CN111499247B

CN111499247B - Red mud-silicate composite anti-aging agent, asphalt mixture and preparation method and application thereof

Info

Publication number: CN111499247B
Application number: CN202010332872.3A
Authority: CN
Inventors: 张吉哲; 姚占勇; 孙法合; 梁明; 蒋红光; 王凯
Original assignee: Shandong University; Shandong High Speed Group Co Ltd
Current assignee: Shandong University; Shandong High Speed Group Co Ltd
Priority date: 2020-04-24
Filing date: 2020-04-24
Publication date: 2021-06-22
Anticipated expiration: 2040-04-24
Also published as: CN111499247A

Abstract

The invention relates to the technical field of asphalt anti-aging agents, in particular to a red mud-silicate composite anti-aging agent, an asphalt mixture, and a preparation method and application thereof, wherein the anti-aging agent comprises the following raw materials in parts by weight: 40-70 parts of red mud, 10-30 parts of silicate materials, 1-10 parts of slaked lime, 1-10 parts of white mud and 10-20 parts of aromatic oil. The anti-aging agent compounded by the red mud and the silicate material is prepared by combining the performance characteristics of the red mud and the silicate material, can effectively improve the warm-rutting resistance, the low-temperature crack resistance and the water stability of the asphalt mixture, obviously improves the dynamic modulus, can reduce the diseases of the asphalt pavement caused by aging during the service period, prolongs the service time of the road and reduces the road maintenance cost.

Description

Red mud-silicate composite anti-aging agent, asphalt mixture and preparation method and application thereof

Technical Field

The invention relates to the technical field of asphalt anti-aging agents. In particular to a red mud-silicate composite anti-aging agent and a preparation method thereof, an asphalt mixture containing the anti-aging agent, and a preparation method and application thereof.

Background

The information disclosed in this background of the invention is only for enhancement of understanding of the general background of the invention and is not necessarily to be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.

With the continuous development of the economy of China, the highway construction of China also enters the rapid development period. By 2019, the total mileage of Chinese roads reaches 484.65 kilometers, and the total mileage of express roads reaches 14.26 kilometers. In actual engineering construction, the typical structure of the pavement of a high-grade highway is a semi-rigid base asphalt pavement, and the proportion of the consumption of the asphalt pavement reaches more than 85 percent. However, the aging phenomenon of asphalt can cause more diseases (cracks, subsidence, pits, slurry pumping and the like) on the asphalt pavement, so that the asphalt pavement is usually maintained and repaired in a large area for 5 to 6 years in the using process and is required to be maintained and repaired in a large area for 2 to 3 years in the short process, the service life of the pavement is far short, the smoothness of traffic and transportation and the driving safety are seriously affected, and the national economy is greatly lost.

At present, many materials have been used for an anti-aging agent for asphalt, for example, carbon black may have an effect of preventing ultraviolet aging, but may cause asphalt to have a reduced low-temperature crack resistance and to be more easily broken in a low-temperature environment. The nano oxide can play a role in absorbing ultraviolet rays in the asphalt due to high specific surface area and high activity, but the low-temperature performance of the asphalt is not ideal, and the agglomeration phenomenon is easy to occur in the asphalt.

Disclosure of Invention

Aiming at the problems, the invention provides the red mud-silicate composite anti-aging agent, the asphalt mixture, and the preparation method and application thereof, which can obviously improve the high-temperature stability, the low-temperature crack resistance and the water stability of the asphalt mixture and effectively prevent the low-temperature cracking and the water damage of the asphalt mixture. The invention discloses the following technical scheme for achieving the aim.

The invention discloses a composite anti-aging agent based on red mud-silicate, which comprises the following raw materials in parts by weight: 40-70 parts of red mud, 10-30 parts of silicate materials, 1-10 parts of slaked lime, 1-10 parts of white mud and 10-20 parts of aromatic oil.

