A method for producing solid waste-based large-void asphalt mixture

Abstract

The present invention provides a method for producing and preparing a solid waste-based large-void asphalt mixture, using steel slag, old asphalt mixture, mineral powder, and new asphalt as raw materials, forming a mortar with mineral powder and asphalt as a steel slag binder, and designing a large-void asphalt mixture according to the film-forming state of the steel slag surface wrapped by the asphalt mortar, the thickness harmonizing effect of the old asphalt mixture asphalt film, and the volume filling theory, to ensure that the steel slag surface has sufficient mortar wrapped and the old asphalt mixture has sufficient asphalt film, so that the steel slag and the old asphalt mixture have strong bonding strength, and improve the high temperature, low temperature, water stability and other aspects of the mixture. The present invention provides a surface area calculation method based on the distribution state of particles with different particle sizes, and realizes the controllability of the mixture performance and volume parameters; the present invention uses solid waste materials as raw materials, and the solid waste blending ratio is relatively high, providing an effective solution to the accumulation of solid waste and the shortage of road construction materials.

Description

Technical Field

[0001] The invention relates to the technical field of road engineering, and in particular to a method for producing a solid waste-based large-void asphalt mixture. Background Art

[0002] With the rapid development of highway construction, the resource and environmental problems it brings are becoming increasingly serious. The disorderly exploitation of mineral resources has led to a shortage of commonly used building materials such as high-quality limestone and river sand. The shortage of ground materials has become the main contradiction restricting the sustainable development of highway construction. Steel slag is a waste product in the steel production process. The geometric shape and mechanical properties of steel slag are basically the same as those of rolled crushed stone. After a certain amount of processing, steel slag can be processed into aggregates of different particle sizes, which can replace natural stones. In addition, steel slag has many pores on the surface, strong adsorption capacity, large internal friction angle, and stronger embedding effect. It is an excellent raw material for asphalt mixture.

[0003] The characteristics of large-void asphalt mixture are that it has more coarse aggregate (generally accounting for more than 85%) and a large void ratio (15% to 25%). It has high requirements for the performance of coarse aggregate, and steel slag has a strong ability to absorb asphalt and a large friction angle between steel slag, which is conducive to improving the high-temperature, low-temperature and water stability of large-void asphalt mixture. Large-void asphalt pavement is a pavement that can quickly drain rainwater from the road surface. Rainwater is quickly discharged from the road surface through the interconnected voids inside its structure. At the same time, it has outstanding advantages such as high anti-skid performance, low noise, suppression of water mist, prevention of water drift, reduction of glare, and comfortable driving. It is an ecological and environmentally friendly asphalt pavement and is widely used.

[0004] Asphalt mixture with large voids is a typical skeleton void structure. The interaction between asphalt and filler in asphalt mixture with large voids includes the physical adsorption process of asphalt layer on the filler surface, the chemical adsorption process on the contact surface of asphalt and filler, and the selective diffusion process of asphalt components to filler. The asphalt mortar composed of mineral powder and asphalt plays a bonding role and fills the voids between coarse and fine aggregates, which determines the high temperature stability and low temperature deformation capacity of asphalt mixture. However, the current design method does not consider the film formation state of asphalt mortar on the aggregate surface. The calculation of aggregate surface area is completely dependent on the experimental fitting formula, and the influence of different particle size states on aggregate surface area is not considered, resulting in the inability to accurately estimate the amount of mortar, and the performance and volume indicators of large-void asphalt mixture cannot be effectively controlled, and the design results are highly variable. Therefore, it is urgent to propose a method for producing and preparing large-void asphalt mixture, taking solid waste as aggregate, accurately calculating the specific surface area of ​​aggregate and filler, designing large-void mixture based on the film-forming state and volume filling of aggregate wrapped by asphalt mortar, and establishing a relationship model between aggregate, filler and asphalt mortar, so as to design a solid waste-based large-void asphalt mixture with superior performance and controllability. Summary of the invention

[0005] The present invention aims to provide a method for producing a solid waste-based asphalt mixture with large voids, in view of the defects in the production and preparation process of solid waste-based asphalt mixture with large voids, such as failure to consider the film-forming state of asphalt mortar on the aggregate surface, inaccurate calculation of aggregate surface area, and inability to accurately estimate the amount of mortar. The method also provides a surface area calculation method based on the distribution state of particles with different particle sizes, establishes a relationship model between aggregate, filler and asphalt mortar, and accurately determines the ratio of aggregate, filler and asphalt, so as to avoid variability in mixture performance and improve the performance of asphalt mixture with large voids.

