Composite structure and reconstruction method for asphalt pavement to inhibit reflection cracks

Abstract

The application discloses a composite structure and a reconstruction method for inhibiting reflection cracks of asphalt pavement, and relates to the technical field of road repairing. The technical scheme points of the composite structure and the reconstruction method are as follows: a self-flowing adhesive is filled in a joint; a crack prevention layer is laid on a cement concrete base layer and covers the joint completely; a stress release layer is covered on the crack prevention layer and is elastic; a plurality of reserved cracks are arranged on the stress release layer and are perpendicular to the length direction of the joint; the reserved cracks correspond to the positions of the joint; and a filler is filled in each reserved crack and is extruded and exploded to release a bonding material when being pressed; and an asphalt concrete surface layer is laid on the stress release layer. The composite structure and the reconstruction method can effectively prevent or delay reflection cracks of the asphalt surface layer caused by the joint of the cement concrete base layer, and improve the service performance and the service life of the asphalt pavement.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of road repair, in particular to a composite structure for inhibiting reflection cracks of asphalt pavement and a reconstruction method. BACKGROUND

[0002] Asphalt pavement is a high-grade pavement widely used in highways, urban roads, airports and other fields, with good performance and economic benefits. However, asphalt pavement also has some common diseases, such as cracks, rutting, potholes, and oil bleeding, which affect the flatness, safety and aesthetics of the pavement, and reduce the service life and level of the pavement.

[0003] Among them, cracks are one of the most common diseases of asphalt pavement, which not only destroys the structural integrity of the pavement, but also allows water, air and pollutants to penetrate into the internal structure of the pavement, accelerating the aging and damage of the pavement. The formation of cracks is caused by many factors, including temperature stress, traffic load, base deformation, material aging, construction quality, etc. According to the direction and shape of the cracks, cracks can be divided into transverse cracks, longitudinal cracks, network cracks and reflection cracks, etc.

[0004] Reflection cracks are cracks formed in the upper layer of asphalt pavement due to the cracks or joints of the lower layer of materials under the action of temperature changes or traffic loads after the addition of asphalt pavement on the old cement concrete pavement or semi-rigid base. Reflection cracks can affect the performance and life of asphalt pavement, so some prevention measures need to be taken.

[0005] Currently, the measures to prevent reflection cracks mainly include the following:

[0006] Improve the performance of asphalt pavement, select high-quality asphalt with high low-temperature deformation ability, and control the mixing quality and paving thickness of asphalt mixture.

[0007] Set up an intermediate layer or thicken the asphalt pavement to reduce or eliminate the influence of the lower layer cracks on the upper layer.

[0008] Apply modified asphalt or other additives, such as polymer modified asphalt, fiber reinforced asphalt, etc., to improve the crack resistance of asphalt mixture.

[0009] Sealing or sealing cracks, filling or covering cracks with modified emulsified asphalt or modified asphalt and other materials to prevent water and pollutants from entering the cracks.

[0010] However, the above measures have certain limitations and shortcomings. For example:

[0011] Improving the performance of asphalt pavement requires increased cost and construction difficulty, and cannot completely eliminate the possibility of reflection cracks.

[0012] Setting an intermediate layer or thickening the asphalt surface layer requires increasing the structure thickness and weight, and has higher requirements for the position and shape of the lower layer cracks.

[0013] Applying modified asphalt or other additives requires special equipment and technology, and has higher requirements for the quality and proportion of raw materials.

[0014] Sealing or sealing requires regular maintenance and replacement, and has higher requirements for the width and depth of the cracks.

[0015] Therefore, the purpose of the present application is to provide a composite structure and reconstruction method for inhibiting reflection cracks of asphalt pavement, which can effectively prevent or delay the reflection cracks caused by the joints of the cement concrete base layer to the asphalt surface layer, and improve the service performance and life of the asphalt pavement. SUMMARY

[0016] The purpose of the present application is to provide a composite structure and reconstruction method for inhibiting reflection cracks of asphalt pavement, which can effectively prevent or delay the reflection cracks caused by the joints of the cement concrete base layer to the asphalt surface layer, and improve the service performance and life of the asphalt pavement.

