Composite pavement with reflection crack prevention function and construction method thereof

Abstract

The application discloses a composite pavement with a reflection crack prevention function and a construction method thereof, and steps of the method comprise the following steps: S1, pouring a common cement concrete layer on the upper part of a bottom base layer and roughening the common cement concrete layer; S2, dividing a rigid stress absorbing layer prefabricated plate laying area and determining a plate surface prefabricated size; S3, layer-by-layer pouring the rigid stress absorbing layer prefabricated plate on the site; S4, spraying a bonding layer on the surface of the common cement concrete layer, hoisting the rigid stress absorbing layer prefabricated plate and laying the rigid stress absorbing layer prefabricated plate; and S5, continuously and uniformly spreading asphalt mixture to form an asphalt surface layer, opening traffic after curing, and completing the construction of the composite pavement with the reflection crack prevention function. The construction method is simple and fast, material preparation is easy, and mechanized operation is facilitated, so that not only manpower cost and a construction period can be saved, but also reflection cracks can be effectively delayed from extending upwards, road structure anti-reflection efficiency can be improved, and the service life of the composite pavement can be greatly prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of road engineering construction, and in particular to a composite pavement with a reflective crack prevention and control function and a construction method thereof. Background Art

[0002] Composite pavements have been in use since the end of the last century. With the rapid development of China's road traffic, their structural forms and construction methods have also been continuously innovated and improved. Composite pavements offer advantages such as high overall pavement stiffness, high base bearing capacity, and excellent driving comfort. However, with the increase in service life and traffic volume, reflective cracks, caused by a combination of driving loads and environmental factors, have gradually become the primary form of structural damage to the asphalt surface layer of composite pavements. The generation, expansion, and penetration of reflective cracks weaken the structural strength to a certain extent, seriously affecting the service life of the composite pavement. Furthermore, the presence of cracks allows surface water to seep into the structure, reducing the original pavement's drainage capacity and accelerating structural damage, leading to the emergence of more pavement diseases.

[0003] At present, traditional composite pavement reflective crack prevention and control measures and construction methods, such as adding an asphalt layer to increase the thickness, adding a geotechnical material interlayer to the composite pavement structure, and setting an asphalt-based flexible stress absorption layer, have not produced significant prevention and control effects.

[0004] Therefore, in response to the increasing problem of reflective cracks in pavement, there is an urgent need to develop a composite pavement with reflective crack prevention and control function and its construction method, which is of great engineering significance for improving the structural performance and service life of the composite pavement and achieving rapid and effective construction. Summary of the Invention

[0005] The purpose of the present invention is to provide a composite pavement with reflective crack prevention and control function and a construction method thereof, so as to reduce the occurrence of reflective cracks, enhance the pavement structural performance, extend the service life of the road, and improve the efficiency and economic benefits of composite pavement construction.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] In a first aspect, the present invention provides a method for constructing a composite pavement with a reflective crack prevention function, comprising the following steps:

[0008] S1. Pour an ordinary cement concrete layer on the upper part of the base layer, roughen the surface of the ordinary cement concrete layer, clean the waste on the rough working surface and keep it clean;

[0009] S2. Based on the locations where stress concentration is likely to occur on the road surface, which can lead to reflective cracks, the laying area of ​​the rigid stress absorption layer prefabricated panels should be reasonably divided and the prefabricated dimensions of the panels should be determined;

[0010] S3. Cast the rigid stress-absorbing layer prefabricated panels in layers on site: first cast the lower layer of fiber-reinforced cement-based composite material, lay the polyester glass fiber composite mesh on its surface, and then cast the upper layer of fiber-reinforced cement-based composite material;

[0011] S4. Spray a bonding layer on the surface of the ordinary cement concrete layer in the paving area, hoist the rigid stress absorbing layer precast panels to the corresponding position for paving, and apply pressure on the road surface machinery so that the rigid stress absorbing layer precast panels are in close contact with the bonding layer;

[0012] S5. The asphalt mixture formed by mixing modified asphalt with fine aggregate gravel is continuously and evenly spread by an asphalt paver and compacted by a roller to form an asphalt surface layer. After curing, the road is opened to traffic, completing the construction of a composite pavement with reflective crack prevention function.