[0006] The technical problem to be solved by the present invention is achieved by adopting the following technical solutions:

[0007] A method for producing a solid waste-based large-void asphalt mixture, characterized in that it comprises the following steps:

[0008] (1) Solid waste-based large-void asphalt mixture includes five parts: steel slag with a particle size of 10 mm ≤ and < 15 mm, steel slag with a particle size of 5 mm ≤ and < 10 mm, old asphalt mixture with a particle size of < 4.75 mm, mineral powder, and new asphalt. The steel slag, mineral powder, and old asphalt mixture are sieved to determine their gradation composition. The old asphalt mixture is sieved to determine its old asphalt content. The specific surface area of ​​the mineral material within different sieve hole sizes is calculated according to the following formula, where the minimum sieve hole size is 0.075 / n:

[0009]

[0010]

[0011]

[0012]

[0013]

[0014] SA=∑SA i

[0015] Where: V i —Total volume of sieve residue per unit mass of mineral material, cm 3 / kg;

[0016] PS i —Percentage of ore passing through the i-level sieve, %;

[0017] PS i+1 —Percentage of ore passing through the sieve hole of the previous level i, %;

[0018] D i —Size of sieve hole at level i, mm; Di+1 —The size of the sieve hole of the previous level i, mm;

[0019] K—a natural number between 0 and n;

[0020] —The volume of a single mineral material at the kth diameter after sieving the i-level sieve, cm 3 ;

[0021] —The number of ore residues per unit mass of ore at the kth diameter on the i-th sieve hole;

[0022] ρ s —Density of mineral material, g / cm 3 ;

[0023] —Surface area of ​​a single mineral material under the kth diameter at the i-level sieve hole, cm 2 ;

[0024] S i —Specific surface area of ​​the residual material on the i-level sieve, cm 2 / kg;

[0025] SA—Total specific surface area of ​​mineral material, cm 2 / kg;

[0026] (2) Solid waste-based large-void asphalt mixture is a permeable skeleton structure. Steel slag forms the basic skeleton of asphalt mixture in the state of maximum density. Steel slag with a particle size of 10 mm ≤ < 15 mm and 5 mm ≤ < 10 mm are mixed in a ratio of 0+10a:100-10a, and the compacted density ρ is measured. sc , and calculate its void ratio, draw a relationship diagram between void ratio and 10mm≤particle size<15mm, 5mm≤particle size<10mm steel slag ratio, the 10mm≤particle size<15mm, 5mm≤particle size<10mm steel slag ratio with the minimum void ratio is the state of maximum density of steel slag mixing, the void ratio calculation formula after steel slag mixing is as follows:

[0027]

[0028]

[0029] Where: s1 —Density of steel slag with particle size 10mm≤particle size<15mm, g / cm 3 ;

[0030] ρ s2 —Density of steel slag with particle size 5mm≤particle size<10mm, g / cm 3 ;

[0031] ρ s0 —Synthetic density of steel slag, g / cm 3 ;

[0032] ρ sc —Synthetic compacted density of steel slag, g / cm 3 ;

[0033] VCA—void ratio after mixing slag, %;

[0034] a—Proportion of steel slag with a particle size of 10 mm ≤ and <15 mm in the steel slag mixture, %;

[0035] (3) The old asphalt mixture, mineral powder, and new asphalt are used to fill the voids formed in the state of steel slag being squeezed, and the remaining voids are the void ratio of the solid waste-based large-void asphalt mixture; combined with the volume parameter changes of the raw materials during the volume filling process, the void ratio of 1m 3 The proportion of steel slag, old asphalt mixture, mineral powder and asphalt in solid waste-based large-void asphalt mixture:

[0036] G=1-VCA

[0037] g+f+P a =VCA-VV

[0038] Where: G—1m 3 Volume of steel slag in asphalt mixture, m 3 ;

[0039] g—1m 3 Volume of old asphalt mixture in asphalt mixture, m 3 ;

[0040] f—1m 3 Volume of mineral powder in asphalt mixture, m 3 ;

