阅读说明：本技术 一种超薄沥青混合料及其制备方法 (Ultrathin asphalt mixture and preparation method thereof ) 是由 朱天同 赵国华 曹祖光 叶奋 于 2019-10-16 设计创作，主要内容包括：本发明提供了一种超薄沥青混合料及其制备方法,其组分含有：集料5-10mm 10-50份、集料3-5mm 20-50份、集料0-3mm 15-35份、矿粉4-10份、改性沥青5-8份、超薄沥青混合料专用添加剂0.2-0.5份以及聚酯纤维0.2-0.4份。本发明相比较于常规的SMA、AC沥青混合料具有较好的高温稳定性能、低温抗裂性能、优异的抗疲劳损伤性能和突出的抗滑性能。(The invention provides an ultrathin asphalt mixture and a preparation method thereof, and the ultrathin asphalt mixture comprises the following components: 10-50 parts of aggregate 5-10mm, 20-50 parts of aggregate 3-5mm, 15-35 parts of aggregate 0-3mm, 4-10 parts of mineral powder, 5-8 parts of modified asphalt, 0.2-0.5 part of special additive for ultrathin asphalt mixture and 0.2-0.4 part of polyester fiber. Compared with the conventional SMA and AC asphalt mixture, the asphalt mixture has better high-temperature stability, low-temperature crack resistance, excellent fatigue damage resistance and outstanding skid resistance.)

1. The ultrathin asphalt mixture is characterized in that a mixture formula comprises the following components in parts by weight: 10-50 parts of aggregate 5-10mm, 20-50 parts of aggregate 3-5mm, 15-35 parts of aggregate 0-3mm, 4-10 parts of mineral powder, 5-8 parts of modified asphalt, 0.2-0.5 part of special additive for ultrathin asphalt mixture and 0.2-0.4 part of polyester fiber.

2. The ultrathin asphalt mixture according to claim 1, characterized in that: the aggregate is 5-10mm and the aggregate is 3-5mm basalt, diabase or steel slag.

3. The ultrathin asphalt mixture according to claim 1, characterized in that: the aggregate with the thickness of 0-3mm is limestone.

4. The ultrathin asphalt mixture according to claim 1, characterized in that: the mineral powder is ground limestone mineral powder.

5. The ultrathin asphalt mixture according to claim 1, characterized in that: the modified asphalt is SBS modified asphalt, and meets the technical requirements of the later I-D of the technical Specification for the construction of the asphalt pavement of the highway.

6. The ultrathin asphalt mixture according to claim 1, characterized in that: the special additive for the ultrathin asphalt mixture is an olefin polymer modified additive, and the melt drop point of the additive is 120-150 ℃ and the viscosity of the additive is 3000-8000 cps.

7. The ultrathin asphalt mixture according to claim 1, characterized in that: the melting point of the polyester fiber is more than or equal to 250 ℃, the length of the polyester fiber is 6-12mm, the tensile strength is more than or equal to 500Mpa, and the elongation at break is more than or equal to 15%.

8. A preparation method of the ultrathin asphalt mixture as claimed in any one of claims 1 to 7, characterized by comprising the following steps:

(1) heating 5-10mm of aggregate, 3-5mm of aggregate and 0-3mm of aggregate to 190-220 ℃;

(2) sequentially weighing 5-10mm of aggregate, 3-5mm of aggregate, 0-3mm of aggregate and mineral powder, adding into a stirring cylinder, and mixing for 10-15s with delay.

(3) During the time delay, the weighed special additive for the ultrathin asphalt mixture and the polyester fiber are simultaneously put into a mixing cylinder by manpower, and are subjected to dry mixing for 10-20 s;

(4) and weighing the modified asphalt, adding the modified asphalt into a stirring cylinder, and stirring for 45-55 s.

Technical Field

The invention relates to the technical field of asphalt mixtures, in particular to an ultrathin asphalt mixture and a preparation method thereof.