[0013] In some specific technical solutions, the thickness of the ordinary cement concrete layer is 50 to 200 mm.

[0014] In some specific technical solutions, the thickness of the rigid stress absorbing layer prefabricated plate is 12 to 18 mm.

[0015] In some specific technical solutions, the thickness of the asphalt surface layer is 30 to 50 mm.

[0016] In some specific technical solutions, in step S2, the prefabricated dimensions of the rigid stress absorbing layer prefabricated panels are 3.5 to 10 m in length, 0.8 to 1.8 m in width, and the panel aspect ratio is ≥3.5.

[0017] In some specific technical solutions, in step S3, the upper layer fiber-reinforced cement-based composite material and the lower layer fiber-reinforced cement-based composite material both include the following component raw materials in percentage by mass: cement 18.25% to 19.75%, fly ash 38.90% to 40.15%, mineral powder 1.07% to 6.43%, microbeads 2.14% to 4.28%, sand 21.05% to 25.60%, water 15.60% to 18.90%, admixture 0.14% to 0.15%, defoaming agent 0.01% to 0.02%, and fiber 0.54% to 1.29%; the compressive strength of the upper layer fiber-reinforced cement-based composite material and the lower layer fiber-reinforced cement-based composite material are ≥50MPa, the flexural strength is ≥14MPa, and the ultimate tensile strain is ≥2.8%.

[0018] Preferably, the cement is ordinary Portland cement P.O42.5, with a specific surface area of ​​≥300m 2 / kg; fly ash is Class I fly ash with a particle size of 2 to 10 μm; slag is S105 grade limestone slag with a specific surface area of ​​≥720 m 2 / kg; the particle size of micro beads is 0.1~1.5μm, and the specific surface area is ≥3000m 2 / kg, CaO content ≤0.5%, in the form of a completely spherical powder; sand is river sand with a particle size ≤2.36mm; the admixture is a polymer high-efficiency polycarboxylic acid water reducer with a solid content of 20-40%; the defoamer is a non-ionic silicone defoamer with an effective substance content ≥99%; the fiber is PE fiber with a length of 12-15mm, a diameter of 40-55μm, a tensile strength ≥1800MPa, an elastic modulus ≥72GPa, and a density of 0.8-1.1g / cm 3 , the elongation at break is 4-7%.

[0019] In some specific technical solutions, in step S3, the specific operation is: first dry-mix the cementitious material and fine aggregate in the mixing drum, then add water and admixtures for further stirring, and finally add fiber for mixing; wherein, a vibrator is installed on the side of the trough containing the fiber, the bottom discharge port is opened and the vibrator is turned on at the same time, and the PE fiber is sprinkled into the mixing drum and evenly stirred by vibrating the trough, and the stirring time is 10 to 14 minutes; the discharge position height of the storage hopper is fixed and adjusted by the support truss, and the unloading mechanism is opened while moving along the guide beams on both sides of the prefabricated board mold for paving, and the height of the scraper plate on the guide beam is adjusted to fit the cement-based slurry, and the equipment moves slowly to cast the lower layer of fiber-reinforced cement-based composite material, and after initial setting, the polyester glass fiber composite mesh is laid and fixed on both sides of the mold, and then the upper layer of fiber-reinforced cement-based composite material is laid and the surface is smoothed to form a rigid stress absorption layer prefabricated board; the thickness of the upper layer of fiber-reinforced cement-based composite material is 8 to 10 mm.

[0020] In some specific technical solutions, in step S3, the thickness of the polyester glass fiber composite mesh is ≤1.2 mm, the maximum elongation is 5%, and the mesh spacing is 4 mm×4 mm.

[0021] In some specific technical solutions, in step S4, the bonding layer is a polyurethane adhesive, and the coating amount is 1.8 to 2.4 kg / m 2 , the coating thickness is ≤2.5mm.

