CN115874502A - A compound pavement with reflective crack prevention function and its construction method - Google Patents

Abstract

The invention discloses a composite pavement with reflection crack prevention function and a construction method thereof. The steps include: S1, pouring an ordinary cement concrete layer on the upper part of the subbase, and roughing it; S2, dividing the rigid stress absorption layer and laying the prefabricated slab area and determine the prefabricated size of the slab surface; S3, pouring the prefabricated slab of the rigid stress absorbing layer through layering on the site; S4, spraying the bonding layer on the surface laying area of the ordinary cement concrete layer, and hoisting the precast slab of the rigid stress absorbing layer for laying; S5, The asphalt mixture is continuously and evenly paved to form an asphalt surface layer, which is opened to traffic after curing, and the construction of a composite pavement with reflective crack prevention functions is completed. The construction method of the invention is simple and fast, the material preparation is easy to obtain, and it is convenient for mechanized operation. It can not only save labor costs and shorten the construction period, but also effectively delay the upward expansion of reflection cracks, improve the anti-reverse performance of road structures, and greatly increase the service life of composite road surfaces. .

Description

Composite pavement with reflective crack prevention function and its construction method

technical field

The invention relates to the technical field of road engineering construction, in particular to a composite pavement with the function of preventing and preventing reflective cracks and a construction method thereof.

Background technique

Composite pavement has been applied since the end of the last century. While the country's road traffic is developing rapidly, its structural form and construction methods are also constantly being innovated and improved. The composite pavement has the advantages of high overall rigidity of the pavement, high bearing capacity of the base layer, and good driving comfort. However, with the increase of service life and traffic volume, the reflective cracks produced under the influence of multiple factors such as traffic load and environmental factors have gradually become the main structural failure form of asphalt pavement in composite pavement. The occurrence, expansion and penetration of reflective cracks weaken the strength of the structure to a certain extent, seriously affecting the service life of the composite pavement, and the existence of cracks leads to the infiltration of road surface water into the structure, reducing the waterproof and drainage capacity of the original pavement and accelerating the structural damage trend , resulting in more road surface diseases.

At present, the traditional prevention and control measures and construction methods for reflective cracks in composite pavement, such as adding asphalt layer to increase the thickness, adding interlayer of geotechnical materials to the composite pavement structure, and setting asphalt-like flexible stress-absorbing layer, etc., have little effect on prevention and control. Not obvious.

Therefore, in response to the increasing problem of reflective cracks in the pavement, it is urgent to develop a composite pavement with the function of preventing reflective cracks and its construction method, which is of great engineering significance for improving the structural performance and service life of the composite pavement and realizing rapid and effective construction. .

Contents of the invention

The purpose of the present invention is to provide a composite pavement with reflective crack prevention function and its construction method, to reduce the occurrence of reflective cracks, enhance the structural performance of the pavement, prolong the service life of the road, and improve the efficiency and economy of composite pavement construction benefit.

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

In a first aspect, the present invention provides a construction method for a compound pavement with reflective crack prevention function, comprising the following steps:

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

S2. According to the position where the stress concentration on the road surface is prone to cause reflection cracks, reasonably divide the laying area of the prefabricated slab of the rigid stress absorbing layer and determine the prefabricated size of the slab surface;

S3. Pouring the prefabricated slab of the rigid stress absorbing layer by layering on the site: first pouring the lower layer of fiber reinforced cement-based composite material, laying polyester fiberglass composite mesh on its surface, and then pouring the upper layer of fiber-reinforced cement-based composite material;

S4. Spray the adhesive layer on the surface laying area of the ordinary cement concrete layer, hoist the prefabricated slab of the rigid stress absorption layer to the corresponding position for laying, and apply mechanical pressure on the road surface to make the prefabricated slab of the rigid stress absorption layer closely contact the adhesive layer;

S5. The asphalt mixture made by mixing modified asphalt and fine aggregate gravel is continuously and evenly paved by asphalt paver, and rolled by road roller to form asphalt surface layer. After curing, it will be open to traffic and complete the reflection crack prevention Functional composite pavement construction.

