Roadbase mixture, preparation method thereof and pavement paving method

Abstract

The invention provides a road base mixture as well as a preparation method and a pavement paving method thereof. The mixture is prepared from the following raw materials in parts by weight: 5 to 30 parts of concrete block recycled aggregate, 55 to 110 parts of pyrolytic steel slag recycled aggregate, 2 to 5 parts of cement and 3 to 21 parts of water. The preparation method comprises the following steps: preparing the concrete block recycled aggregate; preparing steel slag regenerated aggregate; and preparing a mixture: mixing the concrete block regenerated aggregate and the steel slag regenerated aggregate to obtain an aggregate, mixing and dispersing the aggregate and cement, and adding water for wet mixing to obtain the mixture. The problems that in the prior art, road infrastructure construction raw materials are high in obtaining cost, and construction waste is difficult to efficiently recycle and recycle can be solved.

Description

Technical Field

[0001] The present application relates to the technical field of road engineering, and particularly to a road base mixture made of waste autoclaved aerated concrete blocks and thermally steamed steel slag, a preparation method thereof, and a pavement laying method thereof. Background Art

[0002] Currently, large-scale road infrastructure construction in China requires a large amount of natural sand and gravel aggregates. With the country's rectification of quarrying and river sand dredging, the price of sand and gravel has skyrocketed, and it is urgent to find alternative resources for natural sand and gravel. At the same time, with the urban renewal project, a large amount of construction waste will be generated. Among them, the annual output of construction waste in large and medium-sized cities exceeds 2 billion tons. The collection of sand and gravel, the generation of construction waste, and the low recovery rate are all accompanied by the endless exploitation of resources and environmental protection problems.

[0003] It can be seen that in the process of rapid urban development, there is an embarrassing situation where the cost of obtaining raw materials for road infrastructure construction is high, while construction waste is difficult to recycle efficiently. Summary of the Invention

[0004] Aiming at the deficiencies of the prior art, the present application provides a road base mixture made of waste autoclaved aerated concrete blocks and thermally steamed steel slag, a preparation method thereof, and a pavement laying method thereof, so as to solve the problems in the prior art that the cost of obtaining raw materials for road infrastructure construction is high, while construction waste is difficult to recycle efficiently and resourcefully applied.

[0005] In the first aspect of the present application, a road base mixture is provided, which is composed of the following raw materials in parts by weight: 5-30 parts of concrete block recycled aggregate, 55-110 parts of thermally steamed steel slag recycled aggregate, 2-5 parts of cement, and 3-21 parts of water.

[0006] Optionally, the particle size d of the concrete block recycled aggregate 混 is d 混 ≤5mm, and the apparent density is 2250-2350 kg / m 3 .

[0007] Optionally, the thermally steamed steel slag recycled aggregate is composed of the following particle size steel slag ratios in parts by weight: 0-25 parts of primary particle size steel slag, 25-35 parts of secondary particle size steel slag, 15-25 parts of tertiary particle size steel slag, and 15-25 parts of quaternary particle size steel slag; wherein, the primary particle size d1 satisfies d1≤5mm, the secondary particle size d2 satisfies 5mm < d2≤10mm, the tertiary particle size d3 satisfies 10mm < d3≤20mm, and the quaternary particle size d4 satisfies 20mm < d4≤30mm.

[0008] Optionally, the apparent density of the thermally steamed steel slag is 3200-3700 kg / m 3, the immersion expansion rate of the heat-soaked steel slag is 0.1% to 1.9%.

[0009] Optionally, the cement is 42.5-grade ordinary Portland cement.

[0010] In the second aspect of the present application, a method for preparing a road base mixture is provided, including the following steps:

[0011] Preparation of recycled aggregate of concrete blocks: Select waste autoclaved aerated concrete blocks removed from building structure walls, crush and screen the waste autoclaved aerated concrete blocks to obtain recycled aggregate particles of concrete blocks meeting the target particle size.

[0012] Preparation of recycled aggregate of steel slag: Select steel slag after pressure heat soaking treatment in a tank, crush and screen the heat-soaked steel slag to obtain recycled aggregate particles of steel slag meeting the target particle size.