Preferably, the raw material composition of the composite age resister based on the red mud-silicate comprises: 40-60 parts of red mud, 10-30 parts of silicate materials, 5-10 parts of slaked lime, 5-10 parts of white mud and 10-20 parts of aromatic oil. Within the proportion range, the obtained anti-aging agent has more remarkable effects of improving the high-temperature anti-rutting performance, the low-temperature anti-cracking performance, the water stability and the dynamic modulus of the asphalt mixture.

Further, the red mud comprises any one or a mixture of two of sintering process red mud and Bayer process red mud.

Further, the silicate material comprises any one or a mixture of two of cement and montmorillonite.

Furthermore, the main components of the white mud are calcium carbonate and sodium carbonate, and a small amount of lignin fiber components exist, so that the white mud has high tensile strength, and the low-temperature crack resistance of the asphalt mixture can be improved.

Further, the aromatic oil has the main function of enhancing the oxidation aging resistance of the asphalt, and the aromatic oil has good rubber compatibility and can help the mixing and dispersion of the filler in the asphalt mixture.

The invention combines the performance characteristics of the red mud and the silicate material to prepare the anti-aging agent compounded by the red mud and the silicate material, and the anti-aging agent can effectively improve the anti-aging performance of the asphalt mixture and increase the service time of the asphalt pavement. This is because: on one hand, the red mud has a porous structure and a large specific surface area, and can be used as a barrier for blocking ultraviolet rays and oxygen, thereby playing a role in aging resistance. Meanwhile, the silicate material has a special layered structure, and the layered silicate material is a layered silicate mineral with a disordered transition structure. The unique lamellar structure of the phyllosilicate not only can effectively block organic solvent molecules and water molecules, but also has good blocking effect on oxygen, carbon dioxide and other gaseous substances in the air, and slows down the aging of asphalt materials. Therefore, the problem of aging of the asphalt pavement in the road service process can be solved, and the service life of the asphalt pavement is prolonged.

After the silicate material and the red mud are compounded, the silicate material has a special layered structure and can be adsorbed and expanded at the same time, so that the layered structure of the silicate material is expanded, the anti-aging effect is stronger, and meanwhile, the silicate material can give thermal stability to the layered structure of the aromatic oil and the red mud, so that the silicate material can still play a good modifying role after being heated.

In a second aspect of the invention, a preparation method of the composite age resister based on the red mud-silicate is disclosed, which comprises the following steps:

(1) drying the red mud, the silicate, the slaked lime and the white mud respectively for later use.

(2) And (2) respectively crushing the materials dried in the step (1), and then drying again to obtain red mud powder, silicate powder, slaked lime powder and white mud powder for later use.

(3) And (3) uniformly mixing the four kinds of powder in the step (2) and then uniformly mixing the powder with aromatic oil to obtain the composite powder.

Further, in the step (1), the drying temperature is 100-. The excessive moisture in each material can be removed through drying, so that the subsequent uniform mixing is facilitated.

Further, in the step (2), the crushing method comprises the following steps: ball milling for 10-40min, and grinding to the required particle size of the filler in technical Specification for road asphalt pavement construction (JTG F40-2004).

Further, in the step (2), the drying temperature is 100-.

Further, in the step (3), the mixing time may be selected to be 10-40min, or any other suitable mixing time may be used.

The third aspect of the invention discloses an anti-aging asphalt mixture, which comprises the following raw materials in parts by weight: 40-80 parts of coarse aggregate, 10-60 parts of fine aggregate, 3-6 parts of asphalt, 1-6 parts of filler and 1-5 parts of red mud-silicate composite anti-aging agent.

Optionally, the asphalt mix types include: any one of AC13, AC20, AC25, SMA13, and the like.

Optionally, the aggregate comprises any one of limestone, basalt, diabase, granite, etc., which meets the requirements of technical Specification for road asphalt pavement construction (JTG F40-2004) for coarse aggregate.

Optionally, the asphalt comprises any one of No. 70 base asphalt, SBS modified asphalt, rubber modified asphalt, etc., which meets the requirements of technical Specification for road asphalt pavement construction (JTG F40-2004) for asphalt.

