Durable regenerated rubber asphalt and preparation method thereof

Abstract

The invention discloses durable regenerated rubber asphalt and a preparation method thereof, and relates to the technical field of rubber asphalt preparation. The diatomite is coated with chlorinated palm oil methyl ester through surface tension and capillary action, so that the diatomite is hydrophobic, the cold resistance is improved, meanwhile, the heat conductivity coefficient of the diatomite is low, and the flame retardant effect is achieved; then the modified powder is combined with phosphoenolpyruvic acid to prepare modified powder, phosphorus element is introduced, and phosphorus oxyacid, phosphate ester and other substances are generated through decomposition during combustion, so that the flame-retardant effect is achieved; vinyltrihydroxysilane and asphalt are combined to prepare modified asphalt, a stable net structure is formed, heat resistance is improved, meanwhile, a long Si-O bond is introduced, low-temperature molecular agglomeration is reduced, and low-temperature resistance is improved; finally, unsaturated double bonds in the modified asphalt, the activated powder and the rubber powder are subjected to addition reaction and combined, a cross-linked structure is formed, and the heat-resistant, cold-resistant and flame-retardant effects are achieved.

Description

Technical Field

[0001] The invention relates to the technical field of rubber asphalt preparation, in particular to a durable regenerated rubber asphalt and a preparation method thereof. Background Art

[0002] Asphalt pavement has become the main type of highway pavement structure in my country due to its good road performance, comfortable driving environment and high economy. But at the same time, due to the continuous increase in traffic volume, large and heavy vehicles have put forward higher requirements for highway pavements. How to improve the structural performance of asphalt pavements, such as high and low temperature stability, water stability, and fatigue resistance, is a problem that needs to be solved in the current asphalt pavement design. Among many modified asphalts, rubber modified asphalt has always been a hot research direction. Compared with SBS modified asphalt, rubber asphalt has the advantages of relatively low price, easy access to modifiers, and easier process preparation. In addition, rubber asphalt has advantages that other modified asphalts do not have in improving road noise and improving driving comfort.

[0003] Since rubber will oxidize under the action of sunlight and oxygen, rubber asphalt pavement materials will age after long-term use, causing their elasticity and viscosity to decrease significantly, thus affecting the service life and performance of the pavement. Especially in areas with large climate temperature changes, rubber asphalt is more prone to aging. At present, research on the regeneration of rubber modified asphalt is still in its initial stage, so the study of a highly durable recycled rubber asphalt has important economic significance and theoretical value. Summary of the invention

[0004] The purpose of the present invention is to provide a durable regenerated rubber asphalt and a preparation method thereof to solve the problems existing in the prior art.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions: a durable regenerated rubber asphalt, wherein the durable regenerated rubber asphalt is prepared by a mixed reaction of modified asphalt, rubber powder, and modified powder.

[0006] Furthermore, the asphalt is prepared from vinyl trihydroxysilane and base asphalt.

[0007] Furthermore, the matrix asphalt is any one of 70# heavy traffic asphalt and 90# heavy traffic asphalt.

[0008] Furthermore, the rubber powder is waste tire powder with a mesh size of 40 to 60.

[0009] Furthermore, the modified powder is prepared from diatomaceous earth, chloropalm oil methyl ester and phosphoenolpyruvic acid.

[0010] Furthermore, a method for preparing durable recycled rubber asphalt comprises the following preparation steps:

[0011] (1) 12 to 24 parts of diatomaceous earth are placed in a muffle furnace and calcined at 350 to 450° C. for 1 to 2 hours, cooled to 30 to 40° C., added with 60 to 120 parts of anhydrous ethanol, ultrasonicated for 1 to 2 hours, filtered to obtain a solid, washed with deionized water for 3 times, dried at 50 to 60° C. for 8 to 12 hours, added with 48 to 96 parts of petroleum ether and 10 to 20 parts of chloropalm oil methyl ester, stirred at 55 to 65° C. and 1000 rpm for 1 to 2 hours, heated to 70 to 80° C., continued to stir for 3 to 5 hours, filtered to obtain a solid, and dried at 80 to 90° C. for 10 to 16 hours to obtain modified diatomaceous earth;

[0012] (2) adding 6 to 12 parts of phosphoenolpyruvic acid and 9 to 17 parts of triethylamine to 14 to 28 parts of modified diatomaceous earth under stirring at 60 rpm, reacting for 0.5 to 1.5 hours, filtering out the solid, washing it with deionized water three times, and drying it at 60 to 70° C. for 5 to 9 hours to obtain a modified powder;

