A warm mix asphalt mixture and a method of making the same

Abstract

The application relates to the field of asphalt pavement construction, and particularly discloses warm-mixed asphalt mixture and a preparation method thereof. The warm-mixed asphalt mixture is composed of the following raw materials in parts by weight: aggregate 800-1000 parts, modified asphalt 36-45 parts, warm-mixing agent 2-3 parts, water-absorbing expanding agent 10-20 parts, bonding curing agent 12-14 parts and water-conducting filler 10-18 parts. The preparation method comprises the following steps: mixing and stirring the aggregate and the water-conducting filler at 120-130 DEG C for 2 min, then mixing and stirring the modified asphalt and the warm-mixing agent for 2 min, and finally mixing and stirring the water-absorbing expanding agent and the bonding curing agent for 2 min to obtain the warm-mixed asphalt mixture. The warm-mixed asphalt mixture can be used for asphalt pavement construction and has the advantages of high water stability. The preparation method has the advantages of simple operation and reduced energy consumption.

Description

TECHNICAL FIELD

[0001] The application relates to the field of asphalt pavement construction, in particular to warm-mixed asphalt mixture and a preparation method thereof. BACKGROUND

[0002] Asphalt pavement is widely used in high-grade highways due to its good elastic-plasticity, high driving comfort and strong load adaptability. Most asphalt pavement adopts hot-mixed asphalt mixture. The asphalt needs to be heated to above 160 DEG C, the mineral aggregate needs to be heated to about 170 DEG C, and the mixture is mixed at about 160 DEG C. The temperature of the mixture during paving and compaction is usually not lower than 140 DEG C.

[0003] In high-altitude areas, higher temperature is needed to use hot-mixed asphalt mixture due to the influence of air pressure, which causes more energy consumption. The mixing temperature of the warm-mixed asphalt mixture in the ordinary environment is about 130 DEG C, and the paving and compaction temperature is about 120 DEG C, which reduces a large amount of energy consumption compared with the hot-mixed asphalt mixture.

[0004] The warm-mixed asphalt mixture has a lower heating temperature than the hot-mixed asphalt mixture, so it is difficult to fully dry the moisture on the surface of the aggregate, and thus part of the moisture remains on the surface of the aggregate, which adversely affects the water stability of the final mixture. SUMMARY

[0005] In order to reduce the adverse effects of ultraviolet radiation on the durability of asphalt pavement, the application provides a warm-mixed asphalt mixture and a preparation method thereof.

[0006] In the first aspect, the application provides a warm-mixed asphalt mixture, which adopts the following technical scheme:

[0007] A warm-mixed asphalt is composed of the following raw materials by weight: aggregate 800-1000 parts, modified asphalt 36-45 parts, warm-mixed agent 2-3 parts, water-absorbing and expanding agent 10-20 parts, bonding and curing agent 8-12 parts, and water-conducting filler 10-18 parts.

[0008] By adopting the above technical scheme, the water-absorbing and expanding agent and the water-conducting filler absorb the moisture on the aggregate at the same time, the bonding and curing agent improves the bonding strength of the modified asphalt and the aggregate, the water-absorbing and expanding agent expands after absorbing water, and at this time the bonding and curing agent has begun to cure and maintain a certain strength. The expansion of the water-absorbing and expanding agent causes the gaps in the asphalt mixture to be filled, thereby reducing the damage of the water penetration to the structure of the asphalt pavement, and further improving the water stability of the asphalt mixture.

[0009] Preferably, the modified asphalt comprises base asphalt, rubber powder, solubilizer and stabilizer, and the weight ratio of the base asphalt, rubber powder, solubilizer and stabilizer is 160:30:10:1.

[0010] By adopting the technical scheme, the rubber powder improves the high-temperature performance and water stability of the asphalt, and the solubilizer and the stabilizer improve the storage stability and low-temperature stability of the modified asphalt.