[0041] P a —1m 3 Asphalt volume in asphalt mixture, m 3 ;

[0042] VV—void ratio of asphalt mixture, %;

[0043] (4) The new asphalt is evenly coated on the surface of the mineral powder with a certain asphalt film thickness to form asphalt mortar, and the asphalt mortar is coated on the surface of the steel slag with a certain thickness. The new asphalt is used to adjust the asphalt film thickness of the old asphalt mixture. According to the coating characteristics of asphalt and asphalt mortar, and the adjusting effect of the new asphalt on the asphalt film thickness of the old asphalt mixture, the proportion of steel slag, old asphalt mixture, mineral powder, and asphalt is determined according to the following formula:

[0044] S G =0.1a×SAG1 +SA G2 ×(1-0.1a)

[0045]

[0046] P a1 =f×μ×SA f ×ρ f

[0047] P a1 +f=G×ρ s0 ×SA G ×μ j

[0048]

[0049] P a =P a2 +P a1

[0050] In the formula: SA G —Synthetic specific surface area of ​​steel slag, m 2 ;SA G1 —Specific surface area of ​​steel slag with particle size of 10mm≤<15mm, m 2 ;

[0051] SA G2 —Specific surface area of ​​steel slag with particle size of 5mm≤<10mm, m 2 ;

[0052] m 旧 —Asphalt content in old asphalt mixture, %;

[0053] μ j —Asphalt mortar film thickness, um; μ—Asphalt film thickness, um;

[0054] P a1 —Volume of asphalt in asphalt mortar, m 3 ρ a旧 ——Density of old asphalt, kg / m 3 ;

[0055] ρ f ——Mineral powder density, kg / m 3 ρ g ——Density of old asphalt mixture, kg / m 3 ;

[0056] SA f —Specific surface area of ​​mineral powder, m 2 ;SA g —Specific surface area of ​​old asphalt mixture, m 2 ;

[0057] P a2 —Volume of asphalt used to adjust the asphalt film thickness of old asphalt mixture, m 3 ;

[0058] (5) According to the density of steel slag, old asphalt mixture, mineral powder and asphalt, 1m 3 The amount of steel slag, old asphalt mixture, mineral powder and asphalt is calculated according to the following formula:

[0059] m G1 =G×0.1a×ρ s1

[0060] m G2 =G×(1-0.1a)×ρ s2

[0061] m f =f×ρ f

[0062] m g =g×ρ g

[0063] m a =P a ×ρ a

[0064] Where: m G1 ——1m 3 Amount of steel slag with a particle size of 10 mm ≤ and <15 mm in solid waste-based large-void asphalt mixture, kg; m G2 ——1m 3 Amount of steel slag with particle size of 5mm≤<10mm in solid waste-based large-void asphalt mixture, kg; m f ——1m 3 Amount of mineral powder in solid waste-based large-void asphalt mixture, kg; m g ——1m 3 Amount of old asphalt mixture in solid waste-based large-void asphalt mixture, kg; m a ——1m 3 Amount of new asphalt in solid waste-based large-void asphalt mixture, kg; ρ a ——Density of new asphalt, kg / m 3 .

[0065] (6) Mixing solid waste-based large-void asphalt mixture, the mixing process is as follows: heating the steel slag to 180-200°C in heating drum 1, and heating the old asphalt mixture to 120-140°C in heating drum 2; dry-mixing the steel slag and mineral powder in a mixing tank for 10-15 seconds; then adding the old asphalt mixture and new asphalt into the mixing tank and evenly mixing for 35-45 seconds.

[0066] Preferably, a method for producing a solid waste-based large-void asphalt mixture is provided, wherein the asphalt film has a thickness of 16 to 20 um, and the void ratio of the solid waste-based large-void asphalt is 15 to 20%.

[0067] The beneficial effects of the present invention are:

[0068] The present invention provides a method for producing a solid waste-based large-void asphalt mixture, in which mineral powder and asphalt are combined to form a slurry as a steel slag binder, and a large-void asphalt mixture is designed based on the film-forming state of the asphalt slurry wrapped around the surface of the steel slag and its volume filling effect, and the thickness of the asphalt film of the old asphalt mixture is adjusted to ensure that the steel slag surface is sufficiently coated with the slag and the old asphalt mixture has a sufficient asphalt film, thereby ensuring that the steel slag and the old asphalt mixture have a strong bonding strength, and improving the high temperature, low temperature, water stability and other performances of the mixture.