[0017] The above technical purpose of the present application is realized by the following technical scheme: a composite structure for inhibiting reflection cracks of asphalt pavement for inhibiting reflection cracks caused by the joints of the cement concrete base layer to the asphalt concrete surface layer, comprising a self-flowing adhesive filled in the joints; a crack prevention layer laid on the cement concrete base layer and completely covering the joints; a stress release layer with elasticity laid on the crack prevention layer, a plurality of reserved cracks perpendicular to the length direction of the joints are arranged on the stress release layer, each reserved crack corresponds to the position of the joint, and each reserved crack is filled with a filler which will be extruded and release adhesive material when under pressure; and the asphalt concrete surface layer is laid on the stress release layer.

[0018] In some embodiments, the crack prevention layer comprises one or more of geotextile, glass fiber grid and steel mesh.

[0019] In some embodiments, the stress release layer is composed of polymer modified asphalt and rubber particles.

[0020] In some embodiments, the reserved cracks are in the shape of a shuttle, and the width of the widest part is 1-5 mm.

[0021] In some embodiments, the filler is composed of microcapsules, nanofibers and epoxy resin.

[0022] In some embodiments, the asphalt concrete surface layer is provided with a reinforcing rib at a position corresponding to the joint, and the reinforcing rib is arranged along the length direction of the joint.

[0023] In some embodiments, the reinforcing ribs are provided in at least two, each of the reinforcing ribs being independent of each other and arranged in a vertical direction in layers;

[0024] The reinforcing ribs are in an arched structure which is arched upwards or downwards, and the adjacent reinforcing ribs are arched in opposite directions.

[0025] A reconstruction method for inhibiting reflection cracks of asphalt pavement, comprising the following steps:

[0026] S1, cleaning the joint;

[0027] S2, shallow grooves are formed on the surface of the cement concrete base at positions on both sides of the joint, and deep grooves are further formed in the shallow grooves;

[0028] S3, the self-flowing adhesive is injected into the joint until the self-flowing adhesive overflows from the joint and fills the shallow grooves and the deep grooves;

[0029] S4, scraping, standing until the self-flowing adhesive solidifies;

[0030] S5, the anti-cracking layer, the stress release layer and the asphalt concrete surface layer are respectively laid on the cement concrete base.

[0031] In summary, the present application has the following beneficial effects:

[0032] By filling the self-flowing adhesive in the joint of the cement concrete base, the joint can be effectively closed to prevent water and pollutants from penetrating, while the strength and stability of the joint are improved, and the opening and closing changes of the joint are reduced.

[0033] By laying the anti-cracking layer on the cement concrete base, the stress of the lower layer and the upper layer can be effectively isolated, the lower layer crack is prevented from reflecting to the upper layer, and the shear strength and fatigue resistance of the pavement structure are increased.

[0034] By covering the stress release layer on the anti-cracking layer, and forming the reserved cracks in the stress release layer and filling the filler, the stress concentration between the lower layer and the upper layer can be effectively released, the reflection cracks caused by stress concentration are prevented, and the automatic repair of the pavement structure is realized by using the self-repairing function of the filler.

[0035] By laying the asphalt concrete surface layer on the stress release layer, and setting the reinforcing ribs in the asphalt concrete surface layer, the overall performance and bearing capacity of the pavement structure can be effectively improved, and the arch structure of the reinforcing ribs is used to cope with the shear force transmitted upward due to the expansion or deformation of the joint.

[0036] The composite structure of the present application can not only effectively inhibit the generation and expansion of reflection cracks, but also improve the durability, safety and comfort of the pavement structure, and prolong the service life and service level of the pavement structure.

[0037] The reconstruction method of the present application can not only be conveniently applied to the engineering of adding an asphalt surface layer on the old cement concrete pavement or semi-rigid base, but also save materials and costs, simplify the construction process, shorten the construction period, and through the shallow and deep grooves of different depths formed on both sides of the joint, form a tooth-shaped contact surface between the shallow and deep grooves after the self-flowing adhesive solidifies, and since the self-flowing adhesive in the shallow groove, deep groove and joint is integrally solidified, it will form a "T" structure after solidification, which can not only block the joint and bond the cement concrete base, but also firmly hook the cement concrete on both sides of the joint to inhibit further expansion of the joint. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 is a schematic view of the composite structure of the present application;

[0039] Figure 2 is an exploded view of the composite structure of the present application;

[0040] Figure 3 is an enlarged view of A of Figure 2 ; is an enlarged view of B of ; is an enlarged view of C of