[0011] Preferably, the water-absorbing and swelling agent includes an acrylic acid salt slurry and expanded soil, and the weight ratio of the acrylic acid salt slurry to the expanded soil is 4:1.

[0012] By adopting the technical scheme, the water-absorbing and swelling agent increases in volume after absorbing water, thereby filling the gaps between the asphalt mixtures, improving the compactness of the asphalt pavement, effectively reducing the water permeating into the asphalt pavement, and reducing the influence of water on the water stability of the asphalt pavement.

[0013] Preferably, the acrylic acid salt slurry is mixed by water, calcium acrylate, a crosslinking agent N, N'-methylenebisacrylamide, a promoter triethanolamine and an initiator ammonium persulfate according to a weight ratio of 150:75:15:5:3.

[0014] By adopting the technical scheme, the calcium acrylate is dissolved in water, and forms a stable slurry under the action of the crosslinking agent, the promoter and the initiator. When the acrylic acid salt slurry is mixed into the asphalt mixture and solidified, the expanded soil that absorbs water and swells is fixed in the asphalt mixture, the expanded soil swells in situ, thereby filling the gaps of the asphalt pavement structure and effectively improving the stability and water stability of the asphalt pavement structure.

[0015] Preferably, the bonding and curing agent includes water-based epoxy resin, ultraviolet absorber and ultraviolet shielding agent, and the weight ratio of the water-based epoxy resin, the ultraviolet absorber and the ultraviolet shielding agent is (10-12):1:1.

[0016] By adopting the technical scheme, the water-based epoxy resin increases the bonding strength between the asphalt and the aggregate, and reduces the influence of ultraviolet radiation on the bonding performance of the asphalt.

[0017] Preferably, the water guide filler includes zeolite and sepiolite, and the weight ratio of the zeolite to the sepiolite is (2-4):(3-5).

[0018] By adopting the technical scheme, the zeolite and the sepiolite play a role in guiding water, the water on the aggregate enters the pores in the zeolite or the modified sepiolite, thereby guiding the water away, effectively reducing the bonding strength between the aggregate and the modified asphalt, and further reducing the influence on the water stability of the asphalt pavement.

[0019] Preferably, basalt fiber 3-5 parts are further included.

[0020] By adopting the technical scheme, since the basalt fiber has a large aspect ratio, is dispersed in the asphalt mixture, is more likely to overlap each other to form a network, is not easy to deform under external load, and can disperse and transfer the external load, the load resistance of the asphalt mixture is enhanced, and the Marshall stability is improved.

[0021] In a second aspect, the application provides a preparation method of warm-mixed asphalt mixture, which adopts the following technical scheme: a preparation method of warm-mixed asphalt, comprising the following steps: mixing and stirring aggregate and water guide filler at 120-130 DEG C for 2 min, then adding modified asphalt and warm-mixing agent and mixing and stirring for 2 min, and finally adding water absorption expanding agent and bonding curing agent and mixing and stirring for 2 min to obtain the warm-mixed asphalt mixture.

[0022] By adopting the technical scheme, the raw materials are added in stages and stirred and mixed uniformly under the warm-mixing condition, so that the final product is prepared, and energy consumption is effectively reduced.

[0023] In summary, the application has the following beneficial effects:

[0024] 1. Since the application uses the bonding curing agent to improve the bonding strength between the asphalt and the aggregate, and the expanded soil and the acrylic acid salt slurry solidification fill the cracks in the asphalt pavement due to the addition of the water absorption expanding agent, the water entering the asphalt pavement is reduced, and thus the water stability of the asphalt mixture is improved.

[0025] 2. In the application, the asphalt is preferably protected by the ultraviolet absorber and the ultraviolet shielding agent, so that the bonding strength between the asphalt and the aggregate is reduced due to ultraviolet radiation aging, and thus the water stability is reduced.

