阅读说明：本技术 一种厂拌热再生沥青混凝土及其制备方法 (Plant-mixed hot recycled asphalt concrete and preparation method thereof ) 是由 翟笃铸 于 2021-01-20 设计创作，主要内容包括：本申请涉及沥青混凝土技术领域,具体公开了一种厂拌热再生沥青混凝土及其制备方法。其技术要点是：厂拌热再生沥青混凝土包括如下重量份数的组分：新骨料100-150份；旧骨料20-30份；沥青8-12份；矿粉1.5-4份；再生剂1-2份；消石灰0.5-1.1份；增强纤维5-10份；填料0.8-1.2份。通过采用上述各原料组分制备得到的沥青混凝土具有较高的抗压强度和使用寿命。(The application relates to the technical field of asphalt concrete, and particularly discloses hot mix plant recycled asphalt concrete and a preparation method thereof. The technical key points are as follows: the plant-mixed hot recycled asphalt concrete comprises the following components in parts by weight: 100 portions and 150 portions of new aggregate; 20-30 parts of old aggregate; 8-12 parts of asphalt; 1.5-4 parts of mineral powder; 1-2 parts of a regenerant; 0.5-1.1 parts of slaked lime; 5-10 parts of reinforcing fiber; 0.8-1.2 parts of filler. The asphalt concrete prepared by adopting the raw material components has higher compressive strength and longer service life.)

1. The plant-mixed hot recycled asphalt concrete is characterized by comprising the following components in parts by weight:

100 portions and 150 portions of new aggregate;

20-30 parts of old aggregate;

8-12 parts of asphalt;

1.5-4 parts of mineral powder;

1-2 parts of a regenerant;

0.5-1.1 parts of slaked lime;

5-10 parts of reinforcing fiber;

0.8-1.2 parts of filler.

2. The hot mix plant recycled asphalt concrete according to claim 1, wherein the virgin aggregate comprises one or more of basalt and limestone, and the virgin aggregate has a particle size of 0-16 mm.

3. The plant-mixed hot recycled asphalt concrete according to claim 2, wherein the new aggregate comprises, in weight percent:

20-40% of new aggregate with the particle size of 0-4 mm;

40-60% of new aggregate with the particle size of 4-10 mm;

20-40% of new aggregate with the grain diameter of 10-16 mm.

4. The hot mix plant recycled asphalt concrete according to claim 1, wherein the asphalt is one of SBS modified asphalt, SBR modified asphalt and rubber modified asphalt.

5. The hot mix plant recycled asphalt concrete according to claim 1, wherein the filler is one or more of silica fume, glass micro-beads and nano-silica.

6. The hot mix plant recycled asphalt concrete according to claim 1, wherein the reinforcing fibers are one or more of lignin fibers, polyester fibers, and metal fibers.

7. The hot mix plant recycled asphalt concrete according to claim 6, wherein the reinforcing fibers are metal fibers, and the metal fibers are obtained by surface treatment, and the specific surface treatment steps are as follows:

s1, mixing nitric acid, hydrogen fluoride and water according to the volume ratio of 4:1:5 to obtain a first surface treatment solution;

s2, adding 2 parts by weight of imidazoline amide into 100 parts by weight of 30% sulfuric acid solution, stirring and mixing uniformly, adding 10 parts by weight of methyl glucose polyoxyethylene ether and 5 parts by weight of potassium dodecyl sulfonate, and continuously stirring and mixing uniformly to obtain a surface treatment solution II;

s3, immersing the metal fiber into the first surface treatment liquid, standing for 2-3min, washing for 2-3 times by using deionized water, immersing into the second surface treatment liquid, standing for 2-4min, washing for 2-3 times by using deionized water, and drying to obtain the surface-treated metal fiber.

8. The hot mix plant recycled asphalt concrete according to claim 7, wherein the metal fibers are one or more of carbon steel fibers, cast iron fibers, and aluminum fibers.

