Hot in-place recycling asphalt recycling agent and preparation method thereof

Abstract

The invention relates to the field of road asphalt material regeneration and maintenance, in particular to a hot in-place recycling asphalt regenerant and a preparation method thereof. The hot in-place recycling asphalt recycling agent is prepared from the following raw materials in parts by weight: 100 to 140 parts of base oil, 2 to 5 parts of polylactic acid, 0.5 to 3.5 parts of cellulose, 5 to 10 parts of an inorganic auxiliary agent and 1 to 3 parts of an anti-aging agent, the inorganic auxiliary agent comprises one or more of diatomite and hydromica. The regenerant disclosed by the invention is added into the aged asphalt, so that the needle penetration of the aged asphalt is improved by 94.3-101.7 mm, the ductility at 5 DEG C is improved by 36.6-43.2 cm, the softening point is reduced by 5.9-9 DEG C, and the regenerant plays a great role in performance recovery of the aged asphalt.

Description

Technical Field

[0001] The present application relates to the field of road asphalt material regeneration and maintenance, and in particular to an in-situ hot regeneration asphalt regeneration agent and a preparation method thereof. Background Art

[0002] As the mileage of highways in my country increases, asphalt pavements tend to age due to the influence of natural environment such as vehicle load and precipitation. The driving comfort and anti-skid performance of the pavement will decline to varying degrees, affecting the comprehensive performance of the pavement. This requires preventive maintenance and repair measures.

[0003] The recycling of asphalt pavement materials can effectively solve the above problems and has broad development prospects. In-situ hot recycling is a technology that heats and raks the asphalt pavement, mixes a certain amount of regeneration agent, new asphalt, new asphalt mixture, etc., and then recycles the old asphalt pavement through hot mixing, paving, rolling and other processes. The regeneration agent is mainly composed of heavy mineral oil or light oil, and also contains polymers, anti-stripping agents, stabilizers, anti-ultraviolet additives and anti-aging agents.

[0004] Regarding the existing regeneration agents, the applicant believes that the existing hot mix asphalt regeneration agents can only restore the performance of aged asphalt to a certain extent, but are not comprehensive and thorough enough, which greatly reduces the performance of the regenerated asphalt concrete pavement and shortens the service life of the pavement. Summary of the invention

[0005] In order to restore the performance of aged asphalt more comprehensively and extend the service life of the road surface, the present application provides an in-situ hot-regeneration asphalt regeneration agent and a preparation method thereof.

[0006] In a first aspect, the present application provides an in-situ hot regeneration asphalt regeneration agent, which adopts the following scheme.

[0007] An in-situ hot-regeneration asphalt regeneration agent, composed of the following raw materials in parts by weight: 100-140 parts of base oil, 2-5 parts of polylactic acid, 0.5-3.5 parts of cellulose, 5-10 parts of inorganic additives, and 1-3 parts of anti-aging agent; The inorganic auxiliary agent includes one or more of diatomaceous earth and hydromica.

[0008] By adopting the above technical scheme, base oil is used as the main raw material of the regeneration agent, and anti-aging agent is added to improve the heat aging resistance of asphalt. Polylactic acid, cellulose, and inorganic additives are added to the regeneration agent as auxiliary additives. Among them, functional groups such as carboxyl and hydroxyl groups in polylactic acid molecules react chemically with some functional groups in asphalt molecules to form a cross-linked structure or hydrogen bonds with asphalt molecules. At the same time, physical adsorption and dispersion occur between polylactic acid molecules and asphalt molecules, increasing the contact area between old asphalt and new asphalt and aggregates. Polylactic acid forms a strong adhesion with new and old asphalt and mixtures under the combined chemical and physical effects, thereby enhancing the adhesion of the mixture, helping to reduce the cracking and peeling of asphalt mixtures during use, and improving the service life of the road surface. Cellulose is a fibrous polymer substance with good adhesion. It can combine with asphalt molecules to form a strong adhesion, form a network structure in the asphalt mixture, and increase the strength and durability of the road surface. It can effectively prevent the wear and aging of the road surface and extend the service life of the road surface. Inorganic additives can improve the permeability of the regeneration agent, allowing the regeneration agent to penetrate deeper into the aged asphalt, so that the performance of the aged asphalt can be restored more thoroughly.