[0026] 3. The method of the application can effectively reduce energy consumption compared with hot-mixed asphalt by stirring at 120-130 DEG C, and the raw materials are added in stages, which can further dry the moisture and reduce the influence of moisture on the asphalt mixture. DETAILED DESCRIPTION

[0027] In the application, the warm-mixing agent is APTL / 01 warm-mixing agent, which is purchased from the market; the base asphalt is 70# base asphalt, which is purchased from the market; the rubber powder has a fineness of 20 mesh, which is purchased from the market; the solubilizing agent is furfural extract oil, which is purchased from the market; and the stabilizer is sulfur, which has a fineness of 30 mesh, which is purchased from the market.

[0028] The basalt fiber has a length of 4-6 mm and a water content of 3-5%, which is purchased from the market.

[0029] The aggregate is limestone AC-13C gradation.

[0030]

[0031] The aqueous epoxy resin was purchased from the market; the ultraviolet absorber was isooctyl methoxycinnamate, purchased from the market; the ultraviolet shielding agent was nano-titanium dioxide with a particle size of 30 nm, purchased from the market; the zeolite particle size was 2.5 mm, purchased from the market; the sepiolite particle size was 4 mm, purchased from the market; and the expanded soil fineness was 30 mesh, purchased from the market.

[0032] The application will be further described in detail below in combination with examples.

[0033] Preparation Example

[0034] Preparation Example 1

[0035] The preparation example discloses a modified asphalt prepared by the following steps:

[0036] 160 kg of base asphalt was heated to 180 DEG C, and then 30 kg of rubber powder, 10 kg of furfural extract oil and 1 kg of sulfur were added and stirred and mixed at a stirring speed of 5000 r / min, and then stirred for 2 h to prepare the modified asphalt.

[0037] Preparation Example 2

[0038] The preparation example discloses an acrylic acid salt slurry prepared by the following steps: 150 kg of water, 75 kg of calcium acrylate, 15 kg of N, N'-methylenebisacrylamide and 3 kg of ammonium persulfate were mixed, heated and stirred at 100 r / min and 70 DEG C for 10 min, 5 kg of triethanolamine was added and stirred and mixed for 2 min to prepare the acrylic acid salt slurry.

[0039] Example

[0040] Example 1

[0041] The example discloses a warm-mixed asphalt mixture prepared by the following steps:

[0042] 800 kg of aggregate, 4 kg of zeolite and 6 kg of sepiolite were stirred and mixed in an environment at 120 DEG C, stirred at 300 r / min for 2 min, 36 kg of the modified asphalt prepared in the preparation example 1 and 2 kg of a warm-mixing agent were added and continuously stirred for 2 min, and finally 8 kg of the acrylic acid salt slurry prepared in the preparation example 2 and 2 kg of expanded soil and 10 kg of aqueous epoxy resin, 1 kg of ultraviolet absorber and 1 kg of ultraviolet shielding agent were added and stirred and mixed for 2 min to prepare the warm-mixed asphalt mixture.

[0043] Example 2

[0044] The example discloses a warm-mixed asphalt mixture prepared by the following steps:

[0045] 900 kg aggregate, 6 kg zeolite and 8 kg sepiolite are mixed by stirring in an environment of 125°C, stirring at 300 r / min for 2 min, 40.5 kg of modified asphalt prepared in Preparation Example 1 and 2.5 kg of warm-mixing agent are further added and stirred for 2 min, and finally 12 kg of acrylic salt slurry prepared in Preparation Example 2 and 3 kg of expanded soil and 11 kg of water-based epoxy resin, 1 kg of ultraviolet absorber and 1 kg of ultraviolet shielding agent are mixed by stirring for 2 min to prepare a warm-mixing asphalt mixture.

[0046] Example 3

[0047] This example discloses a warm-mixing asphalt mixture prepared by the following steps:

[0048] 1000 kg aggregate, 8 kg zeolite and 10 kg sepiolite are mixed by stirring in an environment of 130°C, stirring at 300 r / min for 2 min, 45 kg of modified asphalt prepared in Preparation Example 1 and 3 kg of warm-mixing agent are further added and stirred for 2 min, and finally 16 kg of acrylic salt slurry prepared in Preparation Example 2 and 4 kg of expanded soil and 12 kg of water-based epoxy resin, 1 kg of ultraviolet absorber and 1 kg of ultraviolet shielding agent are mixed by stirring for 2 min to prepare a warm-mixing asphalt mixture.