[0013] (3) heating 110-150 parts of base asphalt to 130-140° C., stirring at 800 rpm for 10-20 min, adding 3-9 parts of vinyl trihydroxysilane dropwise, and continuing stirring for 1-2 h to obtain modified asphalt;

[0014] (4) Place 93-117 parts of modified asphalt in a high-speed shearing machine, add 186-234 parts of ethanol, 5-18 parts of modified powder, and 1-3 parts of catalyst while stirring at 600 rpm, add 40-60 mesh rubber powder three times, 6-8 parts each time, react for 5-9 hours, heat to 170-190°C, accelerate stirring to 4000 rpm at a certain speed, continue for 60-80 minutes, then stir at 300 rpm for 2-4 hours, cool to 20-30°C, and obtain durable recycled rubber asphalt.

[0015] Furthermore, the frequency of the ultrasound in step (1) is 60 to 80 kHz.

[0016] Furthermore, the dripping rate in step (3) is 1 drop / s.

[0017] Furthermore, the catalyst in step (4) is any one of boron trifluoride, tributyl boron and titanium tetrachloride.

[0018] Furthermore, the stirring speed in step (4) is accelerated to 340 r / min.

[0019] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0020] Firstly, the present invention makes full contact between the diatomite and the chloropalm oil methyl ester through the pore structure of the diatomite, and realizes the coating of the diatomite with the chloropalm oil methyl ester under the surface tension and capillary action, thereby improving the flexibility and elasticity of the material in a cold environment, preventing the material from becoming brittle and cracking at low temperatures, and enhancing the durability. At the same time, the palm oil coating changes the diatomite from being hydrophilic to being hydrophobic, thereby blocking the entry of water, thereby achieving an antifreeze effect. On this basis, the diatomite whose main component is silicon dioxide has a low thermal conductivity, thereby effectively blocking the transfer of heat, thereby achieving a flame retardant effect. Then, the chlorine group in the diatomite is combined with the hydroxyl group of phosphorenolpyruvic acid to obtain a modified powder, and phosphorus is introduced. During combustion, the modified powder is decomposed to produce substances such as phosphorus oxyacid and phosphate ester, which can react with hydrogen and free radicals to form non-combustion products such as phosphate and phosphate ester salt, thereby inhibiting the spread of flames, thereby achieving a flame retardant effect.

[0021] Secondly, modified asphalt is prepared by combining vinyl trihydroxysilane with asphalt to form a stable network structure, which improves the elasticity of asphalt at high temperatures, thereby improving high temperature resistance. At the same time, longer Si-O bonds are introduced to improve the flexibility of the material, reduce low-temperature molecular agglomeration, and improve low-temperature resistance, thereby achieving high durability. Finally, the unsaturated double bonds in the modified asphalt are combined with the activated powder and rubber powder through addition reactions to form a cross-linked structure to achieve heat resistance, cold resistance, and flame retardant effects. DETAILED DESCRIPTION

[0022] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0023] In order to more clearly illustrate the method provided by the present invention, the following examples are used to describe in detail the various index testing methods of the durable regenerated rubber asphalt prepared in the following examples are as follows:

[0024] Softening point: Take the same mass of the embodiment and the comparative example and measure it according to GB / T 4507.

[0025] Freeze-thaw splitting residual strength ratio: Take the same mass of the embodiment and the comparative example and measure it according to the method T0729-2000 in JTJ052-2000 "Test Procedure for Asphalt and Asphalt Mixture in Highway Engineering".

[0026] Fatigue test: Take the same mass of the embodiment and the comparative example and measure it according to NF P98

[0027] Oxygen index: take the same mass of the embodiment and the comparative example and measure it according to NB / SH / T 0815.