[0009] The regeneration agent of the present application can more thoroughly penetrate into the old asphalt, restore the performance of the old asphalt, improve the bonding performance between the old asphalt and the new asphalt mixture, improve the performance of the regenerated asphalt concrete pavement, and extend the service life of the pavement.

[0010] Furthermore, the base oil comprises corn straw oil, linseed oil and aromatic oil in a weight ratio of 1:(1-2):(3-6).

[0011] By adopting the above technical scheme, corn straw oil is mainly composed of acetic acid, hydroxyacetone and acetaldehyde. After adding it to the aged asphalt, the light components of the aged asphalt are supplemented to a certain extent, which softens the aged asphalt to a certain extent, improves the penetration and ductility of the aged asphalt, and restores the performance of the aged asphalt to a certain extent; improves the high temperature performance of the aged asphalt, and has a good regeneration effect on the high temperature performance of the aged asphalt. The components such as oleic acid in linseed oil can be physically adsorbed and chemically combined with asphalt molecules to form a good binding force. The components such as fatty acids in linseed oil can increase the wear resistance and durability of the recycled asphalt mixture. Linseed oil can effectively reduce the viscosity of recycled asphalt, and has excellent compatibility when evenly diffused in waste asphalt, thereby improving its processability and construction performance. Linseed oil can also provide additional aromatic components for recycled asphalt, which can improve the anti-aging ability of asphalt and extend its service life. The components in aromatic oil can dissolve and diffuse with asphalt molecules, thereby increasing the softness of asphalt, reducing the viscosity of asphalt mixtures, and improving its plasticity. Corn straw oil, linseed oil and aromatic oil interact with each other within the ratio range of the present application to improve the thoroughness of the performance recovery of aged asphalt.

[0012] Furthermore, the inorganic auxiliary agent includes diatomaceous earth and hydromica in a weight ratio of 1:(2-3).

[0013] By adopting the above technical solution, diatomite and hydromica are porous and lightweight, and can absorb base oil, penetrate deeper into the old asphalt with the base oil, and give full play to the role of the base oil. In addition, there is a strong bonding effect between diatomite and hydromica and the old asphalt. After absorbing the base oil, the diatomite and hydromica are bonded to the old asphalt, so that the base oil can be more closely combined with the old asphalt, so that the base oil can give full play to the role of the base oil on the old asphalt, and improve the thoroughness of the performance recovery of the old asphalt.

[0014] Furthermore, the weight ratio of the inorganic additive to the base oil is (0.05-0.08):1.

[0015] By adopting the above technical solution, the inorganic additive assists the base oil in playing its role, and the ratio of the inorganic additive to the base oil is limited, so that the inorganic additive carries the base oil and penetrates into the old asphalt, giving full play to the role of the base oil. At the same time, the inorganic additive can also fill the pores in the asphalt mixture and improve the stability of the pavement structure.

[0016] Furthermore, the particle size of the diatomaceous earth is 10-20 μm, and the particle size of the water cloud mesh is 30-40 μm.

[0017] By adopting the above technical solution, the particle size of diatomaceous earth and hydromica is limited, and particle grading is performed. Different particle sizes have different adsorption effects on base oil and bonding properties with old asphalt. Through the grading of diatomaceous earth and hydromica, the auxiliary effect of inorganic additives on base oil is better.

[0018] Furthermore, the inorganic auxiliary agent is a modified inorganic auxiliary agent, and the preparation method thereof is: 1) Dispersing the inorganic auxiliary agent in ethyl acetate, then adding a catalyst, mixing to obtain a mixed system, adding stearyl chloride and acryloyl chloride to the mixed system for reaction, and after the reaction is completed, filtering under reduced pressure, washing, and drying to obtain an esterified inorganic auxiliary agent; 2) At 90-95°C, gelatinize the esterified inorganic additive in water. After the gelatinized liquid becomes clear and bright, cool it to 78-80°C, add ethyl acrylate and introduce protective gas to react, then drop potassium persulfate solution to react and obtain an emulsion; 3) Cool the emulsion to 65-70°C, then add glycidyl methacrylate to react with the initiator, and heat to 80-85°C to continue the reaction, and finally break the emulsion to obtain the modified inorganic additive.

