Modified asphalt capable of improving ductility performance and preparation method thereof

Abstract

The invention discloses modified asphalt with improved ductility and a preparation method thereof, and the modified asphalt comprises the following raw materials by mass: 2-4.5% of rubber powder, 2-3.5% of an SBS modifier, 1-1.5% of rubber oil, 0.1-0.2% of a stabilizer, and the balance of ground-refined asphalt. The method can improve the qualified rate of national standard modified asphalt and reduce the production cost.

Description

Technical Field

[0001] The invention relates to modified asphalt with improved ductility and a preparation method thereof, belonging to the technical field of asphalt modification. Background Art

[0002] Dilian is the abbreviation of local refinery. Local refined asphalt is processed from the residue after crude oil distillation in local refineries. Its main components are oil, resin and asphaltene. Since the RTFOT ductility index of local refined asphalt products is smaller than that of imported asphalt products, there is a large difference in the indexes. Most local refined asphalts need to be modified by adding auxiliary materials to meet the requirements of national standards. In addition, the existing product indicators of different local refined asphalts modified with the same formula are still quite different from those of imported asphalt. In addition, in order to improve the modified qualified rate of local refined asphalt, the existing modifications of local refined asphalt include increasing the amount of auxiliary materials and compounding local refined asphalt with imported asphalt. Although it has improved to a certain extent, the prices of auxiliary materials SBS modifier and imported asphalt are relatively high. For this reason, there is an urgent need to develop a modified asphalt with improved ductility performance, which can improve the qualified rate of modified asphalt meeting national standards. Summary of the Invention

[0003] In order to address at least one problem existing in the above-mentioned prior art, the present invention provides a modified asphalt with improved ductility and a preparation method thereof, which can improve the qualified rate of modified asphalt meeting national standards and reduce production costs.

[0004] In order to achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a modified asphalt with improved ductility performance, which includes the following raw materials, calculated by mass percentage: 2-4.5% rubber powder, 2-3.5% SBS modifier, 1-1.5% rubber oil, 0.1-0.2% stabilizer, and the rest is local refined asphalt.

[0005] Preferably, the modified asphalt comprises the following raw materials, calculated by mass percentage: 3% rubber powder, 3.5% SBS modifier, 1.2% rubber oil, 0.15% stabilizer, and 92.15% local refined asphalt.

[0006] Preferably, the modified asphalt comprises the following raw materials, calculated by mass percentage: 4.5% rubber powder, 2% SBS modifier, 1.5% rubber oil, 0.1% stabilizer, and 91.9% local refined asphalt.

[0007] Preferably, the modified asphalt comprises the following raw materials, calculated by mass percentage: 3% rubber powder, 3% SBS modifier, 1% rubber oil, 0.2% stabilizer, and 92.8% local refined asphalt.

[0008] Preferably, the rubber powder is 80 mesh tire rubber powder or composite rubber particles.

[0009] Preferably, the rubber powder is 80 mesh tire rubber powder.

[0010] Preferably, the local refined asphalt is 70# asphalt.

[0011] Preferably, the SBS modifier is SBS7301.

[0012] Preferably, the modified asphalt further comprises: 0-0.8% diatomaceous earth.

[0013] Preferably, the modified asphalt further comprises: 0.3-0.6% diatomaceous earth.

[0014] Preferably, the modified asphalt further comprises: 0.45% diatomaceous earth.

[0015] The present invention also provides a method for preparing modified asphalt with improved ductility, comprising the following steps:

[0016] (1) First, mix the local refined asphalt and rubber oil evenly and then heat them;

[0017] (2) Add rubber powder and SBS modifier and mix them evenly, then shear them and keep them warm and stir;

[0018] (3) The mixture is sieved through a 40-mesh sieve. If there are no particles on the sieve, a stabilizer is added and mixed evenly to obtain modified asphalt.

[0019] Preferably, in step (1), the temperature is heated to 170-180°C.

[0020] Preferably, in step (1), the temperature of the heat-insulating stirring is 180-190° C., the stirring speed is 250-350 rpm, and the stirring time is 1-2 h.

[0021] Preferably, in step (2), the shearing treatment speed is 3500-4500 rpm, and the time is 30-40 min.