[0069] The present invention provides a method for producing and preparing a solid waste-based large-void asphalt mixture, provides a surface area calculation method based on the distribution state of particles with different particle sizes, establishes a relationship model between steel slag, mineral powder and asphalt mortar, and a method for calculating the amount of new asphalt added during the asphalt film adjustment process of the old asphalt mixture, thereby accurately determining the proportional relationship between steel slag, mineral powder, old asphalt mixture and new asphalt, effectively reducing the variability in the production process of the large-void asphalt mixture, and realizing the controllability of the mixture performance and volume parameters.

[0070] The method for producing a solid waste-based large-void asphalt mixture provided by the present invention uses solid waste materials such as steel slag and old asphalt mixture as raw materials. The steel slag and old asphalt mixture are blended in a relatively high proportion, thereby providing an effective solution to the accumulation of solid waste and the shortage of road construction materials and realizing the recycling of solid waste. DETAILED DESCRIPTION

[0071] In order to make the technical means, creative features, objectives and effects of the present invention easy to understand, the present invention is further described below in conjunction with specific embodiments, but the following embodiments are only preferred embodiments of the present invention, not all. Based on the embodiments in the implementation mode, other embodiments obtained by those skilled in the art without creative work are all within the scope of protection of the present invention.

[0072] A method for producing a solid waste-based large-void asphalt mixture, comprising five parts: steel slag with a particle size of 10 mm ≤ and < 15 mm, steel slag with a particle size of 5 mm ≤ and < 10 mm, old asphalt mixture with a particle size of < 4.75 mm, mineral powder, and new asphalt. The steel slag and mineral powder are screened to determine their gradation composition, and the old asphalt mixture is screened to determine its gradation composition and old asphalt content. The results are shown below:

[0073] Table 1 Raw material screening results

[0074]

[0075] The drawer test method was used to determine that the asphalt content in the old asphalt mixture was 4.5% and the density of the old asphalt was 1.1 g / cm 3 The density of the raw materials is as follows:

[0076] Table 2 Density of raw materials

[0077]

[0078] The calculation formula for the specific surface area of ​​mineral materials within different sieve hole size ranges is shown below. The gradient n is taken as 3 according to the sieve hole size.

[0079]

[0080]

[0081]

[0082]

[0083]

[0084] SA=SA

[0085] The calculation results are shown in the following table

[0086] Table 3 Specific surface area of ​​raw materials

[0087]

[0088] Mix the steel slag with a particle size of 10 mm ≤ and 15 mm in the proportion of 100%, 90%, 80%, 70%, 60%, 50%, 40%, 30%, 20%, 10%, and 0%, and measure its compacted density ρ sc , and calculate its void ratio, draw a graph of the relationship between the void ratio and the ratio of 10mm≤particle size<15mm, 5mm≤particle size<10mm steel slag, the ratio of 10mm≤particle size<15mm, 5mm≤particle size<10mm steel slag is 60:40, the minimum void ratio VCA is 41.12%, and the synthetic density of steel slag ρ s0 =2.628g / cm 3 , which is the state of maximum density of steel slag mixing. The calculation formula of void ratio after steel slag mixing is as follows:

[0089]

[0090]

[0091] Embodiment 1:

[0092] The void ratio VV of solid waste-based large-void asphalt mixture is 15%, and the void ratio of 1m 3 The proportion of steel slag, old asphalt mixture, mineral powder and asphalt in solid waste-based large-void asphalt mixture:

[0093] G=1-0.412=0.588

[0094] g+f+P a =0.412-0.15

[0095] According to the wrapping characteristics of asphalt and asphalt mortar, and the harmonizing effect of new asphalt on the asphalt film thickness of old asphalt mixture, the asphalt film thickness μ is taken as 14um, and the proportion of steel slag, old asphalt mixture, mineral powder and asphalt is determined according to the following formula:

[0096] SA G =0.1a×SA G1 +SA G2 ×(1-0.1a)=16447cm 2 / kg

[0097]

[0098] P a1 =f×μ×SA f ×ρ f =0.61f

[0099] P a1 +f=G×ρ s0 ×SA G ×μ j =0.107m 3

[0100]

[0101] 2671×0.000001=0.2g

[0102] P a =0.2g+0.61f

[0103] After calculation, G = 0.588m 3 , f=0.066m 3 , P a1 =0.041m 3 , g = 0.13m 3 , P a2 =0.026m 3 , P a =0.067m 3 .

