CN114031332B - High-density asphalt concrete and preparation method thereof - Google Patents

Abstract

The application relates to the technical field of concrete, and particularly discloses high-density asphalt concrete and a preparation method thereof, wherein the high-density asphalt concrete is prepared from the following raw materials in parts by weight: 90-130 parts of asphalt, 680 parts of 600-sand gravel, 340 parts of 300-sand river sand, 150 parts of 110-sand water-absorbing filler, 40-80 parts of waste shell powder, 90-170 parts of fly ash and 60-80 parts of mineral powder; the water-absorbing filling material comprises 30-40 parts of nitrile rubber particles, 15-26 parts of glass fibers, 40-44 parts of water-based nano acrylic emulsion, 25-36 parts of polyacrylamide and 15-19 parts of sodium carboxymethylcellulose. The porosity and the water absorption of the high-density asphalt concrete can reach 2.19% and 1.56% at least, the porosity and the water absorption of the asphalt concrete are effectively reduced, and the compactness of the asphalt concrete is improved.

Description

High-density asphalt concrete and preparation method thereof

Technical Field

The application relates to the field of concrete, in particular to high-density asphalt concrete and a preparation method thereof.

Background

The concrete is an engineering composite material formed by cementing aggregate into a whole by using a gel material, and is a non-homogeneous porous material formed by mixing cement serving as the gel material and sandstone serving as the aggregate with water according to a certain proportion, uniformly stirring, densely forming, curing and hardening. Asphalt concrete, commonly known as asphalt concrete, is a building material prepared by manually selecting mineral aggregates, crushed stone or crushed gravel, stone chips or mineral powder and the like with certain gradation composition and mixing the mineral aggregates, crushed stone or crushed gravel, stone chips or mineral powder and asphalt materials in a certain proportion. The asphalt concrete has the advantages of smooth and skid-resistant pavement, high driving comfort, high compressive strength, high bending tensile strength and high abrasion resistance, and is widely applied to road construction.

In the related technology, the asphalt concrete comprises asphalt, coarse aggregate, fine aggregate and mineral powder, and the asphalt concrete is easy to age, most of which have short service life, generally 6-15 years.

Disclosure of Invention

In order to reduce the aging speed of asphalt concrete and improve the water resistance of the asphalt concrete, the application provides high-density asphalt concrete and a preparation method thereof.

In a first aspect, the present application provides a high dense asphalt concrete, which adopts the following technical scheme:

the high-density asphalt concrete is prepared from the following raw materials in parts by weight: 90-130 parts of asphalt, 680 parts of gravel 600-sand, 340 parts of river sand 300-sand, 150 parts of water-absorbing filler 110-sand, 40-80 parts of waste shell powder, 90-170 parts of fly ash and 60-80 parts of mineral powder;

the water-absorbing filling material comprises 30-40 parts of nitrile rubber particles, 15-26 parts of glass fibers, 25-36 parts of polyacrylamide and 15-19 parts of sodium carboxymethylcellulose.

By adopting the technical scheme, the macadam is added as the coarse aggregate and plays a role of a framework in the asphalt concrete; the river sand is used as fine aggregate of the granular loose material, and has the effects of framework and filling. The waste shell powder can be added as fine aggregate, and the shell has the characteristic of high calcium carbonate content and generally contains 95% of calcium carbonate, so that the compactness of asphalt concrete can be improved; meanwhile, trace organic matters rich in the waste shell powder can improve the porosity of the asphalt concrete, so that the effect of improving the compactness of the asphalt concrete is achieved. The research proves that the density of the asphalt concrete is increased along with the mixing amount of the fly ash, and the porosity is reduced along with the increase. In addition, after the mineral powder and the asphalt are fused, a diffusion melting film with a corresponding thickness can be generated, and the asphalt concrete structure is protected.

On one hand, the water-absorbing filling material fills the inner gap of the asphalt concrete, and increases the compressive strength of the asphalt concrete; on the other hand, after water permeates into the asphalt concrete, the water-absorbing filling material absorbs water to expand, so that the compactness of the asphalt concrete is increased.

Specifically, the nitrile rubber particles are composed of molecular chains with strong polarity, are unsaturated polar rubber, have the characteristics of oil resistance, aging resistance, high air tightness and good cohesiveness, and the polyacrylamide is synthetic resin with a three-dimensional cross-linked network, and hydrophilic groups exist on the molecular network of the polyacrylamide. Mix nitrile rubber granule and polyacrylamide through the physics blending method, the molecular chain is in the same place through physics cross-linking effect intertwine, and after the nitrile rubber granule met water, the hydrone permeated to the nitrile rubber granule through capillary action and diffusion inside, along with the entering of hydrone, ionization group on the macromolecular chain began the ionization, owing to the repulsion effect between the same ion simultaneously, make the winding polymer chain stretch the swelling together, thereby make the nitrile rubber granule possess the expanded characteristic of absorbing water.