[0022] Preferably, in step (2), diatomaceous earth is further added, and the diatomaceous earth, rubber powder and SBS modifier are simultaneously subjected to mixing, shearing and heat-insulating stirring processes.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1. Compared with traditional SBS modified asphalt, the modified asphalt with improved ductility of the present invention effectively improves the performance indicators of the modified asphalt through the appropriate ratio of rubber powder and SBS modifier, increases the RTFOT ductility of the modified asphalt, and improves the qualified rate of the national standard modified asphalt.

[0025] 2. In the preparation method of the modified asphalt with improved ductility of the present invention, on the basis of local refined asphalt and rubber oil, the rubber powder is first shear-swelled together with the SBS modifier, and then stability is added, which further improves the national standard modified asphalt qualification rate and the RTFOT ductility of the modified asphalt.

[0026] 3. The modified asphalt with improved ductility of the present invention not only improves the performance of the modified asphalt but also improves the stability of the qualified rate of the prepared modified asphalt by adding an appropriate amount of diatomaceous earth. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 Schematic diagram of the mixing and shearing of rubber powder and SBS modifier of the present invention;

[0028] Figure 2 This is a 40-mesh screen image of the swelling and development of Example 1 of the present invention after screening;

[0029] Figure 3 This is a 40-mesh screen image of the swelling and development of Comparative Example 4 of the present invention after sieving;

[0030] Figure 4 Schematic diagram of the RTFOT ductility measurement results of the modified asphalt prepared in Example 1 of the present invention;

[0031] Figure 5 Schematic diagram of the RTFOT ductility measurement results of the local refined asphalt in the control group of the present invention. DETAILED DESCRIPTION

[0032] The following is a clear and complete description of the technical solutions in the implementation of the present invention. The described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative work are within the scope of protection of the present invention. If specific conditions are not specified in the embodiments, they are carried out according to conventional conditions or the conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments is not specified, they are all conventional products that can be purchased commercially.

[0033] The RTFOT ductility of modified asphalt refers to the ductility of the asphalt material under specific conditions after RTFOT aging treatment.

[0034] RTFOT is a laboratory test method that simulates the aging process that asphalt may undergo during actual construction and early service. It heats and rotates the asphalt sample in a thin layer to accelerate its aging.

[0035] Ductility refers to the ability of asphalt to maintain a certain degree of flexibility and resist fracture at low temperatures or after aging. This is typically done by measuring the elongation of an asphalt specimen at a specified temperature and tensile speed to assess the asphalt's low-temperature crack resistance and performance changes after aging.

[0036] The local refined asphalt used in the present invention is 70# asphalt, which is produced by Jiangsu Xinhai Petrochemical Co., Ltd., batch number LQc019, model 70#A grade road petroleum asphalt.

[0037] The rubber powder used in the present invention is 80-mesh tire rubber powder or compound rubber powder, and the 80-mesh tire rubber powder and compound rubber powder produced by Taihe County Jinhao Rubber Co., Ltd. are selected.

[0038] The SBS modifier used in the present invention is SBS7301H modifier, and the SBS modifier model HZKX-7301H produced by Heze Kexin Chemical Co., Ltd. is selected.

[0039] The rubber oil used in the present invention is the WKD-1 rubber oil produced by Wuhan Kangrun Petrochemical Co., Ltd.

[0040] The stabilizer used in the present invention is the VIRTUOUS-WD stabilizer produced by Lianyungang Dashitong Industrial Co., Ltd.

[0041] The diatomaceous earth used in the present invention is selected from the diatomaceous earth of Hubei Qibajiu Chemical Industry Co., Ltd.

[0042] Example 1

[0043] A modified asphalt with improved ductility comprises the following raw materials, calculated by mass percentage: 2% of 80-mesh tire rubber powder, 3.5% of SBS7301 modifier, 1.2% of rubber oil, 0.15% of stabilizer, and 93.15% of local refined asphalt.

[0044] The steps for preparing modified asphalt are as follows:

[0045] (1) First, mix the local refined asphalt and rubber oil evenly, and heat to 170℃;

[0046] (2) Then continue to add 80 mesh tire rubber powder and SBS7301 modifier and mix evenly, then shear at 3500 rpm for 30 minutes (such as Figure 1 The mixture was stirred at 180°C and 250 rpm for 1 h.

[0047] (3) Then sieve through a 40-mesh sieve. Figure 2 As shown, the screen has no particles, stabilizer is added, and mixed evenly to obtain modified asphalt. The RTFOT ductility of the modified asphalt is as follows Figure 4 shown.

