Combined device for bonding rigid-flexible composite pavement layers and construction method thereof

Abstract

The present invention discloses a combined device for interlayer bonding of a rigid-flexible composite pavement and a construction method thereof, wherein the device comprises a load-bearing unit and a deformation coordination unit which are staggeredly distributed along the longitudinal direction in the rigid-flexible composite pavement; the load-bearing unit comprises an upper wing plate, a web plate, a lower wing plate, a sealing plate, a splicing plate, a shearing member, and an adjustable lifting assembly; and the deformation coordination unit comprises a straight steel bar and a spiral steel bar hoop. The present invention has a simple structure, can effectively improve the interlayer bonding strength and deformation coordination ability of the rigid-flexible composite pavement, and eliminate interlayer shear damage.

Description

Technical Field

[0001] The invention belongs to the field of road engineering, and in particular relates to a combined device for combining rigid-flexible composite pavement layers and a construction method thereof. Background Art

[0002] Rigid-flexible composite pavement refers to a pavement structure with an asphalt concrete surface layer on the upper layer and a cement concrete surface layer on the lower layer. Asphalt concrete is a flexible material with a small rebound modulus and strong deformation capacity, while cement concrete is a rigid material with a large rebound modulus and weak deformation capacity. The interlayer bonding of a rigid-flexible composite pavement refers to the connection area between the asphalt concrete surface layer and the cement concrete surface layer. This area is at the boundary between the deformation of the upper and lower layers, and requires high deformation coordination ability, high load-bearing capacity, and high fatigue resistance under repeated wheel action.

[0003] Traditional interlayer treatment methods mostly use adhesive oil or adhesive oil + crushed stone to form a waterproof adhesive layer. The interlayer strength of the bonding layer formed by this treatment method is mainly composed of the bonding force of the bonding oil material and the friction resistance of the upper and lower layer materials and crushed stone materials. The interlayer bonding strength is low, much smaller than the lower cement concrete surface layer, and also smaller than the upper asphalt concrete surface layer. The interlayer strength is not enough to resist the external load effect and interlayer damage occurs, especially in intersections, bus stations and other areas, where vehicles start and stop repeatedly, the horizontal force is large, the shear damage effect is large, and the interlayer is more prone to fatigue damage. In addition, the thickness of the traditional bonding layer is relatively thin, and the asphalt concrete surface layer and the cement concrete surface layer are almost directly in contact, making it difficult to coordinate the deformation difference between the upper and lower layers under the action of temperature and vehicle load, resulting in interlayer slip failure. Therefore, the traditional bonding layer is the weak surface of the rigid-flexible composite pavement. The bearing capacity of this area is insufficient, the shear strength is weak, and the deformation coordination ability is weak. It is very easy to cause interlayer shear failure under the action of external loads, which in turn causes pavement diseases. Summary of the invention

[0004] The purpose of the present invention is to provide a combined device for bonding interlayers of a rigid-flexible composite pavement and a construction method thereof. The present invention has a simple structure and can effectively improve the bonding strength and deformation coordination ability of the interlayers of the rigid-flexible composite pavement and eliminate interlayer shear damage.

[0005] The technical solution adopted by the present invention is:

[0006] A combined device for combining layers of a rigid-flexible composite pavement, comprising a load-bearing unit and a deformation coordination unit staggeredly distributed along the longitudinal direction in the rigid-flexible composite pavement; the main body of the load-bearing unit is an I-shaped steel structure composed of an upper wing plate, a web plate and a lower wing plate, both ends of the I-shaped steel structure are fixedly connected with a sealing plate, the inner side surfaces of the sealing plate are affixed with a splicing plate, the top surface of the upper wing plate and the bottom surface of the lower wing plate are distributed with shear members, the bottom surface of the lower wing plate is supported and installed on a plurality of adjustable lifting components, the adjustable lifting components are installed on the pavement base, the upper wing plate and the lower wing plate are respectively located in an asphalt concrete surface layer and a cement concrete surface layer; the deformation coordination unit comprises a plurality of straight steel bars distributed in the asphalt concrete surface layer and the cement concrete surface layer and a spiral steel bar hoop that wraps and bypasses all the straight steel bars, both ends of the straight steel bars pass through the sealing plate and the splicing plate and are fastened by fasteners, and both ends of the spiral steel bar hoop are fixedly connected to the sealing plate.