[0013] Mixture preparation: Mix the recycled aggregate of concrete blocks and the recycled aggregate of steel slag to obtain aggregate, and after mixing and dispersing the aggregate with cement, add water for wet mixing to obtain a mixture.

[0014] Optionally, obtaining the recycled aggregate particles of concrete blocks meeting the target particle size includes selecting concrete block recycled aggregate particles with a particle size d 混 being d 混 ≤5mm and performing pre-wetting treatment.

[0015] Optionally, crushing and screening the heat-soaked steel slag to obtain recycled aggregate particles of steel slag meeting the target particle size includes crushing the heat-soaked steel slag and screening and grading it into particles with the following particle size ranges: 0-25 parts of steel slag with a primary particle size, 25-35 parts of steel slag with a secondary particle size, 15-25 parts of steel slag with a tertiary particle size, 15-25 parts of steel slag with a quaternary particle size; among them, the primary particle size d1 satisfies d1≤5mm, the secondary particle size d2 satisfies 5mm<d2≤10mm, the tertiary particle size d3 satisfies 10mm<d3≤20mm, and the quaternary particle size d4 satisfies 20mm<d4≤30mm.

[0016] In the third aspect of the present application, a road surface paving method is provided, spreading the mixture on the target road and performing rolling and curing.

[0017] Optionally, the curing conditions are: temperature is 15-30°C, humidity ≥95%RH.

[0018] The beneficial effects of the present application are:

[0019] 1. The road base mixture of this application uses waste autoclaved aerated concrete blocks and heat-soaked steel slag as raw materials. Applying the waste autoclaved aerated concrete blocks that are difficult to utilize in construction waste and the steel slag that is the most difficult to utilize in the iron and steel smelting industry to road base construction can not only solve the environmental pollution problems brought by the large stockpiles of waste autoclaved aerated concrete blocks and steel slag at present, but also reduce quarrying and sand dredging in rivers, effectively relieve the bottleneck of resource supply, realize the comprehensive utilization of waste autoclaved aerated concrete blocks and steel slag within the region, and promote the development of local circular economy and low-carbon economy;

[0020] 2. Compared with the prior art, the road base mixture of waste autoclaved aerated concrete blocks and heat-soaked steel slag in this application greatly increases the utilization amount of waste autoclaved aerated concrete blocks and steel slag, and at the same time realizes the coordinated disposal of multiple solid waste resources, providing a new disposal way for the areas where waste autoclaved aerated concrete blocks and steel slag are produced. In addition, the method of this application reduces the cement consumption, replaces the natural sand and gravel materials with high prices, and can save 5 - 18 yuan per square meter of water-stabilized material compared with the prior art.

[0021] 3. The method of this application not only realizes the low-cost production of the base mixture, but also the 7-day unconfined compressive strength of the prepared road base mixture of waste autoclaved aerated concrete blocks and heat-soaked steel slag can reach more than 10 MPa, so it has strong market competitiveness. Detailed implementation manners

[0022] To make the purpose, technical solution and advantages of this application clearer, the technical solution of this application will be clearly and completely described below in combination with specific embodiments of this application. Obviously, the described embodiments are only a part of the embodiments of this application, rather than all the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of this application.

[0023] A large number of concrete blocks are used in the building structure walls in our country. Concrete blocks are widely used due to their characteristics such as small density, good sound insulation and heat insulation effects, and convenient construction. However, after demolition, they have low strength and high water absorption, and are difficult to be used as aggregates for high-strength concrete, and can only be used as fine aggregates. On the other hand, the annual output of steel slag in large and medium-sized cities in our country exceeds 100 million tons, but the utilization rate of steel slag is only 30%. Moreover, the volume stability of the steel slag treated by pressure heat soaking in a tank is good, and it can be used as recycled coarse aggregate for the base mixture without long-term storage and aging. In addition, steel slag also has hydraulic cementitious properties and can continuously hydrate and harden in the later stage, improving the strength, erosion resistance, etc. of the road base.

[0024] Therefore, this application proposes to synergistically utilize the concrete blocks in construction waste and the steel slag from steelmaking residues to prepare the road base mixture, which can effectively recycle construction waste and steel slag, realize resource utilization, and is beneficial to the sustainable construction of urban infrastructure.