[0048] Example 2

[0049] A modified asphalt with improved ductility comprises the following raw materials, calculated by mass percentage: 3% of 80-mesh tire rubber powder, 3.5% of SBS7301 modifier, 1.2% of rubber oil, 0.15% of stabilizer, and 92.15% of local refined asphalt.

[0050] The preparation method of modified asphalt is the same as that in Example 1.

[0051] Example 3

[0052] A modified asphalt with improved ductility comprises the following raw materials, calculated by mass percentage: 4.5% of 80-mesh tire rubber powder, 2% of SBS7301 modifier, 1.5% of rubber oil, 0.1% of stabilizer, and 91.9% of local refined asphalt.

[0053] The preparation method of modified asphalt is the same as that in Example 1.

[0054] Example 4

[0055] A modified asphalt with improved ductility comprises the following raw materials, calculated by mass percentage: 3% of 80-mesh tire rubber powder, 3% of SBS7301 modifier, 1% of rubber oil, 0.2% of stabilizer, and 92.8% of local refined asphalt.

[0056] The preparation method of modified asphalt is the same as that in Example 1.

[0057] Example 5

[0058] A modified asphalt with improved ductility comprises the following raw materials, calculated by mass percentage: 2% of composite rubber powder, 3.5% of SSBS7301 modifier, 1.2% of rubber oil, 0.15% of stabilizer, and 93.15% of local refined asphalt.

[0059] The preparation method of modified asphalt is the same as that in Example 1.

[0060] Example 6

[0061] A modified asphalt with improved ductility comprises the following raw materials, calculated by mass percentage: 2% of 80-mesh tire rubber powder, 3.5% of SBS7301 modifier, 1.2% of rubber oil, 0.15% of stabilizer, 0.45% of diatomaceous earth, and 92.7% of local refined asphalt.

[0062] The preparation method of modified asphalt is the same as that of Example 1: in step 2, 80-mesh tire rubber powder, SBS7301 modifier, and diatomaceous earth are added simultaneously.

[0063] Example 7

[0064] A modified asphalt with improved ductility comprises the following raw materials, calculated by mass percentage: 4.5% of 80-mesh tire rubber powder, 2% of SBS7301 modifier, 1.5% of rubber oil, 0.1% of stabilizer, 0.45% of diatomaceous earth, and 91.45% of local refined asphalt.

[0065] The preparation method of modified asphalt is the same as that of Example 1: in step 2, 80-mesh tire rubber powder, SBS7301 modifier, and diatomaceous earth are added simultaneously.

[0066] Example 8

[0067] A modified asphalt with improved ductility comprises the following raw materials, calculated by mass percentage: 2.5% of 80-mesh tire rubber powder, 3% of SBS7301 modifier, 1% of rubber oil, 0.1% of stabilizer, 0.6% of diatomaceous earth, and 92.8% of local refined asphalt.

[0068] The steps for preparing modified asphalt are as follows:

[0069] (1) First, mix the local refined asphalt and rubber oil evenly, and heat to 180℃;

[0070] (2) Then, 80-mesh tire rubber powder, SBS7301 modifier, and diatomaceous earth were added and mixed evenly, and then sheared at 4500 rpm for 35 min, and then kept warm and stirred at 190 ° C and 350 rpm for 2 h;

[0071] (3) The mixture is sieved through a 40-mesh sieve. If there are no particles on the sieve, a stabilizer is added and mixed evenly to obtain modified asphalt.

[0072] Example 9

[0073] A modified asphalt with improved ductility comprises the following raw materials, calculated by mass percentage: 4% of 80-mesh tire rubber powder, 2.5% of SBS7301 modifier, 1% of rubber oil, 0.2% of stabilizer, 0.3% of diatomaceous earth, and 92% of local refined asphalt.

[0074] The steps for preparing modified asphalt are as follows:

[0075] (1) First, mix the local refined asphalt and rubber oil evenly, and heat to 175℃;

[0076] (2) Then, 80-mesh tire rubber powder, SBS7301, and diatomaceous earth were added and mixed evenly, and then sheared at 4000 rpm for 40 min, and then kept warm and stirred at 185°C and 300 rpm for 1.5 h;

[0077] (3) The mixture is sieved through a 40-mesh sieve. If there are no particles on the sieve, a stabilizer is added and mixed evenly to obtain modified asphalt.

[0078] Comparative Example 1

[0079] A modified asphalt with improved ductility comprises the following raw materials, calculated by mass percentage: 3.5% of SBS7301 modifier, 1.2% of rubber oil, 0.15% of stabilizer, and 95.15% of local refined asphalt.