9. The method for preparing hot mix plant recycled asphalt concrete according to any one of claims 1 to 8, comprising the steps of:

step one, putting the new aggregate, the reinforcing fiber and the filler in corresponding parts by weight into a drying barrel for stirring and drying, controlling the temperature at 80-120 ℃, the time at 60-120min and the stirring speed at 1000-1500rpm to obtain a dry mixture;

step two, putting the dried mixture into a mixing cylinder, heating 50 weight percent of asphalt to 180 ℃, uniformly adding the asphalt into the mixing cylinder within 20-30s, and stirring at the stirring speed of 1200-1500 rpm;

step three, preheating the old aggregate, adding the preheated old aggregate and the regenerant into the mixing cylinder together, stirring at the stirring speed of 800-800 rpm for 25-30min, adding the rest part by weight of asphalt, stirring and mixing at the stirring speed of 600-800rpm for 10-15 min;

and step four, continuously adding the mineral powder and the slaked lime into the mixing cylinder, and uniformly mixing to obtain the plant-mixed hot recycled asphalt concrete, wherein the discharge temperature is 160-170 ℃.

Technical Field

The application relates to the technical field of asphalt concrete, in particular to hot mix plant recycled asphalt concrete and a preparation method thereof.

Background

The asphalt concrete is commonly called asphalt concrete, and is a mixture prepared by manually selecting mineral aggregate with a certain gradation composition, broken stone or crushed gravel, stone chips or sand, mineral powder and the like, and mixing the mineral aggregate, the broken stone or crushed gravel, the stone chips or sand, the mineral powder and a certain proportion of road asphalt material under strictly controlled conditions.

The Chinese application patent with the publication number of CN110436828A discloses a hydraulic asphalt concrete containing acid stone and a preparation method thereof, wherein the hydraulic asphalt concrete comprises asphalt, crushed natural sand gravel aggregate, filler, sepiolite wool and rubber, wherein the asphalt, the crushed natural sand gravel aggregate and the filler are mixed according to the following mass percentage: 6-6.8% of asphalt, 70.2-94% of crushed natural gravel aggregate, 10-13% of filler, and sepiolite wool and rubber in a mass ratio of 1:2-4, wherein the sepiolite wool accounts for 0.8-1% of the mass of the asphalt.

In the above-mentioned application patent, through adopting adding into asphalt concrete as the aggregate after adopting the broken natural sand gravel to reduce engineering cost but the acid-base difference of broken natural sand gravel aggregate is great, lead to the associativity between its each component raw materials relatively poor, when asphalt concrete bears great pressure in the use, the crackle appears easily, and then leads to its life greatly reduced.

Disclosure of Invention

In order to improve the compressive strength and the service life of the asphalt concrete, the application provides the hot mix plant recycled asphalt concrete and the preparation method thereof.

In a first aspect, the application provides a hot mix plant recycled asphalt concrete, which adopts the following technical scheme:

the plant-mixed hot recycled asphalt concrete comprises the following components in parts by weight:

100 portions and 150 portions of new aggregate;

20-30 parts of old aggregate;

8-12 parts of asphalt;

1.5-4 parts of mineral powder;

1-2 parts of a regenerant;

0.5-1.1 parts of slaked lime;

5-10 parts of reinforcing fiber;

0.8-1.2 parts of filler.

By adopting the technical scheme, the old aggregate is the old recycled asphalt material, and is obtained by digging, recycling, crushing and screening the old asphalt pavement, and the old asphalt pavement is dismantled and recycled, so that a large amount of asphalt and gravel raw materials can be saved, the waste material treatment and the environmental protection are facilitated, and the economic benefit and the environmental benefit are remarkable. The regenerant can make the asphalt have good penetration and ductility, and the slaked lime can improve the compatible adhesion between the asphalt and the new aggregate.

The reinforcing fiber has good bending resistance and toughness, and also has good high temperature resistance and chemical corrosion resistance, and has good applicability in the processing process of the hot recycled asphalt concrete, so that the hot recycled asphalt concrete has good structural strength and stability. By adding the filler, the filler and the reinforcing fiber are mixed for use, so that the porosity of the asphalt concrete can be greatly reduced, and the integral compactness of the asphalt concrete is improved. In addition, after the reinforcing fibers and the filler are combined, a good and stable space network can be formed in the concrete, so that the structural strength of the plant-mixed hot recycled asphalt concrete is improved, cracks can not occur even if the plant-mixed hot recycled asphalt concrete bears large pressure, the compressive strength is high, and the service life is long.