[0028] Example 1

[0029] (1) 12 parts of diatomaceous earth were placed in a muffle furnace and calcined at 350° C. for 1 hour, cooled to 30° C., added with 60 parts of anhydrous ethanol, ultrasonicated at 60 kHz for 1 hour, filtered to obtain the solid, washed with deionized water 3 times, dried at 50° C. for 8 hours, added with 48 parts of petroleum ether and 10 parts of chloropalm oil methyl ester, stirred at 55° C. and 1000 rpm for 1 hour, heated to 70° C., continued to stir for 3 hours, filtered to obtain the solid, and dried at 80° C. for 10 hours to obtain modified diatomaceous earth;

[0030] (2) Add 6 parts of phosphoenolpyruvic acid and 9 parts of triethylamine to 14 parts of modified diatomaceous earth under stirring at 60 rpm, react for 0.5 h, filter out the solid, wash it with deionized water 3 times, and dry it at 60° C. for 5 h to obtain a modified powder;

[0031] (3) 110 parts of 90# heavy cross-linked asphalt were heated to 130°C, stirred at 800 rpm for 10 min, and 3 parts of vinyl trihydroxysilane were added dropwise at a rate of 1 drop / s, and continued to stir for 1 h to obtain modified asphalt;

[0032] (4) Place 93 parts of modified asphalt in a high-speed shearing machine, add 186 parts of ethanol, 5 parts of modified powder, and 1 part of boron trifluoride while stirring at 600 rpm, add 40-mesh rubber powder three times, 6 parts each time, react for 5 hours, heat to 170°C, accelerate stirring to 4000 rpm at 340 r / min, continue for 60 minutes, then stir at 300 rpm for 2 hours, cool to 20°C, and obtain durable recycled rubber asphalt.

[0033] Example 2

[0034] (1) 18 parts of diatomaceous earth were placed in a muffle furnace and calcined at 400° C. for 1.5 h, cooled to 35° C., added with 90 parts of anhydrous ethanol, ultrasonicated at 70 kHz for 1.5 h, filtered to obtain the solid, washed with deionized water three times, dried at 55° C. for 10 h, added with 72 parts of petroleum ether and 15 parts of chloropalm oil methyl ester, stirred at 60° C. and 1000 rpm for 1.5 h, heated to 75° C., continued to stir for 4 h, filtered to obtain the solid, and dried at 85° C. for 13 h to obtain modified diatomaceous earth;

[0035] (2) 8 parts of phosphoenolpyruvic acid and 13 parts of triethylamine were added to 21 parts of modified diatomaceous earth under stirring at 60 rpm, and the reaction was carried out for 1.0 h. The solid was filtered out, washed with deionized water for 3 times, and dried at 65° C. for 7 h to obtain a modified powder;

[0036] (3) 130 parts of 70# heavy cross-linked asphalt were heated to 135°C, stirred at 800 rpm for 15 min, and 6 parts of vinyl trihydroxysilane were added dropwise at a rate of 1 drop / s, and stirring was continued for 1.5 h to obtain modified asphalt;

[0037] (4) Place 105 parts of modified asphalt in a high-speed shearing machine, add 210 parts of ethanol, 12 parts of modified powder, and 2 parts of tributyl boron while stirring at 600 rpm, add 50-mesh rubber powder three times, 7 parts each time, react for 7 hours, heat to 180°C, accelerate stirring to 4000 rpm at 340 r / min, continue for 70 minutes, then stir at 300 rpm for 3 hours, cool to 25°C, and obtain durable recycled rubber asphalt.

[0038] Example 3

[0039] (1) 24 parts of diatomaceous earth were placed in a muffle furnace and calcined at 450° C. for 2 h, cooled to 40° C., 120 parts of anhydrous ethanol were added, ultrasonicated at 80 kHz for 2 h, solids were filtered out, washed with deionized water 3 times, dried at 60° C. for 12 h, 96 parts of petroleum ether and 20 parts of chloropalm oil methyl ester were added, stirred at 65° C. and 1000 rpm for 2 h, heated to 80° C., stirred for 5 h, filtered out solids, and dried at 90° C. for 16 h to obtain modified diatomaceous earth;

[0040] (2) 12 parts of phosphoenolpyruvic acid and 17 parts of triethylamine were added to 28 parts of modified diatomaceous earth under stirring at 60 rpm, and the reaction was carried out for 1.5 hours. The solid was filtered out, washed with deionized water three times, and dried at 70° C. for 9 hours to obtain a modified powder;

[0041] (3) 150 parts of 70# heavy cross-linking asphalt / 90# heavy cross-linking asphalt were heated to 140°C, stirred at 800 rpm for 20 min, and 9 parts of vinyl trihydroxysilane were added dropwise at a rate of 1 drop / s, and continued to stir for 2 h to obtain modified asphalt;

[0042] (4) Place 117 parts of modified asphalt in a high-speed shearing machine, add 234 parts of ethanol, 18 parts of modified powder, and 3 parts of titanium tetrachloride while stirring at 600 rpm, add 60-mesh rubber powder three times, 8 parts each time, react for 9 hours, heat to 190°C, accelerate stirring to 4000 rpm at 340 r / min, continue for 80 minutes, then stir at 300 rpm for 4 hours, cool to 30°C, and obtain durable recycled rubber asphalt.