[0080] The preparation method of modified asphalt is the same as that in Example 1.

[0081] Comparative Example 2

[0082] A modified asphalt with improved ductility comprises the following raw materials, calculated by mass percentage: 4.5% of SBS7301 modifier, 1.2% of rubber oil, 0.15% of stabilizer, and 94.15% of local refined asphalt.

[0083] The preparation method of modified asphalt is the same as that in Example 1.

[0084] Comparative Example 3

[0085] A modified asphalt with improved ductility comprises the following raw materials, calculated by mass percentage: 6% of SBS7301 modifier, 1.2% of rubber oil, 0.15% of stabilizer, and 92.65% of local refined asphalt.

[0086] The preparation method of modified asphalt is the same as that in Example 1.

[0087] Comparative Example 4

[0088] A modified asphalt with improved ductility comprises the following raw materials and their mass percentages are the same as those in Example 1:

[0089] The steps for preparing modified asphalt are as follows:

[0090] (1) First, mix the local refined asphalt and rubber oil evenly, and heat to 170℃;

[0091] (2) SBS7301 modifier was added and mixed evenly, and then sheared at 3500 rpm for 30 min, and then 80 mesh tire rubber powder was added and mixed, and then kept warm and stirred at 180 ° C and 250 rpm for 1 h;

[0092] (3) Then sieve through a 40-mesh sieve. Figure 3 As shown, the screen has particles, stabilizer is added, and mixed evenly to obtain modified asphalt.

[0093] The control group is the purchased local refined asphalt. The RTFOT ductility of the local refined asphalt is as follows: Figure 5 shown.

[0094] Performance Testing

[0095] 1. In the preparation methods of Example 1 and Comparative Example 4, after the swelling and development are sieved in step 3 and the 40-mesh sieve is passed, the 40-mesh sieve is observed as follows: Figure 2 and Figure 3 shown.

[0096] from Figure 2 and Figure 3 It was found that Figure 2 In the preparation process of Example 1, the rubber powder and the SBS7301 modifier were sheared together by a shearing machine without obvious particles; Figure 3 In Comparative Example 4, the rubber powder had obvious particles without shearing treatment, so the preparation scheme of Example 1 is the preferred scheme.

[0097] 2. According to JTG E20-2011 "Test Procedures for Asphalt and Asphalt Mixtures for Highway Engineering", the modified asphalts of Examples 1 to 9 and Comparative Examples 1 to 3 and the local refined asphalt of the control group were tested. The specific test items and technical requirements are shown in Table 1, and the test results are shown in Table 2 and Figure 4 、 Figure 5 shown.

[0098] Table 1 Test items and technical requirements

[0099]

[0100] Table 2 Performance

[0101]

[0102]

[0103] As can be seen from Table 2, compared with the control group and comparative example 1, Examples 1 to 5 use rubber powder and SBS modifier as additives through appropriate cultivation, which effectively improves the performance indicators of the modified asphalt and increases the RTFOT ductility of the modified asphalt. The RTFOT ductility is greater than 15 cm, and the RTFOT ductility is relatively stable.

[0104] It was further found that the addition of diatomaceous earth to assist rubber powder in Examples 6 to 9 further improved the performance indicators of the modified asphalt, with the RTFOT elongation being greater than 16 cm, and improved the performance stability of the modified asphalt preparation.

[0105] from Figure 4 and Figure 5 It can be found that the tensile distance of local refined asphalt is short and the RTFOT elongation is small. The modified asphalt prepared in Example 1 has a good tensile length, which greatly meets the RTFOT elongation technical requirements.

[0106] 3. Batch production was carried out for the modified asphalts of Examples 1 to 9 and Comparative Examples 1 to 3, and the local refined asphalt of the control group. The RTFOT ductility of each item was then tested to evaluate the qualified rate (%) of the index. The results are shown in Table 3.

[0107] Table 3 RTFOT ductility qualification rate of each production batch

[0108]

[0109]

[0110] It can be seen from Table 3 that the RTFOT ductility of the modified asphalts of Examples 1 to 9 can meet the technical requirements, and the qualified rate is not less than 90%, which improves the qualified rate of the national standard modified asphalt.

