High-performance asphalt concrete for water conservancy projects and method for preparing the same

Abstract

The application discloses high-performance asphalt concrete for hydraulic engineering and a preparation method thereof, and belongs to the field of asphalt concrete, and comprises the following steps: mixing coarse aggregate, fine aggregate, filler and modified fiber, stirring for 2-4 min at 160 DEG C-175 DEG C to obtain dry materials, then mixing the obtained dry materials with modified asphalt, stirring for 3-6 min at a temperature of 170 DEG C-180 DEG C, discharging, pouring into a mold, demolding, curing, and obtaining the high-performance asphalt concrete. The asphalt concrete obtained by the application has good tear resistance, toughness and high-temperature slope stability, meets the requirements of water conservancy anti-seepage structures in fields such as water conservancy engineering, and has high practicability.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of asphalt concrete, and particularly relates to high-performance asphalt concrete for water conservancy projects and a preparation method thereof. BACKGROUND

[0002] Asphalt concrete is increasingly applied in water conservancy projects in China due to its excellent anti-seepage performance, strong deformation capacity, and the ability to be repaired in time once problems occur, and its performance is gradually recognized by the engineering field. In recent years, China has been able to independently complete the construction of asphalt concrete anti-seepage panels, asphalt concrete core walls and other structures. The safety and stability of asphalt concrete as the main material for the anti-seepage structure of hydraulic structures are crucial. For example, Chinese patent CN114409311A discloses a high-performance asphalt concrete and a preparation method thereof. The asphalt concrete is composed of asphalt, a strengthening agent, mineral powder and acid aggregate. The surface of the acid aggregate is rich in polar components such as silicon dioxide, showing strong hydrophilicity. However, asphalt is a non-polar or weakly polar substance, and it is difficult for the two to form effective adsorption between molecules, which can lead to loose mixture structure, aggregate shedding, and insufficient slope stability at high temperatures. In a high-humidity environment, water intrusion can exacerbate interfacial peeling, accelerate aging, and free calcium oxide and magnesium oxide may be left in the steel slag powder, which can easily expand in volume when exposed to water, causing cracks or local deformation during long-term use. SUMMARY

[0003] To solve the problems of easy deformation, easy breakage and high slope flow value, the application provides high-performance asphalt concrete for water conservancy projects and a preparation method thereof.

[0004] The object of the application can be achieved by the following technical solutions:

[0005] The high-performance asphalt concrete for water conservancy projects and the preparation method thereof comprise the following steps:

[0006] Firstly, the following raw materials are prepared: 36-46 parts of modified asphalt, 220-260 parts of coarse aggregate, 240-280 parts of fine aggregate, 60-80 parts of filler and 1-4 parts of modified basalt fiber;

[0007] Secondly, the coarse aggregate, fine aggregate, filler and modified fiber are mixed and stirred at 160-175 DEG C for 2-4 minutes to obtain dry materials, and then the dry materials and modified asphalt are mixed, discharged, poured into a mold, demolded, cured, and high-performance asphalt concrete is obtained.

[0008] Further, the modified asphalt is prepared by the following steps:

[0009] The matrix asphalt, furfural extract oil and layered double hydroxyl complex metal hydroxide are put into an oil bath pot, stirred at 140-160 DEG C for 10-30 min, sheared by a shearing emulsifier at a speed of 3000 r / min for 60-80 min, then the cyclic dextrin is added, and shearing is continued at a speed of 3000 r / min for 5-10 min, to obtain the modified asphalt.

[0010] Further, the mass ratio of the matrix asphalt, the furfural extract oil, the layered double hydroxyl complex metal hydroxide and the cyclic dextrin is 1:0.02-0.05:0.05-0.1:0.01-0.02, and the layered double hydroxyl complex metal hydroxide is Mg 1-X Al X (OH)2(CO3) X / 2·mH2O, wherein the subscript X represents the change of metal element content, 0.2≤X≤0.33, and m represents the content of contained crystal water, 0≤m≤2.

[0011] Further, the modified basalt fiber is prepared by the following steps:

[0012] S1, first, the basalt fiber is washed in acetone by ultrasonic, to obtain washed basalt fiber, then the γ-aminopropyl triethoxysilane and a 95% mass fraction ethanol solution are added into a flask, the basalt fiber is immersed for 30-60 min, taken out, and reacted at 105-115 DEG C for 2-4 h, washed, and dried, to obtain aminated basalt fiber;

[0013] In the above reaction, the dosage ratio of acetone, basalt fiber, γ-aminopropyl triethoxysilane and a 95% mass fraction ethanol solution is 250 mL:20 g:20 mL:200-300 mL.