Optionally, the filler is limestone ore powder, which meets the requirements of technical Specification for Highway asphalt pavement construction (JTG F40-2004) for fillers.

The fourth aspect of the invention discloses a preparation method of the anti-aging asphalt mixture, which comprises the following steps:

(i) and heating and melting the asphalt, proportionally mixing the asphalt with the red mud-silicate composite anti-aging agent, and uniformly mixing to obtain the anti-aging modified asphalt.

(ii) And (3) preheating the coarse aggregate, the fine aggregate and the filler respectively, then uniformly mixing the coarse aggregate and the fine aggregate according to a proportion, and adding the anti-aging modified asphalt obtained in the step (i) to obtain a pre-mixture.

(iii) And (3) adding the filler into the mixture obtained in the step (ii) in proportion, and uniformly mixing to obtain the anti-aging asphalt mixture.

Further, in step (i), the heating conditions are: heating at 130-170 ℃ for 1-3 h.

Further, in step (ii), the preheating conditions are: preheating for 1-5h at 160-180 ℃.

The fifth aspect of the invention discloses application of the red mud-silicate composite anti-aging agent and the anti-aging asphalt mixture in the fields of roads, bridge engineering and the like.

Compared with the prior art, the invention has the following beneficial effects:

(1) the red mud and the silicate material are compounded, so that the effect of blocking ultraviolet rays and oxygen can be achieved, and the aim of resisting ageing of the asphalt mixture is fulfilled.

(2) The anti-aging asphalt mixture provided by the invention has good high-temperature rutting resistance, low-temperature cracking resistance and water stability, the dynamic modulus is obviously improved, the diseases of an asphalt pavement caused by aging in the service period can be reduced, the service time of a road is prolonged, and the maintenance cost of the road is reduced.

(3) The main components of the red mud-silicate anti-aging agent provided by the invention are solid wastes such as red mud, and the like, so that a way is provided for the bulk utilization of the solid wastes, the waste is changed into valuable, a large amount of accumulated waste residues can be treated, the purpose of protecting the environment is achieved, and the construction cost is also reduced.

Detailed Description

It is to be understood that the following detailed description is exemplary and is intended to provide further explanation of the invention as claimed. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of exemplary embodiments according to the invention. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.

As mentioned above, the aging phenomenon of asphalt can cause more diseases (cracks, subsidence, pits, slurry pumping, etc.) on the asphalt pavement, so that the asphalt pavement can not reach the designed service life of the pavement in the using process, and the smoothness of traffic and transportation and the driving safety are seriously affected. Therefore, the invention provides a red mud-silicate composite anti-aging agent, an asphalt mixture and a preparation method thereof; the invention will now be further described with reference to specific embodiments.

In the following examples, the red mud is obtained from Shandong aluminum industry; the red mud is industrial polluting waste discharged when the aluminum oxide is extracted in the aluminum production industry. The white mud is purchased from Shandong province silver star paper mill; the white mud is solid waste produced in the causticizing stage of pulping and papermaking industry, and mainly contains calcium carbonate and sodium carbonate and a small amount of lignin fiber. The silicate material is silicate cement from Shandong Shunjia building materials company, and the main mineral composition of the silicate material is as follows: tricalcium silicate, dicalcium silicate, tricalcium aluminate, tetracalcium aluminoferrite.

First embodiment

1. The preparation method of the red mud-silicate composite anti-aging agent comprises the following steps:

(1) and respectively drying the red mud, the portland cement, the slaked lime and the white mud which are prepared by the sintering method in a drying oven at 105 ℃ for 3 hours.

(2) And (2) ball-milling the four dried raw materials in the step (1) in a ball mill for 30min respectively, and grinding to obtain the particle size required by the filler in technical Specification for road asphalt pavement construction (JTG F40-2004). Then the ball-milled powder is placed in an oven at 105 ℃ for 3h until being dried.

