Composite anti-aging asphalt concrete and preparation method thereof

Abstract

The invention discloses composite anti-aging asphalt concrete and a preparation method thereof, and particularly relates to the technical field of asphalt, the composite anti-aging asphalt concrete comprises the following components in parts by weight: 30-40 parts of coarse aggregate, 20-30 parts of fine aggregate, 5-15 parts of mineral powder, 10-20 parts of pre-coated stone, 4-8 parts of asphalt, and 0.2-1 part of a slow-release regenerant; besides, a preparation method of the composite anti-aging asphalt specifically comprises the following steps: S1, mixing materials: mixing 30-40 parts by weight of coarse aggregate, 20-30 parts by weight of fine aggregate, 5-15 parts by weight of mineral powder, 10-20 parts by weight of pre-coated stone, 4-8 parts by weight of asphalt and 0.2-1 part by weight of a slow-release regenerant to obtain a uniform mixture; and S2, the uniform mixture is subjected to paving, primary pressing, secondary pressing and final pressing, and the composite anti-aging asphalt concrete wearing layer is prepared. According to the present invention, the manner of pre-coating the stone material and the slow-release regenerant is adopted, such that the anti-aging performance is excellent, the certain regeneration reduction ability is provided, and the service life of the pavement can be substantially prolonged.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of asphalt, more particularly, the present application relates to a composite anti-aging asphalt concrete and a preparation method thereof. BACKGROUND

[0002] Since the construction of asphalt pavement, it is affected by oxidation, ultraviolet rays, temperature, moisture and load, etc. The light oil in asphalt will flow and transform with time, which is the aging process of asphalt. On the one hand, the aging of asphalt leads to the increase of brittleness, which is easy to produce transverse and longitudinal cracks under the action of temperature stress and load, and then develops into a network crack (alligator crack) or block crack, resulting in pavement cracking. The further invasion of water causes the secondary diseases such as frost heaving and pumping of the base.

[0003] At present, there are many pavement maintenance schemes for various diseases caused by asphalt aging, mainly including infiltration regeneration, in-situ hot regeneration, field-mixed hot regeneration, field-mixed cold regeneration, etc. The core point of these technical routes is to add light oil to the aged asphalt concrete to achieve the purpose of regeneration. These technologies have serious limitations such as poor regeneration performance, complex construction, high energy consumption and environmental pollution. In view of this, the present application provides a composite anti-aging asphalt concrete and a preparation method thereof. SUMMARY

[0004] In order to overcome the above-mentioned defects of the prior art, the embodiments of the present application provide a composite anti-aging asphalt concrete and a preparation method thereof, which has excellent anti-aging performance and certain regeneration restoration ability, and can greatly prolong the service life of the pavement.

[0005] To achieve the above-mentioned purpose, the present application provides the following technical scheme: A composite anti-aging asphalt concrete comprises the following components and their weight fractions: coarse aggregate 30-40 parts, fine aggregate 20-30 parts, mineral powder 5-15 parts, pre-wrapped stone 10-20 parts, asphalt 4-8 parts, and slow-release regenerating agent 0.2-1 part.

[0006] In a preferred embodiment, the following components and their weight fractions are included: coarse aggregate 32-38 parts, fine aggregate 22-28 parts, mineral powder 7-12 parts, pre-wrapped stone 12-18 parts, asphalt 5-6 parts, and slow-release regenerating agent 0.3-0.7 part.

[0007] In a preferred embodiment, the following components and their weight fractions are included: coarse aggregate 35 parts, fine aggregate 25 parts, mineral powder 10 parts, pre-wrapped stone 15 parts, asphalt 6 parts, and slow-release regenerating agent 0.5 part.

[0008] In a preferred embodiment, the composite anti-aging asphalt described above: the coarse aggregate is 4.75-9.5mm basalt stone, and the fine aggregate is 2.36-4.75mm basalt stone.