[0022] In some specific technical solutions, in step S5, the asphalt mixture forming the asphalt surface layer is mixed with modified asphalt, cement, mineral powder, 0-3 mm crushed stone, 3-6 mm crushed stone, 6-11 mm crushed stone, and 11-16 mm crushed stone in a mass ratio of (4.8-5.2): (1.0-1.1): (2.0-2.2): (28-34): (14-16): (20-27): (25-30); the modified asphalt is a high-viscosity modified emulsified asphalt with a softening point of ≥70°C, a residue on a 1.18 mm sieve of ≤0.1%, and a paving temperature of 30-60°C; the fine aggregate crushed stone is limestone and diabase, with a mixing ratio of (1.48-1.50): 1.0, and an apparent relative density of ≥2.60 t / m 3 .

[0023] In a second aspect, the present invention provides a composite pavement having reflective crack prevention and control function formed by the above-mentioned construction method.

[0024] Compared with the prior art, the present invention provides a composite pavement with reflective crack prevention and control function and a construction method thereof, which has the following beneficial effects:

[0025] (1) The present invention uses high-toughness cement-based composite materials for layered casting, and arranges a polyester glass fiber composite mesh in the middle to prefabricate a rigid stress absorption layer prefabricated board. The performance and advantages of polyethylene fiber and polyester glass fiber composite mesh are fully utilized, the crack resistance and stress absorption performance of the prefabricated board are improved, and the stress concentration generated at the joints or cracks of the concrete base under load is alleviated, so that the compressive stress and tensile stress in the surface layer are diffused, thereby having a good anti-reflective crack effect.

[0026] (2) The rigid stress absorbing layer prefabricated panels of the present invention are prefabricated by batch casting in the factory and hoisted and paved on site, ensuring high construction efficiency and project quality; the rigid stress absorbing layer prefabricated panels and the cement concrete layer are tightly bonded by spraying polyurethane adhesive, the interlayer bonding force is effectively enhanced, and the structural and overall strength are improved; the fatigue resistance of the pavement structure after adding the rigid stress absorbing layer prefabricated panels is 4 to 10 times higher than that of the ordinary pavement structure.

[0027] (3) The construction method of the present invention is simple and fast, and the materials are readily available, facilitating mechanized operations. This method not only saves labor costs and shortens the construction period, but also effectively delays the upward propagation of reflective cracks, improves the anti-reflection performance of road structures, and significantly increases the service life of composite pavements. Furthermore, the present invention can also be used in highway cement concrete bridge deck paving projects. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0029] Figure 1 It is a structural schematic diagram of the composite pavement of the present invention;

[0030] Figure 2 This is a schematic structural diagram of a rigid stress absorbing layer prefabricated plate according to the present invention;

[0031] Figure 3 A side view schematic diagram of laying a rigid stress-absorbing layer prefabricated slab at a cement concrete joint according to the present invention;

[0032] Figure 4 This is a schematic plan view of laying a rigid stress-absorbing layer prefabricated slab at a cement concrete joint according to the present invention;

[0033] Figure 5 This is a schematic diagram of the structure of fibers being sprinkled into the forced mixing drum during the mixing process;

[0034] Figure 6 This is a schematic diagram of the construction structure of the rigid stress absorption layer prefabricated panel;

[0035] Figure 7 The gradation range of fine aggregate in asphalt mixture;

[0036] Figure 8 Comparison of fatigue life and anti-rebound performance of composite pavement structures.

[0037] Figure numerals: 1. base layer; 2. ordinary cement concrete layer; 3. bonding layer; 4. rigid stress absorption layer precast board; 41. lower fiber reinforced cement-based composite material layer; 42. upper fiber reinforced cement-based composite material layer; 43. polyester glass fiber composite mesh; 5. asphalt surface layer; 6. storage hopper; 7. unloading mechanism; 8. hanging plate; 9. guide rail beam; 10. supporting truss; 11. precast board mold; 12. forced mixing drum; 13. material trough; 14. vibrator; 15. discharge port. DETAILED DESCRIPTION

[0038] The technical solutions of the present invention are described clearly and completely below. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are also within the scope of protection of the present invention.