In some specific technical solutions, the thickness of the ordinary cement concrete layer is 50-200mm.

In some specific technical solutions, the thickness of the rigid stress absorbing layer prefabricated board is 12-18mm.

In some specific technical solutions, the thickness of the asphalt pavement is 30-50 mm.

In some specific technical solutions, in step S2, the prefabricated size of the rigid stress absorbing layer prefabricated panel has a length of 3.5-10m, a width of 0.8-1.8m, and a panel aspect ratio ≥ 3.5.

In some specific technical schemes, in step S3, the fiber reinforced cement-based composite material of the upper layer and the fiber-reinforced cement-based composite material of the lower layer both include the following component raw materials in mass percentages: 18.25% to 19.75% of cement, pulverized coal Ash 38.90%-40.15%, mineral powder 1.07%-6.43%, microbeads 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 %.

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

In some specific technical schemes, in step S3, the specific operation is: first dry mix the cementitious material and fine aggregate in the mixing cylinder, then add water and additives for further mixing, and finally put in fibers for mixing; wherein, A vibrator is installed on the side of the fiber trough, and the vibrator is turned on at the same time when the bottom discharge port is opened. The PE fiber is sprinkled into the mixing drum through the vibrating trough and stirred evenly. The stirring time is 10 to 14 minutes; it is fixed and adjusted by the support truss The height of the unloading position of the storage hopper is moved along the guide rail beams on both sides of the prefabricated slab mould, and the unloading mechanism is opened at the same time to pave, adjust the height of the scraper on the guide rail beam and fit the cement-based slurry, and the equipment moves slowly to pour the lower layer of fiber Reinforced cement-based composite material, after the initial setting, lay polyester fiberglass composite mesh and fix it on both sides of the mold, then pave the upper layer of fiber-reinforced cement-based composite material and smooth the surface to form a rigid stress-absorbing layer prefabricated board; the upper layer fiber The thickness of the reinforced cement-based composite material is 8-10mm.

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

In some specific technical solutions, in step S4, the adhesive layer is polyurethane adhesive, the amount of application is 1.8-2.4kg/m ² , and the application thickness is ≤2.5mm.

In some specific technical solutions, in step S5, the asphalt mixture forming the asphalt pavement consists of modified asphalt, cement, mineral powder, 0-3mm crushed stone, 3-6mm crushed stone, 6-11mm crushed stone, 11 ～16mm gravel is mixed according to the 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 high-viscosity modified emulsified asphalt, the softening point is ≥70°C, the remaining amount on the 1.18mm sieve is ≤0.1%, and the paving temperature is 30-60°C; the fine aggregate gravel is limestone and diabase rock, the dosage ratio is (1.48～1.50):1.0, and the apparent relative density is ≥2.60t/m ³ .

In the second aspect, the present invention provides a composite pavement constructed by the above-mentioned construction method and having the function of preventing and preventing reflective cracks.

Compared with the prior art, the present invention provides a compound pavement with reflective crack prevention function and its construction method, which has the following beneficial effects:

(1) The present invention carries out layered pouring by high-toughness cement-based composite materials, and polyester fiberglass composite mesh is arranged in the middle, thereby prefabricating and forming rigid stress absorbing layer prefabricated board, has fully utilized polyethylene fiber and polyester fiberglass composite mesh Performance and advantages, improve the crack resistance and stress absorption performance of prefabricated panels, relieve the stress concentration at the joints or cracks of the concrete base under load, and diffuse the compressive stress and tensile stress in the surface layer, and then have a good Anti-reflective crack effect.

