CN114149221A

CN114149221A - Water-permeable high-strength asphalt concrete and preparation method thereof

Info

Publication number: CN114149221A
Application number: CN202111261516.8A
Authority: CN
Inventors: 丁攀; 高建安; 井海龙
Original assignee: Urumqi Convergence Pavement Engineering Co ltd
Current assignee: Urumqi Convergence Pavement Engineering Co ltd
Priority date: 2021-10-28
Filing date: 2021-10-28
Publication date: 2022-03-08
Anticipated expiration: 2041-10-28
Also published as: CN114149221B

Abstract

The invention provides a permeable high-strength asphalt concrete and a preparation method thereof, belonging to the technical field of concrete. The paint comprises the following components in parts by weight: 150 parts of water-containing material 120, 150 parts of asphalt base material 120, 300 parts of cement-containing material 200, 800 parts of hydrophobic nano-silica microspheres, 12-15 parts of water reducing agent, 7-12 parts of expanding agent, 80-100 parts of mineral powder, 500 parts of crushed stone-containing material 400, 30-50 parts of silica fume and 30-50 parts of reinforcing fiber. The water-permeable high-strength asphalt concrete prepared by the method has excellent water permeability, high concrete strength, better anti-cracking effect and wide application prospect.

Description

Water-permeable high-strength asphalt concrete and preparation method thereof

Technical Field

The invention relates to the technical field of concrete, in particular to pervious high-strength asphalt concrete and a preparation method thereof.

Background

The water-permeable asphalt concrete has good water permeability, so that the water-permeable asphalt concrete is widely applied to the paving field of places such as pavements, bridge decks and the like, and the water-permeable asphalt concrete has the following three using benefits when being used for paving: (1) safety benefits are as follows: the runoff formed by rainwater on the road surface in rainy days is weakened, and the occurrence probability of the water floating phenomenon is reduced along with the increase of the depth of the surface structure. (2) Environmental benefits: the noise of tire and road surface because the suction and the compression of air produced has been reduced from the source to big space has the effect of noise absorption, alleviates the too high phenomenon of summer road surface temperature, alleviates city "heat island effect". (3) Economic benefits are as follows: the reduction of the density can save stone, reduce the driving resistance, reduce the oil consumption of the automobile and the abrasion of tires, improve the road traffic capacity in rainy days and control the time cost caused by congestion.

Chinese patent CN112358257A discloses a pervious asphalt concrete and a preparation method and application thereof, wherein the pervious asphalt concrete comprises the following components in parts by weight: 400 parts of coarse aggregate 200-containing material, 20-40 parts of fine aggregate, 40-50 parts of fly ash, 80-120 parts of portland cement, 80-120 parts of modified asphalt, 10-20 parts of reinforcing agent, 10-20 parts of water reducing agent and 180 parts of water 120-containing material; the fine aggregate comprises expanded vermiculite and/or expanded perlite; the average particle size of the fine aggregate is 2-4 mm. The existing permeable asphalt concrete realizes larger construction depth and communicated pores by changing the proportion of coarse and fine aggregates, and the mechanical property of the existing permeable asphalt concrete is often dependent on the strength of aggregate frameworks and the bonding effect of asphalt mortar, so that the mechanical property is poor, the strength is poor, the application range of the existing permeable asphalt concrete is limited, and the service life of the permeable asphalt concrete is seriously shortened.

Disclosure of Invention

The invention aims to provide the water-permeable high-strength asphalt concrete and the preparation method thereof, which have the advantages of excellent water permeability, high concrete strength, better anti-cracking effect and wide application prospect.

The technical scheme of the invention is realized as follows:

the invention provides a water-permeable high-strength asphalt concrete which comprises the following components in parts by weight: 150 parts of water-containing material 120, 150 parts of asphalt base material 120, 300 parts of cement-containing material 200, 800 parts of hydrophobic nano-silica microspheres, 12-15 parts of water reducing agent, 7-12 parts of expanding agent, 80-100 parts of mineral powder, 500 parts of crushed stone-containing material 400, 30-50 parts of silica fume and 30-50 parts of reinforcing fiber.