Background

At present, various municipal roads, rural highways, partial highways, bridges and tunnels in China are paved by cement pavements, the driving comfort level and the anti-skid performance of the cement pavements are greatly reduced after a certain service life, the driving safety and the driving comfort level are seriously affected, meanwhile, a large number of plate transverse seams bring serious vehicle jumping and strong noise in the driving process of the cement pavements, and the cement pavements are polluted for surrounding residents. If the cement road surface is maintained by adopting the traditional covering method, one method is to dig the cement road surface and rebuild the road; the other cement pavement additionally paved with the asphalt has the thickness of more than 10 cm. The digging reconstruction period is long, the social influence is large, the construction cost is high, and the waste of old road materials is serious; the additional paving of the traditional asphalt mixture with the height of more than 10cm has high manufacturing cost, the elevation increase needs to correspondingly lift the kerb, the guardrail and the like, the bridge is not suitable for additionally paving the over-thick asphalt mixture due to limited bearing capacity, and the elevation cannot be increased too much due to clearance limitation of the tunnel; therefore, it is necessary to develop an ultra-thin asphalt mixture with a minimum thickness of 2cm or less to solve the above problems.

Disclosure of Invention

Technical problem to be solved

The invention aims to provide an ultrathin asphalt mixture, which can solve the problem that the white-to-black pavement of old cement pavements, bridges and tunnels is not suitable for paving over-thick asphalt mixtures, and has better high-temperature stability, better low-temperature crack resistance, excellent fatigue damage resistance and outstanding skid resistance. In order to achieve the purpose, the invention adopts the following technical scheme:

(II) technical scheme

The ultrathin asphalt mixture comprises the following components in parts by weight: 10-50 parts of aggregate 5-10mm, 20-50 parts of aggregate 3-5mm, 15-35 parts of aggregate 0-3mm, 4-10 parts of mineral powder, 5-8 parts of modified asphalt, 0.2-0.5 part of special additive for ultrathin asphalt mixture and 0.2-0.4 part of polyester fiber.

Further, the aggregate is 5-10mm and the aggregate is 3-5mm basalt, diabase or steel slag.

Further, the aggregate with the thickness of 0-3mm is limestone.

Further, the mineral powder is ground limestone mineral powder.

Furthermore, the modified asphalt is SBS modified asphalt, and meets the technical requirements of I-C and I-D of the technical Specification for construction of road asphalt pavement.

Further, the special additive for the ultrathin asphalt mixture is an olefin polymer modified additive, and the melt drop point of the additive is 120-150 ℃ and the viscosity of the additive is 3000-8000 cps.

Furthermore, the melting point of the polyester fiber is more than or equal to 250 ℃, the length of the polyester fiber is 6-12mm, the tensile strength is more than or equal to 500Mpa, and the elongation at break is more than or equal to 15%.

The preparation method of the ultrathin asphalt mixture is characterized by comprising the following steps of:

(1) heating 5-10mm of aggregate, 3-5mm of aggregate and 0-3mm of aggregate to 190-220 ℃;

(2) sequentially weighing 5-10mm of aggregate, 3-5mm of aggregate, 0-3mm of aggregate and mineral powder, adding into a stirring cylinder, and mixing for 10-15s with delay.

(3) During the time delay, the weighed special additive for the ultrathin asphalt mixture and the polyester fiber are simultaneously put into a mixing cylinder by manpower, and are subjected to dry mixing for 10-20 s;

(4) and weighing the modified asphalt, adding the modified asphalt into a stirring cylinder, and stirring for 45-55 s.

(III) advantageous effects

Compared with the prior art, the invention has obvious advantages and beneficial effects, particularly, the invention can achieve a framework embedding and extruding structure through the adjustment of the mineral aggregate gradation, thereby leading the asphalt mixture to have better high-temperature stability; meanwhile, the gap of the framework is fully filled with a mixture of modified asphalt and mineral powder (short for asphalt mastic) without generating framework interference, and sufficient asphalt mastic can ensure the fatigue resistance of the asphalt mixture; the added special additive for the ultrathin asphalt mixture can greatly improve the high-temperature stability of the mixture without reducing the low-temperature crack resistance of the mixture; the added polyester fiber can improve the toughness of the mixture and enhance the crack resistance and fatigue resistance of the mixture.

Therefore, the asphalt mixture can be applied to cement road surface, tunnel and bridge white-to-black projects, the service life can reach more than 5 years, and meanwhile, the anti-skid property and the flatness of the road can be improved, the noise of the road surface is reduced, and the driving comfort and the safety are improved.

Detailed Description

The invention is further illustrated by the following examples, which are not intended to limit the scope of the invention. The experimental methods in the following examples, which are not specified under specific conditions, were selected according to the conventional methods and conditions, or according to the following technical performance indicators.