[0104] Substitute the density of steel slag with a particle size of 10 mm ≤ < 15 mm, steel slag with a particle size of 5 mm ≤ < 10 mm, old asphalt mixture, mineral powder, and asphalt raw materials into the following formula to calculate the density of 1 m 3 Amount of raw materials used in solid waste-based large-void asphalt mixture

[0105] m G1 =G×0.6×ρ s1 =953kg

[0106] m G2 =G×(1-0.6)×ρ s2 =624kg

[0107] m f =f×ρ f =172kg

[0108] m g =g×ρ g =347kg

[0109] m a =P a ×ρ a =75kg

[0110] According to the amount of steel slag, old asphalt mixture, mineral powder and asphalt added per m3, the asphalt mass is taken as 65kg, 75kg and 85kg respectively, and the solid waste-based large-void asphalt mixture is mixed. The mixing process is as follows: steel slag with a particle size of 5mm≤<10mm and steel slag with a particle size of 10mm≤<15mm are heated to 200℃ in heating drum 1, and the old asphalt mixture is heated to 130℃ in heating drum 2; steel slag with a particle size of 10mm≤<15mm and 5mm≤<10mm and mineral powder are dry-mixed in a mixing tank for 12s; then the old asphalt mixture and new asphalt are added into the mixing tank and evenly mixed for 40s.

[0111] The results of the Marshall test are shown in Table 4.

[0112] Table 4 Marshall test results

[0113]

[0114]

[0115] When the void ratio of the mixture is 15%, the amount of high-viscosity modified asphalt is 81 kg, and the road performance verification is carried out. The performance results are shown in Table 5.

[0116] Table 5 Road performance test results

[0117]

[0118] Embodiment 2:

[0119] The void ratio VV of solid waste-based large-void asphalt mixture is taken as 20%, and the void ratio of 1m 3 The proportion of steel slag, old asphalt mixture, mineral powder and asphalt in solid waste-based large-void asphalt mixture:

[0120] G=1-0.412=0.588

[0121] g+f+P a =0.412-0.20

[0122] According to the wrapping characteristics of asphalt and asphalt mortar, and the harmonizing effect of new asphalt on the asphalt film thickness of old asphalt mixture, the asphalt film thickness μ is taken as 20um, and the proportion of steel slag, old asphalt mixture, mineral powder and asphalt is determined according to the following formula:

[0123] S G =0.1a×SA G1 +SA G2 ×(1-0.1a)=16447cm 2 / kg

[0124]

[0125] P a1 =f×μ×SA f ×ρ f =0.87f

[0126] P a1 +f=G×ρ s0 ×SA G ×μ j =0.109m 3

[0127]

[0128] 2671×0.000001=0.26g

[0129] P a =0.26g+0.87f

[0130] After calculation, G = 0.588m 3 , f=0.058m 3 , P a1 =0.051m 3 , g = 0.082m 3 , P a2 =0.021m 3 , P a =0.072m 3 .

[0131] Substitute the density of steel slag with a particle size of 10 mm ≤ < 15 mm, steel slag with a particle size of 5 mm ≤ < 10 mm, old asphalt mixture, mineral powder, and asphalt raw materials into the following formula to calculate the density of 1 m 3 Amount of raw materials used in solid waste-based large-void asphalt mixture

[0132] m G1 =G×0.6×ρ s1 =953kg

[0133] m G2 =G×(1-0.6)×ρ s2 =624kg

[0134] m f =f×ρ f =151kg

[0135] m g =g×ρ g =219kg

[0136] m a =P a ×ρ a =80.6kg

[0137] According to the amount of steel slag, old asphalt mixture, mineral powder and asphalt added per 1m3, the asphalt mass is taken as 70kg, 80kg and 90kg respectively, and the solid waste-based large-void asphalt mixture is mixed. The mixing process is as follows: steel slag with a particle size of 10mm≤<15mm and steel slag with a particle size of 5mm≤<10mm are heated to 190℃ in heating drum 1, and the old asphalt mixture is heated to 125℃ in heating drum 2; steel slag with a particle size of 10mm≤<15mm, steel slag with a particle size of 5mm≤<10mm and mineral powder are dry-mixed in a mixing tank for 14s; then the old asphalt mixture and new asphalt are added into the mixing tank and evenly mixed for 45s.