[0043] Comparative Example 1

[0044] The difference between Comparative Example 1 and the Example is that step (1) is omitted, and step (2) is changed to: 8 parts of phosphoenolpyruvic acid and 13 parts of triethylamine are added to 21 parts of chloropalm oil methyl ester under stirring at 60 rpm, react for 1.0 h, filter out the solid, wash it with deionized water 3 times, and dry it at 65° C. for 7 h to obtain a modified powder. The remaining steps are the same as those of Example 2.

[0045] Comparative Example 2

[0046] The difference between Comparative Example 2 and the Example is that there is no step (1), and step (2) is changed to: 8 parts of phosphoenolpyruvic acid and 13 parts of triethylamine are added to 21 parts of diatomaceous earth under stirring at 60 rpm, react for 1.0 h, filter out the solid, wash it with deionized water 3 times, and dry it at 65° C. for 7 h to obtain a modified powder. The remaining steps are the same as those of Example 2.

[0047] Comparative Example 3

[0048] The difference between Comparative Example 3 and the embodiment is that there is no step (2), and step (4) is changed to: 105 parts of 70# base asphalt are placed in a high-speed shearing machine, 210 parts of ethanol, 12 parts of modified diatomaceous earth, and 2 parts of tributyl boron are added at 600 rpm, and 50-mesh rubber powder is added three times, 7 parts each time, and the reaction is performed for 7 hours, heated to 180°C, and stirred at 340 r / min to 4000 rpm for 70 minutes, then stirred at 300 rpm for 3 hours, and cooled to 25°C to obtain durable regenerated rubber asphalt. The remaining steps are the same as those in Example 2.

[0049] Comparative Example 4

[0050] The difference between Comparative Example 4 and the embodiment is that there is no step (3), and step (4) is changed to: 105 parts of 70# base asphalt are placed in a high-speed shearing machine, 210 parts of ethanol, 12 parts of modified powder, and 2 parts of tributyl boron are added at 600 rpm, and 50-mesh rubber powder is added three times, 7 parts each time, and the reaction is performed for 7 hours, heated to 180°C, and stirred at 340 r / min to 4000 rpm for 70 minutes, then stirred at 300 rpm for 3 hours, and cooled to 25°C to obtain durable regenerated rubber asphalt. The remaining steps are the same as those in Example 2.

[0051] Effect example

[0052] Table 1 below shows the performance analysis results of the durable regenerated rubber asphalt using Examples 1 to 3 of the present invention and Comparative Examples 1 to 4.

[0053] Table 1

[0054]

[0055]

[0056] From the comparison of the experimental data of Examples 1, 2, and 3 with Comparative Example 1, it can be found that the main component of diatomaceous earth is silicon dioxide, which has a low thermal conductivity and can effectively block the transfer of heat, thereby achieving flame retardant and heat-resistant effects; from the comparison of the experimental data of Examples 1, 2, and 3 with Comparative Example 2, it can be found that chloropalm oil methyl ester successfully coats diatomaceous earth under surface tension and capillary action, significantly improving the flexibility and elasticity of the material in a cold environment, preventing the material from becoming brittle and cracking at low temperatures, and at the same time, the coating of palm oil changes the diatomaceous earth from hydrophilic to hydrophobic, blocking the entry of water, thereby achieving an antifreeze effect; from Examples 1, 2, and 3, it can be found that the diatomaceous earth is mainly composed of silicon dioxide, which has a low thermal conductivity and can effectively block the transfer of heat, thereby achieving flame retardant and heat-resistant effects; from the comparison of the experimental data of Examples 1, 2, and 3 with Comparative Example 2, it can be found that chloropalm oil methyl ester successfully coats diatomaceous earth under surface tension and capillary action, significantly improving the flexibility and elasticity of the material in a cold environment, preventing the material from becoming brittle and cracking at low temperatures, and at the same time, the coating of palm oil changes the diatomaceous earth from hydrophilic to hydrophobic, blocking the entry of water, thereby achieving an antifreeze effect; By comparing the experimental data of Comparative Example 3, it can be found that the phosphorus element is introduced through phosphoenolpyruvate, which decomposes during combustion to produce substances such as phosphorus oxide and phosphate esters, which can react with hydrogen and free radicals to form non-combustible products such as phosphates and phosphate ester salts, thereby inhibiting the spread of flame and achieving a flame retardant effect; from the comparison of the experimental data of Examples 1, 2, and 3 with Comparative Example 4, it can be found that the addition of vinyl trihydroxy silane can form a stable network structure, improve the elasticity of asphalt at high temperatures, thereby improving the high temperature resistance effect, and at the same time introduce a longer Si-O bond, improve the flexibility of the material, reduce low-temperature molecular agglomeration, and improve cold resistance.