Furthermore, the hydrophobic nano-silica microspheres are prepared from aminosilane and fluorine-containing silane by a sol-gel method.

Furthermore, the mass ratio of the amino silane to the fluorine-containing silane is (3-5): (1-2)

As a further improvement of the invention, the aminosilane is selected from at least one of gamma-aminopropyltriethoxysilane, N-beta (aminoethyl) -gamma-aminopropyltrimethoxysilane, N-beta (aminoethyl) -gamma-aminopropyltriethoxysilane, N-beta (aminoethyl) -gamma-aminopropylmethyldimethoxysilane, N-beta (aminoethyl) -gamma-aminopropylmethyldiethoxysilane, and diethylenetriaminopropyltrimethoxysilane; the fluorine-containing silane is selected from at least one of 1H,1H,2H, 2H-perfluorodecyltriethoxysilane, 1H,2H, 2H-perfluorodecyltrimethoxysilane, dodecafluoroheptylpropyltrimethoxysilane, dodecafluoroheptylpropylmethyldimethoxysilane, 3,3, 3-trifluoropropylmethyldimethoxysilane, 3, 3-trifluoropropyltrimethoxysilane, 1H,2H, 2H-perfluorooctyltriethoxysilane or 1H,1H,2H, 2H-perfluorooctyltrimethoxysilane.

As a further improvement of the invention, the fluorine-containing silane is a compound mixture of 1H,1H,2H, 2H-perfluorodecyl triethoxysilane and dodecafluoroheptyl propyl trimethoxysilane, and the mass ratio is 3: (3-6), preferably, 3: (4-5).

As a further improvement of the invention, the preparation method of the hydrophobic nano-silica microspheres comprises the following steps:

s1, preparing an oil phase: mixing and dissolving amino silane and fluorine-containing silane in an organic solvent to obtain an oil phase;

s2, preparation of hydrophobic nano silicon dioxide microspheres: and (3) dripping water into the oil phase, emulsifying, stirring for reaction, centrifugally washing and drying to obtain the hydrophobic nano silicon dioxide microspheres.

The organic solvent is at least one selected from ethyl acetate, methyl acetate, dichloromethane, chloroform, petroleum ether, benzene, toluene and xylene; the volume ratio of the water to the oil phase is 5: (7-10).

As a further improvement of the invention, the emulsification condition is 10000-15000r/min, and the time is 2-4 min; the stirring condition is 500-700 r/min; the centrifugation condition is 3000-5000r/min, and the time is 10-15 min; the drying condition is that the temperature is 60-80 ℃ and the time is 2-4 h.

As a further improvement of the invention, the swelling agent is selected from at least one of UEA swelling agent, AEA swelling agent, HEA swelling agent; the water reducing agent is selected from at least one of a polycarboxylic acid water reducing agent, a naphthalene water reducing agent, an aliphatic water reducing agent and a sulfamic acid water reducing agent; the cement is portland cement; the diameter of the macadam is 5-15 mm.

As a further improvement of the invention, the reinforced fiber is a mixture of polyacrylonitrile fiber-based carbon fiber and polypropylene short fiber, and the mass ratio is 10: (2-5).

The invention further provides a preparation method of the pervious high-strength asphalt concrete, which comprises the following steps:

(1) uniformly mixing a water reducing agent and water to obtain an additive aqueous solution;

(2) uniformly mixing the asphalt base material, cement, silica fume and mineral powder, and adding an additive aqueous solution to obtain asphalt cement slurry;

(3) uniformly mixing hydrophobic nano silicon dioxide microspheres, broken stone, reinforcing fiber and an expanding agent to obtain a dry material;

(4) adding the asphalt cement slurry into the dry materials, stirring and mixing uniformly, discharging, pouring into a mould for forming, demoulding and curing to obtain the pervious high-strength asphalt concrete.