[0138] The results of the Marshall test are shown in Table 6.

[0139] Table 6 Marshall test results

[0140]

[0141] When the void ratio of the mixture is 20%, the amount of high-viscosity modified asphalt is 80kg, and the road performance verification is carried out. The performance results are shown in Table 7.

[0142] Table 7 Road performance test results

[0143]

[0144] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. The above embodiments and descriptions are only preferred examples of the present invention and are not intended to limit the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A method for producing solid waste-based large-void asphalt mixture, characterized in that: The steps include: (1) The solid waste-based large-void asphalt mixture includes steel slag with a particle size of 10 mm ≤ < 15 mm and 5 mm ≤ < 10 mm, old asphalt mixture with a particle size of < 4.75 mm, mineral powder, and new asphalt. The steel slag, mineral powder, and old asphalt mixture are sieved to determine their gradation composition. The old asphalt mixture is sieved to determine its old asphalt content. The specific surface area of ​​the steel slag, mineral powder, and old asphalt mixture is calculated according to the calculation formula for the specific surface area of ​​mineral materials within different sieve hole size ranges; The calculation formula for the specific surface area of ​​ore within different sieve hole size ranges is as follows, where the minimum sieve hole size is 0.075 / n: SA = ∑SA i Where: V i —Total volume of sieve residue per unit mass of mineral material, cm 3 / kg; PS i —Percentage of ore passing through the i-level sieve, %; PS i+1 —Percentage of ore passing through the sieve hole of the previous level i, %; D i —Size of sieve hole at level i, mm; D i+1 —The size of the sieve hole of the previous level i, mm; K—a natural number between 0 and n; —The volume of a single mineral material at the kth diameter after sieving the i-level sieve, cm 3 ; —The number of ore residues per unit mass of ore at the kth diameter on the i-th sieve hole; ρ s —Density of mineral material, g / cm 3 ; —Surface area of ​​a single mineral material under the kth diameter at the i-level sieve hole, cm 2 ; SA i —Specific surface area of ​​the residual material on the i-level sieve, cm 2 / kg; SA—Total specific surface area of ​​mineral material, cm 2 / kg (2) Solid waste-based large-void asphalt mixture is a permeable skeleton structure. Steel slag forms the basic skeleton of the asphalt mixture in the state of maximum density. The old asphalt mixture, mineral powder, and new asphalt are used to fill the voids formed in the state of steel slag being squeezed. The remaining voids are the void ratio of the solid waste-based large-void asphalt mixture. Combined with the volume parameter changes of the raw materials during the volume filling process, the void ratio of 1m 3 The composition ratio of steel slag, old asphalt mixture, mineral powder and asphalt; (3) The new asphalt is uniformly wrapped on the surface of the mineral powder with a certain asphalt film thickness to form asphalt mortar, and the asphalt mortar is wrapped on the surface of the steel slag with a certain thickness. The new asphalt is used to adjust the asphalt film thickness of the old asphalt mixture. According to the wrapping characteristics of asphalt and asphalt mortar, and the adjusting effect of the new asphalt on the asphalt film thickness of the old asphalt mixture, the proportion of steel slag, old asphalt mixture, mineral powder, and asphalt is determined; (4) According to 1m 3 Steel slag, old asphalt mixture, mineral powder and asphalt are added to mix the solid waste-based large-void asphalt mixture. The mixing process is as follows: the steel slag is heated to 180-200°C in a heating drum, and the old asphalt mixture is heated to 120-140°C in another heating drum; the steel slag and mineral powder are dry-mixed in a mixing tank for 10-15s; then the old asphalt mixture and new asphalt are added to the mixing tank and evenly mixed for 35-45s.