[0057] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations within the meaning and scope of the equivalent elements of the claims be included in the invention. Any marking in a claim should not be considered as limiting the claim to which it relates.

Claims

1. A durable recycled rubber asphalt, characterized in that: The durable regenerated rubber asphalt is prepared by a mixed reaction of modified asphalt, rubber powder and modified powder.

2. The durable regenerated rubber asphalt according to claim 1, characterized in that: The modified asphalt is prepared from vinyl trihydroxysilane and base asphalt.

3. The durable regenerated rubber asphalt according to claim 2, characterized in that: The matrix asphalt is any one of 70# heavy traffic asphalt and 90# heavy traffic asphalt.

4. The durable regenerated rubber asphalt according to claim 1, characterized in that: The rubber powder is waste tire powder with a mesh size of 40 to 60.

5. The durable regenerated rubber asphalt according to claim 1, characterized in that: The modified powder is prepared from diatomaceous earth, chloropalm oil methyl ester and phosphoenolpyruvic acid.

6. A method for preparing durable recycled rubber asphalt, characterized in that: The method comprises the following preparation steps: (1) 12 to 24 parts of diatomaceous earth are placed in a muffle furnace and calcined at 350 to 450° C. for 1 to 2 hours, cooled to 30 to 40° C., added with 60 to 120 parts of anhydrous ethanol, ultrasonicated for 1 to 2 hours, filtered to obtain a solid, washed with deionized water for 3 times, dried at 50 to 60° C. for 8 to 12 hours, added with 48 to 96 parts of petroleum ether and 10 to 20 parts of chloropalm oil methyl ester, stirred at 55 to 65° C. and 1000 rpm for 1 to 2 hours, heated to 70 to 80° C., continued to stir for 3 to 5 hours, filtered to obtain a solid, and dried at 80 to 90° C. for 10 to 16 hours to obtain modified diatomaceous earth; (2) adding 6 to 12 parts of phosphoenolpyruvic acid and 9 to 17 parts of triethylamine to 14 to 28 parts of modified diatomaceous earth under stirring at 60 rpm, reacting for 0.5 to 1.5 hours, filtering out the solid, washing it with deionized water three times, and drying it at 60 to 70° C. for 5 to 9 hours to obtain a modified powder; (3) heating 110-150 parts of base asphalt to 130-140° C., stirring at 800 rpm for 10-20 min, adding 3-9 parts of vinyl trihydroxysilane dropwise, and continuing stirring for 1-2 h to obtain modified asphalt; (4) Place 93-117 parts of modified asphalt in a high-speed shearing machine, add 186-234 parts of ethanol, 5-18 parts of modified powder, and 1-3 parts of catalyst while stirring at 600 rpm, add rubber powder three times, 6-8 parts each time, react for 5-9 hours, heat to 170-190°C, accelerate stirring to 4000 rpm at a certain rate, continue for 60-80 minutes, then stir at 300 rpm for 2-4 hours, cool to 20-30°C, and obtain durable recycled rubber asphalt.

7. The method for preparing durable regenerated rubber asphalt according to claim 6, characterized in that: The frequency of the ultrasound in step (1) is 60 to 80 kHz.

8. The method for preparing durable regenerated rubber asphalt according to claim 6, characterized in that: The dripping rate in step (3) is 1 drop / s.

9. The method for preparing durable regenerated rubber asphalt according to claim 6, characterized in that: The catalyst in step (4) is any one of boron trifluoride, tributyl boron and titanium tetrachloride.

10. The method for preparing durable regenerated rubber asphalt according to claim 6, characterized in that: The speed of accelerating stirring in step (4) is 340 r / min.

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