(2) The rigid stress absorbing layer prefabricated panel of the present invention adopts batch pouring prefabrication in the factory and on-the-spot hoisting and paving, which ensures higher construction efficiency and engineering quality; spraying is used between the rigid stress absorbing layer prefabricated panel and the cement concrete layer The polyurethane adhesive is closely bonded, the interlayer cohesion is effectively enhanced, and the structural and overall strength is improved; the fatigue resistance of the pavement structure after adding the rigid stress absorbing layer prefabricated board is 4 to 10 times higher than that of the ordinary pavement structure times.

(3) The construction method of the present invention is simple and fast, the material preparation is easy to obtain, and it is convenient for mechanized operation. It can not only save labor costs and shorten the construction period, but also effectively delay the upward expansion of reflection cracks, improve the anti-reverse performance of road structures, and greatly improve the composite road surface service life. In addition, the invention can also be used in road cement concrete bridge deck pavement engineering.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. For those skilled in the art, other drawings can also be obtained according to these drawings without any creative effort.

Fig. 1 is the structural representation of composite pavement of the present invention;

Fig. 2 is the structural representation of rigid stress absorbing layer prefabricated plate of the present invention;

Fig. 3 is the side view schematic diagram of laying the rigid stress absorbing layer prefabricated board at the cement concrete joint of the present invention;

Fig. 4 is the plane schematic diagram of laying the rigid stress absorbing layer prefabricated board at the cement concrete joint of the present invention;

Fig. 5 is the structural representation that fiber sprinkles into the forced mixing drum in the mixing process;

Fig. 6 is a schematic diagram of the construction structure of the rigid stress absorbing layer prefabricated panel;

Figure 7 shows the gradation range of asphalt mixture fine aggregate;

Figure 8 shows the comparison of fatigue life and anti-reverse performance of the composite pavement structure.

Reference signs: 1. Subbase layer; 2. Ordinary cement concrete layer; 3. Adhesive layer; 4. Rigid stress absorbing layer prefabricated board; 41. Lower layer of fiber-reinforced cement-based composite material layer; 42. Upper layer of fiber-reinforced cement-based composite material Material layer; 43. Polyester fiberglass composite mesh; 5. Asphalt surface layer; 6. Storage hopper; 7. Unloading mechanism; 8. Hanging plate; 9. Guide rail beam; 10. Supporting truss; 12. Forced mixing drum; 13. Material trough; 14. Vibrator; 15. Feeding port.

Detailed ways

The technical solutions of the present invention will be clearly and completely described below, obviously, the described embodiments are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

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

Example 1

Referring to Fig. 1 and Fig. 2, the present embodiment provides a composite pavement with the function of preventing and preventing reflective cracks, including an ordinary cement concrete layer 2 with a thickness of 120 mm poured above the subbase layer 1, where the ordinary cement concrete layer 2 is prone to appear The location where reflection cracks are generated due to stress concentration is divided into laying areas. The ordinary cement concrete layer 2 is sprayed with a bonding layer 3 at the laying area, and the bonding layer 3 is polyurethane adhesive. A rigid stress-absorbing layer prefabricated panel 4 with a thickness of 18 mm distributed parallel to the ground is laid above the adhesive layer 3 , and the lower surface of the rigid stress-absorbing layer prefabricated panel 4 is bonded and fixed to the adhesive layer 3 . An asphalt surface layer 5 with a thickness of 50 mm covering the prefabricated slab 4 of the rigid stress absorbing layer is paved above the ordinary cement concrete layer 2 . Wherein, the rigid stress absorbing layer prefabricated panel 4 includes a lower layer of fiber-reinforced cement-based composite material 41 , an upper layer of fiber-reinforced cement-based composite material 42 and a polyester fiberglass composite mesh 43 distributed between them. The thickness of the upper fiber-reinforced cement-based composite material layer 42 is 10mm.

Specifically, the composite pavement is formed using the construction method of the following steps:

S1. Pour an ordinary cement concrete layer 2 with a thickness of 120mm on the upper part of the subbase 1, roughen the surface of the ordinary cement concrete layer 2 by roughing, milling, etc., and clean the waste on the rough working surface and keep it clean.