The invention has the following beneficial effects: the invention has prepared a kind of hydrophobic nanometer silicon dioxide microballoons, dissolve aminosilane and fluorine-containing silane in organic solvent at first, get homogeneous oil phase, after dropping water to this oil phase, the water phase can't be dissolved mutually with the oil phase, and the amino part of aminosilane can be dissolved in water phase, thus form the water-in-oil liquid drop through emulsifying, stiring, the amino part faces to the inside water, and silane part and fluorine-containing group face to the outside oil phase, with the reaction going on, the amino will be protonated, become amphiphilic molecule, can further stabilize the silane liquid drop, amino is protonated at the same time and can provide the alkaline environment, catalyze silane and take place the sol-gel process, thus has formed and regard silicon dioxide as the shell, the surface is the hydrophobic nanometer silicon dioxide microballoons of fluorine-containing group; the hydrophobic nano silicon dioxide microspheres are doped into concrete, after cement is hardened, a special hydrophobic film is formed on the surface of a cementing layer wrapping aggregate, so that water can smoothly permeate through the inner pore channels of the concrete and does not stay in the concrete, a good water permeation effect is achieved, and the strength of the concrete can be improved;

the organic fiber added in the invention is a mixture of polyacrylonitrile fiber-based carbon fiber and polypropylene short fiber, the polyacrylonitrile-based carbon fiber has the advantages of light specific gravity, small density, wear resistance, fatigue resistance, acid and alkali resistance, strong adsorbability and the like, plays a role of supporting a reticular framework in concrete, and can also transmit stress together with mineral powder to play a role of crack resistance. The polypropylene short fibers and the polyacrylonitrile fiber-based carbon fibers are matched, so that the cement hydration is prolonged, the shrinkage rate of the cement is reduced, the internal stress of the concrete is integrally reduced, the risk of concrete cracking is reduced, the mechanical property of the concrete is improved, and the addition of the polypropylene short fibers and the polyacrylonitrile fiber-based carbon fibers has a synergistic effect.

The water-permeable high-strength asphalt concrete prepared by the method has excellent water permeability, high concrete strength, better anti-cracking effect and wide application prospect.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

Fig. 1 is an SEM image of the hydrophobic nano silica microspheres prepared in preparation example 1 of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Preparation example 1

The preparation method of the hydrophobic nano silicon dioxide microspheres comprises the following steps:

s1, preparing an oil phase: mixing 3g of diethylenetriaminopropyltrimethoxysilane and 1g of fluorine-containing silane, and dissolving in 70mL of ethyl acetate to obtain an oil phase; the fluorine-containing silane is a compound mixture of 1H,1H,2H, 2H-perfluorodecyl triethoxysilane and dodecafluoroheptyl propyl trimethoxysilane, and the mass ratio is 3: 4;

s2, preparation of hydrophobic nano silicon dioxide microspheres: and (2) dripping 50mL of water into 70mL of oil phase, emulsifying at the rotation speed of 10000r/min for 2min, stirring at 500r/min for 2h, centrifuging at the rotation speed of 3000r/min for 10min, washing, drying at the temperature of 60 ℃ for 2h to obtain the hydrophobic nano-silica microspheres. FIG. 1 is an SEM image of the hydrophobic nano-silica microspheres prepared in this example, which shows that the particle size of the microspheres is between 200 and 400 nm.

Preparation example 2

s1, preparing an oil phase: mixing 5g N-beta (aminoethyl) -gamma-aminopropyltriethoxysilane and 2g of fluorine-containing silane, and dissolving in 100mL of methyl acetate to obtain an oil phase; the fluorine-containing silane is a compound mixture of 1H,1H,2H, 2H-perfluorodecyl triethoxysilane and dodecafluoroheptyl propyl trimethoxysilane, and the mass ratio is 3: 5;

s2, preparation of hydrophobic nano silicon dioxide microspheres: and (2) dripping 50mL of water into 100mL of oil phase, emulsifying at the rotation speed of 15000r/min for 4min, stirring at 700r/min for 4h, centrifuging at the rotation speed of 5000r/min for 15min, washing, drying at the temperature of 80 ℃ for 4h, and thus obtaining the hydrophobic nano-silica microspheres.