[0025] An embodiment of the present application provides a road base mixture, which is composed of the following raw materials in parts by weight: 5-30 parts of recycled concrete block aggregate, 55-110 parts of recycled hot-pressed steel slag aggregate, 2-5 parts of cement, and 3-21 parts of water.

[0026] In an embodiment of the present application, the added mass fraction of the water is 6-14% of the total mass of the recycled concrete block aggregate, the recycled hot-pressed steel slag aggregate and the cement.

[0027] In an embodiment of the present application, the particle size distribution and apparent density of the recycled concrete block aggregate are measured. The particle size d of the recycled concrete block aggregate 混 is d 混 ≤5 mm, and the apparent density is 2250-2350 kg / m 3 .

[0028] In an embodiment of the present application, the hot-pressed steel slag is the steel slag after pot-type pressurized hot-pressing treatment by iron and steel enterprises; the hot-pressed steel slag is crushed, iron-selected, and screened to obtain recycled hot-pressed steel slag aggregate; the particle size distribution, apparent density and immersion expansion rate of the recycled hot-pressed steel slag aggregate are measured. The particles of the hot-pressed steel slag are respectively primary particle size steel slag, secondary particle size steel slag, tertiary particle size steel slag, and quaternary particle size steel slag; among them, the primary particle size d1 satisfies d1≤5 mm, the secondary particle size d2 satisfies 5 mm < d2≤10 mm, the tertiary particle size d3 satisfies 10 mm < d3≤20 mm, the quaternary particle size d4 satisfies 20 mm < d4≤30 mm, the apparent density of the hot-pressed steel slag is 3200-3700 kg / m 3 , and the immersion expansion rate of the hot-pressed steel slag is 0.1%-1.9%.

[0029] In the embodiment of the present application, different grades of particle size steel slag are selected by primary crushing and screening. The raw materials are easy to obtain and prepare. By adjusting different particle size distributions, different strength effects can be obtained.

[0030] Further, the recycled hot-pressed steel slag aggregate is composed of the following particle size steel slag ratios in parts by weight: 0-25 parts of primary particle size steel slag, 25-35 parts of secondary particle size steel slag, 15-25 parts of tertiary particle size steel slag, and 15-25 parts of quaternary particle size steel slag; among them, the primary particle size d1 satisfies d1≤5 mm, the secondary particle size d2 satisfies 5 mm < d2≤10 mm, the tertiary particle size d3 satisfies 10 mm < d3≤20 mm, the quaternary particle size d4 satisfies 20 mm < d4≤30 mm.

[0031] In an embodiment of the present application, the road base mixture is composed of the following raw materials in parts by weight: the particle size d 混 is d 混5 - 30 parts of recycled aggregate of concrete blocks with a size of ≤5mm, 0 - 25 parts of steel slag with a first - level particle size, 25 - 35 parts of steel slag with a second - level particle size, 15 - 25 parts of steel slag with a third - level particle size, 15 - 25 parts of steel slag with a fourth - level particle size, 2 - 5 parts of cement, and 3 - 21 parts of water; among them, the first - level particle size d1 satisfies d1≤5mm, the second - level particle size d2 satisfies 5mm<d2≤10mm, the third - level particle size d3 satisfies 10mm<d3≤20mm, and the fourth - level particle size d4 satisfies 20mm<d4≤30mm.

[0032] In an embodiment of the present application, the apparent density of the heat - soaked steel slag is 3200 - 3700 kg / m 3 , and the water - immersion expansion rate of the heat - soaked steel slag is 0.1% - 1.9%.

[0033] In an embodiment of the present application, the cement is 42.5 - grade ordinary Portland cement. Further, the mass fraction of the cement is 2 - 5% of the total mass fraction of the recycled aggregate of waste autoclaved aerated concrete blocks and the recycled aggregate of heat - soaked steel slag.