S2. According to the location where stress concentration is likely to cause reflection cracks due to stress concentration on the road surface (such as the joint of cement concrete layer), reasonably divide the laying area of the prefabricated slab of the rigid stress absorbing layer and determine the prefabricated size of the slab surface. Wherein, the prefabricated size of the rigid stress absorbing layer prefabricated slab 4 has a length of 4.0 m, a width of 1.0 m, and a board aspect ratio of 4.

S3. Pouring the prefabricated slab of the rigid stress absorbing layer by layering on the site: first pouring the lower layer of fiber reinforced cement-based composite material, laying polyester fiberglass composite mesh 43 on its surface, and then pouring the upper layer of fiber-reinforced cement-based composite material.

Wherein, the thickness of the polyester fiberglass composite net 43 is ≤1.2mm, the maximum elongation is 5%, and the mesh spacing is 4mm×4mm.

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 mass percentages: cement 18.50%, fly ash 39.03%, mineral powder 2.03%, microbeads 2.16%, sand 21.12% , water 15.80%, admixture 0.15%, defoamer 0.01%, fiber 1.20%; the compressive strength of the upper fiber reinforced cement-based composite material and the lower fiber reinforced cement-based composite material is 54.20MPa, the flexural strength is 14.08MPa, The ultimate tensile strain was 3.10%. The cement is ordinary Portland cement P.O42.5, with a specific surface area ≥ 300m ² /kg; the fly ash is Class I fly ash, with a particle size of 2-10μm; the mineral powder is S105 limestone powder, with a specific surface area ≥ 720m ² /kg; the particle size of the micro-bead floating beads is 0.1-1.5μm, the specific surface area is ≥3000m ² /kg, the CaO content is ≤0.5%, and it is a completely spherical powder; the sand is river sand with a particle size of ≤2.36mm; additives It is a polymer high-efficiency polycarboxylate water reducer with a solid content of 28%; the defoamer is a non-ionic silicone defoamer with an active substance content ≥ 99%; the fiber is PE fiber with a length of 12mm and a diameter of 45μm , the tensile strength is 2200MPa, the modulus of elasticity is 85GPa, the density is 1.1g/cm ³ , and the elongation at break is 5.3%.

Referring to Fig. 5 and Fig. 6, the specific operation of pouring is as follows: first dry mix the cementitious material and fine aggregate in the forced mixing drum 12, then add water and admixture for further stirring, and finally put in fiber for mixing. Wherein, a vibrator 14 is installed on the side of the fiber trough 13, the bottom feeding port 15 is opened and the vibrator 14 is opened at the same time, and the PE fiber is sprinkled into the forced mixing drum 12 by vibrating the trough 13 and stirred evenly. It is 14min. The materials in the forced mixing drum 12 are pumped and loaded into the storage hopper 6 after the mixing is completed, so as to be poured later. The height of the unloading position of the storage hopper 6 is fixed and adjusted by the supporting truss 10, the guide rail beams 9 on both sides of the prefabricated slab mold 11 are moved, and the unloading mechanism 7 is opened at the same time for paving, and the height of the scraper plate 8 on the guide rail beam 9 is adjusted and attached. Combine cement-based slurry, move the equipment slowly to pour the lower layer of fiber-reinforced cement-based composite material, lay polyester fiberglass composite mesh 43 on both sides of the mould, and then lay the upper layer of fiber-reinforced cement-based composite material and smooth the surface , forming a rigid stress-absorbing layer prefabricated panel 4; the thickness of the upper fiber-reinforced cement-based composite material is 10mm.

S4. Spray the bonding layer 3 on the surface laying area of the ordinary cement concrete layer 2, the bonding layer 3 is polyurethane adhesive, the amount of painting is 2.0kg/m ² , and the thickness of painting is 1.8mm; then, refer to Fig. 3 and Figure 4, hoisting the rigid stress-absorbing layer prefabricated slab 4 to the corresponding position for laying, the mechanical pressure on the road surface makes the rigid stress-absorbing layer prefabricated slab 4 closely contact the adhesive layer 3, avoiding debonding and slippage under the action of horizontal force, and ensuring the rigid stress The continuous stress and anti-reflection crack performance of the prefabricated panel 4 of the absorbing layer.

