A crack-resistant road concrete and its preparation method

Abstract

This invention relates to the field of concrete technology and proposes a crack-resistant road concrete and its preparation method. The crack-resistant road concrete comprises the following components by weight: 25-30 parts asphalt, 10-15 parts waste asphalt, 110-120 parts crushed stone, 45-55 parts medium sand, 15-25 parts cement, 5-15 parts lignin, 10-20 parts carbon fiber powder, 15-25 parts pyrophyllite powder, and 10-16 parts additives; the additives include ethylene-vinyl acetate copolymer and hydroxyoctacosanol hydroxystearate; the weight ratio of ethylene-vinyl acetate copolymer to hydroxyoctacosanol hydroxystearate is 1:4-7:1. This technical solution solves the problems of poor high-temperature resistance and poor crack resistance in related technologies for crack-resistant road concrete.

Description

Technical Field

[0001] This invention relates to the field of concrete technology, specifically to a crack-resistant road concrete and its preparation method. Background Technology

[0002] Road concrete is a commonly used composite material in construction engineering, typically formed by binding aggregates together with cementing materials. Based on the materials used and construction techniques, road concrete can be broadly classified into cement concrete and asphalt concrete. The vast majority of road surfaces utilize asphalt concrete. Asphalt concrete pavements generally offer advantages such as smoothness and seamlessness, low vehicle vibration, low noise, and good driving comfort. Furthermore, asphalt concrete materials are recyclable, contributing to environmental protection and resource conservation. However, asphalt concrete pavements also have some drawbacks. They have poor high-temperature resistance and are unable to withstand repeated vehicle loads, especially large external forces, leading to loosening, deformation, and longitudinal and transverse cracks over time. Therefore, developing a road concrete with good high-temperature resistance and crack resistance is crucial for extending the service life of road concrete pavements and reducing the economic losses associated with pavement maintenance. Summary of the Invention

[0003] This invention proposes a crack-resistant road concrete and its preparation method, which solves the problems of poor high-temperature resistance and poor crack resistance of crack-resistant road concrete in related technologies.

[0004] The technical solution of the present invention is as follows:

[0005] This invention proposes a crack-resistant road concrete, comprising the following components in parts by weight:

[0006] 25-30 parts asphalt, 10-15 parts waste asphalt, 110-120 parts crushed stone, 45-55 parts medium sand, 15-25 parts cement, 5-15 parts lignin, 10-20 parts carbon fiber powder, 15-25 parts pyrophyllite powder, and 10-16 parts additives.

[0007] The additives include ethylene-vinyl acetate copolymer and hydroxyoctadecyl hydroxystearate;

[0008] The weight ratio of the ethylene-vinyl acetate copolymer to hydroxyoctadecyl hydroxystearate is 1:4 to 7:1.

[0009] As a further technical solution, the weight parts of the ethylene-vinyl acetate copolymer are greater than the weight parts of the hydroxyoctacosanol hydroxystearate.

[0010] In this invention, when the weight of ethylene-vinyl acetate copolymer is greater than the weight of hydroxyoctacosanol hydroxystearate, the high-temperature resistance and crack resistance of crack-resistant road concrete can be further improved.

[0011] As a further technical solution, the weight ratio of the ethylene-vinyl acetate copolymer to the hydroxyoctadecyl hydroxystearate is 2~5:1.

[0012] By adjusting the weight ratio of ethylene-vinyl acetate copolymer and hydroxyoctadecyl hydroxystearate, the synergistic effect of the two can be optimized when the weight ratio of ethylene-vinyl acetate copolymer and hydroxyoctadecyl hydroxystearate is 2~5:1, which can further improve the high temperature resistance and crack resistance of crack-resistant road concrete.

[0013] As a further technical solution, the carbon fiber powder is modified carbon fiber powder, and the raw materials of the modified carbon fiber powder include carbon fiber powder and 2-acetamidoacrylic acid.

[0014] In this invention, the inventors discovered that surface modification of carbon fiber powder with 2-acetaminoacrylate can further improve the high-temperature resistance and crack resistance of crack-resistant road concrete. The reason for this is speculated to be that surface modification of carbon fiber powder with 2-acetaminoacrylate can make the carbon fiber powder more uniformly dispersed in asphalt and fillers, thereby making the internal stress of the concrete more uniform. This can also reduce the damage to the concrete caused by uneven stress, and thus further improve the high-temperature resistance and crack resistance of crack-resistant road concrete.