[0019] By adopting the above technical scheme, the inorganic additive is modified, the inorganic additive is first esterified, the esterified inorganic additive is polymerized with ethyl acrylate by soap-free emulsion polymerization to obtain inorganic additive core-shell particles with hard core and soft shell, and the inorganic additive core-shell particles are epoxidized with glycidyl methacrylate to form polar epoxy groups on the surface of the inorganic additive, weaken the strong attraction between asphaltene molecules, promote the asphaltene condensed in the aged asphalt to be dissolved and dispersed in the asphalt colloid system, weaken the barrier of the asphaltene space network structure to the penetration of the regeneration agent molecules, thereby improving and accelerating the penetration ability of the regeneration agent. The regeneration agent can act on the aged asphalt more thoroughly, and the performance of the aged asphalt is restored more thoroughly.

[0020] Furthermore, the amount of glycidyl methacrylate used is 2-4% by weight of ethyl acrylate.

[0021] Furthermore, the particle size of the cellulose is 100-130 μm.

[0022] In a second aspect, the present application provides a method for preparing an in-situ hot-regenerated asphalt regeneration agent, using the following scheme.

[0023] A method for preparing an in-situ hot regeneration asphalt regeneration agent comprises the following steps: S1. The base oil is heated to 80-100° C., and then cellulose and an inorganic additive are dispersed in the base oil to obtain a mixed solution; S2. Adding polylactic acid and an anti-aging agent to the mixed solution obtained in step S1, and mixing to obtain a regeneration agent.

[0024] In summary, this application has the following beneficial effects: Using base oil as the main raw material of the regeneration agent, polylactic acid, cellulose, and inorganic additives as auxiliary additives are added to the regeneration agent. The functional groups such as carboxyl and hydroxyl in the polylactic acid molecule react chemically with some functional groups in the asphalt molecule to form a cross-linked structure or hydrogen bonds with the asphalt molecule. Cellulose is a fibrous polymer with good adhesion. It can combine with asphalt molecules to form a strong adhesive force and form a network structure in the asphalt mixture. Inorganic additives can improve the permeability of the regeneration agent, so that the regeneration agent can penetrate deeper into the aged asphalt, so that the performance of the aged asphalt can be more thoroughly restored. The penetration of the regenerated aged asphalt is increased by 94.3-101.7mm, the elongation at 5℃ is increased by 36.6-43.2cm, and the softening point is reduced by 5.9-9℃, so that the performance of the aged asphalt is restored to a great extent. DETAILED DESCRIPTION

[0025] The present application is further described in detail below with reference to the embodiments.

[0026] Raw materials and intermediate preparation examples raw material Corn straw oil was purchased from Shaanxi Zhending Yingjia Technology Co., Ltd.; Linseed oil, 20℃ relative density 0.9382g / cm 3 , 20℃ viscosity 7.5mPa·s; Aromatic oil, 20℃ relative density 1.015g / cm 3 ,100℃ kinematic viscosity 20mm 2 / s; Polylactic acid, 4032D, industrial grade; Cellulose, technical grade; Ethyl acetate, analytical grade; Catalyst, pyridine, analytical grade; Stearoyl chloride, analytical grade; Acryloyl chloride, analytical grade; Ethyl acrylate, analytical grade; Potassium persulfate, analytical grade; Glycidyl methacrylate, analytical grade.