S5. The asphalt mixture made by mixing modified asphalt and fine aggregate gravel is continuously and evenly paved by asphalt paver, and rolled by road roller to form asphalt surface layer 5. After curing, it is opened to traffic and completed with reflective cracks Construction of composite pavement with prevention and control functions.

Among them, the asphalt mixture forming the asphalt surface layer is composed of modified asphalt, cement, mineral powder, 0-3mm crushed stone, 3-6mm crushed stone, 6-11mm crushed stone, and 11-16mm crushed stone according to 4.9:1.0:2.0: It is mixed with a mass ratio of 31.0:15.0:24.0:27.0. The specific asphalt mixture fine aggregate gradation range is shown in Figure 7; the modified asphalt is a high-viscosity modified emulsified asphalt with a softening point of ≥70°C and a 1.18mm sieve The remaining amount is ≤0.1%, and the laying temperature is 30-60°C; the fine aggregate crushed stone is limestone and diabase, the mixing ratio is 1.50:1.0, and the apparent relative density is ≥2.60t/m ³ .

Example 2

Referring to Fig. 1 and Fig. 2, the present embodiment provides a composite pavement with the function of preventing and preventing reflective cracks, including an ordinary cement concrete layer 2 with a thickness of 120 mm poured above the subbase layer 1, where the ordinary cement concrete layer 2 is prone to appear The location where reflection cracks are generated due to stress concentration is divided into laying areas. The ordinary cement concrete layer 2 is sprayed with a bonding layer 3 at the laying area, and the bonding layer 3 is polyurethane adhesive. A rigid stress-absorbing layer prefabricated panel 4 with a thickness of 14 mm distributed parallel to the ground is laid above the adhesive layer 3 , and the lower surface of the rigid stress-absorbing layer prefabricated panel 4 is bonded and fixed to the adhesive layer 3 . An asphalt surface layer 5 with a thickness of 50 mm covering the prefabricated slab 4 of the rigid stress absorbing layer is paved above the ordinary cement concrete layer 2 . Wherein, the rigid stress absorbing layer prefabricated panel 4 includes a lower layer of fiber-reinforced cement-based composite material 41 , an upper layer of fiber-reinforced cement-based composite material 42 and a polyester fiberglass composite mesh 43 distributed between them. The thickness of the upper fiber-reinforced cement-based composite material layer 42 is 10 mm.

Specifically, the composite pavement is formed using the construction method of the following steps:

S1. Pour an ordinary cement concrete layer 2 with a thickness of 120mm on the upper part of the subbase 1, roughen the surface of the ordinary cement concrete layer 2 by roughing, milling, etc., and clean the waste on the rough working surface and keep it clean.

S2. According to the location where stress concentration is likely to cause reflection cracks due to stress concentration on the road surface (such as the joint of cement concrete layer), reasonably divide the laying area of the prefabricated slab of the rigid stress absorbing layer and determine the prefabricated size of the slab surface. Wherein, the prefabricated size of the rigid stress absorbing layer prefabricated slab 4 has a length of 7.5m, a width of 1.8m, and a slab aspect ratio of 4.17.

S3. Pouring the prefabricated slab of the rigid stress absorbing layer by layering on the site: first pouring the lower layer of fiber reinforced cement-based composite material, laying polyester fiberglass composite mesh 43 on its surface, and then pouring the upper layer of fiber-reinforced cement-based composite material.

Wherein, the thickness of the polyester fiberglass composite net 43 is ≤1.2mm, the maximum elongation is 5%, and the mesh spacing is 4mm×4mm.