[0015] As a further technical solution, the weight ratio of the carbon fiber powder to 2-acetamidoacrylic acid is 20:1~3.

[0016] When the weight ratio of carbon fiber powder to 2-acetamidoacrylic acid is 20:1~3, the high temperature resistance and crack resistance of crack-resistant road concrete can be further improved.

[0017] As a further technical solution, the preparation method of the modified carbon fiber powder includes the following steps: dissolving the 2-acetamidoacrylic acid in ethanol, adding the carbon fiber powder, mixing evenly, and drying to obtain the modified carbon fiber powder.

[0018] As a further technical solution, the crushed stone is one or more of basalt crushed stone, diabase crushed stone, and granite crushed stone.

[0019] As a further technical solution, the particle size of the crushed stone is 10~20mm.

[0020] As a further technical solution, the medium sand is one or both of quartz sand and basalt sand.

[0021] As a further technical solution, the particle size of the medium sand is 0.3~0.45mm.

[0022] As a further technical solution, the particle size of the pyrophyllite powder is 10~44μm.

[0023] As a further technical solution, the waste asphalt material comes from Class III aged petroleum asphalt pavement, with a viscosity of 1.5~1.9 Pa·s at 135℃ and a penetration value of 18~23 at 25℃.

[0024] In this invention, the penetration value of waste asphalt material is 0.1 mm, and is measured at 25°C, with a load of 100 g and a penetration time of 5 s.

[0025] This invention also proposes a method for preparing crack-resistant road concrete, comprising the following steps:

[0026] S1. Preheat all components except asphalt and additives, mix them evenly to obtain a mixture;

[0027] S2. Mix the mixture, the asphalt, and the additives evenly to obtain the crack-resistant road concrete.

[0028] As a further technical solution, in step S1, the temperature during preheating is 145~155℃; in step S2, the temperature during uniform mixing is 150~160℃, the stirring time is 1~2h, and the rotation speed is 900~1100r / min.

[0029] The working principle and beneficial effects of this invention are as follows:

[0030] In this invention, asphalt is combined with waste asphalt material, crushed stone, medium sand, cement, lignin, carbon fiber powder, pyrophyllite powder, and additives. This achieves effective bonding between the filler and asphalt while also enabling the reuse of waste asphalt material to a certain extent. The result is a dense and stable, crack-resistant road concrete with excellent high-temperature resistance and crack resistance. The additives include ethylene-vinyl acetate copolymer and hydroxyoctacosanol hydroxystearate. These two additives have a synergistic effect, forming a network structure during the bonding process with asphalt. This promotes the bonding between the asphalt and the filler, enhances the overall stability of the asphalt, and thus improves the high-temperature resistance and crack resistance of the crack-resistant road concrete. Detailed Implementation

[0031] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0032] In the following examples and comparative examples, the asphalt was petroleum asphalt, grade 70#; the waste asphalt material was from grade III aged petroleum asphalt pavement, with a viscosity of 1.8 Pa·s at 135°C and a penetration of 20 at 25°C; the crushed stone was basalt crushed stone with an average particle size of 15 mm; the medium sand was quartz sand with an average particle size of 0.4 mm; the cement was ordinary Portland cement, grade PO42.5; the pyrophyllite powder had a particle size of 15 μm; the lignin was grade JL8544, purchased from Hefei Bomei Biotechnology Co., Ltd.; the carbon fiber powder had a particle size of 13 μm; and the ethylene-vinyl acetate copolymer was grade V961RC.

[0033] Example 1

[0034] A crack-resistant road concrete, comprising the following components in parts by weight:

[0035] 25 parts asphalt, 10 parts waste asphalt material, 110 parts basalt crushed stone, 45 parts quartz sand, 15 parts cement, 5 parts lignin, 10 parts carbon fiber powder, 15 parts pyrophyllite powder, and 10 parts additives.

[0036] The additives include 2 parts ethylene-vinyl acetate copolymer and 8 parts hydroxyoctadecyl hydroxystearate;

[0037] Its preparation method includes the following steps:

[0038] S1. Preheat the remaining components except for asphalt and additives to 145°C, mix them evenly to obtain a mixture;

[0039] S2. Stir the mixture, asphalt, and additives at 150℃ and 900r / min for 2 hours until they are evenly mixed to obtain crack-resistant road concrete.