[0049] Example 4

[0050] This example discloses a warm-mixing asphalt mixture, which is different from Example 2 in that:

[0051] The acrylic salt slurry is added in an amount of 15 kg and the expanded soil is added in an amount of 0 kg.

[0052] Example 5

[0053] This example discloses a warm-mixing asphalt mixture, which is different from Example 2 in that:

[0054] The acrylic salt slurry is added in an amount of 0 kg and the expanded soil is added in an amount of 15 kg.

[0055] Example 6

[0056] This example discloses a warm-mixing asphalt mixture, which is different from Example 2 in that:

[0057] First, 3 kg of basalt fiber is mixed with aggregate.

[0058] Example 7

[0059] This example discloses a warm-mixing asphalt mixture, which is different from Example 6 in that:

[0060] The basalt fiber is added in an amount of 4 kg.

[0061] Example 8

[0062] This example discloses a warm mix asphalt mixture, which differs from Example 6 in that:

[0063] The basalt fiber was added in an amount of 5 kg.

[0064] Example 9

[0065] This example discloses a warm mix asphalt mixture, which differs from Example 2 in that:

[0066] The water-based epoxy resin was added in an amount of 13 kg, and the ultraviolet absorber and the ultraviolet shielding agent were each added in an amount of 0.

[0067] Comparative Example

[0068] Comparative Example 1

[0069] This comparative example discloses a warm mix asphalt mixture, which differs from Example 2 in that:

[0070] No water-absorbing expanding agent was added.

[0071] Comparative Example 2

[0072] This comparative example discloses a warm mix asphalt mixture, which differs from Example 2 in that:

[0073] No water-conducting filler was added.

[0074] Comparative Example 3

[0075] This comparative example discloses a warm mix asphalt mixture, which differs from Example 2 in that:

[0076] No adhesion curing agent was added.

[0077] Comparative Example 4

[0078] This comparative example discloses a warm mix asphalt mixture, which differs from Example 2 in that:

[0079] No water-absorbing expanding agent and no water-conducting filler were added.

[0080] Comparative Example 5

[0081] This comparative example discloses a warm mix asphalt mixture, which differs from Example 2 in that:

[0082] No water-absorbing expanding agent and no adhesion curing agent were added.

[0083] Comparative Example 6

[0084] This comparative example discloses a warm mix asphalt mixture, which differs from Example 2 in that:

[0085] No water-absorbing filler and no adhesion curing agent are added.

[0086] Comparative Example 7

[0087] The present comparative example discloses a warm mix asphalt mixture, which is different from Example 2 in that:

[0088] No water-absorbing filler, no water-absorbing expansion agent and no adhesion curing agent are added.

[0089] Performance detection test

[0090] According to JTG E20-2011 “Highway Engineering Asphalt and Asphalt Mixture Test Procedures” 4 Asphalt Mixture Test T0709-2011 Marshall Stability Test of Asphalt Mixture 4 Immersion Marshall Test Method; T0719-2011 Rut Test of Asphalt Mixture, the dynamic stability performance of the asphalt mixture is detected.