After asphalt concrete is paved or poured, because glass fiber is distributed among the nitrile rubber particles, when water permeates into the asphalt concrete, the water can flow to the nitrile rubber particles along the glass fiber, so that the water absorption and expansion of the nitrile rubber particles can be promoted, and the self-compacting effect is achieved.

Preferably, the method comprises the following steps: the high-density asphalt concrete is prepared from the following raw materials in parts by weight: 100-120 parts of asphalt, 620-660 parts of gravel, 310-330 parts of river sand, 120-130 parts of water-absorbing filler, 50-70 parts of waste shell powder, 150 parts of fly ash and 65-75 parts of mineral powder.

Preferably, the method comprises the following steps: the water-absorbing filling material also comprises the following raw materials in parts by weight: 40-44 parts of water-based nano acrylic emulsion, 8-12 parts of white carbon black, 1-3 parts of p-aminodiphenylamine, 2-4 parts of gamma-glycidyl ether oxypropyltrimethoxysilane coupling agent and 3-5 parts of defoaming agent.

By adopting the technical scheme, the water-based nano acrylic acid and the nitrile rubber are mixed and then wrapped on the surfaces of the nitrile rubber particles, a complete and continuous compact film can be formed after the water-based nano acrylic acid on the surfaces of the nitrile rubber particles is dried, gaps between molecules of the film are usually a plurality of nanometers, natural water is usually in an association state, a large number of water molecules form a large molecular group through the action of hydrogen bonds, the diameter of the group is far larger than the size gap between molecules of water-based nano acrylic emulsion, so that natural water molecules are difficult to pass, the effect of slow permeation is achieved, the preparation and processing of asphalt concrete are facilitated, the nitrile rubber particles gradually absorb water and expand after the asphalt concrete is paved or poured, and the asphalt concrete achieves the self-compaction effect. The sodium carboxymethyl cellulose can play a thickening role in the aqueous nano acrylic emulsion, so that the aqueous nano acrylic emulsion is more easily adhered to the surface of the nitrile rubber particles, and the slow permeation effect is improved.

The p-aminodiphenylamine is grafted to the surface of the white carbon black through the gamma-glycidyl ether oxypropyl trimethoxy silane coupling agent to obtain the white carbon black with anti-aging performance, and the compatibility and the dispersibility of the white carbon black and the water-absorbing filler are improved, so that the reinforcing effect on nitrile rubber particles is improved, and the aging of the nitrile rubber particles is delayed. Meanwhile, the hydrogen activity of the amino on the surface of the p-aminodiphenylamine is high, homogeneous cracking is easy to occur among nitrogen hydrogen bonds to generate hydrogen radicals, and the hydrogen radicals can react with peroxide radicals or oxidation radicals to generate stable products so as to prevent or delay the aging of rubber particles. The defoaming agent can destroy the bubble film by reducing the surface tension of the dense film, and prevent the formation of coating bubbles.

Preferably, the method comprises the following steps: the preparation method of the water-absorbing filling material comprises the following operation steps:

drying nitrile rubber particles, crushing the nitrile rubber particles to 30-70 meshes, and uniformly mixing the nitrile rubber particles, glass fibers and polyacrylamide to obtain a mixture A;

mixing the defoaming agent, sodium carboxymethylcellulose and the water-based nano acrylic emulsion, and uniformly stirring to obtain a mixed solution B;

mixing p-aminodiphenylamine and gamma-glycidyl ether oxypropyl trimethoxy silane coupling agent, and uniformly stirring to obtain an anti-aging coupling agent; placing the anti-aging coupling agent in 95% ethanol by mass, stirring and hydrolyzing for 10-20min to obtain a mixed solution C;

dispersing the white carbon black in 95% ethanol by mass, and then adding the mixture into the mixed solution C for uniform dispersion; refluxing for 3-4h under the protection of nitrogen, concentrating and drying to obtain solid C;

and mixing the solid C, the mixed liquid B and the mixture A, and uniformly stirring to obtain the water-absorbing filler.