[0040] Example 2

[0041] A crack-resistant road concrete, comprising the following components in parts by weight:

[0042] 28 parts asphalt, 13 parts waste asphalt material, 115 parts basalt crushed stone, 50 parts quartz sand, 20 parts cement, 10 parts lignin, 15 parts carbon fiber powder, 20 parts pyrophyllite powder, and 12 parts additives.

[0043] The additives include 6 parts ethylene-vinyl acetate copolymer and 6 parts hydroxyoctadecyl hydroxystearate;

[0044] Its preparation method includes the following steps:

[0045] S1. Preheat the remaining components except for asphalt and additives to 150°C, mix them evenly to obtain a mixture;

[0046] S2. Stir the mixture, asphalt, and additives at 155℃ and 1000r / min for 1.5h until they are evenly mixed to obtain crack-resistant road concrete.

[0047] Example 3

[0048] A crack-resistant road concrete, comprising the following components in parts by weight:

[0049] 30 parts asphalt, 15 parts waste asphalt material, 120 parts basalt crushed stone, 55 parts quartz sand, 25 parts cement, 15 parts lignin, 20 parts carbon fiber powder, 25 parts pyrophyllite powder, and 16 parts additives.

[0050] The additives include 14 parts ethylene-vinyl acetate copolymer and 2 parts hydroxyoctadecyl hydroxystearate;

[0051] Its preparation method includes the following steps:

[0052] S1. Preheat the remaining components except for asphalt and additives to 155°C, mix them evenly to obtain a mixture;

[0053] S2. Stir the mixture, asphalt, and additives at 160℃ and 1100r / min for 1 hour until they are evenly mixed to obtain crack-resistant road concrete.

[0054] Example 4

[0055] The only difference between this embodiment and Embodiment 2 is that, in this embodiment, the additives include 4 parts of ethylene-vinyl acetate copolymer and 8 parts of hydroxyoctadecyl hydroxystearate.

[0056] Example 5

[0057] The only difference between this embodiment and Embodiment 2 is that, in this embodiment, the additives include 7 parts of ethylene-vinyl acetate copolymer and 5 parts of hydroxyoctadecyl hydroxystearate.

[0058] Example 6

[0059] The only difference between this embodiment and Embodiment 5 is that, in this embodiment, the additives include 11 parts of ethylene-vinyl acetate copolymer and 1 part of hydroxyoctadecyl hydroxystearate.

[0060] Example 7

[0061] The only difference between this embodiment and Embodiment 5 is that, in this embodiment, the additives include 8 parts of ethylene-vinyl acetate copolymer and 4 parts of hydroxyoctadecyl hydroxystearate.

[0062] Example 8

[0063] The only difference between this embodiment and Embodiment 5 is that, in this embodiment, the additives include 10 parts of ethylene-vinyl acetate copolymer and 2 parts of hydroxyoctadecyl hydroxystearate.

[0064] Example 9

[0065] The only difference between this embodiment and embodiment 8 is that in this embodiment, the carbon fiber powder is modified carbon fiber powder, and its preparation method includes the following steps: dissolving 0.5 parts of 2-acetamidoacrylic acid in 25 parts of ethanol, adding 20 parts of carbon fiber powder, mixing evenly, and drying to obtain modified carbon fiber powder.

[0066] Example 10

[0067] The only difference between this embodiment and Example 9 is that in this embodiment, 3.5 parts of 2-acetamidoacrylic acid are added.

[0068] Example 11

[0069] The only difference between this embodiment and Example 9 is that in this embodiment, the amount of 2-acetamidoacrylic acid added is 1 part.

[0070] Example 12

[0071] The only difference between this embodiment and Example 9 is that in this embodiment, 3 parts of 2-acetamidoacrylic acid are added.

[0072] Comparative Example 1

[0073] The only difference between this comparative example and Example 1 is that, in this comparative example, the additives include only ethylene-vinyl acetate copolymer.

[0074] Comparative Example 2

[0075] The only difference between this comparative example and Example 1 is that in this comparative example, the additives include only hydroxyoctacosanol hydroxystearate.

[0076] Comparative Example 3

[0077] The only difference between this comparative example and Example 1 is that no additives were added in this comparative example.

[0078] Experiment Example 1: High Temperature Resistance Test

[0079] The crack-resistant road concrete prepared in Examples 1-12 and Comparative Examples 1-3 were subjected to high-temperature rutting dynamic stability tests according to the methods in JTG E20-2011 "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering". The concrete sample size was 300mm×300mm×100mm, the test temperature was 60℃, the wheel pressure was 0.7MPa, and the total applied load was 780N. The test result is the average value of the three samples.