[0027] Preparation Example Preparation Example 1 A modified inorganic auxiliary agent, the preparation method of which is: 1) Disperse 1 kg of inorganic auxiliary agent in 3 kg of ethyl acetate, then add 0.05 kg of catalyst and mix to obtain a mixed system. After mechanically stirring the mixed system at 50 °C for 0.5 h, add 0.06 kg of stearyl chloride and 0.06 kg of acryloyl chloride to the mixed system to react for 2 h. After the reaction is completed, filter the mixed solution under reduced pressure, rinse with ethanol 3 times, and dry at 50 °C to obtain an esterified inorganic auxiliary agent. 2) At 95°C, 1 kg of the esterified inorganic auxiliary agent obtained in step 1) was added to 7 kg of water, and the mixture was mechanically stirred and gelatinized at 90°C for 0.5 h. After the gelatinized liquid became clear and transparent, the temperature was lowered to 80°C, 2.5 kg of ethyl acrylate was added, and protective gas was introduced to react. 0.03 kg of potassium persulfate was completely dissolved in water to obtain a potassium persulfate solution, and then the potassium persulfate solution was added dropwise and reacted for 12 h to obtain an emulsion; 3) The emulsion was cooled to 65°C, and then 0.05 kg of glycidyl methacrylate and 0.001 kg of initiator were added to react, and the temperature was raised to 85°C to continue the reaction for 2.5 hours, and finally the emulsion was broken to obtain the modified inorganic additive.

[0028] Preparation Example 2 Different from Preparation Example 1, the amount of glycidyl methacrylate added in Preparation Example 2 is 0.1 kg.

[0029] Preparation Example 3 Different from Preparation Example 1, the amount of glycidyl methacrylate added in Preparation Example 3 is 0.08 kg.

[0030] Preparation Example 4 Different from Preparation Example 1, the amount of glycidyl methacrylate added in Preparation Example 4 is 0.15 kg.

[0031] Example Examples 1-5 An in-situ hot regeneration asphalt regeneration agent, and a preparation method thereof is as follows: S1. Prepare the raw materials according to the ratio in Table 1, heat the base oil to 90°C, and then disperse the cellulose and the inorganic additive in the base oil to obtain a mixed solution; S2. Adding polylactic acid and an anti-aging agent to the mixed solution obtained in step S1, and mixing to obtain a regeneration agent.

[0032] Table 1 Raw material ratio table (kg)

[0033] The base oil is corn straw oil, linseed oil and aromatic oil in a weight ratio of 1:1:6; the inorganic additive is diatomaceous earth with a particle size of 15 μm; and the particle size of cellulose is 120 μm.

[0034] Example 6 Different from Example 2, the inorganic auxiliary agent in Example 6 is hydromica, and the hydromica particle size is 35 μm.

[0035] Example 7 Different from Example 2, the inorganic auxiliary agent in Example 7 is diatomaceous earth and hydromica in a weight ratio of 1:2, wherein the particle size of the diatomaceous earth is 15 μm, and the particle size of the hydromica is 35 μm.

[0036] Example 8 Different from Example 2, the inorganic additive in Example 8 is diatomaceous earth and hydromica in a weight ratio of 1:3, wherein the particle size of the diatomaceous earth is 15 μm, and the particle size of the hydromica is 35 μm.

[0037] Example 9 Different from Example 2, the inorganic additives in Example 9 are diatomaceous earth and hydromica in a weight ratio of 2:1, wherein the particle size of the diatomaceous earth is 15 μm, and the particle size of the hydromica is 35 μm.

[0038] Example 10 Different from Example 2, the inorganic additive in Example 10 is diatomaceous earth and hydromica in a weight ratio of 1:2, wherein the particle size of the diatomaceous earth is 10 μm, and the particle size of the hydromica is 40 μm.

[0039] Embodiment 11 Different from Example 2, the inorganic additive in Example 11 is diatomaceous earth and hydromica in a weight ratio of 1:2, wherein the particle size of the diatomaceous earth is 20 μm, and the particle size of the hydromica is 30 μm.

[0040] Example 12 Different from Example 8, the base oil in Example 12 includes corn straw oil, linseed oil and aromatic oil in a weight ratio of 1:2:4.

[0041] Embodiment 13 Different from Example 8, the base oil in Example 13 includes linseed oil and aromatic oil in a weight ratio of 3:4.