[0009] A preparation method of a composite anti-aging asphalt concrete, for preparing the composite anti-aging asphalt described above, specifically comprising the following steps: S1, mixing, according to the weight fraction, 30-40 parts of coarse aggregate, 20-30 parts of fine aggregate, 5-15 parts of mineral powder, 10-20 parts of pre-wrapped stone, 4-8 parts of asphalt, and 0.2-1 part of slow-release regenerative agent, to obtain a uniform mixture; S2, uniformly spread the mixture, primary pressure, re-pressing and final pressing to prepare the composite anti-aging asphalt concrete wearing layer.

[0010] In a preferred embodiment, the pre-wrapped stone in step S1 is obtained by the following steps: according to the weight fraction, 100 parts of fine aggregate and 4-10 parts of emulsified asphalt are added to the mixing device, the stirring paddle is started to mix until the emulsified asphalt is demulsified, then the stirring is stopped, the material is taken out and naturally air-dried, and after lightly tapping to disperse the agglomerated part, the pre-wrapped stone is obtained. According to the weight fraction, 10-20 parts are taken for preparing the asphalt described above.

[0011] In a preferred embodiment, the emulsified asphalt comprises the following components and their weight fractions: asphalt 50-60 parts, water 40-50 parts, emulsifier 0.4-0.8 parts, nano zinc oxide 0.5-3 parts, and hydrochloric acid in appropriate amount.

[0012] In a preferred embodiment, the emulsified asphalt is prepared by the following steps: Step 1: heat 50-60 parts of asphalt to 130-150℃, add 0.5-3 parts of nano zinc oxide, mix thoroughly to obtain mixture A and maintain the temperature; Step 2: heat 40-50 parts of water to 50-65℃, add 0.4-0.8 parts of emulsifier to obtain a soap solution; add hydrochloric acid to the soap solution to adjust the pH value of the soap solution to 2.0; Step 3: add the acid-adjusted soap solution to the colloid mill, start the colloid mill, and uniformly and slowly add mixture A; when the liquid in the colloid mill becomes uniformly brown or dark brown, turn off the colloid mill to obtain the emulsified asphalt.

[0013] In a preferred embodiment, the slow-release regenerative agent comprises the following components and their weight fractions: gelatin 4-6 parts, gum arabic 4-6 parts, water 80-100 parts, divided into two equal parts, emulsifier 1-3 parts, oil 8-10 parts, formaldehyde 6-8 parts; The emulsifier is preferably selected from sugar esters, and the oil is selected from one or more of turpentine oil, castor oil, soybean oil and white oil.

[0014] In a preferred embodiment, the slow-release rejuvenator is prepared by the following steps: Step 1: Take 50% of the total water, add 4-6 parts of gelatin, heat to 40-60 DEG C, to obtain a gelatin solution; Step 2: Take the remaining water, add an equal amount of gum arabic to the gelatin, heat to 40-60 DEG C, to obtain a gum arabic solution; Step 3: Add the emulsifier to the gum arabic solution, dissolve thoroughly, then add the oil, and homogenize the resulting mixture at a speed of 8000-12000 r / min for 5-15 min to obtain a homogenized solution; Step 4: Add the gelatin solution obtained in step 1 to the homogenized solution obtained in step 2, maintain the temperature at 50-55 DEG C, stir, then adjust the pH of the mixture to 4.0-4.5, maintain the stirring speed at 1200-1500 r / min, and stir for 30-180 min to obtain a coagulation solution; Step 5: Maintain the temperature, add 6-8 parts of formaldehyde to the coagulation solution, maintain the stirring speed at 1200-1500 r / min, and continue stirring for 30-90 min, then adjust the pH of the resulting mixture to 8.0-9.0, and reduce the temperature to 10-20 DEG C to obtain a finished solution; Step 6: Allow the finished solution obtained in step 5 to stand, remove the supernatant, obtain the precipitate, dry the precipitate, granulate, and obtain the finished slow-release rejuvenator.