[0014] S2, maleic anhydride grafted SBS is added into toluene and swelled for 1-2 d, to obtain a swelling liquid, the aminated basalt fiber is dispersed in toluene by ultrasonic for 20-30 min, the swelling liquid is added, and reacted at 90-110 DEG C for 40-80 min, then triethylamine is added, and reacted at 105-115 DEG C for 2-4 d, and dried, to obtain modified basalt fiber.

[0015] In the above reaction, the dosage ratio of maleic anhydride grafted SBS, aminated basalt fiber and triethylamine is 2-5 g:20 g:1 mL.

[0016] Further, the coarse aggregate and the fine aggregate are both limestone.

[0017] Further, the mixing temperature of the dry material and the modified asphalt is 170 DEG C-180 DEG C, and the stirring time is 3-6 min.

[0018] The present application has the following beneficial effects:

[0019] 1. The application discloses a modified asphalt concrete, which is prepared by mixing coarse aggregate, fine aggregate, filler and modified fiber to obtain dry materials, and then mixing the dry materials and modified asphalt, wherein the coarse aggregate and the fine aggregate are both limestone, which belongs to alkaline aggregate instead of acid aggregate, and the obtained asphalt concrete has good tear resistance, toughness and high-temperature slope stability, and can meet the requirements of water conservancy engineering and other fields.

[0020] 2. The application forms an intercalation complex by adsorbing the polar components in the asphalt through the positive charge between the layers of the layered double hydroxide (LDH), enhances the cohesion between the asphalt molecules, and inhibits high-temperature flow, and the circular dextrin inhibits the high-temperature volatilization and migration of the low-molecular-weight hydrocarbons in the asphalt by covering the low-molecular-weight hydrocarbons through the hydrophobic cavity, and forms an "intercalation-coating" double network together with the LDH, thereby improving the high-temperature stability of the asphalt concrete material.

[0021] 3. The application grafts the amino group and the Si-O-Si structure on the surface of the basalt fiber through a chemical method, improves the hydrophobicity of the basalt fiber, facilitates the amidation reaction between the amino group and the acid anhydride group, forms a covalent bond, significantly inhibits the interface peeling, and the furfural extracted oil is rich in aromatic hydrocarbons, can enhance the compatibility between the asphalt and the SBS, and can form a "fiber-SBS-asphalt" three-dimensional elastic network as a bridge to inhibit the expansion of cracks. DETAILED DESCRIPTION

[0022] The technical solutions in the embodiments of the application will be clearly and completely described below with reference to the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the application.

[0023] In the application, the fiber has a length of 6-9 mm, a diameter of 10-15 mu m, a tensile strength of 1500-3200 MPa, and an elastic modulus of 80-120 GPa.

[0024] The layered double hydroxide composite metal hydroxide is provided by Jiangyin Ruifa Chemical Co., Ltd.

[0025] The maleic anhydride grafted SBS is provided by Yangzhou Henghui Chemical Co., Ltd.

[0026] Embodiment 1

[0027] A modified asphalt is prepared by the following steps:

[0028] Put 2000g base pitch, 20g furfural extract oil and 50g layered double hydroxyl complex metal hydroxide into an oil bath pot, stir at 140℃ for 10min, shear with a shear emulsifier at a rate of 3000r / min for 60min, then add 20g cyclic dextrin, continue to shear at a rate of 3000r / min for 5min, to obtain modified pitch.

[0029] Example 2

[0030] A modified pitch is prepared by the following steps:

[0031] Put 2000g base pitch, 50g furfural extract oil and 100g layered double hydroxyl complex metal hydroxide into an oil bath pot, stir at 140-160℃ for 30min, shear with a shear emulsifier at a rate of 3000r / min for 80min, then add 20g cyclic dextrin, continue to shear at a rate of 3000r / min for 10min, to obtain modified pitch.

[0032] Example 3

[0033] A modified basalt fiber is prepared by the following steps:

[0034] S1, first wash 20g basalt fiber in 250mL acetone by ultrasonic, to obtain washed basalt fiber, then add 20mL γ-aminopropyl triethoxysilane, 200mL 95% mass fraction ethanol solution into a flask, immerse for 30min, take out the immersed basalt fiber, react at 105℃ for 2h, wash, dry, to obtain aminated basalt fiber;

[0035] S2, add 2g maleic anhydride to 200mL toluene, swell for 1d, to obtain a swelling liquid, put 20g aminated basalt fiber into 400mL toluene, ultrasonic disperse for 20min, add the swelling liquid, react at 90℃ for 40min, then add 1mL triethylamine, react at 105℃ for 2d, dry, to obtain modified basalt fiber.