[0034] The embodiment of the present application provides a method for preparing a road base mixture, including the following steps:

[0035] Preparation of recycled aggregate of concrete blocks: Select waste autoclaved aerated concrete blocks from the demolition of building structure walls, crush and screen the waste autoclaved aerated concrete blocks to obtain concrete block recycled aggregate particles that meet the target particle size;

[0036] Preparation of recycled aggregate of steel slag: Select steel slag after pot - type pressurized heat - soaking treatment, crush and screen the heat - soaked steel slag to obtain steel slag recycled aggregate particles that meet the target particle size;

[0037] Preparation of the mixture: Mix the recycled aggregate of concrete blocks and the recycled aggregate of steel slag to obtain aggregate, and after mixing and dispersing the aggregate with cement, add water for wet mixing to obtain the mixture.

[0038] In an embodiment of the present application, obtaining the concrete block recycled aggregate particles that meet the target particle size includes selecting concrete block recycled aggregate particles with a particle size d 混 of d 混 ≤5mm and performing pre - wetting treatment. Due to the low water - binder ratio of concrete materials, serious autogenous shrinkage often occurs during the preparation process. In the past, expansion agents were added to concrete to solve the problem of concrete shrinkage. In the present application, by pre - wetting the concrete block recycled aggregate particles, the degree of autogenous shrinkage can be effectively reduced. In an embodiment of the present application, the humidity balance is achieved by soaking or covering the concrete block recycled aggregate particles with water, and the pre - wetting time of the pre - wetting treatment is 1 - 3h.

[0039] In an embodiment of the present application, the process of crushing and screening the heat-soaked steel slag to obtain steel slag recycled aggregate particles meeting the target particle size includes crushing the heat-soaked steel slag and screening and grading it into particles of the following levels and particle size ranges: primary particle size steel slag, secondary particle size steel slag, tertiary particle size steel slag, and quaternary particle size steel slag. Among them, the primary particle size d1 satisfies d1 ≤ 5 mm, the secondary particle size d2 satisfies 5 mm < d2 ≤ 10 mm, the tertiary particle size d3 satisfies 10 mm < d3 ≤ 20 mm, and the quaternary particle size d4 satisfies 20 mm < d4 ≤ 30 mm. The required number of parts of steel slag recycled aggregate particles is taken according to the particle gradation. Of course, in addition to the particle sizes listed in this embodiment, there may be steel slag with other range of particle sizes, which can be further recycled to avoid waste.

[0040] Further, after crushing the heat-soaked steel slag, an iron separation operation is further carried out. Steel slag is the molten slag discharged during the steelmaking process, mainly including oxides formed by the oxidation of various elements in the metal charge, eroded furnace lining materials and furnace repair materials, impurities brought in by the metal charge, and slag-making materials specially added for smelting different steel grades, resulting in the iron content in steel slag reaching 3% - 4%. The iron content in the steel slag discharged by the iron and steel industry in China each year reaches more than 15 million tons. The present application further effectively removes the iron in the steel slag through the steel slag iron separation process, which not only reduces the difficulty of crushing and grinding the steel slag and improves the quality of the steel slag powder product, but also reduces a large amount of waste of iron resources. The steel slag iron separation process can separate out iron particles and iron powder. The iron content in the steel slag tailings after treatment is usually below 1%, and the recovery rate of iron elements in the steel slag is relatively high. The heat-soaked steel slag is crushed and screened after iron separation.

[0041] In an embodiment of the present application, after preparing the mixture, road paving is carried out. The mixture is spread on the target road and compacted and cured.

[0042] The conditions for curing are: temperature is 15 - 30 °C, and humidity ≥ 95% RH.

[0043] It should be noted that in the expression of the content of raw material components in the present application, endpoint values are included. For example: 2 - 5 parts of cement, which means: 2 parts ≤ the weight parts of fly ash ≤ 5 parts.