The upper layer of fiber reinforced cement-based composite material and the lower layer of fiber-reinforced cement-based composite material both include the following component raw materials in mass percentages: cement 19.00%, fly ash 39.00%, mineral powder 1.50%, microbeads 2.14%, sand 21.05% , water 16.05%, admixture 0.15%, defoamer 0.01%, fiber 1.10%; the compressive strength of the upper fiber reinforced cement-based composite material and the lower fiber reinforced cement-based composite material is 57.4MPa, the flexural strength is 13.88MPa, The ultimate tensile strain was 2.82%. The cement is ordinary Portland cement P.O42.5, with a specific surface area ≥ 300m ² /kg; the fly ash is Class I fly ash, with a particle size of 2-10μm; the mineral powder is S105 limestone powder, with a specific surface area ≥ 720m ² /kg; the particle size of the micro-bead floating beads is 0.1-1.5μm, the specific surface area is ≥3000m ² /kg, the CaO content is ≤0.5%, and it is a completely spherical powder; the sand is river sand with a particle size of ≤2.36mm; additives It is a polymer high-efficiency polycarboxylate water reducer with a solid content of 28%; the defoamer is a non-ionic silicone defoamer with an active substance content ≥ 99%; the fiber is PE fiber with a length of 12mm and a diameter of 45μm , the tensile strength is 2200MPa, the modulus of elasticity is 85GPa, the density is 1.1g/cm ³ , and the elongation at break is 5.3%.

Referring to Fig. 5 and Fig. 6, the specific operation of pouring is as follows: first dry mix the cementitious material and fine aggregate in the forced mixing drum 12, then add water and admixture for further stirring, and finally put in fiber for mixing. Wherein, a vibrator 14 is installed on the side of the fiber trough 13, the bottom feeding port 15 is opened and the vibrator 14 is opened at the same time, and the PE fiber is sprinkled into the forced mixing drum 12 by vibrating the trough 13 and stirred evenly. It is 14min. The materials in the forced mixing drum 12 are pumped and loaded into the storage hopper 6 after the mixing is completed, so as to be poured later. The height of the unloading position of the storage hopper 6 is fixed and adjusted by the supporting truss 10, the guide rail beams 9 on both sides of the prefabricated slab mold 11 are moved, and the unloading mechanism 7 is opened at the same time for paving, and the height of the scraper plate 8 on the guide rail beam 9 is adjusted and attached. Combine cement-based slurry, move the equipment slowly to pour the lower layer of fiber-reinforced cement-based composite material, lay polyester fiberglass composite mesh 43 on both sides of the mould, and then lay the upper layer of fiber-reinforced cement-based composite material and smooth the surface , forming a rigid stress-absorbing layer prefabricated panel 4; the thickness of the upper fiber-reinforced cement-based composite material is 10mm.

S4. Spray the bonding layer 3 on the surface laying area of the ordinary cement concrete layer 2, the bonding layer 3 is polyurethane adhesive, the amount of painting is 2.0kg/m ² , and the thickness of painting is 1.8mm; then, refer to Fig. 3 and Figure 4, hoisting the rigid stress-absorbing layer prefabricated slab 4 to the corresponding position for laying, the mechanical pressure on the road surface makes the rigid stress-absorbing layer prefabricated slab 4 closely contact the adhesive layer 3, avoiding debonding and slippage under the action of horizontal force, and ensuring the rigid stress The continuous stress and anti-reflection crack performance of the prefabricated panel 4 of the absorbing layer.

S5. The asphalt mixture made by mixing modified asphalt and fine aggregate gravel is continuously and evenly paved by asphalt paver, and rolled by road roller to form asphalt surface layer 5. After curing, it is opened to traffic and completed with reflective cracks Construction of composite pavement with prevention and control functions.