[0042] Embodiment 14 Different from Example 8, the base oil in Example 14 includes corn straw oil and aromatic oil in a weight ratio of 3:4.

[0043] Embodiment 15 Different from Example 12, in Example 15, the inorganic auxiliary agent is modified by the method of Preparation Example 1 to obtain a modified inorganic auxiliary agent.

[0044] Examples 16-18 Different from Example 15, in Examples 16-18, the inorganic additives were modified according to the methods of Preparation Examples 2-4 to obtain modified inorganic additives.

[0045] Comparative Example Comparative Example 1 The difference from Example 1 is that in Comparative Example 1, an equal amount of cellulose is used to replace the inorganic auxiliary agent.

[0046] Comparative Example 2 Different from Example 1, in Comparative Example 2, cellulose is replaced by an equal amount of inorganic additives.

[0047] Comparative Example 3 Different from Example 1, in Comparative Example 3, an equal amount of base oil was used to replace polylactic acid.

[0048] Performance Testing Refer to the relevant test methods in the "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering" (JTG E20-2011) to test and record the basic performance indicators of old asphalt; The hot-in-situ asphalt regeneration agent obtained in the example and the comparative example was added to the old asphalt at a ratio of 5%. Then, referring to the relevant test methods in the "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering" (JTG E20-2011), the basic performance indicators of the regenerated asphalt were tested and recorded, and the change value of the regenerated asphalt performance (regenerated asphalt performance test value-aged asphalt test value) was calculated. The results are shown in Table 2.

[0049] Table 2 Performance test results

[0050] After aging, the penetration of asphalt decreases, the ductility decreases, and the softening point increases, indicating that aging will weaken the deformation ability of asphalt.

[0051] Combining Examples 1-18 with Comparative Examples 1-3 and Table 2, it can be seen that the increase in penetration, increase in ductility and decrease in softening point of the aged asphalt to which the regeneration agent is added in Examples 1-18 relative to the aged asphalt are greater than those in Comparative Examples 1-3, which indicates that the regeneration agent of the present application can restore the performance of the aged asphalt more thoroughly.

[0052] Combining Example 1 with Comparative Examples 1-3 and Table 2, it can be seen that, relative to Example 1, Comparative Example 1 does not contain an inorganic additive, Comparative Example 2 does not contain cellulose, and Comparative Example 3 does not contain polylactic acid. The regeneration agents in Comparative Examples 1-3 have lower performance recovery effects on aged asphalt than Example 1, which indicates that the combination of inorganic additives, cellulose and polylactic acid can improve the performance recovery effect of the regeneration agent on aged asphalt.

[0053] Combining Examples 1-5 and Table 2, it can be seen that the regeneration agents in Examples 1-5 have good effects on the performance recovery of old asphalt, among which the raw material ratio in Example 2 is better. Combining Example 2 and Examples 4-5, it can be seen that the ratio of inorganic additives to base oil will affect the recovery effect of the regeneration agent on aged asphalt, among which the ratio in Example 2 is better. This may be because the ratio of inorganic additives to base oil is limited, so that the inorganic additives can better carry the base oil to penetrate into the old asphalt and give full play to the role of the base oil.

[0054] Combining Example 2 and Examples 6-11, and Table 2, it can be seen that the effect of the regeneration agent in Examples 7-11 on the performance recovery of aged asphalt is better than that in Examples 2 and 6, which shows that the composite of diatomite and hydromica is more effective in the performance recovery of aged asphalt. The gradations of diatomite and hydromica in Examples 7-11 are different, and the effects on the performance recovery of aged asphalt are also different, among which the gradation in Example 8 is better.

[0055] In combination with Example 8 and Examples 12-14, and in combination with Table 2, it can be seen that the regeneration agent obtained by compounding corn straw oil, linseed oil and aromatic oil as the base oil has a better effect on the performance recovery effect of aged asphalt. This may be because corn straw oil has a certain softening effect on aged asphalt, improves the penetration and ductility of aged asphalt, and restores the performance of aged asphalt to a certain extent; improves the high temperature performance of aged asphalt, and has a good regeneration effect on the high temperature performance of aged asphalt. Linseed oil can effectively reduce the viscosity of regenerated asphalt, and has excellent compatibility when evenly diffused in waste asphalt. The components in aromatic oil can dissolve and diffuse with asphalt molecules, thereby increasing the softness of asphalt, reducing the viscosity of asphalt mixture, and improving its plasticity. Corn straw oil, linseed oil and aromatic oil interact with each other within the ratio range of this application to improve the thoroughness of the performance recovery of aged asphalt.