(3) And (3) mixing the four powder bodies obtained after ball milling in the step (3) with 15 parts of aromatic oil according to the proportion (55 parts of sintering red mud, 20 parts of portland cement, 5 parts of slaked lime and 5 parts of white mud), and stirring for 30min to obtain the red mud-silicate composite anti-aging agent.

2. The preparation method of the anti-aging asphalt mixture comprises the following steps:

(1) weighing raw materials: weighing the following components in parts by weight: 60 parts of limestone coarse aggregate, 30 parts of limestone fine aggregate, 4 parts of No. 70 matrix asphalt, 3 parts of anti-aging agent and 3 parts of limestone mineral powder (filler). Each technical index of each raw material meets the relevant requirements in technical Specification for construction of asphalt road surfaces for highways (JTG F40-2004); type of asphalt mixture: and (3) AC-20.

(2) Heating No. 70 matrix asphalt at 145 ℃ for 2 hours until the matrix asphalt is melted, then proportionally adding the red mud-silicate composite anti-aging agent prepared in the embodiment, and stirring for 1 hour by using a stirrer until the mixture is uniformly mixed, wherein the stirring speed is 300 revolutions per minute, and the stirring temperature is 145 ℃, so as to obtain the anti-aging modified asphalt.

(3) And (3) preheating the coarse aggregate, the fine aggregate and the filler at 170 ℃ for 3h, then pouring the coarse aggregate and the fine aggregate into a mixing pot, stirring for 90s, then adding the anti-aging modified asphalt obtained in the step (2), and stirring for 90s to obtain a pre-mixture.

(4) And (4) adding the filler into the mixture obtained in the step (3), and stirring for 90s to obtain the anti-aging asphalt mixture.

Second embodiment

(1) and respectively placing the Bayer process red mud, montmorillonite, slaked lime and white mud in a drying oven at 100 ℃ for drying for 5 hours.

(2) And (2) ball-milling the four dried raw materials in the step (1) in a ball mill for 20min, and grinding to obtain the particle size required by the filler in technical Specification for road asphalt pavement construction (JTG F40-2004). Then the powder after ball milling is placed in an oven at 100 ℃ for 5 hours until being dried.

(3) And (3) mixing the four powder bodies obtained after ball milling in the step (3) with 10 parts of aromatic oil according to the proportion (40 parts of Bayer process red mud, 30 parts of montmorillonite, 10 parts of slaked lime and 10 parts of white mud), and stirring for 30min to obtain the red mud-silicate composite anti-aging agent.

(1) weighing raw materials: weighing the following components in parts by weight: 50 parts of limestone coarse aggregate, 40 parts of limestone fine aggregate, 3 parts of No. 70 matrix asphalt, 5 parts of anti-aging agent and 2 parts of limestone mineral powder (filler). Each technical index of each raw material meets the relevant requirements in technical Specification for construction of asphalt road surfaces for highways (JTG F40-2004); type of asphalt mixture: and (3) AC-20.

Third embodiment

(1) the red mud, the portland cement, the slaked lime and the white mud which are produced by the sintering method are respectively placed in an oven with the temperature of 125 ℃ for drying for 2 hours.

(2) And (2) ball-milling the four dried raw materials in the step (1) in a ball mill for 20min, and grinding to obtain the particle size required by the filler in technical Specification for road asphalt pavement construction (JTG F40-2004). Then the powder after ball milling is placed in an oven at 125 ℃ for 2h until being dried.

(3) And (3) mixing the four powder bodies obtained after ball milling in the step (3) with 20 parts of aromatic oil according to the proportion (60 parts of sintering red mud, 10 parts of portland cement, 5 parts of slaked lime and 5 parts of white mud), and stirring for 35min to obtain the red mud-silicate composite anti-aging agent.

(1) weighing raw materials: weighing the following components in parts by weight: 60 parts of basalt coarse aggregate, 30 parts of basalt fine aggregate, 4 parts of No. 70 matrix asphalt, 1 part of anti-aging agent and 5 parts of limestone mineral powder (filler). Each technical index of each raw material meets the relevant requirements in technical Specification for construction of asphalt road surfaces for highways (JTG F40-2004); type of asphalt mixture: and (4) AC-25.