Among them, the asphalt mixture forming the asphalt surface layer is composed of modified asphalt, cement, mineral powder, 0-3mm crushed stone, 3-6mm crushed stone, 6-11mm crushed stone, and 11-16mm crushed stone according to 4.9:1.0:2.0: It is mixed with a mass ratio of 31.0:15.0:24.0:27.0. The specific asphalt mixture fine aggregate gradation range is shown in Figure 7; the modified asphalt is a high-viscosity modified emulsified asphalt with a softening point of ≥70°C and a 1.18mm sieve The remaining amount is ≤0.1%, and the laying temperature is 30-60°C; the fine aggregate crushed stone is limestone and diabase, the mixing ratio is 1.48:1.0, and the apparent relative density is ≥2.60t/m ³ .

Taking the composite pavement structure without rigid stress-absorbing layer prefabricated slabs as a control example, the fatigue life and anti-reverse performance of the composite pavement structure were compared and analyzed together with Example 1 and Example 2, as shown in Figure 8.

According to the analysis of the data in Figure 8, compared with the conventional composite pavement structure without rigid stress absorbing layer prefabricated slabs in the comparative example, the fatigue life of the pavement structure provided with rigid stress absorbing layer prefabricated slabs in Examples 1 and 2 is greatly extended , the anti-reflection performance of the pavement structure is better, and the rigid stress-absorbing layer prefabricated board has good stress-absorbing performance. Compared with the pavement structure in the comparative example, the fatigue life of the pavement structure of embodiment 1 has been promoted by 11.4 times, and the fatigue life of the pavement structure of embodiment 2 has been promoted by 7.1 times, and the results show that appropriately increasing the thickness of the rigid stress absorbing layer precast plate can Enhanced anti-reflective crack performance of composite pavement structures.

To sum up, the present invention has a better effect of preventing reflection cracks by setting the rigid stress-absorbing layer prefabricated slab. It can be seen that the construction method of the present invention is highly feasible and innovative, and has great value for popularization and application.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the scope of the present invention. within the scope of protection.

In addition, it should be understood that although this specification is described according to implementation modes, not each implementation mode only contains an independent technical solution, and this description in the specification is only for clarity, and those skilled in the art should take the specification as a whole , the technical solutions in the various embodiments can also be properly combined to form other implementations that can be understood by those skilled in the art.

Claims (10)