[0015] The technical effects and advantages of the present application are as follows: 1. The present application disperses zinc oxide into emulsified asphalt by pre-wrapping the stone, which is different from the conventional method of directly mixing nano zinc oxide with other components in the asphalt mixture, which causes uneven dispersion of zinc oxide powder and local white spots in the asphalt mixture. By adding zinc oxide to the asphalt first and then emulsifying the asphalt, the dispersion of zinc oxide is more uniform, the anti-aging effect is better, the aging speed is slower than that of conventional asphalt concrete, and the white color of zinc oxide can be covered up, eliminating the problem of local white spots in the finished asphalt mixture.

[0016] 2. The present application forms oil slow-release microcapsules in asphalt concrete by preparing a slow-release rejuvenator. With the rolling of vehicle load, the oil in the slow-release rejuvenator will slowly release in the asphalt concrete, which can regenerate and repair the road surface, thereby greatly extending the service life of the road surface and delaying the maintenance time point of the road surface, thereby saving maintenance funds. DETAILED DESCRIPTION

[0017] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the embodiments in the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by a person of ordinary skill in the art without creative effort belong to the protection scope of the present application.

[0018] Embodiment 1 The composite anti-aging asphalt concrete comprises the following components and their weight fractions: coarse aggregate 30-40 parts, fine aggregate 20-30 parts, mineral powder 5-15 parts, pre-wrapped stone 10-20 parts, asphalt 4-8 parts, and slow-release rejuvenator 0.2-1 part.

[0019] In the embodiment, the components are specifically: coarse aggregate 35 parts, fine aggregate 25 parts, mineral powder 10 parts, pre-wrapped stone 15 parts, asphalt 6 parts, and slow-release rejuvenator 0.5 part.

[0020] Further, in the above components, the asphalt is SBSI-D type modified asphalt; the coarse aggregate is 4.75-9.5 mm basalt stone, and the fine aggregate is 2.36-4.75 mm basalt stone. On the basis of the above, a preparation method of the composite anti-aging asphalt concrete is further provided for preparing the composite anti-aging asphalt, and the specific preparation steps are as follows: S1, mixing, 35 parts of coarse aggregate, 25 parts of fine aggregate, 10 parts of mineral powder, 15 parts of pre-wrapped stone, 6 parts of asphalt, and 0.5 part of slow-release rejuvenator are mixed according to the weight fraction to obtain a uniform mixture; S2, the uniform mixture is spread, primary pressing, re-pressing, and final pressing to prepare a composite anti-aging asphalt concrete wearing layer.

[0021] The pre-wrapped stone is obtained by the following steps: 100 parts of fine aggregate and 10 parts of emulsified asphalt are added to a mixing device, and a stirring paddle is started to mix until the emulsified asphalt is demulsified, then the stirring is stopped, the material is taken out and naturally air-dried, and the part of the material that is lightly tapped and dispersed is the pre-wrapped stone. 15 parts of the pre-wrapped stone are taken according to the weight fraction to prepare the above asphalt.

[0022] Further, the emulsified asphalt comprises the following components and their weight fractions: asphalt 55 parts, water 42 parts, emulsifier 0.6 part, and nano zinc oxide 2 parts, and hydrochloric acid in an appropriate amount.

[0023] Further, the emulsified asphalt is prepared by the following steps: Step 1: 55 parts of asphalt are heated to 150℃, 2 parts of nano zinc oxide are added, and the mixture A is obtained by fully mixing and keeping the temperature; Step 2: 42 parts of water is heated to 65℃, 0.46 parts of emulsifier is added to obtain a soap solution; hydrochloric acid is added dropwise to the soap solution to adjust the PH value of the soap solution to 2.0; Step 3: The acid-adjusted soap solution is added to a colloid mill, the colloid mill is started, and the mixture A is uniformly and slowly added; when the liquid in the colloid mill becomes uniform brown or dark brown, the colloid mill is turned off to obtain the emulsified asphalt.

[0024] Further, the slow-release rejuvenator comprises the following components and their weight fractions: gelatin 5 parts, gum arabic 5 parts, water 90 parts, divided into two equal parts, emulsifier 2 parts, oil 9 parts, formaldehyde 7 parts, wherein the emulsifier is preferably sucrose ester, and the oil can be one or a mixture of several of pine oil, castor oil, soybean oil, and white oil.