[0036] Example 4

[0037] A modified basalt fiber is prepared by the following steps:

[0038] S1, first wash 20g basalt fiber in 250mL acetone by ultrasonic, to obtain washed basalt fiber, then add 20mL γ-aminopropyl triethoxysilane, 300mL 95% mass fraction ethanol solution into a flask, immerse for 60min, take out the immersed basalt fiber, react at 115℃ for 4h, wash, dry, to obtain aminated basalt fiber;

[0039] S2, 5g of maleic anhydride grafted SBS was added to 200mL of toluene to swell for 2d to obtain a swelling solution, 20g of aminated basalt fiber was dispersed in 400mL of toluene by ultrasonic for 30min, the swelling solution was added, and the reaction was carried out at 110℃ for 80min, then 1mL of triethylamine was added, and the reaction was carried out at 115℃ for 4d, and then dried to obtain the modified basalt fiber.

[0040] Example 5

[0041] A modified basalt fiber was prepared by the following steps:

[0042] S1, 20g of basalt fiber was first washed with 250mL of acetone by ultrasonic to obtain washed basalt fiber, then 20mL of γ-aminopropyl triethoxysilane and 250mL of 95% ethanol solution were added to the flask, and the basalt fiber was immersed for 40min, then taken out and reacted at 110℃ for 3h, washed and dried to obtain aminated basalt fiber;

[0043] S2, 4g of maleic anhydride grafted SBS was added to 200mL of toluene to swell for 1.5d to obtain a swelling solution, 20g of aminated basalt fiber was dispersed in 400mL of toluene by ultrasonic for 25min, the swelling solution was added, and the reaction was carried out at 105℃ for 60min, then 1mL of triethylamine was added, and the reaction was carried out at 110℃ for 3d, and then dried to obtain the modified basalt fiber.

[0044] Example 6

[0045] A method for preparing high-performance asphalt concrete for water conservancy projects, comprising the following steps:

[0046] Firstly, the following raw materials were prepared: 36 parts of modified asphalt, 220 parts of coarse aggregate, 240 parts of fine aggregate, 60 parts of filler, and 1 part of modified basalt fiber;

[0047] Secondly, the coarse aggregate, fine aggregate, filler and modified fiber were mixed and stirred at 160℃ for 2min to obtain dry materials, and then the dry materials and modified asphalt were mixed at a mixing temperature of 170℃ for 6min, discharged, poured into a mold, demolded, and cured to obtain high-performance asphalt concrete.

[0048] Example 7

[0049] Firstly, the following raw materials were prepared: 46 parts of modified asphalt, 260 parts of coarse aggregate, 280 parts of fine aggregate, 80 parts of filler, and 4 parts of modified basalt fiber;

[0050] Second step, mix coarse aggregate, fine aggregate, filler and modified fiber, stir at 175℃ for 4min to obtain dry material, then mix the obtained dry material and modified asphalt, the mixing temperature is 180℃, the stirring time is 6min, discharge, pour into the mold, demold, maintain, obtain high performance asphalt concrete.

[0051] Example 8

[0052] First step, prepare the following raw materials by weight: modified asphalt 40 parts, coarse aggregate 240 parts, fine aggregate 260 parts, filler 74 parts, modified basalt fiber 2 parts;

[0053] Second step, mix coarse aggregate, fine aggregate, filler and modified fiber, stir at 165℃ for 3min to obtain dry material, then mix the obtained dry material and modified asphalt, the mixing temperature is 175℃, the stirring time is 5min, discharge, pour into the mold, demold, maintain, obtain high performance asphalt concrete.

[0054] Comparative example 1

[0055] Compared with example 8, replace "modified asphalt" in example 8 with "matrix asphalt", and the rest of the raw materials and preparation process are the same as example 8.

[0056] Comparative example 2

[0057] Compared with example 8, replace "modified basalt fiber" in example 8 with "basalt fiber", and the rest of the raw materials and preparation process are the same as example 8.

[0058] Comparative example 3

[0059] Compared with example 8, replace "modified asphalt" and "modified basalt fiber" in example 8 with "matrix asphalt" and "basalt fiber", and the rest of the raw materials and preparation process are the same as example 8.

[0060] The performance test is carried out on the obtained example 6- example 8 and comparative example 1- comparative example 2, according to the "hydraulic asphalt concrete test procedure" DL / T5362-2018, the asphalt concrete is subjected to slope flow test, the test temperature is 80℃, and the slope flow value is detected after 48 hours.

[0061] The asphalt concrete is made into a test piece with a diameter of 100mm and a height of 60mm, which is placed at a temperature of-20℃ for 7days, and then the splitting performance and compressive performance of the asphalt concrete are tested according to the method of JTJ052-2000.