More preferably, the novel aggregate comprises one or more of basalt and limestone, and the particle size of the novel aggregate is 0-16 mm.

By adopting the technical scheme, the basalt is a basic ejecting rock, the main component is silicon dioxide, and the volume density of the basalt is 2.8-3.3g/cm³The compact asphalt concrete has high compression strength up to 300MPa and high durability, and can be used as a new aggregate to further enhance the structural strength of asphalt concrete. The limestone has good processability, polishing property and cementing property, and is easy to form a colloid network with alternate density with old aggregates and asphalt in the asphalt concrete, so that the asphalt concrete has good structural strength.

Further preferably, the new aggregate comprises the following components in percentage by weight:

20-40% of new aggregate with the particle size of 0-4 mm;

40-60% of new aggregate with the particle size of 4-10 mm;

20-40% of new aggregate with the grain diameter of 10-16 mm.

By adopting the technical scheme, the particle size distribution of the new aggregate is controlled to be 20-40% of the new aggregate with the particle size of 0-4mm, 40-60% of the new aggregate with the particle size of 4-10mm and 20-40% of the new aggregate with the particle size of 10-16mm, so that the interior of the asphalt concrete has a good space structure, cracks are not easy to generate in the use process of the asphalt concrete, and the compressive strength is high.

More preferably, the asphalt is one of SBS modified asphalt, SBR modified asphalt and rubber modified asphalt.

By adopting the technical scheme, the modified asphalt is obtained by modifying asphalt by SBS, SBR or used tire rubber, the SBS, SBR or used tire rubber is uniformly dispersed in the asphalt by methods of shearing, stirring and the like, and meanwhile, a certain proportion of special stabilizer is added to form a blending material, so that the temperature performance, the tensile property, the elasticity, the cohesion and adhesion performance of the asphalt, the stability and the aging resistance of a mixture and the like can be effectively improved.

More preferably, the filler is one or more of silicon powder, glass beads and nano silicon dioxide.

By adopting the technical scheme, the silicon powder, the glass beads and the nano silicon dioxide have good dispersibility in the asphalt concrete and higher strength, and the whole structural strength of the recycled asphalt concrete is favorably improved. In addition, the filler and the reinforcing fiber have good compatibility and adhesion, and can be filled in gaps among raw materials of each component, so that the compactness of the asphalt concrete is greatly improved, and the stability of the asphalt concrete in the using process is further improved.

More preferably, the reinforcing fiber is one or more of a lignin fiber, a polyester fiber and a metal fiber.

By adopting the technical scheme, the lignin fiber is of a hollow pipe structure, can contain more free asphalt and mainly plays a role in adsorption in the plant-mixed hot recycled asphalt concrete; the polyester fiber has higher specific surface area and can adsorb more asphalt, so that the bonding performance of the fiber and the asphalt is improved, the asphalt concrete has good toughness, and the asphalt concrete is not easy to break in the using process; the metal fiber has good mechanical property, not only has higher fracture specific strength and tensile specific modulus, but also can resist bending and has good toughness, and simultaneously, the metal fiber also has good high temperature resistance and chemical corrosion resistance, so that the metal fiber has good applicability in the processing process of the plant-mixed hot recycled asphalt concrete, and further the plant-mixed hot recycled asphalt concrete has higher structural strength and good stability.