Preparation example 3

s1, preparing an oil phase: mixing 4g of gamma-aminopropyltriethoxysilane and 1.5g of fluorine-containing silane, and dissolving in 85mL of ethyl acetate to obtain an oil phase; the fluorine-containing silane is a compound mixture of 1H,1H,2H, 2H-perfluorodecyl triethoxysilane and dodecafluoroheptyl propyl trimethoxysilane, and the mass ratio is 2: 3;

s2, preparation of hydrophobic nano silicon dioxide microspheres: and (2) dripping 50mL of water into 85mL of oil phase, emulsifying at the rotation speed of 12500r/min for 3min, stirring at 600r/min for reaction for 3h, centrifuging at the rotation speed of 4000r/min for 12min, washing, drying at the temperature of 70 ℃ for 3h to obtain the hydrophobic nano-silica microspheres.

Preparation example 4

Compared with the preparation example 3, the dosage of the gamma-aminopropyl triethoxysilane is 2.75g, the dosage of the fluorine-containing silane is 2.75g, and other conditions are not changed.

Preparation example 5

Compared with preparation example 3, the dosage of gamma-aminopropyl triethoxysilane is 5g, the dosage of fluorine-containing silane is 0.5g, and other conditions are not changed.

Preparation example 6

Compared with the preparation example 3, the fluorine-containing silane is 1H,1H,2H, 2H-perfluorodecyl triethoxysilane, and other conditions are not changed.

Preparation example 7

Compared with preparation example 3, the fluorine-containing silane is dodecafluoroheptyl propyl trimethoxy silane, and other conditions are not changed.

Comparative preparation example 1

Compared with preparation example 3, the dosage of gamma-aminopropyl triethoxysilane was 5.5g, no fluorine-containing silane was added, and other conditions were not changed.

Comparative preparation example 2

Compared with preparation example 3, the amount of the fluorine-containing silane was 5.5g, and no gamma-aminopropyltriethoxysilane was added, and other conditions were not changed.

Because no aminosilane is added, no alkaline environment is formed to catalyze silane hydrolysis, microspheres are not obtained within a specified time, and subsequent tests cannot be carried out.

Example 1

The raw materials comprise the following components in parts by weight: 120 parts of water, 120 parts of asphalt base material, 200 parts of PO42.5R Portland cement, 600 parts of hydrophobic nano-silica microspheres prepared in preparation example 1, 12 parts of water reducing agent, 7 parts of expanding agent, 80 parts of mineral powder, 400 parts of crushed stone, 30 parts of silica fume and 30 parts of reinforcing fiber. The reinforced fiber is a mixture of polyacrylonitrile fiber-based carbon fiber and polypropylene short fiber, and the mass ratio is 10: 2. the diameter of the macadam is 5-15 mm. The method comprises the following steps:

Examples 2 to 7, comparative example 1

The other conditions were the same as in example 1 except that the hydrophobic nano-silica microspheres were prepared in preparation examples 2 to 7, respectively, and comparative preparation example 1.

Example 8

Compared with the example 3, the reinforced fiber is polyacrylonitrile fiber-based carbon fiber, and other conditions are not changed.

Example 9

Compared with the example 3, the reinforcing fiber is polypropylene short fiber, and other conditions are not changed.

Test example 1

The pervious high-strength asphalt concrete prepared in examples 1-9 of the present invention and comparative examples 1-2 were subjected to performance tests, and the results are shown in table 1.