By adopting the technical scheme, the water-based nano acrylic emulsion is mixed with the defoaming agent and then mixed with the nitrile rubber particles added with the ammonium polyacrylate, so that the slow swelling effect of the water-based nano acrylic on the nitrile rubber particles can be improved. The solid C is the white carbon black grafted with the p-aminodiphenylamine on the surface, so that the reinforcing effect of the white carbon black is improved, and the anti-aging effect of the nitrile rubber particles is improved.

Preferably, the method comprises the following steps: the defoaming agent is one or more of metal soap mineral oil, polydimethylsiloxane, fluorosilicone or ethylene glycol siloxane.

Preferably, the method comprises the following steps: the weight ratio of the nitrile rubber particles to the aqueous nano acrylic emulsion is 1: (1.1-1.3).

By adopting the technical scheme, the proportion of the water-based nano acrylic emulsion and the nitrile rubber particles influences the slow expansion effect of the nitrile rubber particles, and the effect of delaying the water absorption expansion of the nitrile rubber particles has a great effect on paving and pouring asphalt concrete.

Preferably, the method comprises the following steps: the weight ratio of the polyacrylamide to the nitrile rubber particles is 1: (1.1-1.3).

By adopting the technical scheme, the water absorption and expansion effects of the nitrile rubber particles can be improved by the use amount ratio of the polyacrylamide to the nitrile rubber particles, so that the compactness of asphalt concrete is influenced.

Preferably, the method comprises the following steps: the weight ratio of the glass fiber to the nitrile rubber particles is 1: (1.6-2).

By adopting the technical scheme, because the glass fiber plays a filling role in the water-absorbing filler, the weight ratio of the glass fiber to the nitrile rubber particles is more critical in order to ensure the functions of the nitrile rubber particles and the glass fiber in an asphalt concrete system, and the ratio and the dosage of the glass fiber to the nitrile rubber particles influence the water-absorbing expansion capacity of the nitrile rubber particles in the asphalt concrete and the compressive strength of the asphalt concrete.

In a second aspect, the present application provides a method for preparing any one of the above high dense asphalt concretes, which is specifically realized by the following technical scheme:

a preparation method of high-density asphalt concrete comprises the following operation steps:

mixing broken stone, river sand, mineral powder, fly ash, water-absorbing filler and waste shell powder, and uniformly stirring to obtain a dry material A;

heating the asphalt to 160-170 ℃, uniformly stirring, mixing with the dry material A, and uniformly stirring to obtain the high-density asphalt concrete.

In summary, the present application includes at least one of the following beneficial technical effects:

(1) the porosity and the water absorption of the high-density asphalt concrete can be as low as 2.19% and 1.56%, the porosity and the water absorption of the asphalt concrete are effectively reduced, and the compactness of the asphalt concrete is relatively improved; meanwhile, the stability of the soaking residue, the compressive strength before treatment and the compressive strength after treatment are respectively 92.8%, 69.5MPa and 66.2MPa, so that the stability of the soaking residue, the compressive strength before treatment and the compressive strength after treatment are improved, and the service life of the asphalt concrete is relatively prolonged.

(2) The porosity and the water absorption rate of the asphalt concrete are improved by adding the waste shell powder, the fly ash, the water-absorbing filler and the glass fiber, the sodium carboxymethyl cellulose and the aqueous nano acrylic emulsion in the water-absorbing filler, and the compactness of the asphalt concrete is relatively improved.

Detailed Description

The present application will be described in further detail with reference to specific examples.

The following raw materials in the application are all commercially available products, and specifically: the waste shell powder is obtained from Guohui mineral product processing factories in Lingshou county, and the particle size is 200 meshes; the water-based nano acrylic emulsion is selected from Nippon Dai-Kogyo Co., Ltd; river sand with the particle size of 70-100 meshes; the polyacrylamide is selected from Guangshun environmental protection science and technology limited company of Ningju city, and the content of effective substances is 99 percent; the white carbon black is selected from Shandong Kuoda biological technology limited; the p-aminodiphenylamine is selected from Shanghai Ji to Biochemical technology Co.Ltd; the gamma-glycidoxypropyltrimethoxysilane coupling agent is selected from Jeccard chemical company, and has effective concentration of 98%; the metal soap mineral oil is selected from Guangzhou American New Material science and technology Limited, and the content of effective substances is 99%; the polydimethylsiloxane is selected from Shandong Huiyan chemical industry Co., Ltd, and the content of effective substances is 99%; the fluorosilicone is selected from Wuhan navigation associated color polymer, and the content of effective substances is 80%; the ethylene glycol siloxane is selected from Nexan family New materials Co.