[0041] ; and is an enlarged view of D of Figure 4 . Figure 2

[0042] Figure 5 Figure 2

[0043] In the figure: 1, cement concrete base; 101, joint; 102, shallow groove; 103, deep groove; 104, self-flowing adhesive; 2, crack prevention layer; 3, stress release layer; 301, reserved crack; 302, filler; 4, asphalt concrete surface layer; 401, reinforcing rib.DETAILED DESCRIPTION

[0044] The embodiments of the present application will be described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the accompanying drawings are exemplary and are intended to explain the present application, and cannot be understood as a limitation of the present application.

[0045] ​In the description of the present application, it should be understood that the terms "length", "width", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0046] In addition, the terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly specified and limited.

[0047] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection", "fixing" and the like should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0048] The present application provides a composite structure for inhibiting reflection cracks of asphalt pavement, which is used for inhibiting reflection cracks caused by the joint 101 of cement concrete base 1 to asphalt concrete surface layer 4, comprising a self-flowing adhesive 104 filled in the joint 101, the self-flowing adhesive 104 is a liquid material with good flowability and bonding performance, which can automatically fill the joint 101 and form a firm bond with the cement concrete base 1. The self-flowing adhesive 104 can be one or more of cement-based, asphalt-based or resin-based. For example, the self-flowing adhesive 104 can be a cement-based self-leveling material composed of cement, sand, water, expanding agent and other additives; it can also be an asphalt-based self-leveling material composed of modified asphalt, diluent and other additives; it can also be a resin-based self-leveling material composed of epoxy resin, curing agent and other additives. The present application is not limited to the above examples, and other types or combinations of self-flowing adhesives 104 can also be used.

[0049] The composite structure of the asphalt pavement for inhibiting reflection cracks further comprises a crack prevention layer 2 laid on the cement concrete base 1 and covering the joint 101 completely. In some embodiments, the crack prevention layer 2 comprises one or more of geotextile, fiberglass grid, and steel mesh. The crack prevention layer 2 can effectively isolate the stress of the lower layer and the upper layer, prevent the reflection of the lower layer cracks to the upper layer, and increase the shear strength and fatigue resistance of the pavement structure. The crack prevention layer 2 is prepared as follows: first, a layer of modified emulsified asphalt is brushed on the cement concrete base 1 as a bonding agent; then, the geotextile, fiberglass grid, or steel mesh is laid on the modified emulsified asphalt before it dries, and is compacted by a road roller; finally, a layer of modified emulsified asphalt is brushed on the geotextile, fiberglass grid, or steel mesh as a protective layer. The present application is not limited to the above example, and other types or combinations of crack prevention materials and preparation methods can also be used.

[0050] The composite structure of the asphalt pavement for inhibiting reflection cracks further comprises a stress release layer 3 laid on the crack prevention layer 2 and having elasticity, and an asphalt concrete surface layer 4 laid on the stress release layer 3. The asphalt concrete surface layer 4 adopts an intermittent graded skeleton dense structure and has high strength and high stability. A plurality of reserved cracks 301 perpendicular to the length direction of the joint 101 are formed on the stress release layer 3, and each reserved crack 301 corresponds to the position of the joint 101. A filler 302 is filled in each reserved crack 301. The filler 302 is extruded and exploded under pressure and releases a bonding substance. In some embodiments, the stress release layer 3 is composed of polymer modified asphalt and rubber particles. The polymer modified asphalt is preferably SBS modified asphalt or SBR modified asphalt, and the rubber particles are preferably waste tire rubber particles or natural rubber particles. The stress release layer 3 has good elasticity and ductility, can effectively release the stress concentration between the lower layer and the upper layer, and prevent reflection cracks caused by stress concentration. The stress release layer 3 is prepared as follows: first, the polymer modified asphalt and the rubber particles are mixed in a certain proportion, heated to a certain temperature, and fully dissolved and uniformly distributed; then, the mixed material is spread on the crack prevention layer 2 and compacted by a road roller; finally, the reserved cracks 301 are formed on the stress release layer 3, and the filler 302 is injected into the reserved cracks 301. The present application is not limited to the above example, and other types or combinations of stress release materials and preparation methods can also be used.