[0039] The present invention will be further described in detail below through detailed embodiments in conjunction with the accompanying drawings.

[0040] Example 1

[0041] refer to Figure 1 and Figure 2 This embodiment provides a composite pavement with reflective crack prevention capabilities. The pavement comprises a 120mm thick ordinary cement concrete layer 2 cast atop a subbase 1. Paving areas are defined at locations in the ordinary cement concrete layer 2 where stress concentration, which can lead to reflective cracking, is sprayed with a bonding layer 3 made of a polyurethane adhesive. 18mm thick rigid stress-absorbing prefabricated panels 4 are laid parallel to the ground above the bonding layer 3. The lower surfaces of the rigid stress-absorbing prefabricated panels 4 are bonded to the bonding layer 3. A 50mm thick asphalt surface layer 5 is also laid atop the ordinary cement concrete layer 2, covering the rigid stress-absorbing prefabricated panels 4. The rigid stress-absorbing prefabricated panels 4 comprise a lower fiber-reinforced cement-based composite material layer 41, an upper fiber-reinforced cement-based composite material layer 42, and a polyester-glass fiber composite mesh 43 disposed therebetween. The upper fiber-reinforced cement-based composite material layer 42 is 10mm thick.

[0042] Specifically, the composite pavement is formed by a construction method comprising the following steps:

[0043] S1. Pour a 120 mm thick ordinary cement concrete layer 2 on the upper part of the base layer 1, perform roughening treatments such as roughening and milling on the surface of the ordinary cement concrete layer 2, clean the waste on the rough working surface and keep it clean.

[0044] S2. Based on locations where stress concentration, which can lead to reflective cracks, is likely to occur on the road surface (e.g., joints in cement concrete layers), the rigid stress-absorbing layer precast slabs are rationally divided into laying areas and the precast slab dimensions are determined. The precast dimensions of the rigid stress-absorbing layer precast slab 4 are 4.0 m in length and 1.0 m in width, with an aspect ratio of 4.

[0045] S3. Cast the rigid stress absorption layer prefabricated panels in layers on site: first cast the lower layer of fiber reinforced cement-based composite material, lay the polyester glass fiber composite mesh 43 on the surface, and then cast the upper layer of fiber reinforced cement-based composite material.

[0046] The polyester glass fiber composite mesh 43 has a thickness of ≤1.2 mm, a maximum elongation of 5%, and a mesh spacing of 4 mm×4 mm.

[0047] The upper and lower fiber-reinforced cement-based composite materials each include the following raw materials by mass: cement 18.50%, fly ash 39.03%, mineral powder 2.03%, micro-beads 2.16%, sand 21.12%, water 15.80%, admixture 0.15%, defoamer 0.01%, and fiber 1.20%. The upper and lower fiber-reinforced cement-based composite materials each have a compressive strength of 54.20 MPa, a flexural strength of 14.08 MPa, and an ultimate tensile strain of 3.10%. The cement is ordinary Portland cement P.O42.5, with a specific surface area of ​​≥300 m2. 2 / kg; fly ash is Class I fly ash with a particle size of 2 to 10 μm; slag is S105 grade limestone slag with a specific surface area of ​​≥720 m 2 / kg; the particle size of micro beads is 0.1~1.5μm, and the specific surface area is ≥3000m 2 / kg, CaO content ≤0.5%, completely spherical powder; sand is river sand with a particle size ≤2.36mm; the admixture is a polymer high-efficiency polycarboxylic acid water reducer with a solid content of 28%; the defoamer is a non-ionic silicone defoamer with an effective substance content ≥99%; the fiber is PE fiber with a length of 12mm, a diameter of 45μm, a tensile strength of 2200MPa, an elastic modulus of 85GPa, and a density of 1.1g / cm 3 , the elongation at break is 5.3%.