The following are examples of the preparation of the water-absorbent filling in the present application:

preparation example 1

The water-absorbing filling material is prepared by the following method:

according to the mixing amount shown in the table 1, nitrile rubber particles are dried, crushed into 50 meshes and uniformly mixed with glass fibers and polyacrylamide to obtain a mixture A;

and mixing the sodium carboxymethylcellulose with the mixture A, and uniformly stirring to obtain the water-absorbing filling material.

Preparation examples 2 to 5

The water-absorbent fillers of preparation examples 2 to 5 were prepared in the same manner as in preparation example 1, except that the respective raw material components were different, as shown in Table 1.

TABLE 1 preparation of Water-absorbent Filler in Each raw Material blending amount (unit: g) of preparation examples 1 to 5

Raw materials	Preparation example 1	Preparation example 2	Preparation example 3	Preparation example 4	Preparation example 5
						Nitrile rubber particles	300	325	350	375	400
Glass fiber	150	180	190	200	260
						Polyacrylamide	250	280	290	300	360
Sodium carboxymethylcellulose	150	160	170	180	190

Preparation example 6

The water-absorbing filling material is prepared by the following method:

according to the mixing amount shown in the table 2, nitrile rubber particles are dried, crushed into 50 meshes and uniformly mixed with glass fibers and polyacrylamide to obtain a mixture A;

mixing the defoaming agent metal soap mineral oil, sodium carboxymethylcellulose and the aqueous nano acrylic emulsion, and uniformly stirring to obtain a mixed solution B;

mixing p-aminodiphenylamine and gamma-glycidyl ether oxypropyl trimethoxy silane coupling agent, and uniformly stirring to obtain an anti-aging coupling agent; placing the anti-aging coupling agent in 95% ethanol solution by mass percentage, and performing magnetic stirring hydrolysis for 20min to obtain mixed solution C;

dispersing white carbon black in 95% ethanol solution by mass percentage, performing ultrasonic treatment for 15min, adding into the mixed solution B, continuously dispersing for 20min, refluxing for 3h under the protection of nitrogen, concentrating and drying, collecting solid, drying the solid at 50 ℃ in vacuum for 6h, washing with absolute ethyl alcohol, and drying to obtain solid C; and mixing the solid C, the mixed solution B and the mixture A, and uniformly stirring to obtain the water-absorbing filler.

Preparation example 7

The water-absorbing filler of preparation example 7 was prepared in exactly the same manner as in preparation example 6, except that: the raw materials are not added with the water-based nano acrylic emulsion, and the details are shown in table 2.

Preparation examples 8 to 11

The water-absorbent fillers of preparation examples 8 to 11 were prepared in the same manner as in preparation example 6, except that: the antifoaming agents of preparation examples 7 to 8 were a mixture of polydimethylsiloxane and fluorosilicone, and the antifoaming agents of preparation examples 9 to 11 were ethylene glycol siloxane, polydimethylsiloxane and polydimethylsiloxane, respectively, and the amounts of the respective raw materials were different, as shown in table 2.

TABLE 2 amount of each raw material for water absorbent fillers of preparation examples 6 to 11 (unit: g)

Raw materials	Preparation example 6	Preparation example 7	Preparation example 8	Preparation example 9	Preparation example 10	Preparation example 11
							Nitrile rubber particles	350	350	350	350	350	350
Glass fiber	190	190	190	190	190	190
							Aqueous nano acrylic emulsion	400	0	410	420	430	440
Polyacrylamide	290	290	290	290	290	290
							Sodium carboxymethylcellulose	170	170	170	170	170	170
White carbon black	80	80	90	100	110	120
							P-aminodiphenylamine	10	10	15	20	25	30
Gamma-glycidoxypropyltrimethoxysilane coupling agent	20	20	25	30	35	40
							Defoaming agent	30	30	35	40	45	50

Preparation examples 12 to 16

The water-absorbing fillers of preparation examples 12 to 16 were prepared in the same manner as in preparation example 9, except that the amounts of the respective raw materials were different, as shown in Table 3.

TABLE 3 amount of each raw material for water-absorbent fillers of preparation examples 12 to 16 (unit: g)

Raw materials	Preparation example 12	Preparation example 13	Preparation example 14	Preparation example 15	Preparation example 16
						Nitrile rubber particles	380	360	330	400	300
Glass fiber	190	190	190	190	190
						Aqueous nano acrylic emulsion	418	432	429	420	420
Polyacrylamide	290	290	290	290	290
						Sodium carboxymethylcellulose	170	170	170	170	170
White carbon black	100	100	100	100	100
						P-aminodiphenylamine	20	20	20	20	20
Gamma-glycidoxypropyltrimethoxysilane coupling agent	30	30	30	30	30
						Defoaming agent	40	40	40	40	40

Preparation examples 17 to 21

The water-absorbent fillers of preparation examples 17 to 21 were prepared in the same manner as in preparation example 13, except that the amounts of the respective raw materials were different, as shown in Table 4.