More preferably, the reinforcing fibers are metal fibers, and the metal fibers are obtained by surface treatment, and the specific surface treatment steps are as follows:

s1, mixing nitric acid, hydrogen fluoride and water according to the volume ratio of 4:1:5 to obtain a first surface treatment solution;

s2, adding 2 parts by weight of imidazoline amide into 100 parts by weight of 30% sulfuric acid solution, stirring and mixing uniformly, adding 10 parts by weight of methyl glucose polyoxyethylene ether and 5 parts by weight of potassium dodecyl sulfonate, and continuously stirring and mixing uniformly to obtain a surface treatment solution II;

s3, immersing the metal fiber into the first surface treatment liquid, standing for 2-3min, washing for 2-3 times by using deionized water, immersing into the second surface treatment liquid, standing for 2-4min, washing for 2-3 times by using deionized water, and drying to obtain the surface-treated metal fiber.

Through adopting above-mentioned technical scheme, handle the metal fiber surface for the metal fiber surface becomes roughly, thereby does benefit to and combines between each raw materials component, improves compatible adhesion nature, makes the network structure that metal fiber formed in asphalt concrete more stable, and then improves asphalt concrete's overall structure intensity, prolongs asphalt concrete's life.

Firstly, the surface of the metal fiber is subjected to primary treatment by using the surface treatment liquid, so that dirt and grease on the surface of the metal fiber are removed, the treatment effect of the subsequent surface treatment liquid on the surface of the metal fiber is improved, and the surface roughness is uniform. Corroding the surface of the metal fiber by using acid liquor to form a rough surface structure by using the surface treatment liquid II; imidazoline amide has certain corrosion inhibition effect so as to prevent the acid liquor from completely corroding the surface of the metal fiber to damage the overall toughness and strength of the fiber; the surface tension of the reaction system can be controlled by using the methyl glucose polyoxyethylene ether and the potassium dodecyl sulfonate together, so that the reaction system has good surface performance and stability, in addition, the methyl glucose polyoxyethylene ether and the potassium dodecyl sulfonate are good control agents, the corrosion speed of the acid liquor on the surface of the metal fiber can be controlled by adding the acid liquor, so that the surface of the metal fiber is corroded into a uniform rough structure, and the metal fiber is ensured to have higher toughness and structural strength.

More preferably, the metal fiber is one or more of carbon steel fiber, cast iron fiber and aluminum fiber.

In a second aspect, the application provides a preparation method of hot mix plant recycled asphalt concrete, which adopts the following technical scheme:

a preparation method of plant-mixed hot recycled asphalt concrete comprises the following steps:

step one, putting the new aggregate, the reinforcing fiber and the filler in corresponding parts by weight into a drying barrel for stirring and drying, controlling the temperature at 80-120 ℃, the time at 60-120min and the stirring speed at 1000-1500rpm to obtain a dry mixture;

step two, putting the dried mixture into a mixing cylinder, heating 50 weight percent of asphalt to 180 ℃, uniformly adding the asphalt into the mixing cylinder within 20-30s, and stirring at the stirring speed of 1200-1500 rpm;

step three, preheating the old aggregate, adding the preheated old aggregate and the regenerant into the mixing cylinder together, stirring at the stirring speed of 800-800 rpm for 25-30min, adding the rest part by weight of asphalt, stirring and mixing at the stirring speed of 600-800rpm for 10-15 min;

step four, continuously adding the mineral powder and the slaked lime into the mixing cylinder, and uniformly mixing to obtain the plant-mixed hot recycled asphalt concrete, wherein the discharge temperature is 160-170 DEG C

By adopting the technical scheme, the new aggregate is dried, the mutual adhesion of the new aggregate and the hot plant mix recycled asphalt concrete due to moisture is avoided, the hot plant mix recycled asphalt concrete has good quality, part of asphalt and the new aggregate are firstly mixed, and then the old regenerated asphalt mixture and the residual asphalt are added, so that the new aggregate can be more wrapped on the added asphalt, and the asphalt in the hot plant mix recycled asphalt concrete can be more uniformly distributed. Then the asphalt is heated and then is mixed with new aggregate and old aggregate, and the discharge temperature is maintained at 160-170 ℃, so that the plant-mixed hot recycled asphalt concrete prepared by the process has good quality and higher production efficiency.