[0007] Preferably, the adjustable lifting assembly comprises an upper screw rod, a threaded sleeve and a lower screw rod which are threadedly connected in sequence, the upper screw rod is fixedly connected to the bottom surface of the lower wing plate, the lower screw rod is fixedly connected to the anchor plate, and the anchor plate is installed on the anchor bolt of the pavement base.

[0008] Preferably, the upper edge and the lower edge of the sealing plate are welded to the upper wing plate and the lower wing plate respectively, and the middle part of the back side of the sealing plate is welded to the web.

[0009] Preferably, both ends of the straight steel bar are threaded sections, and the fasteners are nuts that match the threaded sections.

[0010] Preferably, in the deformation coordination unit, the straight steel bars are distributed in a rectangular shape, and the end connection points of the spiral steel bar stirrups are located at the center of the rectangle.

[0011] Preferably, welding holes are provided at the intersection of the web plate and the upper wing plate, and at the intersection of the web plate and the lower wing plate on the sealing plate.

[0012] The construction method of the above-mentioned combined device for combining rigid-flexible composite pavement layers includes the following steps: 1. Designing the size of each load-bearing unit and deformation coordination unit according to the plate division of the cement concrete surface layer, and prefabricating each load-bearing unit and deformation coordination unit in a factory; 2. Constructing the pavement base layer; 3. Transporting each load-bearing unit and deformation coordination unit to the site, first installing the adjustable lifting assembly on the pavement base layer, and then using the splicing plate and fasteners to fix the straight steel bars on the sealing plate, and fix the end of the spiral steel bar hoop on the sealing plate, and then adjusting the height of the adjustable lifting assembly to make the longitudinal slope of the entire device consistent with the longitudinal slope of the pavement, and try to make the center axis of the web located at the interface between the asphalt concrete surface layer and the cement concrete surface layer, and then operating the fasteners to tighten and straighten the straight steel bars and the spiral steel bar hoop; 4. Constructing the cement concrete surface layer; 5. Constructing the asphalt concrete surface layer.

[0013] Preferably, in step 2, the road base adopts a semi-rigid base, i.e., cement-stabilized gravel. After the construction of the semi-rigid base, the layer thickness, compaction, flatness, and road crown cross slope are inspected. If unqualified, it is repaired and cleaned. After passing the inspection, penetrating oil is spread.

[0014] Preferably, in step 4, when constructing the cement concrete surface layer, first apply anti-corrosion paint to the load-bearing unit and the deformation coordination unit, then set up the formwork and support on the pavement base, and choose whether to lay the steel mesh according to demand, then pour the cement concrete surface layer, vibrate it to make it dense, smooth it, and maintain it. Stop maintenance after the flexural strength of the cement concrete reaches the requirement.

[0015] Preferably, in step 5, when constructing the asphalt concrete surface layer, after checking that the flexural strength, flatness and thickness of the cement concrete surface layer are qualified, first spread the adhesive layer oil, then lay the asphalt concrete, and roll it to form a dense shape.

[0016] The beneficial effects of the present invention are:

[0017] The present invention has the advantages of simple structure, strong practicability and good economy. The load-bearing unit, deformation coordination unit, asphalt concrete surface layer and cement concrete surface layer form a combined structure to jointly bear the vehicle load, which can effectively improve the bonding strength of the asphalt concrete surface layer and the cement concrete surface layer, significantly improve the deformation coordination ability of the two, and eliminate interlayer shear damage; wherein, most of the horizontal force and normal radiation fatigue stress generated between layers by acceleration, deceleration, start and stop of vehicle load are borne by the load-bearing unit, and the asphalt concrete surface layer and the cement concrete surface layer bear them together under the constraint of the deformation coordination unit, and the longitudinal tensile and compressive stress is mainly transmitted to the load-bearing unit by the sealing plate, and the vertical compressive stress is transmitted to the pavement base via the adjustable lifting component. Specifically: the upper wing plate is embedded in the asphalt concrete surface layer and has a shear key on the top surface, which can be fully connected with the asphalt concrete and can bear the horizontal shear force and variable amplitude fatigue tensile stress in the asphalt concrete surface layer; the lower wing plate is embedded in the cement concrete surface layer and has a shear key on the bottom surface, which can be fully connected with the cement concrete and can bear the horizontal shear force in the cement concrete and can transfer the vertical compressive stress from the asphalt concrete surface layer to the cement concrete surface layer; the web can form the upper wing plate, the lower wing plate and the surrounding asphalt concrete and cement concrete into a whole; the sealing plate can transfer the axial stress in the surface layer to the bearing unit; the adjustable lifting assembly can adjust the longitudinal slope and height of the entire device to adapt to the road surface thickness and route slope, and can transfer the stress absorbed by the bearing unit to the road surface base; the splicing plate and the preloaded parts can splice the prefabricated bearing unit and the deformation coordination unit on site; the straight steel bar and the spiral steel bar hoop can connect the bearing unit and the deformation coordination unit, and can transfer the force between the bearing units, and the spiral steel bar hoop can constrain and coordinate the deformation of the asphalt concrete surface layer and the cement concrete surface layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1It is a partial longitudinal section view of a combined device for bonding rigid-flexible composite pavement layers in an embodiment of the present invention.