According to the grading of the permeable asphalt pavement technical regulation (CJJ/T190-2012), the mineral aggregate grading refers to PAC-13 asphalt mixture grading in CJJ/T1902012, the permeable asphalt pavement technical regulation. The aggregate is divided into three grades of 10-15mm, 5-10mm and 0-5mm, and the mineral aggregate gradation proportion determined by the target void ratio is 10-15 mm: 5-10 mm: 0-5 mm: 58 percent of mineral powder: 30%: 9%: and 3% according to the current construction standard, testing the water seepage coefficient, selecting 10 test points, and taking an average value.

(2) A formed Marshall test piece with double-side compacting under 50 ℃ is adopted, placed for 24 hours at room temperature, soaked for 24 hours at normal temperature, then placed in a water tank for vacuumizing for 15 minutes to ensure that water can fully enter gaps inside a mixture, then frozen in a refrigerator with the temperature of 18 ℃ below zero for 16 hours together with the water tank, taken out, immediately placed in a constant-temperature water tank with the temperature of 60 ℃ for heat preservation for 24 hours, then placed in a water tank with the temperature of 25 ℃ for heat preservation for 2 hours, and finally tested for the cleavage strength.

TABLE 1

Group of	Splitting strength (MPa)	Freezing and thawing cleavage strength (MPa)	Water permeability coefficient (mL/min)
				Example 1	0.94	0.74	1370
Example 2	0.92	0.73	1374
				Example 3	0.97	0.77	1382
Example 4	0.89	0.61	1289
				Example 5	0.96	0.72	1210
Example 6	0.94	0.69	1270
				Example 7	0.95	0.70	1282
Example 8	0.81	0.54	1368
				Example 9	0.79	0.52	1360
Comparative example 1	0.94	0.63	1020

The pervious high-strength asphalt concrete prepared by the embodiments 1-3 of the invention has good mechanical strength and water permeability. Fully indicates that the organic fiber is a mixture of polyacrylonitrile fiber-based carbon fiber and polypropylene short fiber, and the addition of the polyacrylonitrile fiber-based carbon fiber and the polypropylene short fiber has a synergistic effect. By adding the hydrophobic nano silicon dioxide microspheres into the concrete, after the cement is hardened, a special hydrophobic film can be formed on the surface of a cementing layer wrapping the aggregate, so that water can smoothly permeate through the inner pore passage of the concrete and does not stay in the concrete, a good water permeating effect is achieved, and the strength of the concrete can be improved.

Example 4 compared with example 3, the mass ratio of aminosilane to fluorine-containing silane is smaller, so that the content of aminosilane is too low, which results in that a part of fluorine-containing silane can not exist stably, and finally, silane is self-polymerized to form solid microspheres, which are smaller, cannot have good hydrophobic effect, and the mechanical property is reduced.

In example 5, the mass ratio of aminosilane to fluorosilane was larger than that in example 3, and the number of fluorine groups on the surface of the microsphere was smaller, so that the hydrophobicity of the microsphere was decreased and the water permeability was decreased.

Compared with the embodiment 3, the fluorine-containing silane is only single 1H,1H,2H, 2H-perfluorodecyl triethoxysilane or dodecafluoroheptyl propyl trimethoxysilane, the two silanes are matched with each other to form a better hydrophobic effect, and the hydrophobic effect of the single fluorine-containing silane is reduced, so that the water permeability of the concrete is reduced.

Compared with the embodiment 3, the embodiment 8 and the embodiment 9 have the advantages that the reinforcing fiber is single polyacrylonitrile fiber-based carbon fiber or polypropylene short fiber, the mechanical property is obviously reduced, the polyacrylonitrile-based carbon fiber has the advantages of light specific gravity, small density, wear resistance, fatigue resistance, acid and alkali resistance, strong adsorbability and the like, the polyacrylonitrile-based carbon fiber plays a role in supporting a reticular framework in concrete, and can also transfer stress together with mineral powder to play a crack-resistant effect. The polypropylene short fibers and the polyacrylonitrile fiber-based carbon fibers are matched, so that the cement hydration is prolonged, the shrinkage rate of the cement is reduced, the internal stress of the concrete is integrally reduced, the risk of concrete cracking is reduced, the mechanical property of the concrete is improved, and the addition of the polypropylene short fibers and the polyacrylonitrile fiber-based carbon fibers has a synergistic effect. Compared with the example 3, the comparative example 1 has no fluorine-containing silane, the prepared microsphere is a common silicon dioxide microsphere, and the water permeability is obviously reduced.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Claims

