Preparation method of pavement asphalt mixture

Abstract

The invention provides a preparation method of a pavement asphalt mixture. The preparation method comprises the following steps: material selection: selecting coarse aggregate, fine aggregate, filler and asphalt which meet the requirements of Technical Specification for Construction of Highway Asphalt Pavement (JTG F40-2004); the coarse aggregate, the fine aggregate, the filler and the asphalt are weighed and mixed according to the construction proportion; the steel slag asphalt mixture is uniformly mixed, the mixing time of the asphalt mixture is not less than 45 seconds, the dry mixing time is not less than 5-10 seconds, and the wet mixing time is not less than 40 seconds; and transporting the asphalt mixture. The construction operation is simple, production equipment, paving equipment and rolling equipment which are the same as those of hot-mixed asphalt concrete can be utilized, the mechanical degree is high, one-time paving forming is achieved, and the quality is controllable; the steel slag replaces basalt to serve as coarse aggregate of the asphalt pavement, so that the problem of shortage of basalt aggregate is solved, and the skid resistance and durability of the asphalt pavement are improved.

Description

Technical Field

[0001] The invention relates to the technical field of building construction methods, and in particular to a method for preparing a road asphalt mixture. Background Art

[0002] Steel slag is a common industrial waste. Because it contains a large amount of iron, calcium, magnesium and other elements, it is widely used in the field of building materials. In recent years, the application of steel slag in asphalt pavement surface has gradually attracted people's attention; asphalt pavement is a common road construction material, and its main components are asphalt and mineral aggregates. In the construction process of asphalt pavement, it is often necessary to add some auxiliary materials to improve the performance and service life of the pavement. And steel slag is an auxiliary material that can be used to improve the performance of asphalt pavement.

[0003] The mechanical properties, wear resistance, particle grading, adhesion and other characteristics of steel slag coarse aggregate are a series of technical difficulties in the construction of this asphalt pavement. The multi-objective evaluation mix design of steel slag asphalt concrete and the research on the correlation between paving temperature and compaction degree in the construction process require us to improve and innovate the conventional steel slag asphalt concrete construction technology to achieve the purpose of quality control, energy conservation and environmental protection. Summary of the invention

[0004] The technical problem solved by the present invention is to provide a method for preparing a road asphalt mixture to solve the problems raised in the above background technology.

[0005] The technical problem solved by the present invention is achieved by adopting the following technical solution: A method for preparing a road asphalt mixture, comprising:

[0006] Material selection: select coarse aggregate, fine aggregate, filler and asphalt that meet the requirements of "Technical Specifications for Highway Asphalt Pavement Construction" (JTG F40-2004); the coarse aggregate uses 5-10mm and 10-15mm steel slag as coarse aggregate;

[0007] Batching: Weigh and mix the coarse aggregate, fine aggregate, filler and asphalt according to the construction ratio;

[0008] Mixing of asphalt mixture: Steel slag asphalt mixture should be mixed evenly. The mixing time of asphalt mixture should not be less than 45s, of which the dry mixing time should not be less than 5-10s and the wet mixing time should not be less than 40s;

[0009] Transportation of asphalt mixture: Use large clean dump trucks with metal bottoms. The number and transportation capacity of the dump trucks should be able to meet the paving speed and have some surplus. Ensure that there are unloading trucks waiting to unload in front of the paver during construction to ensure continuous paving. Paving can only begin when there are more than 5 waiting trucks.

[0010] Furthermore, the fine aggregate is hard, clean, dry, non-weathered, impurity-free and properly graded machine-made sand; and the filler is mineral powder obtained by grinding limestone.

[0011] Furthermore, a fiber stabilizer is added to the selected materials, the fiber stabilizer is lignin fiber, and the addition amount of lignin fiber is 0.3% of the mass of the asphalt mixture; when adding the lignin fiber, it is patted loose in advance to prevent it from agglomerating and mixing into the asphalt mixture.

[0012] Furthermore, the steel slag asphalt mixture mixed and shipped out of the factory should be uniform and bright black in color, without any white material, clumping or separation of coarse and fine aggregates; otherwise it shall not be used, and the reasons shall be checked and analyzed, and corresponding adjustments shall be made.

[0013] Furthermore, during the transportation of the asphalt mixture, a digital display insertion thermocouple thermometer is used to detect the factory temperature and the temperature of the asphalt mixture when it is transported to the site; the insertion depth must be greater than 15 cm, and a special detection hole is set in the middle of the side of the material transport truck, with the hole opening 30 cm away from the bottom of the vehicle box.

[0014] Furthermore, during the winter construction of the asphalt mixture transportation, the use of thermal insulation tarpaulin should be reasonably increased in consideration of the ambient temperature and the transportation distance.