TABLE 4 amount of each raw material for water-absorbent fillers of preparation examples 17 to 21 (unit: g)

Raw materials	Preparation example 17	Preparation example 18	Preparation example 19	Preparation example 20	Preparation example 21
						Nitrile rubber particles	360	360	360	360	360
Glass fiber	190	190	190	190	190
						Aqueous nano acrylic emulsion	432	432	432	432	432
Polyacrylamide	327	300	277	360	257
						Sodium carboxymethylcellulose	170	170	170	170	170
White carbon black	100	100	100	100	100
						P-aminodiphenylamine	20	20	20	20	20
Gamma-glycidoxypropyltrimethoxysilane coupling agent	30	30	30	30	30
						Defoaming agent	40	40	40	40	40

Preparation examples 22 to 26

The water-absorbent fillers of preparation examples 22 to 26 were prepared in the same manner as in preparation example 17, except that the amounts of the respective raw materials were different, as shown in table 5.

TABLE 5 amount of each raw material for water-absorbent fillers of preparation examples 21 to 25 (unit: g)

Raw materials	Preparation example 22	Preparation example 23	Preparation example 24	Preparation example 25	Preparation example 26
						Nitrile rubber particles	360	360	360	360	360
Glass fiber	225	200	180	257	164
						Aqueous nano acrylic emulsion	432	432	432	432	432
Polyacrylamide	300	300	300	300	300
						Sodium carboxymethylcellulose	170	170	170	170	170
White carbon black	100	100	100	100	100
						P-aminodiphenylamine	20	20	20	20	20
Gamma-glycidoxypropyltrimethoxysilane coupling agent	30	30	30	30	30
						Defoaming agent	40	40	40	40	40

Example 1

Mixing broken stone, river sand, mineral powder, fly ash, the water-absorbing filler prepared in the preparation example 1 and the waste shell powder according to the mixing amount in the table 6, and uniformly stirring to obtain a dry material A;

and heating the asphalt to 170 ℃, stirring uniformly, quickly mixing with the dry material A, and stirring uniformly to obtain the high-density asphalt concrete.

Examples 2 to 5

The highly compacted asphalt concretes of examples 2 to 5 were prepared by the same method and the same types of raw materials as those of example 1, except that the amounts of the raw materials were different, as shown in Table 6.

TABLE 6 blending amounts (unit: kg) of respective raw materials of the high strength anti-cracking concretes of examples 1 to 5

Raw materials	Example 1	Example 2	Example 3	Example 4	Example 5
						Asphalt	90	100	110	120	130
Crushing stone	600	620	640	660	680
						River sand	300	310	320	330	340
Water-absorbing filling material	110	120	130	140	150
						Waste shell powder	40	50	60	70	80
Fly ash	90	110	130	150	170
						Mineral powder	60	65	70	75	80

Examples 6 to 9

The highly compacted asphalt concretes of examples 6 to 9 were prepared in the same manner as in example 3, except that the water-absorbing fillers of examples 2 to 5 were used as the water-absorbing fillers, and the kinds and amounts of the other raw materials were the same as in example 3.

Examples 10 to 15

The highly compacted asphalt concretes of examples 10 to 15 were prepared in the same manner as in example 7, except that the water-absorbing fillers of examples 6 to 11 were used as the water-absorbing fillers, and the kinds and amounts of the other raw materials were the same as in example 7.

Examples 16 to 20

The highly compacted asphalt concretes of examples 16 to 20 were prepared in the same manner as in example 13, except that the water-absorbing fillers of examples 12 to 16 were used as the water-absorbing fillers, and the kinds and amounts of the other raw materials were the same as those of example 12.

Examples 21 to 25

The highly compacted asphalt concretes of examples 21 to 25 were prepared in the same manner as in example 17, except that the water-absorbent fillers of examples 17 to 21 were used as the water-absorbent fillers, and the kinds and amounts of the other materials were the same as those of example 16.

Examples 26 to 30

The highly compacted asphalt concretes of examples 26 to 30 were prepared in the same manner as in example 22, except that the water-absorbent fillers of examples 22 to 26 were used as the water-absorbent fillers, and the kinds and amounts of the other materials were the same as in example 22.