[0048] refer to Figure 5 and Figure 6 The specific pouring process is as follows: first, dry-mix the cementitious material and fine aggregate in the forced mixing drum 12, then add water and admixtures for further mixing, and finally, add the fiber for mixing. A vibrator 14 is installed on the side of the fiber trough 13. Opening the bottom feed port 15 and simultaneously activating the vibrator 14, the trough 13 vibrates, allowing the PE fiber to be evenly mixed within the forced mixing drum 12 for 14 minutes. After mixing, the material in the forced mixing drum 12 is pumped into the storage hopper 6 for subsequent pouring. The discharge position height of the storage hopper 6 is fixed and adjusted by the support truss 10, and the guide beams 9 on both sides of the precast panel mold 11 are moved while the discharge mechanism 7 is opened for paving. The height of the scraper plate 8 on the guide beam 9 is adjusted and fits the cement-based slurry. The equipment moves slowly to cast the lower layer of fiber-reinforced cement-based composite material. After initial setting, the polyester glass fiber composite mesh 43 is laid and fixed on both sides of the mold, and then the upper layer of fiber-reinforced cement-based composite material is laid and the surface is smoothed to form a rigid stress absorption layer precast panel 4; the thickness of the upper layer of fiber-reinforced cement-based composite material is 10 mm.

[0049] S4. Spray the bonding layer 3 on the surface of the ordinary cement concrete layer 2. The bonding layer 3 is a polyurethane adhesive with a coating amount of 2.0 kg / m2 , the coating thickness is 1.8mm; then, refer to Figure 3 and Figure 4 , hoist the rigid stress absorption layer prefabricated panel 4 to the corresponding position for laying, and apply mechanical pressure to the road surface to make the rigid stress absorption layer prefabricated panel 4 closely contact the bonding layer 3 to avoid debonding and slippage under the action of horizontal force, thereby ensuring the continuous stress bearing and anti-reflective crack performance of the rigid stress absorption layer prefabricated panel 4.

[0050] S5. The asphalt mixture formed by mixing modified asphalt with fine aggregate gravel is continuously and evenly spread by an asphalt paver and compacted by a roller to form an asphalt surface layer 5. After curing, the road is opened to traffic, completing the construction of the composite pavement with reflective crack prevention function.

[0051] The asphalt mixture forming the asphalt surface layer is made of modified asphalt, cement, mineral powder, 0-3mm crushed stone, 3-6mm crushed stone, 6-11mm crushed stone, and 11-16mm crushed stone in a mass ratio of 4.9:1.0:2.0:31.0:15.0:24.0:27.0. The specific range of fine aggregate gradation of asphalt mixture is shown in Figure 7 The modified asphalt is a high-viscosity modified emulsified asphalt with a softening point of ≥70°C, a residue on a 1.18mm sieve of ≤0.1%, and a paving temperature of 30-60°C. The fine aggregate gravel is limestone and diabase, with a mixing ratio of 1.50:1.0 and an apparent relative density of ≥2.60t / m 3 .

[0052] Example 2

[0053] refer to Figure 1 and Figure 2 This embodiment provides a composite pavement with reflective crack prevention capabilities. The pavement comprises a 120 mm thick ordinary cement concrete layer 2 cast on a subbase layer 1. Paving areas are defined at locations in the ordinary cement concrete layer 2 where stress concentration, which can lead to reflective cracking, is sprayed with a bonding layer 3 made of a polyurethane adhesive. A 14 mm thick rigid stress-absorbing prefabricated board 4 is laid above the bonding layer 3, parallel to the ground. The lower surface of the rigid stress-absorbing prefabricated board 4 is bonded to the bonding layer 3. A 50 mm thick asphalt surface layer 5 is also laid above the ordinary cement concrete layer 2, covering the rigid stress-absorbing prefabricated board 4. The rigid stress-absorbing prefabricated board 4 comprises a lower fiber-reinforced cement-based composite material layer 41, an upper fiber-reinforced cement-based composite material layer 42, and a polyester-glass fiber composite mesh 43 disposed therebetween. The upper fiber-reinforced cement-based composite material layer 42 is 10 mm thick.