[0015] Furthermore, when transporting the asphalt mixture, the mixture cannot be loaded into a cone shape at one time. During the loading process of the dump truck, in order to avoid separation of loading and transportation, the truck position must be moved. The vehicle receives the material three times under the silo, namely "front, back and middle", forming three small piles at the front, back and middle to reduce the rolling distance of the aggregate.

[0016] Furthermore, when transporting and unloading the asphalt mixture, the material transport vehicle should stop 10-30 cm in front of the paver and should not hit the paver to affect the flatness; the vehicle should be in neutral gear during the unloading process and be pushed forward by the paver; when the material transport vehicle is unloading with the bucket, the top should not be raised too high at one time. After the paver hopper is full, the material should be unloaded slowly and evenly into the hopper of the paver to avoid overflow of the mixture during unloading, so as to prevent segregation of the asphalt mixture due to excessive bucket lifting speed.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention is simple to construct and operate, and can utilize the same production equipment, paving and rolling equipment as hot mix asphalt concrete, with a high degree of mechanization, one-time paving and forming, and controllable quality; steel slag replaces basalt as coarse aggregate for asphalt pavement, solving the problem of basalt aggregate shortage and improving the anti-skid and durability performance of asphalt pavement. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of the present invention. DETAILED DESCRIPTION

[0019] In order to make the technical means for realizing the present invention, the creative features, the objectives and effects to be achieved easy to understand, the present invention is further explained below in conjunction with specific diagrams. In the description of the present invention, it should be noted that, unless otherwise clearly stipulated and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense. For example, it can be a fixed connection or a detachable connection, or an integral connection can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be internal communication between two elements.

[0020] like Figure 1 As shown, a method for preparing a road asphalt mixture comprises:

[0021] Material selection: select coarse aggregate, fine aggregate, filler and asphalt that meet the requirements of "Technical Specifications for Highway Asphalt Pavement Construction" (JTG F40-2004); the coarse aggregate adopts 5-10mm and 10-15mm steel slag as coarse aggregate; the fine aggregate adopts hard, clean, dry, non-weathered, impurity-free and properly graded machine-made sand; the filler is mineral powder obtained by grinding limestone; fiber stabilizer is added in the material selection, the fiber stabilizer is lignin fiber, and the addition amount of lignin fiber is 0.3% of the mass of asphalt mixture; when adding lignin fiber, it is patted loose in advance to prevent it from clumping and mixing into the asphalt mixture.

[0022] Batching: Weigh and mix the coarse aggregate, fine aggregate, filler and asphalt according to the construction ratio;

[0023] Mixing of asphalt mixture: Steel slag asphalt mixture should be mixed evenly. The mixing time of asphalt mixture should not be less than 45s, of which the dry mixing time should not be less than 5-10s, and the wet mixing time should not be less than 40s. The steel slag asphalt mixture mixed and shipped out of the factory should be uniform and bright black in color, without any white material, clumping or separation of coarse and fine aggregates. Otherwise, it shall not be used, and the reasons shall be checked and analyzed, and corresponding adjustments shall be made.

[0024] Transportation of asphalt mixture: Use large clean dump trucks with metal bottoms. The number and transportation capacity of the dump trucks should be able to meet the paving speed and have some surplus. Ensure that there are unloading trucks waiting to unload in front of the paver during construction to ensure continuous paving. Paving can only begin when there are more than 5 waiting trucks.

[0025] When transporting asphalt mixture, a digital display insertion type thermocouple thermometer is used to detect the factory temperature of the asphalt mixture and the temperature when it is transported to the site; the insertion depth must be greater than 15cm, and a special detection hole is set in the middle of the side of the material transport truck, with the hole opening 30cm away from the bottom of the vehicle box; when transporting asphalt mixture, winter construction should be combined with the ambient temperature and transportation distance, and the insulation tarpaulin should be reasonably added.

[0026] When transporting asphalt mixture, the mixture cannot be loaded into a cone shape at one time. During the loading process of the dump truck, in order to avoid separation between loading and transportation, the truck position must be moved. The vehicle receives the material three times under the silo, forming three small piles at the front, back and middle, to reduce the rolling distance of the aggregate.

[0027] When transporting and unloading asphalt mixture, the material transport vehicle should stop 10-30cm in front of the paver and must not hit the paver to affect the flatness; the vehicle should be in neutral gear during the unloading process and be pushed forward by the paver; when the material transport vehicle is unloading with the bucket, the top should not be raised too high at one time. After the paver hopper is full of material, the material should be unloaded slowly and evenly into the hopper of the paver to avoid overflow of the mixture during unloading, so as to prevent segregation of the asphalt mixture due to excessive bucket lifting speed.