(2) Heating No. 70 matrix asphalt at 155 ℃ for 2 hours until the matrix asphalt is melted, then proportionally adding the red mud-silicate composite anti-aging agent prepared in the embodiment, and stirring for 1 hour by using a stirrer until the mixture is uniformly mixed, wherein the stirring speed is 300 revolutions per minute, and the stirring temperature is 145 ℃, so as to obtain the anti-aging modified asphalt.

Fourth embodiment

(1) and respectively placing the sintering process red mud, the portland cement, the slaked lime and the white mud in a drying oven at 150 ℃ for drying for 1 h.

(2) And (2) ball-milling the four dried raw materials in the step (1) in a ball mill for 40min respectively, and grinding to obtain the particle size required by the filler in technical Specification for road asphalt pavement construction (JTG F40-2004). Then the powder after ball milling is placed in an oven at 150 ℃ for 1h until being dried.

(3) And (3) mixing the four powder bodies obtained after ball milling in the step (3) with 10 parts of aromatic oil according to the proportion (60 parts of sintering red mud, 10 parts of Portland cement, 10 parts of slaked lime and 10 parts of white mud), and stirring for 35min to obtain the red mud-silicate composite anti-aging agent.

(1) weighing raw materials: weighing the following components in parts by weight: 80 parts of diabase coarse aggregate, 60 parts of diabase fine aggregate, 5 parts of No. 70 matrix asphalt, 5 parts of anti-aging agent and 4 parts of limestone mineral powder (filler). Each technical index of each raw material meets the relevant requirements in technical Specification for construction of asphalt road surfaces for highways (JTG F40-2004); type of asphalt mixture: and (6) AC-13.

(2) Heating No. 70 matrix asphalt at 170 ℃ for 21h until the matrix asphalt is melted, then proportionally adding the red mud-silicate composite anti-aging agent prepared in the embodiment, and stirring for 1h by using a stirrer until the mixture is uniformly mixed, wherein the stirring speed is 300 r/min, and the stirring temperature is 145 ℃, so as to obtain the anti-aging modified asphalt.

(3) And (3) preheating the coarse aggregate, the fine aggregate and the filler at 180 ℃ for 1h, then pouring the coarse aggregate and the fine aggregate into a mixing pot, stirring for 90s, then adding the anti-aging modified asphalt obtained in the step (2), and stirring for 90s to obtain a pre-mixture.

Fifth embodiment

(1) drying the Bayer process red mud, the portland cement, the slaked lime and the white mud in a 120 ℃ oven for 3 hours respectively.

(2) And (2) ball-milling the four dried raw materials in the step (1) in a ball mill for 10min respectively, and grinding to obtain the particle size required by the filler in technical Specification for road asphalt pavement construction (JTG F40-2004). Then the powder after ball milling is placed in an oven at 120 ℃ for 3h until being dried.

(3) And (3) mixing the four powder bodies obtained after ball milling in the step (3) with 10 parts of aromatic oil according to the proportion (70 parts of Bayer process red mud, 30 parts of Portland cement, 1 part of slaked lime and 10 parts of white mud), and stirring for 40min to obtain the red mud-silicate composite anti-aging agent.

(1) weighing raw materials: weighing the following components in parts by weight: 40 parts of granite coarse aggregate, 10 parts of granite fine aggregate, 6 parts of 7SBS modified asphalt, 3 parts of anti-aging agent and 2 parts of limestone mineral powder (filler). Each technical index of each raw material meets the relevant requirements in technical Specification for construction of asphalt road surfaces for highways (JTG F40-2004); type of asphalt mixture: SMA 13.