[0025] Still further, the slow-release rejuvenator is prepared by the following steps: Step 1: Take 50% of the total water, i.e. 45 parts, add 5 parts of gelatin, and heat to 60℃ to obtain a gelatin solution; Step 2: Take the remaining water, add an equal amount of gum arabic to the gelatin, and heat to 60℃ to obtain a gum arabic solution; Step 3: Add the emulsifier to the gum arabic solution, dissolve thoroughly, then add the oil, and homogenize the resulting mixture at a speed of 12000 r / min for 15 min to obtain a homogenized solution; Step 4: Add the gelatin solution obtained in step 1 to the homogenized solution obtained in step 2, maintain the temperature at 55℃ and stir, then adjust the PH of the mixture to 4.5, maintain the stirring speed at 1500 r / min for 180 min to obtain a coagulation liquid; Step 5: Maintain the temperature, add 7 parts of formaldehyde to the coagulation liquid, maintain the stirring speed at 1500 r / min for 90 min, then adjust the PH of the resulting mixture to 9.0, and reduce the temperature to 20℃ to obtain a finished liquid; Step 6: Let the finished liquid obtained in step 5 stand, remove the supernatant, obtain the precipitate, dry the precipitate, granulate, and obtain the finished slow-release rejuvenator.

[0026] Example 2: The difference between this example and Example 1 is: The composite anti-aging asphalt comprises the following components and their weight fractions: coarse aggregate 40 parts, fine aggregate 30 parts, mineral powder 15 parts, pre-wrapped stone 20 parts, asphalt 8 parts, and slow-release rejuvenator 1 part.

[0027] In addition, The emulsified asphalt comprises the following components and their weight fractions: asphalt 50 parts, water 42 parts, emulsifier 0.6 parts, nano zinc oxide 2 parts, hydrochloric acid in proper amount; The slow-release regenerating agent comprises the following components and their weight fractions: gelatin 6 parts, acacia 6 parts, water 100 parts, emulsifier 3 parts, oil 10 parts, formaldehyde 8 parts.

[0028] Example 3: The difference between this example and Example 1 is that: The composite anti-aging asphalt comprises the following components and their weight fractions: coarse aggregate 30 parts, fine aggregate 20 parts, mineral powder 5 parts, pre-wrapped stone 10 parts, asphalt 4 parts, slow-release regenerating agent 0.2 parts.

[0029] In addition, The emulsified asphalt comprises the following components and their weight fractions: asphalt 60 parts, water 45 parts, emulsifier 0.8 parts, nano zinc oxide 3 parts, hydrochloric acid in proper amount; The slow-release regenerating agent comprises the following components and their weight fractions: gelatin 4 parts, acacia 4 parts, water 80 parts, emulsifier 1 part, oil 8 parts, formaldehyde 6 parts.

[0030] Example 4: The difference between this example and Example 1 is that: The composite anti-aging asphalt comprises the following components and their weight fractions: coarse aggregate 35 parts, fine aggregate 25 parts, mineral powder 10 parts, pre-wrapped stone 20 parts, asphalt 6 parts, slow-release regenerating agent 0.5 parts.

[0031] In addition, The emulsified asphalt comprises the following components and their weight fractions: asphalt 55 parts, water 40 parts, emulsifier 0.8 parts, nano zinc oxide 3 parts, hydrochloric acid in proper amount; The slow-release regenerating agent comprises the following components and their weight fractions: gelatin 5 parts, acacia 5 parts, water 100 parts, emulsifier 3 parts, oil 10 parts, formaldehyde 7 parts.

[0032] Example 5: The difference between this example and Example 1 is that: The composite anti-aging asphalt comprises the following components and their weight fractions: coarse aggregate 35 parts, fine aggregate 25 parts, mineral powder 10 parts, pre-wrapped stone 15 parts, asphalt 4 parts, slow-release regenerating agent 1 part.