[0054] Specifically, the composite pavement is formed by a construction method comprising the following steps:

[0055] S1. Pour a 120 mm thick ordinary cement concrete layer 2 on the upper part of the base layer 1, perform roughening treatments such as roughening and milling on the surface of the ordinary cement concrete layer 2, clean the waste on the rough working surface and keep it clean.

[0056] S2. Based on locations where stress concentration, which can lead to reflective cracks, is likely to occur on the road surface (e.g., joints in cement concrete layers), the rigid stress-absorbing layer precast slabs are rationally divided into laying areas and their precast dimensions are determined. The precast dimensions of the rigid stress-absorbing layer precast slabs 4 are 7.5 meters in length and 1.8 meters in width, with an aspect ratio of 4.17.

[0057] S3. Cast the rigid stress absorption layer prefabricated panels in layers on site: first cast the lower layer of fiber reinforced cement-based composite material, lay the polyester glass fiber composite mesh 43 on the surface, and then cast the upper layer of fiber reinforced cement-based composite material.

[0058] The polyester glass fiber composite mesh 43 has a thickness of ≤1.2 mm, a maximum elongation of 5%, and a mesh spacing of 4 mm×4 mm.

[0059] The upper and lower fiber-reinforced cement-based composite materials each include the following raw materials by mass: cement 19.00%, fly ash 39.00%, mineral powder 1.50%, micro-beads 2.14%, sand 21.05%, water 16.05%, admixture 0.15%, defoamer 0.01%, and fiber 1.10%. The compressive strength, flexural strength, and ultimate tensile strain of the upper and lower fiber-reinforced cement-based composite materials are 57.4 MPa, 13.88 MPa, and 2.82%, respectively. The cement is ordinary Portland cement P.O42.5, with a specific surface area of ​​≥300 m 2 / kg; fly ash is Class I fly ash with a particle size of 2 to 10 μm; slag is S105 grade limestone slag with a specific surface area of ​​≥720 m 2 / kg; the particle size of micro beads is 0.1~1.5μm, and the specific surface area is ≥3000m 2 / kg, CaO content ≤0.5%, completely spherical powder; sand is river sand with a particle size ≤2.36mm; the admixture is a polymer high-efficiency polycarboxylic acid water reducer with a solid content of 28%; the defoamer is a non-ionic silicone defoamer with an effective substance content ≥99%; the fiber is PE fiber with a length of 12mm, a diameter of 45μm, a tensile strength of 2200MPa, an elastic modulus of 85GPa, and a density of 1.1g / cm 3 , the elongation at break is 5.3%.

[0060] refer to Figure 5 and Figure 6The specific pouring process is as follows: first, dry-mix the cementitious material and fine aggregate in the forced mixing drum 12, then add water and admixtures for further mixing, and finally, add the fiber for mixing. A vibrator 14 is installed on the side of the fiber trough 13. Opening the bottom feed port 15 and simultaneously activating the vibrator 14, the trough 13 vibrates, allowing the PE fiber to be evenly mixed within the forced mixing drum 12 for 14 minutes. After mixing, the material in the forced mixing drum 12 is pumped into the storage hopper 6 for subsequent pouring. The discharge position height of the storage hopper 6 is fixed and adjusted by the support truss 10, and the guide beams 9 on both sides of the precast panel mold 11 are moved while the discharge mechanism 7 is opened for paving. The height of the scraper plate 8 on the guide beam 9 is adjusted and fits the cement-based slurry. The equipment moves slowly to cast the lower layer of fiber-reinforced cement-based composite material. After initial setting, the polyester glass fiber composite mesh 43 is laid and fixed on both sides of the mold, and then the upper layer of fiber-reinforced cement-based composite material is laid and the surface is smoothed to form a rigid stress absorption layer precast panel 4; the thickness of the upper layer of fiber-reinforced cement-based composite material is 10 mm.

[0061] S4. Spray the bonding layer 3 on the surface of the ordinary cement concrete layer 2. The bonding layer 3 is a polyurethane adhesive with a coating amount of 2.0 kg / m 2 , the coating thickness is 1.8mm; then, refer to Figure 3 and Figure 4 , hoist the rigid stress absorption layer prefabricated panel 4 to the corresponding position for laying, and apply mechanical pressure to the road surface to make the rigid stress absorption layer prefabricated panel 4 closely contact the bonding layer 3 to avoid debonding and slippage under the action of horizontal force, thereby ensuring the continuous stress bearing and anti-reflective crack performance of the rigid stress absorption layer prefabricated panel 4.