[0044] The embodiment of the present application also provides a method for preparing a road base mixture specimen, which is realized according to the following steps:

[0045] 1) Select waste autoclaved aerated concrete blocks from the demolition of building structure walls, and select steel slag after pot-type pressurized heat-soaking treatment;

[0046] 2) The waste autoclaved aerated concrete blocks are crushed and screened to obtain a particle size d 混 of d 混≤5 mm recycled fine aggregate. The hot-pressed steel slag is crushed, magnetically separated to remove iron, and screened to obtain mixed recycled aggregate, including steel slag with a first-grade particle size, steel slag with a second-grade particle size, steel slag with a third-grade particle size, and steel slag with a fourth-grade particle size. Among them, the first-grade particle size d1 satisfies d1 ≤ 5 mm, the second-grade particle size d2 satisfies 5 mm < d2 ≤ 10 mm, the third-grade particle size d3 satisfies 10 mm < d3 ≤ 20 mm, and the fourth-grade particle size d4 satisfies 20 mm < d4 ≤ 30 mm.

[0047] 3) Pre-wet the waste autoclaved aerated concrete blocks, and then mix them with the hot-pressed steel slag in proportion to make aggregate.

[0048] 4) Add cement to the aggregate and mix to obtain the base mixture of waste autoclaved aerated concrete blocks and hot-pressed steel slag.

[0049] 5) Put the base mixture of waste autoclaved aerated concrete blocks and hot-pressed steel slag into a mold, and adopt the mode of vibrating compaction with a small pressure machine. After compaction and forming, put it into a curing box for curing for 7 days and then demold.

[0050] During the process of loading the mold, keep the inner wall of the mold clean. A thin layer of release agent such as mineral oil can be evenly coated on its inner wall, and the release agent should be evenly distributed without obvious deposition.

[0051] Determine the appropriate forming method according to factors such as the consistency of the mixture to ensure that the concrete is fully dense and avoid segregation. For example, a vibrating table can be selected for vibration compaction or a manual vibrating rod can be used for vibration compaction. Then, a plastic film or a weight plate can be pressed on the surface to facilitate forming.

[0052] Example 1

[0053] The base mixture of waste autoclaved aerated concrete blocks and hot-pressed steel slag in this example is composed of the following components in parts by weight: recycled aggregate of concrete blocks with a particle size d 混 being d 混 ≤5 mm of 5 parts, 25 parts of steel slag with a first-grade particle size, 30 parts of steel slag with a second-grade particle size, 20 parts of steel slag with a third-grade particle size, 20 parts of steel slag with a fourth-grade particle size, 4 parts of cement, and 8 parts of water. Among them, the first-grade particle size d1 satisfies d1 ≤ 5 mm, the second-grade particle size d2 satisfies 5 mm < d2 ≤ 10 mm, the third-grade particle size d3 satisfies 10 mm < d3 ≤ 20 mm, and the fourth-grade particle size d4 satisfies 20 mm < d4 ≤ 30 mm.

[0054] Weigh the raw materials according to the above ratio. After pre-wetting the recycled aggregate of waste autoclaved aerated concrete blocks, mix it with the steel slag aggregate, then add cement and water and mix to obtain the base mixture of waste autoclaved aerated concrete blocks and hot-pressed steel slag. Put it into a mold and adopt the mode of vibrating compaction with a small pressure machine. After compaction and forming, put it into a curing box for curing for 7 days and then demold. Obtain the test pieces of the road base mixture at the age of 7 days.

[0055] Example 2

[0056] The waste autoclaved aerated concrete block and the hot-pressed steel slag base mixture in this embodiment are composed of the following components in parts by weight: the particle size d 混 is d 混 ≤5mm recycled aggregate of concrete blocks 10 parts, primary particle size steel slag 20 parts, secondary particle size steel slag 30 parts, tertiary particle size steel slag 20 parts, quaternary particle size steel slag 20 parts, cement 4 parts, water 9 parts; wherein, the primary particle size d1 satisfies d1≤5mm, the secondary particle size d2 satisfies 5mm<d2≤10mm, the tertiary particle size d3 satisfies 10mm<d3≤20mm, and the quaternary particle size d4 satisfies 20mm<d4≤30mm.

[0057] Weigh the raw materials according to the above proportions. After pre-wetting the recycled aggregate of the waste autoclaved aerated concrete block, mix it with the steel slag aggregate, then add cement and water and mix them to obtain the waste autoclaved aerated concrete block and the hot-pressed steel slag base mixture. Put it into a mold and adopt the mode of vibrating compaction with a small pressure machine. After compaction and molding, put it into a curing box for curing for 7 days and then demold it. Obtain the road base mixture specimens with a 7-day age.

[0058] Example 3

[0059] The waste autoclaved aerated concrete block and the hot-pressed steel slag base mixture in this embodiment are composed of the following components in parts by weight: the particle size d 混 is d 混 ≤5mm recycled aggregate of concrete blocks 20 parts, primary particle size steel slag 10 parts, secondary particle size steel slag 30 parts, tertiary particle size steel slag 20 parts, quaternary particle size steel slag 20 parts, cement 4 parts, water 10 parts; wherein, the primary particle size d1 satisfies d1≤5mm, the secondary particle size d2 satisfies 5mm<d2≤10mm, the tertiary particle size d3 satisfies 10mm<d3≤20mm, and the quaternary particle size d4 satisfies 20mm<d4≤30mm..

[0060] Weigh the raw materials according to the above proportions. After pre-wetting the recycled aggregate of the waste autoclaved aerated concrete block, mix it with the steel slag aggregate, then add cement and water and mix them to obtain the waste autoclaved aerated concrete block and the hot-pressed steel slag base mixture. Put it into a mold and adopt the mode of vibrating compaction with a small pressure machine. After compaction and molding, put it into a curing box for curing for 7 days and then demold it. Obtain the road base mixture specimens with a 7-day age.

[0061] Example 4

[0062] The waste autoclaved aerated concrete block and the hot-pressed steel slag base mixture in this embodiment are composed of the following components in parts by weight: the particle size d 混 is d 混30 parts of recycled aggregate of autoclaved aerated concrete block with size ≤ 5mm, 0 part of steel slag with primary particle size, 30 parts of steel slag with secondary particle size, 20 parts of steel slag with tertiary particle size, 20 parts of steel slag with quaternary particle size, 4 parts of cement, and 12 parts of water; among them, the primary particle size d1 satisfies d1 ≤ 5mm, the secondary particle size d2 satisfies 5mm < d2 ≤ 10mm, the tertiary particle size d3 satisfies 10mm < d3 ≤ 20mm, and the quaternary particle size d4 satisfies 20mm < d4 ≤ 30mm.

[0063] Weigh the raw materials according to the above proportions. After pre-wetting the recycled aggregate of waste autoclaved aerated concrete block, mix it with steel slag aggregate, then add cement and water and mix them to prepare the mixture of waste autoclaved aerated concrete block and hot-piled steel slag base course. Load it into the mold and adopt the vibration compaction mode of small-scale pressure machinery. After compaction and forming, put it into the curing box for curing for 7 days and then demold it. Obtain the road base course mixture specimens with 7-day age.

[0064] Control Example

[0065] In this control example, prepare the base course mixture, which is composed of the following components by weight: 30 parts of natural river sand with particle size of 0 - 5mm (including 5mm), 0 part of steel slag with particle size of 0 - 5mm (including 5mm), 30 parts of natural crushed stone with particle size of 5 (excluding 5) - 10mm (including 10mm), 20 parts of natural crushed stone with particle size of 10 (excluding 10) - 20mm (including 20mm), 20 parts of natural crushed stone with particle size of 20 (excluding 20) - 30mm (including 30mm), 4 parts of cement, and 12 parts of water.

[0066] Weigh the raw materials according to the above proportions. After mixing natural river sand and natural crushed stone, add cement and water and mix them to prepare the base course mixture. Load it into the mold and adopt the vibration compaction mode of small-scale pressure machinery. After compaction and forming, put it into the curing box for curing for 7 days and then demold it. Obtain the road base course mixture specimens with 7-day age.

[0067] Conduct unconfined compressive strength tests on the road base course mixture specimens with 7-day age prepared in Examples 1 - 4 containing waste autoclaved aerated concrete block and hot-piled steel slag aggregate, and the road base course mixture specimens with 7-day age prepared in the control example one by one. The test results are shown in Table 1 for the compressive strength test results.

[0068] Table 1 Compressive Strength Test Results

[0069]

[0070]

[0071] As can be seen from Table 1, the 7-day unconfined compressive strength of the road base course mixture specimens prepared in Examples 1 - 4 can reach more than 10MPa, which is better than the unconfined compressive strength of the base course mixture prepared with natural aggregate.

[0072] In addition, in Examples 1 to 4, the content of recycled aggregate of concrete blocks shows an increasing trend, the content of steel slag aggregate shows a decreasing trend, and the compressive strength of the specimens decreases. It can be seen that Example 1 is a preferred example in this application. Examples 1 to 4 can all meet the strength requirements of road base components, and adding steel slag aggregate to the road base mixture can effectively improve the compressive strength.

[0073] The above are only examples of this application and are not intended to limit this application. For those skilled in the art, various changes and modifications can be made to this application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of this application shall be included within the scope of the claims of this application.

Claims

1. A road base mixture, characterized in that, It consists of the following raw materials by weight parts: 5-30 parts of recycled aggregate of concrete blocks, 55-110 parts of recycled aggregate of heat-smothered steel slag, 2-5 parts of cement, and 3-21 parts of water.

2. The road base mixture according to claim 1, characterized in that, The particle size d of the recycled aggregate of the concrete block 混 is d 混 ≤ 5 mm, and the apparent density is 2250 - 2350 kg / m 3 .

3. A road base mixture according to claim 1, characterized in that, The recycled aggregate of heat-smothered steel slag is composed of steel slag with the following particle size ratios by weight parts: 0-25 parts of steel slag with the first-grade particle size, 25-35 parts of steel slag with the second-grade particle size, 15-25 parts of steel slag with the third-grade particle size, and 15-25 parts of steel slag with the fourth-grade particle size; among them, the first-grade particle size d1 satisfies d1≤5mm, the second-grade particle size d2 satisfies 5mm<d2≤10mm, the third-grade particle size d3 satisfies 10mm<d3≤20mm, and the fourth-grade particle size d4 satisfies 20mm<d4≤30mm.

4. The road base mixture according to claim 1, characterized in that, The apparent density of the heat-soaked steel slag is 3,200 to 3,700 kg / m 3 , and the immersion expansion rate of the heat-soaked steel slag is 0.1% to 1.9%.

5. The road base mixture according to claim 1, characterized in that, The cement is 42.5-grade ordinary Portland cement.

6. A method for preparing a road base mixture, characterized in that, It includes the following steps: Preparation of recycled aggregate of concrete blocks: Select waste autoclaved aerated concrete blocks from the demolition of building structure walls, crush and screen the waste autoclaved aerated concrete blocks to obtain recycled aggregate particles of concrete blocks that meet the target particle size. Preparation of recycled aggregate of steel slag: Select steel slag after pot-type pressurized heat-smothering treatment, crush and screen the heat-smothered steel slag to obtain recycled aggregate particles of steel slag that meet the target particle size. Preparation of the mixture: Mix the recycled aggregate of concrete blocks and the recycled aggregate of steel slag to obtain aggregate, mix and disperse the aggregate with cement, and then add water for wet mixing to obtain the mixture.

7. The method for preparing a road base mixture according to claim 6, characterized in that, The obtaining of the recycled aggregate particles of concrete blocks that meet the target particle size includes selecting the recycled aggregate particles of concrete blocks with a particle size d 混 being d 混 ≤ 5 mm and performing pre-wetting treatment.

8. The method for preparing a road base mixture according to claim 6, characterized in that The step of crushing and screening the heat-smothered steel slag to obtain recycled aggregate particles of steel slag that meet the target particle size includes crushing the heat-smothered steel slag and screening and grading it into particles with the following particle size ranges: the first-grade particle size d1 satisfies d1≤5mm, the second-grade particle size d2 satisfies 5mm<d2≤10mm, the third-grade particle size d3 satisfies 10mm<d3≤20mm, the fourth-grade particle size d4 satisfies 20mm<d4≤30mm, and taking the required number of parts of recycled aggregate particles of steel slag according to the particle gradation.

9. A road surface paving method, characterized in that, Spread the mixture on the target road and carry out rolling and curing.

10. A road surface paving method according to claim 9, characterized in that, The conditions for curing: the temperature is 15-30°C and the humidity ≥95%RH.

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