Example 31

The highly compacted asphalt concrete of example 31 was prepared in the same manner as in example 27 except that the water-absorbent filler was not added with silica, and the kinds and amounts of the remaining raw materials were the same as those in example 27.

Example 32

The highly compacted asphalt concrete of example 32 was prepared in the same manner as in example 27 except that no defoaming agent was added to the water-absorbent filler material, and the kind and amount of the remaining material were the same as those in example 26.

Example 33

The highly compacted asphalt concrete of example 33 was prepared in the same manner as in example 27 except that p-aminodiphenylamine was not added to the water-absorbent filler material, and the kind and amount of the remaining materials were the same as those in example 26.

Comparative example 1

The highly compacted asphalt concrete of comparative example 1 was prepared in exactly the same manner as in example 1, except that: the waste shell powder in the raw materials is replaced by limestone, and the other raw materials and the mixing amount are the same as those in the example 1.

Comparative example 2

The highly compacted asphalt concrete of comparative example 2 was prepared exactly the same as that of example 1, except that: water-absorbing fillers are not added in the raw materials, and the other raw materials and the mixing amount are the same as those of the example 1.

Comparative example 3

The highly compacted asphalt concrete of comparative example 3 was prepared exactly the same as that of example 1, except that: the water-absorbing filler raw materials are not added with glass fiber, and the other raw materials and the mixing amount are the same as those of the embodiment 1.

Comparative example 4

The highly compacted asphalt concrete of comparative example 4 was prepared exactly the same as that of example 1, except that: the water-absorbing filling material is not added with sodium carboxymethyl cellulose, and the other raw materials and the mixing amount are the same as those in the example 1.

Performance detection

The porosity and the stability of the water immersion residue when the standard test blocks 28d of the high-density asphalt concretes of the examples 1 to 33 and the comparative examples 1 to 4 are respectively manufactured by adopting the detection method and the standard of JTGF40-2004 'technical Specification for construction of road asphalt pavement', and the test results are shown in Table 7.

The compressive strengths of the asphalt concretes of examples 1 to 33 and comparative examples 1 to 4 before treatment were tested according to ASTM D1074 + 1993 test method for the compressive strength of asphalt mixtures, the test results are shown in Table 7; then, the high-density asphalt concrete samples of examples 1 to 33 and comparative examples 1 to 4 were subjected to ultraviolet exposure for 8 hours, then condensed for 4 hours, and then soaked in water for 2 days, and the compressive strength after the treatment was measured, and the test results are shown in table 7.

By adopting the detection method and standard of DB32/T3696-2019 appendix F concrete water absorption test method, standard test blocks of 150mm × 150mm × 150mm are respectively made on the high-density asphalt concretes of examples 1-33 and comparative examples 1-4, 3 blocks of each group are drilled to obtain concrete core samples with the diameter of 75mm, cylindrical core samples with the height of 75mm are prepared after the upper and lower surfaces are cut off, the cylindrical core samples are weighed through drying, cooling, weighing, soaking, surface water wiping and weighing, the water absorption of the asphalt concretes of examples 1-33 and comparative examples 1-4 are detected, and the test results are shown in Table 7.

TABLE 7 Performance test results for different highly compacted asphalt concretes

As shown in Table 7, the highly compacted asphalt concretes of examples 1 to 33 have lower porosity and water absorption than those of comparative examples 1 to 4, and the highly compacted asphalt concretes of examples 1 to 33 have higher stability of water-soaking residue, compressive strength before treatment and compressive strength after treatment than those of comparative examples 1 to 4. The porosity and the water absorption of the high-density asphalt concrete can reach 2.19% and 1.56% at least, the porosity and the water absorption of the asphalt concrete are effectively reduced, the compactness of the asphalt concrete is relatively improved, meanwhile, the water immersion residual stability, the compressive strength before treatment and the compressive strength after treatment are respectively 92.8%, 69.5MPa and 66.2MPa, the water immersion residual stability, the compressive strength before treatment and the compressive strength after treatment are improved, and the service life of the asphalt concrete is relatively prolonged.

In examples 1 to 5, the porosity and water absorption of the asphalt concrete of example 3 were 2.64% and 2.00%, respectively, which were lower than those of the asphalt concrete of examples 1 to 2 and examples 4 to 5; meanwhile, the asphalt concrete of example 3 had a residual stability in water immersion, a compressive strength before treatment and a compressive strength after treatment of 89.0%, 65.5MPa and 63.2MPa, respectively, which were higher than those of the asphalt concrete of examples 1-2 and examples 4-5. It is shown that the weight parts of the raw materials of the high-density asphalt concrete of example 3 are more suitable.