[0056] Combining Example 12 and Examples 15-18, and Table 2, it can be seen that the effect of the regeneration agent in Examples 15-18 on the performance recovery of aged asphalt is better than that in Example 12, which shows that the modification of the inorganic additive can further improve the performance recovery effect of the regeneration agent on the aged asphalt. This may be because the surface of the modified inorganic additive has polar epoxy groups, which weakens the strong attraction between asphaltene molecules, prompts the condensed asphaltene in the aged asphalt to be dissolved and dispersed in the asphalt colloid system, and weakens the barrier of the asphaltene space network structure to the penetration of the regeneration agent molecules, thereby improving and accelerating the penetration ability of the regeneration agent. The regeneration agent can act more thoroughly on the aged asphalt, so that the performance of the aged asphalt is restored more thoroughly.

[0057] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. An in-situ hot regeneration asphalt regeneration agent, characterized in that: The method is composed of the following raw materials in parts by weight: 100-140 parts of base oil, 2-5 parts of polylactic acid, 0.5-3.5 parts of cellulose, and 5-10 parts of inorganic additives; The inorganic auxiliary agent includes one or more of diatomaceous earth and hydromica.

2. The in-situ hot regeneration asphalt regeneration agent according to claim 1, characterized in that: The base oil includes corn straw oil, linseed oil and aromatic oil in a weight ratio of 1:(1-2):(3-6).

3. The in-situ hot-regeneration asphalt regeneration agent according to claim 1, characterized in that: The inorganic auxiliary agent includes diatomaceous earth and hydromica in a weight ratio of 1:(2-3).

4. The in-situ hot regeneration asphalt regeneration agent according to claim 3, characterized in that: The weight ratio of the inorganic additive to the base oil is (0.05-0.08):

1.

5. The in-situ hot regeneration asphalt regeneration agent according to claim 3, characterized in that: The particle size of the diatomaceous earth is 10-20 μm, and the particle size of the water cloud mesh is 30-40 μm.

6. The in-situ hot-regeneration asphalt regeneration agent according to claim 1, characterized in that: The inorganic auxiliary agent is a modified inorganic auxiliary agent, and its preparation method is as follows: 1) dispersing the inorganic auxiliary agent in ethyl acetate, then adding a catalyst, mixing to obtain a mixed system, adding stearyl chloride and acryloyl chloride to the mixed system for reaction, and filtering under reduced pressure, washing, and drying after the reaction to obtain an esterified inorganic auxiliary agent; 2) At 90-95°C, gelatinize the esterified inorganic additive in water. After the gelatinized liquid becomes clear and bright, cool it to 78-80°C, add ethyl acrylate and introduce protective gas to react, then drop potassium persulfate solution to react and obtain an emulsion; 3) Cool the emulsion to 65-70°C, then add glycidyl methacrylate to react with the initiator, and heat to 80-85°C to continue the reaction, and finally demulsify to obtain the modified inorganic additive.

7. The in-situ hot regeneration asphalt regeneration agent according to claim 6, characterized in that: The usage of the glycidyl methacrylate is 2-4% of the weight of ethyl acrylate.

8. The in-situ hot-regeneration asphalt regeneration agent according to claim 1, characterized in that: The particle size of the cellulose is 100-130 μm.

9. A method for preparing an in-situ hot-regenerated asphalt regeneration agent according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1. The base oil is heated to 80-100° C., and then cellulose and an inorganic additive are dispersed in the base oil to obtain a mixed solution; S2. Adding polylactic acid and an anti-aging agent to the mixed solution obtained in step S1, and mixing to obtain a regeneration agent.

Images