[0062] The freeze break test is carried out on the asphalt concrete according to the "hydraulic asphalt concrete test procedure" DL / T5362-2018, and the freeze break temperature is detected under the test condition of 30℃ / h.

[0063] The test results are shown in Table 1:

[0064] Table 1

[0065]

[0066] As can be seen from Table 1, the asphalt concrete slope flow values of Examples 6-8 are 0.583-0.762 mm, and the stability in high temperature is higher; the asphalt concrete splitting strength of Examples 6-8 is 4.32-4.84 MPa, the compressive strength is 10.26-11.84 MPa, and the freeze break temperature is minus 55.62 to minus 53.28, and the crack resistance and toughness in low temperature are better.

[0067] It should be noted that the relational terms herein such as first and second and the like are used solely to distinguish one entity or action from another, without necessarily requiring or implying any such actual relationship or order between such entities or actions. Moreover, the terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can include other elements not expressly listed or inherent to such process, method, article, or apparatus.

[0068] Although embodiments of the present application have been shown and described, it is to be understood that various modifications, substitutions, alternatives, and variations can be made in the embodiments without departing from the spirit and scope of the present application as defined by the appended claims and their equivalents.

Claims

1. A method for preparing high-performance asphalt concrete for hydraulic engineering, characterized by, It comprises the following steps: The first step, prepare the following weight parts of raw materials: modified asphalt 36-46 parts, coarse aggregate 220-260 parts, fine aggregate 240-280 parts, filler 60-80 parts, modified basalt fiber 1-4 parts; The second step, mix the coarse aggregate, fine aggregate, filler and modified fiber, stir at 160-180 DEG C for 2-4 min to obtain dry material, then mix the obtained dry material and modified asphalt, discharge, pour into the mold, demold, maintain, obtain high-performance asphalt concrete; The modified asphalt is prepared by the following steps: Put the base asphalt, furfural extract oil and layered double hydroxyl composite metal hydroxide into an oil bath pot, stir at 140-160 DEG C for 10-30 min, shear with a shear emulsifier at a speed of 3000 r / min for 60-80 min, then add cyclic dextrin, continue to shear at a speed of 3000 r / min for 5-10 min to obtain modified asphalt; The modified basalt fiber is prepared by the following steps: S1, first wash the basalt fiber in acetone by ultrasonic to obtain washed basalt, then add gamma-aminopropyl triethoxysilane and 95% mass fraction ethanol solution into the flask, immerse for 30-60 min, take out the immersed basalt fiber, react at 105-115 DEG C for 2-4 h, wash, dry to obtain aminated basalt fiber; S2, swell SBS grafted with maleic anhydride in toluene for 1-2 d to obtain a swelling liquid, disperse the aminated basalt fiber in toluene by ultrasonic for 20-30 min, add the swelling liquid, react at 90-110 DEG C for 40-80 min, then add triethylamine, react at 105-115 DEG C for 2-4 d, and dry to obtain modified basalt fiber.

2. The method of claim 1, wherein the high performance asphalt concrete for hydraulic engineering is prepared by adding 0.1 to 0.3 parts by weight of the additive to 100 parts by weight of the aggregate. The mass ratio of the base pitch, furoin extracted oil, layered double hydroxide composite metal hydroxide and cyclic dextrin is 1:0.02-0.05:0.05-0.1:0.01-0.02, the layered double hydroxide composite metal hydroxide is Mg 1-X Al X (OH)2( CO3) X / 2·mH2O, the subscript X represents the change of the content of metal elements, 0.2≤X≤0.33, m represents the content of contained crystal water, 0≤m≤2.

3. The method of claim 1, wherein the high performance asphalt concrete for hydraulic engineering is prepared by adding 0.1 to 0.3 parts by weight of the additive to 100 parts by weight of the aggregate. The amount ratio of maleic anhydride grafted SBS, aminated basalt fiber and triethylamine in S2 is 2-5 g:20 g:1 mL.

4. The method of claim 1, wherein the high performance asphalt concrete for hydraulic engineering is prepared by adding 0.1 to 0.3 parts by weight of the additive to 100 parts by weight of the aggregate. The coarse aggregate and fine aggregate are both limestone; the particle size of the coarse aggregate is 2.5-16 mm, and the particle size of the fine aggregate is 0.15-2.5 mm.

5. The method of claim 1, wherein the high performance asphalt concrete for hydraulic engineering is prepared by adding 0.1 to 0.3 parts by weight of the additive to 100 parts by weight of the aggregate. The mixing temperature of the dry material and modified asphalt is 170-180 DEG C, and the stirring time is 3-6 min.

6. A high performance asphalt concrete for hydraulic engineering, characterized by, Prepared by the preparation method of any one of claims 1-5.

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