[0091] Table 1 Performance detection data table

[0092] Dynamic stability (sec / mm) Immersion residual stability (%) Example 1 3612 89.4 Example 2 3770 89.8 Example 3 3745 89.6 Example 4 3612 86.5 Example 5 3524 85.3 Example 6 3826 90.1 Example 7 3841 90.3 Example 8 3834 90.3 Example 9 3618 86.6 Comparative Example 1 2645 79.4 Comparative Example 2 2719 79.8 Comparative Example 3 2731 80.2 Comparative Example 4 2026 77.5 Comparative Example 5 1937 77.2 Comparative Example 6 1815 76.8 Comparative Example 7 1242 75.2

[0093] It can be seen from Examples 2 and Comparative Examples 1-7 in combination with Table 1 that the water-absorbing expansion agent and the water-absorbing filler absorb water on the aggregate at the same time, the adhesion curing agent improves the adhesion strength of the modified asphalt and the aggregate, the volume of the water-absorbing expansion agent increases after absorbing water, at this time the adhesion curing agent has begun to cure and maintain a certain strength, and the expansion of the water-absorbing expansion agent causes the gaps of the asphalt mixture to be filled, thereby reducing the damage of the water penetrating into the asphalt pavement structure, and further improving the water stability of the asphalt mixture.

[0094] It can be seen from Examples 2, 4 and 5 in combination with Table 1 that the expanded soil increases in volume after absorbing water, thereby filling the gaps between the asphalt mixtures, the diacrylate salt slurry penetrates into the expanded soil and other raw materials, and the expanded soil absorbing water is fixed in the asphalt mixture, thereby improving the tightness of the asphalt pavement, effectively reducing the water penetrating into the asphalt pavement, and thereby reducing the influence of water on the water stability of the asphalt pavement.

[0095] It can be seen from Examples 2, 6-8 in combination with Table 1 that the basalt fibers are dispersed in the asphalt mixture, are more likely to overlap each other to form a network, are not easy to deform under external load, and can disperse and transfer external load, so that the load resistance of the asphalt mixture is enhanced, and the Marshall water stability is improved.

[0096] It can be seen from Examples 2 and 9 in combination with Table 2 that the influence of reducing ultraviolet radiation on the adhesion performance of asphalt due to asphalt aging is reduced, the adhesion strength of the water-based epoxy resin to the asphalt and the aggregate is improved, and the Marshall water stability of the asphalt pavement is improved.

[0097] The embodiments are only illustrative of the present application, and are not intended to limit the present application, and those skilled in the art can make modifications to the embodiments without creative contribution after reading the specification, but as long as the modifications are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A warm mix asphalt mixture characterized in that, The raw material composition comprises the following weight parts: aggregate 800-1000 parts, modified asphalt 36-45 parts, warm mixing agent 2-3 parts, water absorption expanding agent 10-20 parts, bonding curing agent 12-14 parts, and water conducting filler 10-18 parts; the modified asphalt comprises base asphalt, rubber powder, solubilizer, and stabilizer, and the weight ratio of the four is 160:30:10:1; the stabilizer is sulfur with fineness of 30 mesh; the water conducting filler comprises zeolite and sepiolite, and the weight ratio of the two is (2-4):(3-5), and the sepiolite has a particle size of 4 mm; the bonding curing agent comprises water-based epoxy resin, ultraviolet absorber, and ultraviolet shielding agent, and the weight ratio of the three is (10-12):1:1; the water absorption expanding agent comprises acrylic acid salt slurry and expanded soil, and the expanded soil has a fineness of 30 mesh; the weight ratio of the two is 4:1; the acrylic acid salt slurry is prepared by mixing water, calcium acrylate, crosslinking agent N,N'-methylene bisacrylamide, accelerator triethanolamine, and initiator ammonium persulfate in a weight ratio of 150:75:15:5:3; The preparation steps of the warm mix asphalt mixture are as follows: the aggregate and the water conducting filler are mixed and stirred at 120-130 DEG C for 2 min, then the modified asphalt and the warm mixing agent are added and mixed and stirred for 2 min, and finally the water absorption expanding agent and the bonding curing agent are added and mixed and stirred for 2 min to obtain the warm mix asphalt mixture.

2. The warm mix asphalt mixture of claim 1, wherein, The basalt fiber is 3-5 parts, and has a length of 4-6 mm and a water content of 3-5%.

3. The warm mix asphalt mixture of claim 1, wherein, The solubilizer is furfural extract oil, and the warm mixing agent is APTL / 01 warm mixing agent.

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