[0033] In addition, The emulsified asphalt comprises the following components and their weight fractions: asphalt 50 parts, water 45 parts, emulsifier 0.4 parts, nano-zinc oxide 0.5 parts, hydrochloric acid in proper amount; The slow-release rejuvenator comprises the following components and their weight fractions: gelatin 6 parts, acacia 6 parts, water 80 parts, emulsifier 2 parts, oil 9 parts, formaldehyde 7 parts.

[0034] Comparative Example 1 The difference between this example and Example 1 is that no pre-wrapped aggregate is added.

[0035] Comparative Example 2 The difference between this example and Example 1 is that pre-wrapped aggregate and slow-release rejuvenator are added. This example is the same as the asphalt mixture prepared by the conventional method.

[0036] Comparative Example 3 The difference between this example and Example 1 is that no slow-release rejuvenator is added.

[0037] In summary, in Examples 1-5 and Comparative Examples 1-3, the components of asphalt concrete and their weight fractions, pre-wrapped aggregate, and slow-release rejuvenator are as follows: Table 1, Components of Asphalt Concrete and Their Weight Fractions:

[0038] Table 2, Pre-wrapped Aggregate:

[0039] Table 3, Slow-release Rejuvenator:

[0040] Through the above examples, different bitumens can be obtained, and the bitumen mixtures obtained in the above examples and comparative examples are respectively made into bitumen mixture test pieces according to the test method of T0702-2011 in the Highway Engineering Bitumen and Bitumen Mixture Test Regulation (JTG E20-2011). After 24 hours of curing, the formed test pieces are placed into a SYD-ZWL type (produced by Shanghai Changji) multifunctional bitumen ultraviolet aging instrument for aging test, and the test pieces are taken out after 10 days (i.e. 240 hours) of aging, and then the recovered bitumen of each test piece is obtained according to the regulation of T0727-2011. The penetration, ductility and softening point of the recovered bitumen are respectively detected according to the detection methods of T0604-2011, T0605-2011 and T0606-2011, and the anti-aging performance of each example and the comparative example is judged by comparison with the corresponding indicators of the original bitumen before aging. The results show that the anti-aging bitumens in the five examples have different changes in performance, and in the testing process, the obtained parameters are compared as follows:

[0041] From the above data, it can be known that examples 1-5 all show that the softening point rises, the penetration decreases and the ductility decreases, and the bitumen is slightly aged; The bitumen indicators of comparative examples 1-3 show that the softening point greatly rises, the penetration greatly decreases, and the ductility greatly decreases and even appears brittle fracture, indicating that the aging is very serious.

[0042] Through the comprehensive comparison of examples 1-5 and comparative examples 1-3, it is shown that the bitumen prepared in examples 1-5 has good anti-aging ability, and the anti-aging effect is improved through the pre-wrapping of stone and the formation of slow-release regenerant. The slowly released oil in the slow-release regenerant can regenerate and repair the road surface, and realize the repair ability to aging.

[0043] Finally: the above only describes the preferred embodiments of the present application, and is not used to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A composite anti-aging asphalt concrete, characterized in that, It includes the following components and their weight proportions: 30-40 parts coarse aggregate, 20-30 parts fine aggregate, 5-15 parts mineral powder, 10-20 parts pre-coated stone, 4-8 parts asphalt, and 0.2-1 parts slow-release regenerator.

2. The composite anti-aging asphalt concrete according to claim 1, characterized in that, It includes the following components and their weight parts: 32-38 parts coarse aggregate, 22-28 parts fine aggregate, 7-12 parts mineral powder, 12-18 parts pre-coated stone, 5-6 parts asphalt, and 0.3-0.7 parts slow-release regenerator.

3. The composite anti-aging asphalt concrete according to claim 1, characterized in that, It includes the following components and their weight parts: 35 parts coarse aggregate, 25 parts fine aggregate, 10 parts mineral powder, 15 parts pre-coated stone, 6 parts asphalt, and 0.5 parts slow-release regenerator.

4. A composite anti-aging asphalt concrete according to any one of claims 1-3, characterized in that: In the above composition, the coarse aggregate is basalt stone with a diameter of 4.75-9.5mm, and the fine aggregate is basalt stone with a diameter of 2.36-4.75mm.