(2) The SBS modified asphalt is heated for 2 hours at 160 ℃ until the SBS modified asphalt is melted, then the red mud-silicate composite anti-aging agent prepared in the embodiment is added in proportion, and the mixture is stirred for 1 hour by using a stirrer until the mixture is uniformly mixed, wherein the stirring speed is 300 revolutions per minute, and the stirring temperature is 145 ℃, so that the anti-aging modified asphalt is obtained.

Sixth embodiment

(1) the red mud, the portland cement, the slaked lime and the white mud are respectively placed in a drying oven at 105 ℃ for drying for 3 hours.

(2) And (2) ball-milling the four dried raw materials in the step (1) in a ball mill for 40min respectively, and grinding to obtain the particle size required by the filler in technical Specification for road asphalt pavement construction (JTG F40-2004). Then the ball-milled powder is placed in an oven at 105 ℃ for 3h until being dried.

(3) And (3) mixing the four powder bodies obtained after ball milling in the step (3) with 10 parts of aromatic oil according to the proportion (25 parts of Bayer process red mud and sintering process red mud, 30 parts of montmorillonite, 10 parts of slaked lime and 1 part of white mud), and stirring for 30min to obtain the red mud-silicate composite anti-aging agent.

(1) weighing raw materials: weighing the following components in parts by weight: 55 parts of diabase coarse aggregate, 20 parts of diabase fine aggregate, 4 parts of No. 70 matrix asphalt, 6 parts of anti-aging agent and 1 part of limestone mineral powder (filler). Each technical index of each raw material meets the relevant requirements in technical Specification for construction of asphalt road surfaces for highways (JTG F40-2004); type of asphalt mixture: and (3) AC-20.

(2) Heating No. 70 matrix asphalt at 130 ℃ for 3 hours until the matrix asphalt is melted, then proportionally adding the red mud-silicate composite anti-aging agent prepared in the embodiment, and stirring for 1 hour by using a stirrer until the mixture is uniformly mixed, wherein the stirring speed is 300 revolutions per minute, and the stirring temperature is 145 ℃, so as to obtain the anti-aging modified asphalt.

(3) And (3) preheating the coarse aggregate, the fine aggregate and the filler at 160 ℃ for 5h, then pouring the coarse aggregate and the fine aggregate into a mixing pot, stirring for 90s, then adding the anti-aging modified asphalt obtained in the step (2), and stirring for 90s to obtain a pre-mixture.

Seventh embodiment

The preparation method of the anti-aging asphalt mixture comprises the following steps:

(1) and respectively drying the sintering red mud, slaked lime and white mud in a drying oven at 105 ℃ for 3 hours.

(3) And (3) mixing the four powder bodies obtained after ball milling in the step (3) with 15 parts of aromatic oil according to the proportion (75 parts of sintering red mud, 5 parts of slaked lime and 5 parts of white mud), and stirring for 30min to obtain the red mud-silicate composite anti-aging agent.

(4) The anti-aging agent prepared in the embodiment and other raw materials are prepared into the anti-aging asphalt mixture by the same method as the embodiment 1.

Eighth embodiment

(1) respectively placing the portland cement, the slaked lime and the white mud in a 105 ℃ oven for drying for 3 hours.

(3) And (3) mixing the four powder bodies obtained after ball milling in the step (3) with 15 parts of aromatic oil according to the proportion (75 parts of Portland cement, 5 parts of slaked lime and 5 parts of white mud), and stirring for 30min to obtain the red mud-silicate composite anti-aging agent.

Ninth embodiment

(2) Heating the No. 70 matrix asphalt at 130 ℃ for 3h until the matrix asphalt is melted for standby.

(3) And (3) preheating the coarse aggregate, the fine aggregate and the filler at 160 ℃ for 5h, then pouring the coarse aggregate and the fine aggregate into a mixing pot, stirring for 90s, then adding the melted asphalt obtained in the step (2), and stirring for 90s to obtain a pre-mixture.

Tenth embodiment

(2) Heating the No. 70 matrix asphalt at 145 ℃ for 2h until the matrix asphalt is melted for standby.