In summary, the present application has the following beneficial effects:

(1) by adding the reinforcing fiber and the filler, the porosity of the asphalt concrete can be greatly reduced and the overall compactness of the asphalt concrete can be improved. In addition, after the two are combined, a good and stable space network can be formed in the concrete, so that the structural strength of the plant-mixed hot recycled asphalt concrete is improved, and cracks can not appear even if the concrete bears higher pressure;

(2) by selecting the particle size distribution of the new aggregate to 20-40% of the new aggregate with the particle size of 0-4mm, 40-60% of the new aggregate with the particle size of 4-10mm and 20-40% of the new aggregate with the particle size of 10-16mm, the interior of the asphalt concrete can have a good space structure, so that the asphalt concrete is not easy to crack in the using process and has high compressive strength;

(3) through carrying out surface treatment to the metal fiber who adds for the fibre surface presents coarse structure, improves the bonding adhesion between fibre and each raw materials component, makes the network structure that metal fiber formed in asphalt concrete more stable, and then improves asphalt concrete's overall structure intensity, prolongs asphalt concrete's life.

Detailed Description

The present application will be described in further detail with reference to examples.

The mineral powder grading range in the application is as follows:

mesh (mm)0.30.150.075

Transmittance (%) 10099.896.6.

The metal fiber is carbon steel fiber with the diameter of 0.5 mm; SBS modified asphalt, SBR modified asphalt and rubber asphalt are all purchased from Aobang Darman Co Ltd of Zibo city; silicon powder is purchased from sanyuan silicon materials ltd; the glass beads are purchased from 3M hollow glass beads of Shanghai electric International trade Co., Ltd; the nanometer silicon dioxide is purchased from a micro-nano chemical plant of Changtai of shouguang city in Shandong province, and the particle diameter is 15-25 nm; the lignin fiber is purchased from super-green cellulose factory of SunLiangcun in great City; polyester fiber was purchased from Shandong Sen Hongyang engineering materials, Inc.;

preparation example

Preparation example 1

A metal fiber, obtained by processing the following steps:

s1, mixing 400mL of nitric acid, 100mL of hydrogen fluoride and 500mL of water to obtain a first surface treatment solution;

s2, adding 2g of imidazoline amide into 100g of 30% sulfuric acid solution, stirring and mixing uniformly, adding 10g of methyl glucose polyoxyethylene ether and 5g of potassium dodecyl sulfonate, and continuously stirring and mixing uniformly to obtain a second surface treatment solution;

and S3, soaking the carbon steel fiber into the first surface treatment liquid, standing for 2min, washing for 3 times by using deionized water, then soaking the carbon steel fiber into the second surface treatment liquid, standing for 2min, washing for 3 times by using deionized water, and drying to obtain the surface-treated metal fiber.

Preparation example 2

A metal fiber, obtained by processing the following steps:

s1, mixing 200mL of nitric acid, 50mL of hydrogen fluoride and 250mL of water to obtain a first surface treatment solution;

s2, adding 4g of imidazoline amide into 200g of 30% sulfuric acid solution, stirring and mixing uniformly, adding 20g of methyl glucose polyoxyethylene ether and 10g of potassium dodecyl sulfonate, and continuously stirring and mixing uniformly to obtain a second surface treatment solution;

and S3, soaking the carbon steel fiber into the first surface treatment liquid, standing for 3min, washing for 3 times by using deionized water, then soaking the carbon steel fiber into the second surface treatment liquid, standing for 4min, washing for 3 times by using deionized water, and drying to obtain the surface-treated metal fiber.

Preparation example 3

A metal fiber, which is different from the preparation example 1 in that it is obtained by the following steps:

s1, mixing 400mL of nitric acid, 100mL of hydrogen fluoride and 500mL of water to obtain a first surface treatment solution;

s2, adding 2g of imidazoline amide into 100g of 30% sulfuric acid solution, and stirring and mixing uniformly to obtain a surface treatment solution II;

and S3, soaking the carbon steel fiber into the first surface treatment liquid, standing for 2min, washing for 3 times by using deionized water, then soaking the carbon steel fiber into the second surface treatment liquid, standing for 2min, washing for 3 times by using deionized water, and drying to obtain the surface-treated metal fiber.