In examples 6-9, the properties of the highly compacted asphalt concrete of example 7 are superior to those of examples 1-5, and in examples 6-9, the porosity and water absorption of the highly compacted asphalt concrete of example 7 are 2.57% and 1.85%, respectively, which are lower than those of the asphalt concretes of examples 6 and 8-9; meanwhile, the residual stability of asphalt concrete after soaking, the compressive strength before treatment and the compressive strength after treatment of example 7 were 89.4%, 66.0MPa and 63.6MPa, respectively, which were higher than those of asphalt concrete of examples 6 and 8 to 9. It can be seen that the raw material weight parts of the high-density asphalt concrete of example 7 are more suitable.

In examples 10-15, the porosity and water absorption of the highly dense asphalt concrete of example 13 were 2.40% and 1.76%, respectively, which were lower than those of the asphalt concretes of examples 10-12 and examples 14-15; meanwhile, the asphalt concrete of example 13 had a residual stability in water immersion, a compressive strength before treatment and a compressive strength after treatment of 90.0%, 67.1MPa and 64.5MPa, respectively, which were higher than those of the asphalt concrete of examples 10 to 12 and examples 14 to 15. It can be seen that the raw material weight parts of the high-density asphalt concrete of example 13 are more suitable.

In examples 16-20, the porosity and water absorption of the highly dense asphalt concrete of example 17 were 2.36% and 1.70%, respectively, which were lower than those of the asphalt concretes of examples 16 and 18-20; meanwhile, the residual stability of asphalt concrete after soaking, the compressive strength before treatment and the compressive strength after treatment of example 17 were 91.3%, 67.5MPa and 65.0MPa, respectively, which were higher than those of asphalt concrete of examples 16 and 18 to 20. Therefore, when the weight ratio of the nitrile rubber particles to the aqueous nano acrylic emulsion in the raw materials of the high-density asphalt concrete water-absorbing filler is 1:1.2, the asphalt concrete has excellent performance indexes such as porosity, water absorption and the like.

In examples 21-25, the porosity and water absorption of the highly dense asphalt concrete of example 22 were 2.23% and 1.60%, respectively, which were lower than those of the asphalt concretes of examples 21 and 23-25; meanwhile, the residual stability of asphalt concrete after soaking, the compressive strength before treatment and the compressive strength after treatment of example 21 were 92.9%, 69.2MPa and 65.9MPa, respectively, which were higher than those of asphalt concrete of examples 21 and 23 to 25. Therefore, when the weight ratio of the polyacrylamide to the nitrile rubber particles in the raw materials of the high-density asphalt concrete water-absorbing filler is 1:1.2, the asphalt concrete has excellent performance indexes such as porosity, water absorption and the like.

In examples 26-30, the porosity and water absorption of the highly dense asphalt concrete of example 27 were 2.19% and 1.56%, respectively, which were lower than those of the asphalt concretes of examples 26 and examples 28-30; meanwhile, the residual stability of asphalt concrete after soaking, the compressive strength before treatment and the compressive strength after treatment of example 26 were 92.6%, 69.5MPa and 66.2MPa, respectively, which were higher than those of asphalt concrete of examples 26 and examples 28 to 30. Therefore, when the weight ratio of the glass fiber to the nitrile rubber particles in the raw materials of the high-density asphalt concrete water-absorbing filler is 1:8, the asphalt concrete has excellent performance indexes such as porosity, water absorption and the like.

It can be seen from examples 31-33 that the addition of white carbon black, defoamer and p-aminodiphenylamine to the water-absorbing filler can improve the indexes of the asphalt concrete such as porosity and water absorption.

In addition, according to various index data of comparative example 1 and comparative examples 1 to 4, the porosity and water absorption of the asphalt concrete are obviously improved by selecting the added waste shell powder, the fly ash and the water-absorbing filler and adding the glass fiber and the sodium carboxymethyl cellulose in the water-absorbing filler, and the compactness of the asphalt concrete is relatively improved.