[0062] S5. The asphalt mixture formed by mixing modified asphalt with fine aggregate gravel is continuously and evenly spread by an asphalt paver and compacted by a roller to form an asphalt surface layer 5. After curing, the road is opened to traffic, completing the construction of the composite pavement with reflective crack prevention function.

[0063] The asphalt mixture forming the asphalt surface layer is made of modified asphalt, cement, mineral powder, 0-3mm crushed stone, 3-6mm crushed stone, 6-11mm crushed stone, and 11-16mm crushed stone in a mass ratio of 4.9:1.0:2.0:31.0:15.0:24.0:27.0. The specific range of fine aggregate gradation of asphalt mixture is shown in Figure 7 The modified asphalt is a high-viscosity modified emulsified asphalt with a softening point of ≥70°C, a residue on a 1.18mm sieve of ≤0.1%, and a paving temperature of 30-60°C. The fine aggregate gravel is limestone and diabase with a mixing ratio of 1.48:1.0 and an apparent relative density of ≥2.60t / m 3 .

[0064] The composite pavement structure without the rigid stress absorbing layer prefabricated plate is used as a control example, and the fatigue life and anti-rebound performance of the composite pavement structure are compared and analyzed together with Examples 1 and 2. Figure 8 shown.

[0065] According to the analysis Figure 8 The data show that compared to the conventional composite pavement structure without a rigid stress-absorbing precast panel in the control example, the pavement structures in Examples 1 and 2, equipped with rigid stress-absorbing precast panels, significantly extended their fatigue life and demonstrated superior anti-reflection cracking performance. The rigid stress-absorbing precast panels exhibited excellent stress absorption properties. Compared to the control example, the fatigue life of Example 1 increased by 11.4 times, and that of Example 2 increased by 7.1 times. These results demonstrate that appropriately increasing the thickness of the rigid stress-absorbing precast panels can enhance the composite pavement structure's resistance to reflective cracking.

[0066] In summary, the present invention has a good effect in preventing and controlling reflective cracks by providing a rigid stress absorption layer prefabricated board. It can be seen that the construction method of the present invention has high feasibility and innovation, and has great value for promotion and application.

[0067] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

[0068] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A construction method for a composite pavement with a reflective crack prevention function, characterized in that: The following steps are involved: S1. Pour an ordinary cement concrete layer on the upper part of the base layer, roughen the surface of the ordinary cement concrete layer, clean the waste on the rough working surface and keep it clean; S2. Based on the locations where stress concentration is likely to occur on the road surface, which can lead to reflective cracks, the laying area of ​​the rigid stress absorbing layer prefabricated panels should be reasonably divided and the prefabricated dimensions of the panels should be determined. The prefabricated dimensions of the rigid stress absorbing layer prefabricated panels should be 3.5-10m in length and 0.8-1.8m in width, with a panel aspect ratio of ≥3.