Examples

Example 1

A hot mix plant recycled asphalt concrete, the components and their corresponding weight (kg) are shown in Table 1, and is prepared by the following steps:

step one, according to the use amounts of the raw material components in the table 1, putting new aggregate, reinforcing fiber and filler into a drying barrel to be stirred and dried, controlling the temperature at 80 ℃, the time at 120min and the stirring speed at 1500rpm, and obtaining a dry mixture;

step two, putting the dried mixture into a mixing cylinder, heating 50% of asphalt by weight to 160 ℃, uniformly adding the asphalt into the mixing cylinder within 30s, and stirring at the speed of 1500 rpm;

step three, preheating old aggregate, adding the preheated old aggregate and a regenerant into the mixing cylinder, stirring at the stirring speed of 800rpm for 30min, adding the rest part by weight of asphalt, and stirring and mixing at the stirring speed of 600rpm for 15 min;

and step four, continuously adding the mineral powder and the slaked lime into the mixing cylinder, and uniformly mixing to obtain the plant-mixed hot recycled asphalt concrete, wherein the discharging temperature is 160 ℃.

The new aggregate in the embodiment adopts basalt, and comprises the following components in percentage by weight: 20% of new aggregate with the grain diameter of 0-4mm, 60% of new aggregate with the grain diameter of 4-10mm and 20% of new aggregate with the grain diameter of 10-16 mm.

Mixing old aggregate with asphalt; the asphalt adopts SBS modified asphalt, the filler adopts silica powder, and the reinforcing fiber adopts metal fiber; the regenerant is purchased from Hualutong New Material Co., Ltd, cigarette Tai city, and has a model number of 90.

Examples 2 to 6

A hot mix plant recycled asphalt concrete, which is different from example 1 in that each component and the corresponding weight (kg) thereof are shown in table 1.

TABLE 1 Components and weights (kg) thereof in examples 1-6

Example 7

A plant-mixed hot recycled asphalt concrete, which is different from the concrete prepared in example 1 in that the concrete is prepared by the following steps:

step one, putting the new aggregate, the reinforcing fiber and the filler in corresponding parts by weight into a drying barrel, stirring and drying at the temperature of 120 ℃ for 60min at the stirring speed of 1000rpm to obtain a dry mixture;

step two, putting the dried mixture into a mixing cylinder, heating 50% of asphalt by weight to 180 ℃, uniformly adding the asphalt into the mixing cylinder within 20s, and stirring at the stirring speed of 1200 rpm;

step three, preheating old aggregate, adding the preheated old aggregate and a regenerant into the mixing cylinder, stirring at the stirring speed of 1200rpm for 25min, adding the rest of asphalt by weight, and stirring and mixing at the stirring speed of 800rpm for 10 min;

and step four, continuously adding the mineral powder and the slaked lime into the mixing cylinder, and uniformly mixing to obtain the plant-mixed hot recycled asphalt concrete, wherein the discharging temperature is 170 ℃.

The new aggregate in the embodiment adopts a mixture of basalt and limestone with a weight ratio of 1:2, and comprises the following components in percentage by weight: 40% of new aggregate with the grain diameter of 0-4mm, 40% of new aggregate with the grain diameter of 4-10mm and 20% of new aggregate with the grain diameter of 10-16 mm.

The asphalt adopts SBR modified asphalt, the filler adopts a mixture of silicon powder and glass beads in a weight ratio of 1:1, and the reinforcing fiber adopts a mixture of lignin fiber and polyester fiber in a weight ratio of 1: 1.