1. A construction method of a compound pavement with reflective crack prevention and control function, is characterized in that, comprises the following steps: S1. Pour an ordinary cement concrete layer on the upper part of the subbase, roughen the surface of the ordinary cement concrete layer, clean up the waste on the rough working surface and keep it clean; S2. According to the position where the stress concentration on the road surface is prone to cause reflection cracks, reasonably divide the laying area of the prefabricated slab of the rigid stress absorbing layer and determine the prefabricated size of the slab surface; S3. Pouring the prefabricated slab of the rigid stress absorbing layer by layering on the site: first pouring the lower layer of fiber reinforced cement-based composite material, laying polyester fiberglass composite mesh on its surface, and then pouring the upper layer of fiber-reinforced cement-based composite material; S4. Spray the adhesive layer on the surface laying area of the ordinary cement concrete layer, hoist the prefabricated slab of the rigid stress absorption layer to the corresponding position for laying, and apply mechanical pressure on the road surface to make the prefabricated slab of the rigid stress absorption layer closely contact the adhesive layer; S5. The asphalt mixture made by mixing modified asphalt and fine aggregate gravel is continuously and evenly paved by asphalt paver, and rolled by road roller to form asphalt surface layer. After curing, it will be open to traffic and complete the reflection crack prevention Functional composite pavement construction. 2. The construction method according to claim 1, characterized in that, the thickness of the ordinary cement concrete layer is 50-200 mm; the thickness of the prefabricated plate of the rigid stress absorbing layer is 12-18 mm; The thickness of the asphalt surface layer is 30-50mm. 3. The construction method according to claim 1, characterized in that, in step S2, the prefabricated length of the rigid stress absorbing layer prefabricated slab is 3.5-10m, the width is 0.8-1.8m, and the length of the slab surface is 3.5-10m. Aspect ratio ≥ 3.5. 4. The construction method according to claim 1, characterized in that, in step S3, the fiber reinforced cement-based composite material of the upper layer and the fiber-reinforced cement-based composite material of the lower layer both include the following component raw materials in mass percentage: Cement 18.25%-19.75%, fly ash 38.90%-40.15%, mineral powder 1.07%-6.43%, microbeads 2.14%-4.28%, sand 21.05%-25.60%, water 15.60%-18.90%, additives 0.14% to 0.15%, defoamer 0.01% to 0.02%, fiber 0.54% to 1.29%; the compressive strength of the fiber reinforced cement-based composite material of the upper layer and the fiber reinforced cement-based composite material of the lower layer is ≥50MPa, and the flexural strength ≥14MPa, ultimate tensile strain ≥2.8%. 5. The construction method according to claim 4, characterized in that the cement is ordinary Portland cement P.O42.5 with a specific surface area ≥ 300m ² /kg; the fly ash is Class I fly ash with a particle diameter of 2-10μm; the mineral powder is S105 grade limestone powder, the specific surface area is ≥720m ² /kg; the particle size of micro-beads is 0.1-1.5μm, the specific surface area is ≥3000m ² /kg, and the CaO content is ≤0.5%. Completely spherical powder; the sand is river sand with a particle size of ≤2.36mm; the admixture is a polymer high-efficiency polycarboxylate water reducer with a solid content of 20-40%; the defoamer is a non-ionic substance with an active substance content of ≥99% Type silicone defoamer; the fiber is PE fiber, the length is 12-15mm, the diameter is 40-55μm, the tensile strength is ≥1800MPa, the elastic modulus is ≥72GPa, the density is 0.8-1.1g/cm ³ , and the elongation at break is 4-7%. 6. The construction method according to claim 5, characterized in that, in step S3, the specific operation is: first dry mix the cementitious material and fine aggregate in the mixing cylinder, then add water and admixture to further Stir, and finally put in the fiber and stir; among them, a vibrator is installed on the side of the trough containing the fiber, open the bottom feeding port and open the vibrator at the same time, the PE fiber is sprinkled into the mixing drum through the vibrating trough and stirred evenly, and the stirring time is 10 ~14min; Fix and adjust the height of the unloading position of the storage hopper through the supporting truss, move along the guide rail beams on both sides of the precast slab mold and open the unloading mechanism to pave, adjust the height of the scraper on the guide rail beam and fit the cement-based slurry The equipment moves slowly to pour the lower layer of fiber-reinforced cement-based composite material. After the initial setting, the polyester fiberglass 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 fiber reinforced cement-based composite material in the upper layer is 8-10 mm. 7. The construction method according to claim 1, characterized in that, in step S3, the thickness of the polyester fiberglass composite net is ≤1.2mm, the maximum elongation is 5%, and the mesh spacing is 4mm ×4mm. 8. The construction method according to claim 1, characterized in that, in step S4, the adhesive layer is polyurethane adhesive, the coating amount is 1.8-2.4kg/m ² , and the coating thickness is ≤2.5 mm. 9. The construction method according to claim 1, characterized in that, in step S5, the asphalt mixture forming the asphalt pavement is composed of modified asphalt, cement, mineral powder, 0-3mm gravel, 3-6mm crushed Stone, 6-11mm gravel, 11-16mm gravel according to (4.8-5.2): (1.0-1.1): (2.0-2.2): (28-34): (14-16): (20-27): (25-30) mass ratio; the modified asphalt is high-viscosity modified emulsified asphalt, softening point ≥ 70 ° C, 1.18mm sieve residue ≤ 0.1%, paving temperature 30-60 ° C; The aggregate gravel is limestone and diabase, the mixing ratio is (1.48-1.50): 1.0, and the apparent relative density is ≥2.60t/m ³ . 10. A compound pavement with reflective crack prevention function formed by the construction method described in any one of claims 1-9.

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