[0080] Experiment Example 2: Crack Resistance Test

[0081] The crack-resistant road concrete prepared in Examples 1-12 and Comparative Examples 1-3 was tested for splitting tensile strength according to the method in JTG E20-2011 "Test Procedure for Asphalt and Asphalt Mixtures in Highway Engineering". The concrete specimen was a cylindrical specimen with a diameter of 100 mm and a height of 40 mm. The test temperature was 15℃ and the loading rate was 50 mm / min. The test result was the average value of the three specimens.

[0082] The test results are shown in Table 1 below:

[0083] Table 1 Performance test results of Examples 1-12 and Comparative Examples 1-3

[0084]

[0085] Compared with Comparative Examples 1-3, the high-temperature rutting dynamic stability and splitting tensile strength of Example 1 were significantly improved, indicating that when the additives include ethylene-vinyl acetate copolymer and hydroxyoctacosanol hydroxystearate, the ethylene-vinyl acetate copolymer and hydroxyoctacosanol hydroxystearate have a synergistic effect, which can improve the high-temperature resistance and crack resistance of crack-resistant road concrete.

[0086] Compared with Examples 2 and 4, Examples 5-8 showed improved high-temperature rutting dynamic stability and splitting tensile strength, indicating that when the weight of ethylene-vinyl acetate copolymer is greater than that of hydroxyoctadecyl hydroxystearate, the high-temperature resistance and crack resistance of crack-resistant road concrete can be further improved.

[0087] Compared with Examples 5-6, Examples 7-8 showed improved high-temperature rutting dynamic stability and splitting tensile strength, indicating that when the weight ratio of ethylene-vinyl acetate copolymer to hydroxyoctadecyl hydroxystearate is 2-5:1, the high-temperature resistance and crack resistance of crack-resistant road concrete can be further improved.

[0088] Compared with Example 8, the high-temperature rutting dynamic stability and splitting tensile strength of Examples 9-12 are improved, indicating that surface modification of carbon fiber powder with 2-acetamidoacrylic acid can further improve the high-temperature resistance and crack resistance of crack-resistant road concrete.

[0089] Compared with Examples 9-10, Examples 11-12 showed improved high-temperature rutting dynamic stability and splitting tensile strength, indicating that when the weight ratio of carbon fiber powder to 2-acetamidoacrylic acid is 20:1-3, the high-temperature resistance and crack resistance of crack-resistant road concrete can be further improved.

[0090] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A crack-resistant road concrete, characterized in that, The components include the following parts by weight: 25-30 parts asphalt, 10-15 parts waste asphalt, 110-120 parts crushed stone, 45-55 parts medium sand, 15-25 parts cement, 5-15 parts lignin, 10-20 parts carbon fiber powder, 15-25 parts pyrophyllite powder, and 10-16 parts additives. The additives include ethylene-vinyl acetate copolymer and hydroxyoctadecyl hydroxystearate; The weight ratio of the ethylene-vinyl acetate copolymer to the hydroxyoctacosanol hydroxystearate is 2~5:1; The carbon fiber powder is modified carbon fiber powder, and the raw materials of the modified carbon fiber powder include carbon fiber powder and 2-acetamidoacrylic acid in a weight ratio of 20:1~3.

2. The crack-resistant road concrete according to claim 1, characterized in that, The preparation method of the modified carbon fiber powder includes the following steps: dissolving the 2-acetamidoacrylic acid in ethanol, adding the carbon fiber powder, mixing evenly, and drying to obtain the modified carbon fiber powder.

3. The crack-resistant road concrete according to claim 1, characterized in that, The crushed stone is one or more of basalt crushed stone, diabase crushed stone, and granite crushed stone.

4. The crack-resistant road concrete according to claim 1, characterized in that, The medium sand is one or both of quartz sand and basalt sand.

5. The crack-resistant road concrete according to claim 1, characterized in that, The waste asphalt material comes from Class III aged petroleum asphalt pavement, with a viscosity of 1.5~1.9 Pa·s at 135℃ and a penetration value of 18~23 at 25℃.

6. A method for preparing crack-resistant road concrete according to any one of claims 1 to 5, characterized in that, Includes the following steps: S1. Preheat all components except asphalt and additives, mix them evenly to obtain a mixture; S2. Mix the mixture, the asphalt, and the additives evenly to obtain the crack-resistant road concrete.

Images