1. The permeable high-strength asphalt concrete is characterized by comprising the following components in parts by weight: 150 parts of water, 150 parts of asphalt base material, 300 parts of cement, 600 parts of hydrophobic nano-silica microspheres, 12-15 parts of water reducing agent, 7-12 parts of expanding agent, 80-100 parts of mineral powder, 500 parts of crushed stone, 30-50 parts of silica fume and 30-50 parts of reinforcing fibers; the hydrophobic nano silicon dioxide microspheres are prepared from amino silane and fluorine-containing silane by a sol-gel method, wherein the mass ratio of the amino silane to the fluorine-containing silane is (3-5): (1-2).

2. The pervious high-strength asphalt concrete according to claim 1, characterized in that said aminosilane is selected from at least one of gamma-aminopropyltriethoxysilane, N-beta (aminoethyl) -gamma-aminopropyltrimethoxysilane, N-beta (aminoethyl) -gamma-aminopropyltriethoxysilane, N-beta (aminoethyl) -gamma-aminopropylmethyldimethoxysilane, N-beta (aminoethyl) -gamma-aminopropylmethyldiethoxysilane, and diethylenetriaminopropyltrimethoxysilane.

3. The pervious high-strength asphalt concrete according to claim 1, wherein said fluorine-containing silane is selected from at least one of 1H,1H,2H, 2H-perfluorodecyltrimethoxysilane, dodecafluoroheptylpropyltrimethoxysilane, dodecafluoroheptylpropylmethyldimethoxysilane, 3,3, 3-trifluoropropylmethyldimethoxysilane, 3,3, 3-trifluoropropyltrimethoxysilane, 1H,2H, 2H-perfluorooctyltriethoxysilane, or 1H,1H,2H, 2H-perfluorooctyltrimethoxysilane.

4. The pervious high-strength asphalt concrete according to claim 1 or 3, characterized in that the fluorine-containing silane is a compound mixture of 1H,1H,2H, 2H-perfluorodecyl triethoxysilane and dodecafluoroheptyl propyl trimethoxysilane, and the mass ratio is 3: (3-6), preferably, 3: (4-5).

5. The pervious high-strength asphalt concrete according to claim 1, wherein the hydrophobic nano silica microspheres are prepared by the following method:

6. The pervious high-strength asphalt concrete according to claim 5, wherein the organic solvent is at least one selected from the group consisting of ethyl acetate, methyl acetate, dichloromethane, chloroform, petroleum ether, benzene, toluene, xylene; the volume ratio of the water to the oil phase is 5: (7-10).

7. The pervious high-strength asphalt concrete as claimed in claim 5, wherein the emulsification condition is 10000-15000r/min, and the time is 2-4 min; the stirring condition is 500-700 r/min; the centrifugation condition is 3000-5000r/min, and the time is 10-15 min; the drying condition is that the temperature is 60-80 ℃ and the time is 2-4 h.

8. The pervious high-strength asphalt concrete according to claim 1, wherein the swelling agent is selected from at least one of UEA swelling agent, AEA swelling agent, HEA swelling agent; the water reducing agent is selected from at least one of a polycarboxylic acid water reducing agent, a naphthalene water reducing agent, an aliphatic water reducing agent and a sulfamic acid water reducing agent; the cement is portland cement; the diameter of the macadam is 5-15 mm.

9. The pervious high-strength asphalt concrete according to claim 1, characterized in that the reinforcing fibers are a mixture of polyacrylonitrile fiber-based carbon fibers and polypropylene short fibers in a mass ratio of 10: (2-5).

10. The method for preparing the pervious high-strength asphalt concrete of any one of claims 1 to 9, comprising the steps of: