Construction method of airport pavement composite cushion

Abstract

The application discloses a construction method of an airport pavement composite cushion, which comprises the following operation steps: step A: classifying, crushing and grading construction waste regenerated materials; step B: mixing and blending the construction waste regenerated materials after crushing and grading according to a standard mixing ratio; step C: using the mixed and blended construction waste to construct a lower cushion; and step D: using the mixed and blended construction waste to construct an upper cushion. The composite cushion has high strength and high compression and shear resistance, effectively solves the problems that the cement pavement cushion of an airport is prone to breaking, the use performance is affected, the material source is tight, the engineering cost is increased, a large amount of construction waste of the airport occupies land resources and harms the environment, the construction waste is used as cushion filler, the construction waste is reduced and recycled, the problem of urban construction waste is solved, the urban sanitary environment is improved, the land resources occupied by the construction waste are reduced, the cost of the cushion material is reduced, and the transportation cost of the construction waste generated by the demolished buildings is saved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of airport pavement construction technology, in particular to a construction method of an airport pavement composite cushion. BACKGROUND

[0002] The cement pavement cushion of a civil airport generally uses graded gravel, mountain stone and other materials, which has the effect of improving the humidity and temperature conditions of the soil foundation, ensuring the strength stability and frost heaving resistance of the surface layer and the base layer; in the traditional construction process, it is easy to be affected by factors such as shortage of material sources and long transportation distance, thereby increasing the engineering cost; cement concrete is a brittle material, and its tensile strength is much smaller than its compressive strength; once the airport pavement foundation appears to be not dense, loose and hollow, the concrete slab of the airport pavement is prone to cracking, slab breaking and other diseases, thereby directly affecting the use performance of the airport pavement; at the same time, there are a large number of demolished buildings in the airport, which will generate a large amount of construction waste; a large amount of construction waste will occupy a large amount of land resources when concentratedly stacked, and will also involve environmental problems. SUMMARY

[0003] In order to solve the problems of the existing civil airport cement pavement cushion that is easy to break and affects the use performance, the shortage of material sources increases the engineering cost, and the airport has a large amount of construction waste that occupies land resources and harms the environment, the present application provides a construction method of an airport pavement composite cushion

[0004] The technical scheme of the present application is realized by the following scheme: a construction method of an airport pavement composite cushion, characterized in that it comprises the following operation steps:

[0005] Step A: classify, crush and grade the construction waste regeneration material;

[0006] Step B: mix and blend the crushed and graded construction waste regeneration material according to the specified mixing ratio;

[0007] Step C: use the mixed and blended construction waste for lower cushion construction;

[0008] Step D: use the mixed and blended construction waste for upper cushion construction.

[0009] Through the above technical scheme, the present application utilizes the construction waste improvement as a cushion filler, realizes the reduction, resource utilization and harmlessness of construction waste, solves the problem of urban construction waste, and improves the urban sanitation environment; can alleviate the environmental problems caused by construction waste, and reduce the land resources occupied by the concentrated stacking of construction waste. Resource utilization protects the earth's environment; it can also reduce the cost of runway cushion materials and save the transportation cost of construction waste generated by the demolition of buildings.

[0010] As a preferred embodiment, the step A comprises:

[0011] a1: the recycled construction waste is divided into brick-mixed construction waste and cement concrete construction waste, and the particle size of the recycled construction waste is 1mm-200mm;

[0012] a2: the recycled construction waste is crushed by a crusher, and the particle size is controlled to be less than 150mm;

[0013] a3: the crushed recycled construction waste is classified according to different particle sizes.

[0014] Through the above technical scheme, the recycled construction waste is recycled and the particle size is controlled to be 1mm-200mm, and the crushed recycled construction waste is classified, which effectively ensures that the performance of the material in the subsequent construction process is optimal.

[0015] As preferred, the step B comprises:

[0016] b1: the brick-mixed construction waste is mixed and stirred with a stabilizer and water to form 2% cement brick-mixed construction waste;

[0017] b2: the cement concrete construction waste is mixed and stirred with water.

[0018] As preferred, the stabilizer in step b1 is PO425 ordinary portland cement, the dosage of the PO425 ordinary portland cement is 2% of the mass of the brick-mixed construction waste, and the dosage of the water is 5.7% of the mass of the brick-mixed construction waste.

[0019] Through the above technical scheme, it is obtained through the performance test of the cushion recycled construction waste mixture that the strength and water stability of the 2% cement brick-mixed construction waste prepared by adding 2% of the portland cement and 5.7% of the water into the brick-mixed construction waste are optimal.

[0020] As preferred, the dosage of the water in step b2 is 7.1% of the mass of the cement concrete construction waste.

[0021] Through the above technical scheme, it is obtained through the performance test of the cushion recycled construction waste mixture that the drainage performance of the cement concrete construction waste prepared by adding 7.1% of the water into the cement concrete construction waste is optimal.

[0022] As preferred, the content of the material particles with a particle size of 20mm-80mm in the 2% cement brick-mixed construction waste after mixing and stirring in step b1 is greater than 50% of the total mass, the mud content in the total mass is less than 5%, the non-uniformity coefficient is greater than or equal to 5, and the curvature coefficient is 1-3.

[0023] Preferably, in step b2, the content of 20mm to 120mm particles in the cement concrete-type building slag after uniform mixing is greater than 50% of the total mass, the mud content in the total mass is less than 5%, the non-uniformity coefficient is greater than or equal to 5, and the curvature coefficient is 1 to 3.

[0024] Through the above technical solutions, the uniformity coefficient of 2% cement brick-mixed construction waste and cement concrete construction waste after being mixed and stirred evenly is greater than or equal to 5, and the curvature coefficient is 1 to 3, which are well-graded materials. The voids of coarse particles are just filled by medium particles, and the voids of medium particles are just filled by fine particles. This step-by-step filling makes the sand form the densest packing state, with the porosity reaching the minimum value and the packing density reaching the maximum value. This can save cement and improve the comprehensive performance of concrete.

[0025] Preferably, the 2% cement brick-mixed construction waste prepared in step b1 is used for the subbase construction in step C.

[0026] Based on the above technical solutions, considering that brick-concrete slag is cheaper than traditional mountain stone cushion layer but has lower strength, 2% cement is used for treatment to improve the material's adhesion, density, and thickness, thereby improving the strength and water stability of the brick-concrete slag cushion layer. Therefore, using 2% cement to treat brick-concrete slag in the lower cushion layer can effectively improve the cushion layer's strength and prevent cracking.

[0027] Preferably, step C includes:

[0028] c1: Work section division, each flow section is divided into 50m segments;

[0029] c2: Spreading and leveling, using a combination of bulldozers and graders to spread 2% cement brick-mixed construction waste, with each construction section being 50m. After unloading and spreading, the bulldozers level the material, and the graders level the material after the initial leveling by the bulldozers.

[0030] c3: Compaction. After the surface is leveled by a roller, the elevation is checked. Once the surface passes the inspection, a road roller is immediately used to compact the subbase across its entire width, rolling from both sides towards the center.

[0031] Preferably, the cement concrete-type construction waste described in step b2 is used for the construction of the upper subbase in step D, and the construction process of the upper subbase is the same as that of the lower subbase.

[0032] Through the above technical solutions, cement concrete-type construction waste with good water-water ratio has good drainage performance and can be used for the construction of the upper subbase, which accelerates the drainage and consolidation of the subbase, improves the shear strength of the subbase, restrains the lateral deformation of the subbase, improves the stability of the subbase, and improves its deformation properties.

[0033] In summary, the present invention has the following beneficial effects:

[0034] 1. This invention utilizes a scientifically sound technical solution to modify construction waste and use it as a subbase filler, achieving the reduction, resource recovery, and harmless treatment of construction waste. This solves the urban construction waste problem and improves the urban sanitation environment. It alleviates environmental problems caused by construction waste and reduces the land resources occupied by centralized construction waste dumping. Resource utilization protects the Earth's environment; it also reduces the cost of runway subbase materials and saves on transportation costs for construction waste generated from demolished buildings. By recycling and reusing construction waste, it unifies the social benefits of environmental protection and conservation with the economic benefits of reduced material costs. This is an important embodiment of the construction of "safe, green, smart, and people-oriented" airports and a significant pioneering exploration in promoting green airport construction.

[0035] 2. This invention, through performance testing of recycled construction waste mixtures for subbase layers, reveals that 2% cement-concrete composite building waste, prepared by adding 2% silicate cement and 5.7% water to the brick-concrete composite building waste, exhibits the best strength and water stability. The 2% cement-concrete composite building waste, after thorough mixing, has a uniformity coefficient greater than or equal to 5 and a curvature coefficient of 1-3, indicating well-graded materials. The voids in coarse particles are precisely filled by medium particles, and the voids in medium particles are precisely filled by fine particles, thus creating a densest packing state with minimal porosity and maximum bulk density. This approach saves cement and improves the overall performance of concrete. Considering that brick-concrete composite building waste is cheaper than traditional granite subbase layers but has lower strength, 2% cement treatment is used to improve the material's adhesion, density, and thickness, thereby enhancing the strength and water stability of the brick-concrete composite building waste subbase. Therefore, using 2% cement treatment for brick-concrete composite building waste in the subbase layer effectively improves the subbase strength and reduces cracking.

[0036] 3. The present invention, through performance testing of recycled construction waste mixture for subbase, found that the cement concrete-like construction waste with 7.1% water added to it exhibits the best drainage performance. The cement concrete-like construction waste with a good water ratio has good drainage performance and can be used for subbase construction, accelerating the drainage and consolidation of the subbase, improving the shear strength of the subbase, restraining the lateral deformation of the subbase, improving the stability of the subbase, and improving its deformation properties. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the construction method of the present invention;

[0038] Figure 2 This is a cross-sectional view of the composite cushion layer of the present invention.

[0039] Explanation of reference numerals in the attached diagram: 1. Upper cushion layer, 2. Upper cushion layer. Detailed Implementation

[0040] In order to more clearly understand the above-mentioned purposes, features and advantages of the present application, the present application is further described below in conjunction with the accompanying drawings and examples.

[0041] In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. However, it will be recognized by one skilled in the art that the present application can be practiced without the specific details, or with an alternative combination of different elements, and, therefore, the scope of the present application is not limited to the specific examples disclosed in the following description.

[0042] A construction method of an airport pavement composite cushion, comprising the following operation steps:

[0043] Step A: classifying, crushing and grading the construction waste recycled material; specifically classified into:

[0044] a1: the recycled construction waste recycled material can be roughly divided into recycled brick and concrete, recycled cement concrete and recycled asphalt concrete; considering that the strength of asphalt concrete is relatively low, the recycled construction waste recycled material is divided into brick and concrete construction waste and cement concrete construction waste as the raw material of recycled material as the base material, and the particle size of the waste is distributed in the range of 1mm-200mm;

[0045] a2: using a crusher to crush the two types of construction waste recycled material respectively, and the particle size of the crushed construction waste recycled material is controlled within 150m;

[0046] a3: grading the crushed construction waste recycled material according to different particle sizes.

[0047] Step B: mixing the crushed and graded construction waste recycled material according to the standard mixing ratio;

[0048] b1: mixing the brick and concrete construction waste with stabilizer and water and stirring uniformly to make 2% cement brick and concrete construction waste;

[0049] According to the Highway Geotechnical Test Regulation JTG3430, the compaction test of the building waste regeneration material is carried out, the heavy compaction method is selected, 10 different water contents are set for the cement brick mixed building slag, and each group of samples is 3 kg; the compaction curve of the regeneration material can be obtained under the action of a certain compaction work, so as to obtain the maximum dry density and the optimum water content, and the change of the grading before and after compaction can be determined, which reflects the impact resistance of the recycled regeneration material to a certain extent; according to the compaction test results of the brick mixed building slag, the optimum mixing proportion of the stabilizer and water and the brick mixed material under different stabilizer contents (2% / 4% / 6%) is studied; according to the Highway Geotechnical Test Regulation JTG3430, the heavy compaction test is carried out to obtain the optimum water-cement ratio and the maximum dry density; it is concluded that the stabilizer is PO425 ordinary portland cement, the dosage of PO425 ordinary portland cement is 2% of the mass of the brick mixed building slag, and the dosage of water is 5.7% of the mass of the brick mixed building slag; the content of 20mm-80mm material particles in the 2% cement brick mixed building slag is greater than 50% of the total mass, the mud content in the total mass is less than 5%, the non-uniformity coefficient of the 2% cement brick mixed building slag is greater than or equal to 5, and the curvature coefficient is 1-3; the non-uniformity coefficient is greater than or equal to 5, the curvature coefficient is between 1-3, which is a well-graded material, the voids of coarse particles are filled by medium particles, and the voids of medium particles are filled by fine particles, so that the sand forms the most compact packing state, the void ratio reaches the minimum value, and the packing density reaches the maximum value; it can save cement and improve the comprehensive performance of concrete.

[0050] b2: mix and stir the cement concrete building slag and water uniformly.

[0051] According to the Highway Cement Cement Concrete Test Regulation JTG 3420, for cement: complete cement consistency water consumption, setting time, stability test; for cement concrete building slag and water mixture, complete consistency, bleeding, setting time, bulk density test; for finished cement concrete building slag, complete compressive strength, and the water content is 7.1% of the mass of the cement concrete building slag, 7.1% of water is added to the cement concrete building slag, and the drainage performance of the cement concrete building slag is the best at this time; the content of 20mm-120mm material particles in the mixed and stirred cement concrete building slag is greater than 50% of the total mass, the mud content in the total mass is less than 5%, the non-uniformity coefficient is greater than or equal to 5, and the curvature coefficient is 1-3; the cement concrete building slag with good water ratio has good drainage performance and is used for upper cushion construction, which can accelerate the drainage and consolidation of the cushion, improve the shear strength of the cushion, constrain the lateral deformation of the cushion, improve the stability of the cushion, and improve the deformation properties.

[0052] Step C: The lower cushion layer is constructed using mixed 2% cement brick and concrete construction waste. Considering that the price of brick and concrete construction waste is cheaper than traditional mountain stone cushion layer, but the strength is lower, 2% cement treatment is adopted to improve the adhesion and density of the material and increase the thickness to improve the strength and water stability of the brick and concrete construction waste cushion layer. Therefore, the lower cushion layer using 2% cement treated brick and concrete construction waste can effectively improve the strength of the cushion layer and prevent cracking.

[0053] c1: The work section is divided; each flow section is divided into 50m sections. After unloading 50m, it can be pushed, scraped, and vibrated and rolled;

[0054] c2: Paving and leveling; combined paving using a bulldozer and a grader, with 50m as a construction section. After unloading and distributing the material, the bulldozer is used to level and initially level the bulldozer. According to the layout elevation and the virtual paving thickness, white lime is used to mark obvious marks to indicate the bulldozer height for the bulldozer to push and level. The grader is used for leveling after the bulldozer initially levels. First, use the roller to press once, and then use the grader to level.

[0055] c3: Rolling; after the grader is scraped, the surface elevation is detected. After passing the detection, the roller is immediately used to compact the cushion layer within the full width, from both sides to the center.

[0056] Step D: The upper cushion layer is constructed using mixed cement concrete construction waste. The water-cement concrete construction waste has good drainage performance and is used for upper cushion layer construction, which accelerates the drainage and consolidation of the cushion layer, improves the shear strength of the cushion layer, restricts the lateral deformation of the cushion layer, improves the stability of the cushion layer, and improves its deformation properties. The upper cushion layer construction process is consistent with the lower cushion layer. The thickness of the upper cushion layer is 20cm.

[0057] This construction method uses building waste modification as cushion filler, realizes the reduction, resource utilization, and harmlessness of building waste, solves the problem of urban building waste, and improves the urban sanitation environment. It can alleviate the environmental problems caused by building waste and reduce the land resources occupied by the centralized storage of building waste. Resource utilization protects the earth's environment; it can also reduce the cost of runway cushion materials and save the transportation cost of building waste generated by the demolition of buildings. Recycling building waste, environmental and social benefits and economic benefits of reducing material costs are unified, which is an important embodiment of the four types of airport construction of "safety, green, wisdom, and humanity", and an important exploration and exploration of promoting green airport construction.

[0058] The above merely describes preferred embodiments of the present application, but is not intended to limit the present application in other forms. Any person skilled in the art can make changes or modifications to the above disclosed technical contents into equivalent embodiments with equivalent changes, and apply them to other fields. However, any simple modification or equivalent change made to the above embodiments without departing from the technical solution of the present application, and according to the technical essence of the present application, still belongs to the protection scope of the technical solution of the present application.

Claims

1. A construction method for a composite subbase layer for airport pavement, characterized in that, The following steps are included: Step A: Sort, crush, and classify the recycled construction waste; Step B: Mix the crushed and graded recycled construction waste materials according to the standard mixing ratio; Step C: Use the mixed construction waste for the subbase construction; Step D: Use the mixed construction waste for the upper subbase construction; Step A includes: a1: The recycled construction waste is divided into two categories: brick-concrete type construction waste and cement-concrete type construction waste. At this time, the particle size distribution range of the recycled construction waste is 1mm to 200mm. a2: Use a crusher to crush the two types of recycled construction waste separately, and control the particle size to within 150mm after crushing; a3: The crushed construction waste recycled material is sorted according to different particle sizes; Step B includes: b1: Mix the brick-concrete building waste with stabilizer and water evenly to prepare 2% cement brick-concrete building waste; b2: Mix the cement concrete-type construction waste with water and stir evenly; The stabilizer mentioned in step b1 is PO425 ordinary Portland cement, the dosage of PO425 ordinary Portland cement is 2% of the mass of brick-concrete building waste, and the dosage of water is 5.7% of the mass of brick-concrete building waste. In step b2, the amount of water added is 7.1% of the mass of cement concrete slag. In step b1, after mixing and stirring evenly, the content of 20mm to 80mm particles in the 2% cement brick-mixed building slag is greater than 50% of the total mass, the mud content in the total mass is less than 5%, the non-uniformity coefficient is greater than or equal to 5, and the curvature coefficient is 1 to 3. In step b2, the cement concrete-type construction slag after being mixed and stirred evenly contains more than 50% of the material particles with a diameter of 20mm to 120mm, less than 5% of the mud content in the total mass, a non-uniformity coefficient greater than or equal to 5, and a curvature coefficient of 1 to 3.

2. The construction method of a composite subbase for airport pavement as described in claim 1, characterized in that: The 2% cement brick-concrete slag prepared in step b1 is used for the subbase construction in step C.

3. The construction method of a composite subbase for airport pavement as described in claim 2, characterized in that: Step C includes: c1: Work section division, each flow section is divided into 50m segments; c2: Spreading and leveling, using a combination of bulldozers and graders to spread 2% cement brick-mixed construction waste, with each construction section being 50m. After unloading and spreading, the bulldozers level the material, and the graders level the material after the initial leveling by the bulldozers. c3: Compaction. After the surface is leveled by a roller, the elevation is checked. Once the surface passes the inspection, a road roller is immediately used to compact the subbase across its entire width, rolling from both sides towards the center.

4. The construction method of a composite subbase for airport pavement as described in claim 1, characterized in that: The cement concrete-type construction waste described in step b2 is used in the upper subbase construction of step D. The construction process of the upper subbase is the same as that of the lower subbase construction.

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