(3) And (3) preheating the coarse aggregate, the fine aggregate and the filler at 170 ℃ for 3h, then pouring the coarse aggregate and the fine aggregate into a mixing pot, stirring for 90s, then adding the melted asphalt obtained in the step (2), and stirring for 90s to obtain a pre-mixture.

Performance testing

In order to evaluate the influence of the red mud-silicate anti-aging agent on the performance of the asphalt mixture, seventh to tenth examples are used as comparison examples, wherein the seventh and eighth examples are the comparison examples of the first example, and the seventh and eighth examples are asphalt mixtures prepared by using the anti-aging agent obtained by adding only the red mud or only the silicate material; the ninth and tenth examples are controls of the first and sixth examples, respectively, and are asphalt mixes prepared without adding the red mud-silicate anti-aging agent.

The asphalt mixtures prepared in the first to tenth examples were evaluated for high-temperature rutting resistance, low-temperature crack resistance, water stability, and dynamic modulus with reference to the test procedure of road engineering asphalt and asphalt mixture test protocol (JTG E20-2011), and the specific evaluation indexes are shown in table 1.

TABLE 1

Example number	1	2	3	4	5	6	7	8	9	10
											Freeze-thaw split strength ratio (%)	89.1	90.7	92.3	91.4	90.4	89.7	85.3	84.1	84.6	83.1
Rut depth (mm)	1.2	1.3	1.3	1.2	1.4	1.6	1.6	1.9	2.1	2.4
											Marshall stability (KN)	14.6	13.8	13.1	14.9	12.6	11..9	10.5	11.2	8.9	7.4
Maximum bending strain (mu epsilon)	2486	2374	2219	2654	2434	2573	2298	2301	2176	2095
											Stability of immersion residue (%)	91.2	89.4	88.7	85.6	87.9	88.1	83.7	85.1	81.4	80.1
Dynamic modulus (MPa)	20163	18462	19743	18791	18037	19207	17698	17193	16897	16473

From the above performance test results it can be seen that: (1) after the red mud-silicate anti-aging agent is added, the freeze-thaw splitting strength ratio and the soaking residual stability of the asphalt mixture obtained by performing the freeze-thaw splitting test and the soaking Marshall test are obviously improved, which shows that the red mud-silicate anti-aging agent prepared by the invention can effectively improve the water stability of the asphalt mixture. (2) After the red mud-silicate anti-aging agent prepared by the invention is added, the maximum bending strain of the asphalt mixture obtained by a trabecular bending test of the asphalt mixture is obviously improved, which shows that the red mud-silicate anti-aging agent prepared by the invention can effectively improve the low-temperature crack resistance of the asphalt mixture. (3) After the red mud-silicate anti-aging agent prepared by the invention is added, the Marshall stability and the dynamic stability of the asphalt mixture obtained by carrying out the Marshall stability test and the Hamburg rutting test are obviously improved, which shows that the red mud-silicate anti-aging agent prepared by the invention can effectively improve the high-temperature rutting resistance of the asphalt mixture. (4) After the red mud-silicate anti-aging agent prepared by the invention is added, a Simple Performance Test (SPT) is carried out, so that the dynamic modulus of the asphalt mixture added with the red mud-silicate anti-aging agent is greatly improved. (5) In addition, when the red mud and the silicate material are used together, various performances of the asphalt mixture can be greatly improved, and only one of the materials is selected, so that the improvement effect is not strong.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. The composite anti-aging agent based on the red mud-silicate is characterized in that: the raw materials comprise the following components in parts by weight: 40-70 parts of red mud, 10-30 parts of layered silicate material, 1-10 parts of slaked lime, 1-10 parts of white mud and 10-20 parts of aromatic oil;

the layered silicate material is portland cement.

2. The red mud-silicate based composite age resister of claim 1, wherein: the composite anti-aging agent based on the red mud-silicate comprises the following raw materials: 40-60 parts of red mud, 10-30 parts of layered silicate material, 5-10 parts of slaked lime, 5-10 parts of white mud and 10-20 parts of aromatic oil.