[0051] In some embodiments, the reserved crack 301 is in the shape of a shuttle, with a width of 1-5 mm at its widest part, preferably 5 mm. When the joint 102 expands due to temperature changes or traffic loads, the reserved crack 301 will be stretched along its length direction and its width will be narrowed at this time, so that the filler 302 inside the reserved crack 301 will be easily squeezed and release the adhesive material, thereby achieving automatic repair of the pavement structure. The reserved crack 301 can be formed by the following method: first, draw a plurality of straight lines on the stress release layer 3 perpendicular to the length direction of the joint 101, and mark the positions corresponding to the joint 101 on the straight lines; then, cut the reserved crack 301 along the straight lines at the marked positions using a cutting machine; finally, inject the filler 302 into the reserved crack 301. The present application is not limited to the above example, and other shapes or sizes of reserved cracks and forming methods can also be used.

[0052] In some embodiments, the filler 302 is composed of microcapsules, nanofibers and epoxy resin. The filler 302 has good self-repairing function and durability, can effectively fill the reserved crack 301, and will be squeezed and release the adhesive material when under pressure, thereby achieving automatic repair of the pavement structure, wherein the microcapsules are preferably chitosan microcapsules or polyurethane microcapsules, the nanofibers are preferably carbon nanotubes or graphene nanoribbons, and the epoxy resin is preferably bisphenol A type epoxy resin or bisphenol F type epoxy resin.

[0053] In some embodiments, the asphalt concrete surface layer 4 is provided with a reinforcing rib 401 at a position corresponding to the joint 101, and the reinforcing rib 401 is arranged along the length direction of the joint 101. The reinforcing rib 401 can effectively improve the overall performance and bearing capacity of the pavement structure, and at the same time, the arch-shaped structure of the reinforcing rib 401 can be used to resist the shear force transmitted upward due to the expansion or deformation of the joint 101. The reinforcing rib 401 is provided with at least two, and five reinforcing ribs 401 are used in the present embodiment. Each reinforcing rib 401 is independent and arranged in layers along the vertical direction, and the reinforcing rib 401 is in an arch-shaped structure that arches upward or downward. The arching directions of adjacent reinforcing ribs 401 are opposite. This can effectively disperse and balance the influence of the joint 101 on the asphalt concrete surface layer 4, and increase the crack resistance of the asphalt concrete surface layer 4. Moreover, the arch-shaped structures of different directions can resist shear forces in different directions, thereby greatly improving the strength of the asphalt concrete surface layer 4 and making the asphalt concrete surface layer 4 less likely to crack. The preferred preparation method of the reinforcing rib 401 is as follows: the asphalt concrete surface layer 4 is laid in layers, and one reinforcing rib 401 is placed for each layer of asphalt concrete surface layer 4, and the process is repeated until the entire asphalt concrete surface layer 4 is laid.

[0054] The present application also provides a reconstruction method for inhibiting reflection cracks in asphalt pavement, comprising the following steps:

[0055] S1, cleaning the joint 101 to remove sundries and loose materials in the joint 101;

[0056] S2, forming a shallow groove 102 on the cement concrete base 1 at positions on both sides of the joint 101, and then forming a deep groove 103 in the shallow groove 102, the width and depth of the shallow groove 102 and the deep groove 103 being determined according to actual conditions;

[0057] S3, injecting the self-flowing adhesive 104 into the joint 101 until the self-flowing adhesive 104 overflows from the joint 101 and fills the shallow groove 102 and the deep groove 103;

[0058] S4, smoothing and standing still until the self-flowing adhesive 104 solidifies;

[0059] S5, laying the anti-cracking layer 2, the stress release layer 3 and the asphalt concrete surface layer 4 on the cement concrete base 1, respectively.

[0060] The reconstruction method of the present application can not only be conveniently applied to the project of adding the asphalt surface layer on the old cement concrete pavement or semi-rigid base, but also can save materials and cost, simplify the construction process, shorten the construction period, and through forming the deep and shallow grooves 102 and 103 on both sides of the joint 101, the tooth-shaped contact surface between the self-flowing adhesive 104 and the grooves 102 and 103 is formed after the self-flowing adhesive 104 solidifies, and since the self-flowing adhesive 104 in the grooves 102 and 103 and the joint 101 is integrally solidified, a “T”-shaped structure is formed after solidification, which can not only block the joint 101 and bond the cement concrete base 1, but also firmly hook the cement concrete on both sides of the joint 101 to inhibit the further expansion of the joint 101.