Testing the porosity and the stability of the soaking residue of standard test blocks 1d, 3d and 7d in example 10 and example 11 by adopting a detection method and a standard of JTGF40-2004 'Highway asphalt pavement construction technical Specification'; the compressive strengths of the asphalt concretes 1d, 3d and 5d of examples 10 and 11 were tested according to ASTM D1074 + 1993 test method for the compressive strength of asphalt mixtures; the water absorption of the asphalt concretes 1d, 3d and 7d in the examples 10 and 11 is detected by using a detection method and a standard of DB32/T3696-2019 appendix F concrete water absorption test method, and the test results are shown in Table 8.

TABLE 8 Performance test results for different highly compacted asphalt concretes

The results of Table 8 show that the addition of the aqueous sodium nano-acrylate to the water-absorbing filler in example 10 in example 11 can greatly reduce the swelling of the nitrile rubber particles, since the porosity, the stability of the water-retaining residue, the compressive strength before treatment and the water absorption of the asphalt concrete in example 10 at 1d are all similar to the data of the performance indexes of the asphalt concrete in example 11 at 7d, and the addition of the aqueous sodium nano-acrylate to the water-absorbing filler can greatly reduce the swelling of the nitrile rubber particles.

The present embodiment is only for explaining the present application, and it is not limited to the present application, and those skilled in the art can make modifications of the present embodiment without inventive contribution as needed after reading the present specification, but all of them are protected by patent law within the scope of the claims of the present application.

Claims (7)

1. The high-density asphalt concrete is characterized by being prepared from the following raw materials in parts by weight: 90-130 parts of asphalt, 680 parts of 600-sand gravel, 340 parts of 300-sand river sand, 150 parts of 110-sand water-absorbing filler, 40-80 parts of waste shell powder, 90-170 parts of fly ash and 60-80 parts of mineral powder;

the water-absorbing filling material comprises 30-40 parts of nitrile rubber particles, 15-26 parts of glass fibers, 25-36 parts of polyacrylamide, 15-19 parts of sodium carboxymethylcellulose, 40-44 parts of water-based nano acrylic emulsion, 8-12 parts of white carbon black, 1-3 parts of p-aminodiphenylamine, 2-4 parts of gamma-glycidyl ether oxypropyl trimethoxysilane coupling agent and 3-5 parts of defoaming agent;

the preparation method of the water-absorbing filling material comprises the following operation steps:

drying nitrile rubber particles, crushing the nitrile rubber particles to 30-70 meshes, and uniformly mixing the nitrile rubber particles, glass fibers and polyacrylamide to obtain a mixture A;

mixing the defoaming agent, sodium carboxymethylcellulose and the water-based nano acrylic emulsion, and uniformly stirring to obtain a mixed solution B;

mixing p-aminodiphenylamine and gamma-glycidyl ether oxypropyl trimethoxy silane coupling agent, and uniformly stirring to obtain an anti-aging coupling agent; placing the anti-aging coupling agent in 95% ethanol by mass, stirring and hydrolyzing for 10-20min to obtain a mixed solution C;

dispersing the white carbon black in 95% ethanol by mass, and then adding the mixture into the mixed solution C for uniform dispersion; refluxing for 3-4h under the protection of nitrogen, concentrating and drying to obtain solid C;

and mixing the solid C, the mixed liquid B and the mixture A, and uniformly stirring to obtain the water-absorbing filler.

2. The high-density asphalt concrete according to claim 1, which is prepared from the following raw materials in parts by weight: 100-120 parts of asphalt, 620-660 parts of gravel, 310-330 parts of river sand, 120-130 parts of water-absorbing filler, 50-70 parts of waste shell powder, 150 parts of fly ash and 65-75 parts of mineral powder.

3. The high dense asphalt concrete according to claim 1, wherein: the defoaming agent is one or more of metal soap mineral oil, polydimethylsiloxane, fluorosilicone or ethylene glycol siloxane.

4. The high-density asphalt concrete according to claim 1, wherein the weight ratio of the nitrile rubber particles to the aqueous nano acrylic emulsion is 1: (1.1-1.3).

5. The high dense asphalt concrete according to claim 1, wherein the weight ratio of the polyacrylamide to the nitrile rubber particles is 1: (1.1-1.3).

6. The high-density asphalt concrete according to claim 1, wherein the weight ratio of the glass fiber to the nitrile rubber particles is 1: (1.6-2).

7. A process for the preparation of a highly compacted bituminous concrete according to any one of claims 1 to 6, characterized in that it comprises the following operative steps:

mixing broken stone, river sand, mineral powder, fly ash, water-absorbing filler and waste shell powder, and uniformly stirring to obtain a dry material A;

heating the asphalt to 160-170 ℃, uniformly stirring, mixing with the dry material A, and uniformly stirring to obtain the high-density asphalt concrete.