[0111] 4. Calculate the raw material costs of Example 1, Example 5, Comparative Example 1, Comparative Example 2, and Comparative Example 3 of the present invention (the total raw materials are calculated based on 1 ton and the mass percentage of each raw material composition): The present invention is calculated based on the price in 2024 (different brands will vary): SBS modifier material 15,000 yuan / ton, composite rubber particles 4,500 yuan / ton, rubber powder 3,800 yuan / ton, rubber oil 5,500 yuan / ton, stabilizer 5,500 yuan / ton, local asphalt 3,500 yuan / ton and diatomaceous earth 16,500 yuan / ton; as shown in Table 4.

[0112] Table 4 Modified asphalt raw material prices

[0113] Example 1 Example 5 Example 6 Comparative Example 2 Comparative Example 3 Yuan / ton 3932.5 3946.5 3924.2 4041.5 4214

[0114] It can be seen from Table 4 that, compared with Example 5, Example 1 uses 80-mesh tire rubber powder, and the total raw material price is reduced by 14 yuan / ton. Combined with Table 2 and Table 3, Example 1 uses 80-mesh tire rubber powder, which has a greater advantage; compared with Example 6, Example 1 keeps the proportion of other raw materials unchanged, reduces the proportion of local asphalt, and adds diatomaceous earth, which reduces the total raw material price by 8.3 yuan / ton. Example 6 uses diatomaceous earth to assist rubber powder, which has a better effect and reduces the raw material cost; compared with Comparative Examples 2 and 3, Example 1 increases the amount of SBS modifier added, and combines Table 1 and Table 3. Although the performance indicators can meet the requirements, the total raw material price increases by at least 109 yuan / ton, and the raw material cost is high.

[0115] In summary, the present invention utilizes an appropriate ratio of rubber powder and SBS modifier to effectively improve the performance indicators of modified asphalt, increase the RTFOT ductility of modified asphalt, and improve the qualified rate of modified asphalt meeting national standards.

[0116] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be embodied in other specific forms without departing from the spirit and essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations that come within the meaning and range of equivalents of the claims be embraced therein.

[0117] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A modified asphalt with improved ductility, characterized in that: Calculated by mass percentage, the raw materials include: 2-4.5% rubber powder, 2-3.5% SBS modifier, 1-1.5% rubber oil, 0.1-0.2% stabilizer, and the rest is local refined asphalt.

2. The modified asphalt with improved ductility according to claim 1, characterized in that: The rubber powder is 80 mesh tire rubber powder or composite rubber particles.

3. The modified asphalt with improved ductility according to claim 2, characterized in that: The rubber powder is 80 mesh tire rubber powder.

4. The modified asphalt with improved ductility according to claim 1, characterized in that: The invention comprises the following raw materials, calculated in percentage by mass: 3% of rubber powder, 3.5% of SBS modifier, 1.2% of rubber oil, 0.15% of stabilizer, and 92.15% of local refined asphalt.

5. The modified asphalt with improved ductility according to claim 1, characterized in that: The invention comprises the following raw materials, calculated in percentage by mass: 4.5% of rubber powder, 2% of SBS modifier, 1.5% of rubber oil, 0.1% of stabilizer, and 91.9% of local refined asphalt.

6. The modified asphalt with improved ductility according to claim 1, characterized in that: The modified asphalt comprises the following raw materials, calculated by mass percentage: 3% rubber powder, 3% SBS modifier, 1% rubber oil, 0.2% stabilizer, and 92.8% local refined asphalt.

7. The modified asphalt with improved ductility according to claim 1, characterized in that: The invention also comprises diatomaceous earth, wherein the mass percentage of the diatomaceous earth is 0 to 0.6%.

8. The modified asphalt with improved ductility according to claim 7, characterized in that: The mass percentage of the diatomaceous earth is 0.3-0.6%.

9. A method for preparing a modified asphalt with improved ductility according to any one of claims 4 to 9, characterized in that: The following steps are involved: (1) First, mix the local refined asphalt and rubber oil evenly and then heat them; (2) Add rubber powder and SBS modifier and mix them evenly, then shear them and keep them warm and stir; (3) The mixture is sieved through a 40-mesh sieve. If there are no particles on the sieve, a stabilizer is added and mixed evenly to obtain modified asphalt.

10. The method for preparing modified asphalt with improved ductility according to claim 9, characterized in that: In step (2), diatomaceous earth is also added, and the diatomaceous earth, rubber powder and SBS modifier are simultaneously subjected to mixing, shearing and heat-insulating stirring processes.

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