The ultrathin asphalt mixture comprises the following components in parts by weight: 10-50 parts of aggregate 5-10mm, 20-50 parts of aggregate 3-5mm, 15-35 parts of aggregate 0-3mm, 4-10 parts of mineral powder, 5-8 parts of modified asphalt, 0.2-0.5 part of special additive for ultrathin asphalt mixture and 0.2-0.4 part of polyester fiber.

Wherein, the aggregate of 5-10mm and the aggregate of 3-5mm adopt basalt or diabase, and can also adopt steel slag, which needs to meet the following technical requirements:

the technical performance indexes of the coarse aggregates (5-10mm and 3-5mm)

Coarse aggregate (5-10mm, 3-5mm) specification

Wherein, aggregate 0-3mm adopts limestone, which needs to meet the following technical requirements:

technical performance index of fine aggregate (0-3mm)

Fine aggregate (0-3mm) specification

Wherein, the mineral powder is limestone mineral powder, which needs to meet the following technical requirements:

technical performance index of mineral powder

In order to enhance the oil absorption effect and improve the fatigue resistance and crack resistance of the mixture, a polyester fiber stabilizer is added into the mixture, the addition proportion is 0.2-0.4% of the mass of the mixture, and the polyester fiber does not deteriorate or become brittle at the dry-mixing temperature of 200 ℃ and does not harm the health. The polyester fiber needs to meet the following technical requirements:

index of polyester fiber Properties

Meanwhile, the special additive for the ultrathin asphalt mixture and the modified asphalt also meet the following technical requirements:

technical requirements of special additive for ultrathin asphalt mixture

Technical requirements of modified asphalt

The preparation method of the ultrathin asphalt mixture comprises the following steps:

(1) heating 5-10mm of aggregate, 3-5mm of aggregate and 0-3mm of aggregate to 190-220 ℃;

(2) sequentially weighing 5-10mm of aggregate, 3-5mm of aggregate, 0-3mm of aggregate and mineral powder, adding into a stirring cylinder, and mixing for 10-15s with delay.

(3) During the time delay, the weighed special additive for the ultrathin asphalt mixture and the polyester fiber are simultaneously put into a mixing cylinder by manpower, and are subjected to dry mixing for 10-20 s;

(4) and weighing the modified asphalt, adding the modified asphalt into a stirring cylinder, and stirring for 45-55 s.

The raw materials are selected according to the technical requirements of the raw materials and prepared by referring to the method, and the raw material proportion, the preparation method and the test result of all the examples and the comparative examples are shown in the following table: table 1 is a list of formulations of examples and comparative examples, table 2 is a list of preparation methods of examples and comparative examples, and table 3 is a list of test results of examples and comparative examples.

TABLE 1 summary of the formulations of the examples and comparative examples

TABLE 2 summary of preparation methods of examples and comparative examples

For the ultra-thin asphalt mixtures prepared in the above-mentioned examples 1-4 and comparative examples 1-2, performance tests were performed according to the test methods of "test procedure for asphalt and asphalt mixtures for road engineering" (JTGE20-2011) of the department of transportation.

TABLE 3 summary of test results for examples and comparative examples

As can be seen from the test results in the table 3, the Marshall stability index of the maximum load borne by the ultrathin asphalt mixture prepared by the invention is greatly improved, and the invention is proved to have more excellent mechanical property technical indexes; the loss of the mixture or the preparation in the soaking and flying test of the Kentuckberg greatly reduces, and the Kentuckberg has more excellent flying resistance; the freeze-thaw cleavage strength of the invention is greatly improved compared with the index, and the invention is proved to have more excellent water loss resistance; the dynamic stability index of the invention is greatly improved, and the invention is proved to have more excellent anti-rutting performance; the fatigue life index of the invention is greatly improved, and the invention is proved to have more excellent fatigue resistance.

In summary, the following steps: the asphalt mixture material has various properties higher than those of a modified SMA or AC asphalt mixture, and has good high-temperature stability, low-temperature crack resistance, fatigue resistance and skid resistance; the method can be widely applied to the projects of changing white into black on cement pavements, cement bridge decks and tunnel road surfaces, can effectively reduce the pavement thickness of the traditional pavements, saves materials, and is an energy-saving and environment-friendly asphalt mixture scheme.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the technical scope of the present invention, so that any minor modifications, equivalent changes and modifications made to the above embodiment according to the technical spirit of the present invention are within the technical scope of the present invention.