5. A method for preparing composite anti-aging asphalt concrete, used to prepare the composite anti-aging asphalt according to any one of claims 1-3, characterized in that, Specifically, the steps include the following: S1. Mixing: According to the weight percentages, mix 30-40 parts coarse aggregate, 20-30 parts fine aggregate, 5-15 parts mineral powder, 10-20 parts pre-coated stone, 4-8 parts asphalt, and 0.2-1 parts slow-release recycling agent to obtain a uniform mixture. S2. The uniform mixture is spread, initially compacted, then compacted again and finally compacted to prepare a composite anti-aging asphalt concrete wear layer.

6. The method for preparing composite anti-aging asphalt concrete according to claim 5, characterized in that: The pre-coated aggregate in S1 is obtained by the following steps: according to the weight parts, 100 parts of fine aggregate and 4-10 parts of emulsified asphalt are added to the mixing device, the mixing paddle is turned on and mixed until the emulsified asphalt breaks down, then the mixing is stopped, the material is taken out and air-dried, and the clumps are gently tapped to disperse them, thus obtaining the pre-coated aggregate.

7. The method for preparing composite anti-aging asphalt concrete according to claim 6, characterized in that: The emulsified asphalt comprises the following components and their weight percentages: 50-60 parts asphalt, 40-50 parts water, 0.4-0.8 parts emulsifier, 0.5-3 parts nano zinc oxide, and an appropriate amount of hydrochloric acid.

8. The method for preparing composite anti-aging asphalt concrete according to claim 7, characterized in that: The emulsified asphalt is prepared by the following steps: Step 1: Heat 50-60 parts of asphalt to 130-150℃, add 0.5-3 parts of nano zinc oxide, mix thoroughly to obtain mixture A and maintain the temperature; Step 2: Heat 40-50 parts of water to 50-65℃, add 0.4-0.8 parts of emulsifier to obtain soap solution; add hydrochloric acid dropwise to adjust the pH value of the soap solution to 2.0; Step 3: Add the acid-treated soap solution to the colloid mill, start the colloid mill, and slowly and evenly add mixture A. When the liquid in the colloid mill turns into a uniform brown or dark brown color, turn off the colloid mill to obtain emulsified asphalt.

9. The method for preparing composite anti-aging asphalt concrete according to claim 5, characterized in that: The slow-release regenerator comprises the following components and their weight proportions: 4-6 parts gelatin, 4-6 parts gum arabic, 80-100 parts water, 1-3 parts emulsifier, 8-10 parts oil, and 6-8 parts formaldehyde.

10. The method for preparing composite anti-aging asphalt concrete according to claim 9, characterized in that: The slow-release regenerant is prepared by the following steps: Step 1: Take 50% of the total water volume, add 4-6 parts of gelatin, and heat to 40-60℃ to obtain a gelatin solution; Step 2: Take the remaining water, add an equal amount of gum arabic to the gelatin, and heat to 40-60℃ to obtain a gum arabic solution; Step 3: Add the emulsifier to the gum arabic solution, and after it is fully dissolved, add the oil. Homogenize the resulting mixture at 8000-12000 r / min for 5-15 min to obtain a homogenized solution. Step 4: Add the gelatin solution obtained in Step 1 to the homogenized solution obtained in Step 2, maintain the temperature at 50-55℃ and stir, then adjust the pH of the mixture to 4.0-4.5, and stir at 1200-1500 r / min for 30-180 min to obtain the coagulated liquid. Step 5: Maintain the temperature, add 6-8 parts of formaldehyde to the coagulation liquid, and stir continuously at a speed of 1200-1500 r / min for 30-90 min. Then adjust the pH value of the resulting mixture to 8.0-9.0, and lower the temperature to 10-20℃ to obtain the completed liquid. Step 6: Let the completed liquid obtained in Step 5 stand, remove the supernatant, obtain the precipitate, dry the precipitate, granulate it, and obtain the finished slow-release regenerator.

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