Example 8

A plant-mixed hot recycled asphalt concrete, which is different from the concrete prepared in example 1 in that the concrete is prepared by the following steps:

step one, according to the use amounts of the raw material components in the table 1, putting new aggregate, reinforcing fiber and filler into a drying barrel to be stirred and dried, controlling the temperature at 100 ℃, the time at 90min and the stirring speed at 1250rpm, and obtaining a dry mixture;

step two, putting the dried mixture into a mixing cylinder, heating 50% of asphalt by weight to 170 ℃, uniformly adding the asphalt into the mixing cylinder within 25s, and stirring at the stirring speed of 1350 rpm;

step three, preheating old aggregate, adding the preheated old aggregate and a regenerant into the mixing cylinder, stirring at the stirring speed of 1000rpm for 28min, adding the rest of asphalt by weight, and stirring and mixing at the stirring speed of 700rpm for 13 min;

and step four, continuously adding the mineral powder and the slaked lime into the mixing cylinder, and uniformly mixing to obtain the plant-mixed hot recycled asphalt concrete, wherein the discharging temperature is 170 ℃.

The new aggregate in the embodiment adopts a mixture of basalt and limestone with a weight ratio of 1:2, and comprises the following components in percentage by weight: 20% of new aggregate with the grain diameter of 0-4mm, 40% of new aggregate with the grain diameter of 4-10mm and 40% of new aggregate with the grain diameter of 10-16 mm.

The asphalt is rubber modified asphalt, the filler is a mixture of silicon powder, glass beads and nano silicon dioxide in a weight ratio of 1:1:0.5, and the reinforcing fiber is a mixture of lignin fiber, polyester fiber and metal fiber in a weight ratio of 1:1: 1.

Example 9

A hot mix plant recycled asphalt concrete, which is different from example 1 in that the surface-treated metal fiber of preparation example 1 is used as the metal fiber.

Example 10

A hot mix plant recycled asphalt concrete, which is different from example 1 in that the surface-treated metal fiber of preparation example 2 was used as the metal fiber.

Comparative example

Comparative example 1

A hot mix plant recycled asphalt concrete, which differs from example 1 in that no reinforcing fiber is added.

Comparative example 2

A hot mix plant recycled asphalt concrete, which differs from example 1 in that no filler is added.

Comparative example 3

The plant-mixed hot recycled asphalt concrete is different from the embodiment 1 in that basalt is adopted as a new aggregate, and comprises the following components in percentage by weight:

10% of new aggregate with the particle size of 0-4 mm;

80% of new aggregate with the grain diameter of 4-10 mm;

10% of new aggregate with the grain diameter of 10-16 mm.

Comparative example 4

A hot mix plant recycled asphalt concrete, which is different from example 8 in that the surface-treated metal fiber of preparation example 3 was used as the metal fiber.

Performance test

The hot mix recycled asphalt concretes prepared in examples 1 to 10 and comparative examples 1 to 3 were respectively subjected to Marshall stability and compressive strength tests according to the test procedure for road engineering asphalt and asphalt mixture (JTJ052-2000), and the test results are shown in the following Table 2.

As can be seen from the test data in Table 2, the selection of the grading ranges of the reinforcing fibers, the filler and the virgin aggregate improves the Marshall stability and compressive strength of the hot mix recycled asphalt concrete in comparison examples 1-8 and comparative examples 1-3.

From example 1 and examples 8-9, it can be seen that the metal fiber after surface treatment can greatly improve the marshall stability and compressive strength of the asphalt concrete, thereby prolonging the service life of the asphalt concrete, because the surface of the metal fiber after surface treatment forms a rough structure, which is beneficial to the combination with other raw material components in the concrete, thereby improving the overall structural stability and structural strength of the concrete.

It is understood from example 1 and comparative example 4 that the surface-treated metal fibers did not improve the overall marshall stability and compressive strength of the asphalt concrete, but rather reduced the stability and compressive strength of the asphalt concrete. It is proved that the surface of the metal fiber is seriously corroded by the acid liquor in the acid liquor treatment process, the corrosion is uneven, the performance such as the toughness of the metal fiber is reduced, and the integral structural strength of the concrete can not be greatly improved when the metal fiber is added into the asphalt concrete.

Table 2 results of performance testing

The above description is only a preferred embodiment of the present application, and the protection scope of the present application is not limited to the above embodiments, and all technical solutions belonging to the idea of the present application belong to the protection scope of the present application. It should be noted that several improvements and modifications to the present application without departing from the principles of the present application will occur to those skilled in the art, and such improvements and modifications should also be considered within the scope of the present application.