2. The method for producing a solid waste-based large-void asphalt mixture according to claim 1, characterized in that: The maximum density of steel slag is formed by mixing 10-15mm and 5-10mm steel slag in a ratio of 0+10a:100-10a, and measuring its compaction density ρ sc , and calculate its void ratio, draw a relationship diagram between void ratio and 10-15mm, 5-10mm steel slag ratio. The ratio of 10-15mm, 5-10mm steel slag with the minimum void ratio is the state of maximum density of steel slag mixing. The void ratio calculation formula after steel slag mixing is as follows: Where: s1 —Density of steel slag with particle size 10mm≤particle size<15mm, g / cm 3 ; ρ s2 —Density of steel slag with particle size 5mm≤particle size<10mm, g / cm 3 ; ρ s0 —Synthetic density of steel slag, g / cm 3 ; ρ sc —Synthetic compacted density of steel slag, g / cm 3 ; VCA—void ratio after mixing slag, %; a—Proportion of steel slag with particle size of 10mm≤<15mm in the steel slag mixture, %.

3. The method for producing a solid waste-based large-void asphalt mixture according to claim 2, characterized in that: The volume parameter change of the raw material during the volume filling process is determined according to the following formula: 3 The proportion of steel slag, old asphalt mixture, mineral powder and asphalt in solid waste-based large-void asphalt mixture: G=1-VCA g+f+P a =VCA-VV Where: G—1m 3 Volume of steel slag in asphalt mixture, m 3 ; g—1m 3 Volume of old asphalt mixture in asphalt mixture, m 3 ; f—1m 3 Volume of mineral powder in asphalt mixture, m 3 ; P a —1m 3 Asphalt volume in asphalt mixture, m 3 ; VV—void ratio of asphalt mixture, %.

4. The method for producing a solid waste-based large-void asphalt mixture according to claim 3, characterized in that: According to the encapsulation characteristics of asphalt and asphalt mortar, and the harmonizing effect of new asphalt on the asphalt film thickness of old asphalt mixture, the proportion of steel slag, old asphalt mixture, mineral powder and asphalt is determined according to the following formula: IN G =0.1a×SA G1 +IN G2 ×(1-0.1a) P a1 =f×μ×SA f ×ρ f P a1 +f=G×ρ s0 ×SA G ×μ j P a =P a2 +P a1 In the formula: SA G —Synthetic specific surface area of ​​steel slag, cm 2 / kg;SA G1 —Specific surface area of ​​steel slag with particle size of 10mm≤<15mm, cm 2 / kg; SA G2 —Specific surface area of ​​steel slag with particle size of 5mm≤<10mm, cm 2 / kg; m 旧 —Asphalt content in old asphalt mixture, %; μ j —Asphalt mortar film thickness, um; μ—Asphalt film thickness, um; P a1 —Volume of asphalt in asphalt mortar, m 3 ; ρ a旧 ——Density of old asphalt, kg / m 3 ; ρ f ——Mineral powder density, kg / m 3 ρ g ——Density of old asphalt mixture, kg / m 3 ; SA f —Specific surface area of ​​mineral powder, cm 2 / kg;SA g —Specific surface area of ​​old asphalt mixture, cm 2 / kg; P a2 —Volume of asphalt used to adjust the asphalt film thickness of old asphalt mixture, m 3 .

5. The method for producing a solid waste-based large-void asphalt mixture according to claim 4, characterized in that: 1m 3 The amount of steel slag, old asphalt mixture, mineral powder and asphalt is calculated according to the following formula: m G1 =G×0.1a×ρ s1 m G2 =G×(1-0.1a)×ρ s2 m f =f×ρ f m g =g×ρ g m a =P a ×ρ a Where: m G1 ——1m 3 Amount of 10-15 mm steel slag in solid waste-based large-void asphalt mixture, kg; m G1 ——1m 3 Amount of 5-10 mm steel slag in solid waste-based large-void asphalt mixture, kg; m f ——1m 3 Amount of mineral powder in solid waste-based large-void asphalt mixture, kg; m g ——1m 3 Amount of old asphalt mixture in solid waste-based large-void asphalt mixture, kg; m a ——1m 3 Amount of new asphalt in solid waste-based large-void asphalt mixture, kg; ρ a ——Density of new asphalt, kg / m 3 .

6. The method for producing a solid waste-based large-void asphalt mixture according to claim 1, characterized in that: The thickness of the asphalt film is 16-20um, and the void ratio of the solid waste-based macrovoid asphalt is 15-20%.

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