preheated to 170° C., and then the aggregate is mixed in the pot for 100 seconds, and then the short-cut modified polyarylate fiber of step (4) is added and stirred for 20 seconds. The short-cut fiber is added in 4 times to make the fiber mix uniformly; the aggregate is composed of coarse aggregate and fine aggregate, wherein the coarse aggregate is basalt, and the fine aggregate is machine-made sand;

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

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

[0058] The values ​​of the length of the chopped polyarylate fibers, the amount of polyarylate fibers, and the amount of coupling agent added in the asphalt mixture preparation process of Examples 1 to 8 and Comparative Examples 1 to 5 are shown in Table 2.

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

[0060] Table 2 Values ​​of relevant parameters involved in the preparation process of asphalt mixtures of Examples 1 to 8 and Comparative Examples 1 to 5 and performance test results of the prepared asphalt mixtures

[0061]

[0062] The above description is not intended to limit the present invention, and the present invention is not limited to the above examples. Any changes, modifications, additions or substitutions made by a person skilled in the art within the spirit and scope of the present invention shall also fall within the protection scope of the present invention.

Claims

1. A method for preparing a modified polyarylate fiber asphalt mixture, characterized in that: The steps include: (1) Fiber pretreatment: Detergent and deionized water are prepared into a washing solution, and then the polyarylate fiber is placed in the washing solution for immersion, and then ultrasonically washed in the washing solution of the same concentration, and finally dried; (2) preparing a silane coupling agent: preparing an ethanol solution by mixing anhydrous ethanol and water in a certain proportion; then adding the silane coupling agent to the ethanol solution in an amount of 5 wt% to 10 wt% of the ethanol solution; stirring the mixture thoroughly and allowing it to stand to allow the silane coupling agent to be fully hydrolyzed; (3) Coupling agent treatment of fibers: soaking the fibers obtained in step (1) in the silane coupling agent prepared in step (2) to allow the two to react fully; then drying in an oven to obtain modified polyarylate fibers; (4) Weighing and chopping the modified fiber: Weigh the modified polyarylate fiber obtained in step (3) at 0.5% to 1% of the weight of the asphalt, and chop it into 1 to 4 mm; (5) Aggregate and fiber dry mixing: After the aggregate is dried, it is weighed according to the grading, the aggregate and the mixing pot are preheated, and then the aggregate is mixed in the pot, and then the short-cut modified polyarylate fiber of step (4) is added and stirred, and the short fiber is added in multiple times to ensure that the fibers are evenly mixed; (6) preparing an asphalt mixture: adding preheated asphalt to the dry mixture obtained in step (5), wherein the amount of the asphalt added is 71% to 83% of the weight of the aggregate, and stirring; then adding dried and preheated mineral powder to a mixing pot, wherein the amount of the mineral powder added is 7% to 11% of the weight of the aggregate, and stirring; Then the mixture is kept warm to obtain a modified polyarylate fiber asphalt mixture.

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

3. The method for preparing a modified polyarylate fiber asphalt mixture according to 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 according to 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 according to claim 1, characterized in that: In step (4), the monofilament diameter of the modified polyarylate fiber is 22 to 30 μm, and the multifilament strength of the modified polyarylate fiber is 22 to 25 cN / dtex.

6. The method for preparing a modified polyarylate fiber asphalt mixture according to 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 machine-made sand.

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

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

9. The method for preparing a modified polyarylate fiber asphalt mixture according to claim 1, characterized in that: In step (6), the mineral powder is shale mineral powder; and the preheating temperature of the mineral powder is 180-200°C.

10. A modified polyarylate fiber asphalt mixture, characterized in that: The modified polyarylate fiber asphalt mixture is prepared by the method for preparing the modified polyarylate fiber asphalt mixture as described in any one of claims 1 to 9.

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