3. The red mud-silicate based composite age resister according to claim 1 or 2, characterized in that: the red mud comprises any one or a mixture of two of sintering process red mud and Bayer process red mud.

4. The method for preparing the red mud-silicate based composite anti-aging agent according to any one of claims 1 to 3, wherein: the method comprises the following steps:

(1) respectively drying the red mud, the layered silicate material, the slaked lime and the white mud;

(2) respectively crushing the materials dried in the step (1), and then drying again to respectively obtain four kinds of powder;

5. The method for preparing the red mud-silicate based composite anti-aging agent according to claim 4, wherein the method comprises the following steps: in the step (1), the drying temperature is 100-150 ℃, and the time is 2-5 h.

6. The method for preparing the red mud-silicate based composite anti-aging agent according to claim 4, wherein the method comprises the following steps: in the step (2), the crushing method comprises the following steps: ball milling for 10-40min, and grinding to the particle size required by the filler in technical Specification for road asphalt pavement construction (JTG F40-2004).

7. The method for preparing the red mud-silicate based composite anti-aging agent according to claim 4, wherein the method comprises the following steps: in the step (2), the drying temperature is 100-150 ℃, and the time is 1-5 h.

8. The method for preparing the red mud-silicate based composite anti-aging agent according to claim 4, wherein the method comprises the following steps: in the step (3), the four kinds of powder are mixed uniformly and then mixed with the aromatic oil for 10-40 min.

9. An anti-aging asphalt mixture is characterized in that: the raw materials comprise the following components in parts by weight: 40-80 parts of coarse aggregate, 10-60 parts of fine aggregate, 3-6 parts of asphalt, 1-6 parts of filler and 1-5 parts of red mud-silicate composite anti-aging agent according to any one of claims 1-3.

10. The anti-aging asphalt mixture according to claim 9, wherein: asphalt mix types include: any one of AC13, AC20, AC25 and SMA 13.

11. The anti-aging asphalt mixture according to claim 9, wherein: the coarse aggregate comprises any one of limestone, basalt, diabase and granite, and meets the requirements of technical Specification for road asphalt pavement construction JTG F40-2004 on the coarse aggregate.

12. The anti-aging asphalt mixture according to claim 9, wherein: the asphalt comprises any one of 70# base asphalt, SBS modified asphalt and rubber modified asphalt, and meets the requirements of technical Specification for road asphalt pavement construction JTG F40-2004 on the asphalt.

13. The anti-aging asphalt mixture according to claim 9, wherein: the filler is limestone mineral powder, and meets the requirements of technical Specification for Highway asphalt pavement construction JTG F40-2004 on the filler.

14. The method for preparing an anti-aging asphalt mixture according to any one of claims 9 to 13, characterized by: the method comprises the following steps:

(i) heating and melting asphalt, proportionally mixing the asphalt with the red mud-silicate composite anti-aging agent, and uniformly mixing to obtain anti-aging modified asphalt;

(ii) respectively preheating coarse aggregates, fine aggregates and fillers, then uniformly mixing the coarse aggregates and the fine aggregates according to a proportion, and adding the anti-aging modified asphalt obtained in the step (i) to obtain a pre-mixture;

(iii) and (3) adding the filler into the mixture obtained in the step (ii) in proportion, and uniformly mixing to obtain the composite material.

15. The method according to claim 14, wherein in the step (i), the heating conditions are: heating at 130-170 ℃ for 1-3 h.

16. The method of claim 14, wherein in step (ii), the preheating conditions are: preheating for 1-5h at 160-180 ℃.

17. The use of the composite age resister of red mud-silicate according to any of claims 1 to 3 and/or the composite age resister of red mud-silicate prepared by the method according to any of claims 4 to 8 in the field of road and bridge engineering.

18. Use of the anti-aging asphalt mixture according to any one of claims 9 to 13 and/or the anti-aging asphalt mixture prepared by the method according to any one of claims 14 to 16 in the field of road and bridge engineering.