[0061] The present application sets multiple measures to prevent and treat reflection cracks, including filling the self-flowing adhesive 104 in the joint 101 of the cement concrete base 1 to block the joint 101 and improve the strength and stability of the joint 101; laying the anti-cracking layer 2 on the cement concrete base 1 to isolate the stress of the lower layer and the upper layer and increase the shear strength and fatigue resistance of the pavement structure; covering the stress release layer 3 on the anti-cracking layer 2, and forming the reserved cracks 301 in the stress release layer 3 and filling the fillers 302 to release the stress concentration and realize the self-repair of the pavement structure; laying the asphalt concrete surface layer 4 on the stress release layer 3, and setting the reinforcing ribs 401 in the asphalt concrete surface layer 4 to improve the overall performance and bearing capacity of the pavement structure and resist the shear force. The composite structure and reconstruction method of the present application can not only effectively inhibit the generation and expansion of reflection cracks, but also improve the durability, safety and comfort of the pavement structure, and prolong the service life and service level of the pavement structure.

[0062] The specific embodiments are only illustrative of the present application, and are not intended to limit the present application. Those skilled in the art can make modifications to the embodiments without creative contribution after reading the specification, and the modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A composite structure for suppressing reflection cracks of an asphalt pavement for suppressing reflection cracks of a joint (101) of a cement concrete base (1) to an asphalt concrete surface layer (4), characterized by, The application relates to a cement concrete base (1) and a method for preventing cracks in the cement concrete base (1). The application comprises the following: a self-flowing adhesive (104) filled in the joint (101); a crack prevention layer (2) laid on the cement concrete base (1) and completely covering the joint (101); a stress release layer (3) laid on the crack prevention layer (2) and being elastic, the stress release layer (3) is provided with a plurality of reserved cracks (301) perpendicular to the length direction of the joint (101), each of the reserved cracks (301) corresponds to the position of the joint (101), and each of the reserved cracks (301) is filled with a filler (302) which is extruded and releases adhesive material when pressed; the filler (302) is composed of microcapsules, nanofibers and epoxy resin; the asphalt concrete surface layer (4) is laid on the stress release layer (3); the reserved cracks (301) are in the shape of a shuttle, and the width of the widest part is 1-5 mm; 2. The composite structure for suppressing reflection cracking of asphalt pavement according to claim 1, characterized in that: the self-flowing adhesive (104) is integrated with the shallow groove, the deep groove and the self-flowing adhesive (104) filled in the joint (101) to form a T-shaped structure after solidification.

3. The composite structure for suppressing reflection cracking of asphalt pavement according to claim 1, characterized in that: The crack prevention layer (2) comprises one or more of geotextile, glass fiber grid and steel wire mesh.

4. The composite structure for suppressing reflective cracking of asphalt pavement according to claim 1, characterized by: The stress release layer (3) is composed of polymer modified asphalt and rubber particles.

5. The composite structure for suppressing reflective cracking of asphalt pavement according to claim 4, characterized in that: The asphalt concrete surface layer (4) is provided with a reinforcing rib (401) corresponding to the position of the joint (101), and the reinforcing rib (401) is arranged along the length direction of the joint (101). The reinforcing rib (401) is provided with at least two reinforcing ribs (401), and each of the reinforcing ribs (401) is independently arranged in a vertical direction.

6. A method for the rehabilitation of asphalt pavements against reflective cracking, based on the composite structure against reflective cracking according to any one of claims 1-5, characterized in that, The reinforcing rib (401) is in an arch shape which is arched upwards or downwards, and the arching directions of adjacent reinforcing ribs (401) are opposite. The application comprises the following steps: cleaning the joint (101); opening a shallow groove (102) on the surface of the cement concrete base (1) at positions on both sides of the joint (101), and then opening a deep groove (103) in the shallow groove (102); injecting the self-flowing adhesive (104) into the joint (101) until the self-flowing adhesive (104) overflows from the joint (101) and fills the shallow groove (102) and the deep groove (103); smoothing, standing and solidifying the self-flowing adhesive (104); laying the crack prevention layer (2), the stress release layer (3) and the asphalt concrete surface layer (4) on the cement concrete base (1) respectively.

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