5. S3. Cast the rigid stress-absorbing layer precast panels in layers on site: first cast the lower layer of fiber-reinforced cement-based composite material, lay a polyester glass fiber composite mesh with a thickness of ≤1.2mm, a maximum elongation of 5%, and a mesh spacing of 4mm×4mm on its surface, and then cast the upper layer of fiber-reinforced cement-based composite material; S4. Spray polyurethane adhesive as a bonding layer on the surface of the ordinary cement concrete layer in the paving area, with a coating amount of 1.8~2.4kg / m 2 , the coating thickness is ≤2.5mm, the rigid stress absorbing layer prefabricated panels are hoisted to the corresponding position for laying, and the road surface machinery applies pressure to make the rigid stress absorbing layer prefabricated panels closely contact the bonding layer; S5. The asphalt mixture formed by mixing modified asphalt with fine aggregate gravel is continuously and evenly spread using an asphalt paver and compacted using a roller to form an asphalt surface layer. After curing, the road is opened to traffic, completing the construction of a composite pavement with reflective crack prevention function. The upper fiber reinforced cement-based composite material and the lower fiber reinforced cement-based composite material both include the following component raw materials in percentage by mass: cement 18.25%-19.75%, fly ash 38.90%-40.15%, mineral powder 1.07%-6.43%, micro beads 2.14%-4.28%, sand 21.05%-25.60%, water 15.60%-18.90%, admixture 0.14%-0.15%, defoamer 0.01%-0.02%, fiber 0.54%-1.29%; the compressive strength of the upper fiber reinforced cement-based composite material and the lower fiber reinforced cement-based composite material is ≥50MPa, the flexural strength is ≥14MPa, and the ultimate tensile strain is ≥2.8%; the cement is ordinary Portland cement P.O42.5, and the specific surface area is ≥300m 2 / kg; fly ash is Class I fly ash with a particle size of 2-10 μm; slag is S105 grade limestone slag with a specific surface area of ​​≥720 m 2 / kg; the particle size of micro beads is 0.1~1.5μm, and the specific surface area is ≥3000m 2 / kg, CaO content ≤0.5%, in the form of completely spherical powder; sand is river sand with a particle size ≤2.36mm; the admixture is a polymer high-efficiency polycarboxylic acid water reducer with a solid content of 20-40%; the defoamer is a non-ionic silicone defoamer with an effective substance content ≥99%. The fiber is PE fiber with a length of 12~15mm, a diameter of 40~55μm, a tensile strength ≥1800MPa, an elastic modulus ≥72GPa, and a density of 0.8~1.1g / cm 3 , elongation at break is 4~7%; The asphalt mixture forming the asphalt surface layer is prepared by mixing modified asphalt, cement, mineral powder, 0-3 mm crushed stone, 3-6 mm crushed stone, 6-11 mm crushed stone and 11-16 mm crushed stone in a mass ratio of (4.8-5.2): (1.0-1.1): (2.0-2.2): (28-34): (14-16): (20-27): (25-30); the modified asphalt is a high-viscosity modified emulsified asphalt with a softening point of ≥70°C, a residue on a 1.18 mm sieve of ≤0.1%, and a paving temperature of 30-60°C; the fine aggregate crushed stone is limestone and diabase with a mixing ratio of (1.48-1.50):1.0 and an apparent relative density of ≥2.60 t / m 3 .

2. The construction method of a composite pavement with reflective crack prevention function according to claim 1, characterized in that: The thickness of the ordinary cement concrete layer is 50-200 mm; the thickness of the rigid stress absorption layer prefabricated board is 12-18 mm; and the thickness of the asphalt surface layer is 30-50 mm.

3. The construction method of a composite pavement with reflective crack prevention function according to claim 1, characterized in that: In step S3, the specific operation is as follows: first, dry-mix the cementitious material and fine aggregate in the mixing drum, then add water and admixtures for further stirring, and finally add fiber for mixing; wherein, a vibrator is installed on the side of the trough containing the fiber, and the bottom discharge port is opened and the vibrator is turned on at the same time, and the PE fiber is sprinkled into the mixing drum and evenly stirred by vibrating the trough, and the stirring time is 10-14 minutes; the discharge position height of the storage hopper is fixed and adjusted by the support truss, and the unloading mechanism is opened while moving along the guide beams on both sides of the precast board mold for paving, and the height of the scraper plate on the guide beam is adjusted to fit the cement-based slurry, and the equipment moves slowly to cast the lower layer of fiber-reinforced cement-based composite material, and after initial setting, the polyester glass fiber composite mesh is laid and fixed on both sides of the mold, and then the upper layer of fiber-reinforced cement-based composite material is laid and the surface is smoothed to form a rigid stress absorption layer precast board; the thickness of the upper layer of fiber-reinforced cement-based composite material is 8-10 mm.

4. A composite pavement with reflective crack prevention function constructed by the construction method according to any one of claims 1 to 3.

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