[0028] For construction noise from construction machinery and transport vehicles, in order to protect the health of construction workers, it is reasonable to arrange for workers to take turns to operate road construction machinery to reduce the time of exposure to high noise, or to arrange high-noise work in an interspersed manner. For construction workers who are close to the noise source, in addition to taking effective measures such as protective earplugs or helmets, their working hours should also be shortened. At the same time, attention should be paid to regular maintenance of machinery to minimize its noise as much as possible.

[0029] When the distance between the construction site and the residential area is less than 150m, mechanical construction with loud noise (above 55db) shall not be arranged at night, and the construction time shall be controlled. When transport vehicles pass through sections near towns and villages during the day, they shall slow down to prevent noise and dust pollution. During the construction and transportation of asphalt concrete, a special sprinkler truck shall be prepared to sprinkle water on the dust generated along the construction line and the sections where vehicles pass to keep moisture and avoid dust. When transporting asphalt concrete, the transport vehicles shall be covered with tarpaulins to prevent spillage.

[0030]

[0031] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A method for preparing a road asphalt mixture, characterized in that: include: Material selection: select coarse aggregate, fine aggregate, filler and asphalt that meet the requirements of "Technical Specifications for Highway Asphalt Pavement Construction" (JTG F40-2004); the coarse aggregate uses 5-10mm and 10-15mm steel slag as coarse aggregate; Batching: Weigh and mix the coarse aggregate, fine aggregate, filler and asphalt according to the construction ratio; Mixing of asphalt mixture: Steel slag asphalt mixture should be mixed evenly. The mixing time of asphalt mixture should not be less than 45s, of which the dry mixing time should not be less than 5-10s and the wet mixing time should not be less than 40s; Transportation of asphalt mixture: Use large clean dump trucks with metal bottoms. The number and transportation capacity of the dump trucks should be able to meet the paving speed and have some surplus. Ensure that there are unloading trucks waiting to unload in front of the paver during construction to ensure continuous paving. Paving can only begin when there are more than 5 waiting trucks.

2. A method for preparing a pavement asphalt mixture according to claim 1, characterized in that: The fine aggregate is hard, clean, dry, non-weathered, impurity-free and properly graded machine-made sand; the filler is mineral powder obtained by grinding limestone.

3. The method for preparing a road asphalt mixture according to claim 1, characterized in that: A fiber stabilizer is added to the selected materials, the fiber stabilizer is lignin fiber, and the addition amount of the lignin fiber is 0.3% of the mass of the asphalt mixture; when adding the lignin fiber, it is patted loose in advance to prevent it from agglomerating and mixing into the asphalt mixture.

4. A method for preparing a road asphalt mixture according to claim 1, characterized in that: The steel slag asphalt mixture mixed and shipped out of the factory should be uniform and bright black in color, without any white material, clumping or separation of coarse and fine aggregates; otherwise it shall not be used, and the reasons shall be checked and analyzed, and corresponding adjustments shall be made.

5. The method for preparing a road asphalt mixture according to claim 1, characterized in that: During the transportation of the asphalt mixture, a digital display insertion type thermocouple thermometer is used to detect the factory temperature and the temperature of the asphalt mixture when it is transported to the site; the insertion depth must be greater than 15 cm, and a special detection hole is set in the middle of the side of the material transport truck, with the hole opening 30 cm away from the bottom of the truck box.

6. A method for preparing a road asphalt mixture according to claim 1, characterized in that: When transporting asphalt mixture in winter, the ambient temperature and transportation distance should be taken into consideration, and insulation tarpaulin should be added appropriately.

7. The method for preparing a pavement asphalt mixture according to claim 1, characterized in that: When transporting the asphalt mixture, the mixture cannot be loaded into a cone shape at one time. During the loading process of the dump truck, in order to avoid separation of loading and transportation, the truck position must be moved. The vehicle receives the material three times under the silo, namely "front, back and middle", to form three small piles at the front, back and middle to reduce the rolling distance of the aggregate.

8. The method for preparing a pavement asphalt mixture according to claim 1, characterized in that: When transporting and unloading the asphalt mixture, the material transport vehicle should stop 10-30cm in front of the paver and should not hit the paver to affect the flatness; the vehicle should be in neutral gear during the unloading process and be pushed forward by the paver; when the material transport vehicle is unloading with the bucket, the top should not be raised too high at one time. After the paver hopper is full of material, the material should be unloaded slowly and evenly into the hopper of the paver to avoid overflow of the mixture during unloading, so as to prevent segregation of the asphalt mixture due to excessive bucket lifting speed.

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