[0019] Figure 2 yes Figure 1 Cross-section view at AA in the middle.

[0020] In the figure: 1-sealing plate; 2-upper wing plate; 3-lower wing plate; 4-web plate; 5-shear member; 6-adjustable lifting assembly; 6a-upper screw; 6b-lower screw; 6c-threaded sleeve; 7-anchor bolt; 8-anchor plate; 9-fastener; 10-splicing plate; 11-straight steel bar; 12-spiral steel bar hoop; 13-through welding hole; 14-cement concrete surface layer; 15-asphalt concrete surface layer. DETAILED DESCRIPTION

[0021] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0022] like Figure 1 and Figure 2 As shown, a combined device for combining layers of a rigid-flexible composite pavement includes a load-bearing unit and a deformation coordination unit that are staggeredly distributed along the longitudinal direction in the rigid-flexible composite pavement; the main body of the load-bearing unit is an I-shaped steel structure composed of an upper wing plate 2, a web plate 4 and a lower wing plate 3, both ends of the I-shaped steel structure are fixedly connected with a sealing plate 1, the inner side of the sealing plate 1 is attached with a splicing plate 10, the top surface of the upper wing plate 2 and the bottom surface of the lower wing plate 3 are distributed with shear members 5, and the bottom surface of the lower wing plate 3 is supported and installed on a plurality of adjustable lifting assemblies 6, the adjustable lifting assembly 6 is installed on the pavement base, the upper wing plate 2 and the lower wing plate 3 are respectively located in the asphalt concrete surface layer 15 and the cement concrete surface layer 14; the deformation coordination unit includes a plurality of straight steel bars 11 distributed in the asphalt concrete surface layer 15 and the cement concrete surface layer 14 and a spiral steel bar hoop 12 that wraps and bypasses all the straight steel bars 11, both ends of the straight steel bars 11 pass through the sealing plate 1 and the splicing plate 10 and are fastened by the fastener 9, and both ends of the spiral steel bar hoop 12 are fixedly connected to the sealing plate 1.

[0023] like Figure 1 and Figure 2 As shown, preferably, the adjustable lifting assembly 6 includes an upper screw rod 6a, a threaded sleeve 6c and a lower screw rod 6b which are threadedly connected in sequence, the upper screw rod 6a is fixedly connected to the bottom surface of the lower wing plate 3, the lower screw rod 6b is fixedly connected to the anchor plate 8, and the anchor plate 8 is installed on the anchor bolt 7 of the pavement base.

[0024] like Figure 1 and Figure 2 As shown, preferably, the upper edge and the lower edge of the sealing plate 1 are welded to the upper wing plate 2 and the lower wing plate 3 respectively, and the middle part of the back side of the sealing plate 1 is welded to the web 4.

[0025] like Figure 1 and Figure 2As shown, preferably, both ends of the straight steel bar 11 are threaded sections, and the fastener 9 is a nut that matches the threaded section.

[0026] like Figure 1 and Figure 2 As shown, preferably, in the deformation coordination unit, the straight steel bars 11 are distributed in a rectangular shape, and the end connection point of the spiral steel bar hoop 12 is located at the center of the rectangle.

[0027] like Figure 1 and Figure 2 As shown, preferably, welding holes 13 are provided at the intersection of the upper web 4 and the upper wing plate 2 of the sealing plate 1 and at the intersection of the web 4 and the lower wing plate 3 to facilitate welding and avoid stress concentration.

[0028] The construction method of the above-mentioned combined device for combining rigid-flexible composite pavement layers includes the following steps: 1. Designing the size of each load-bearing unit and deformation coordination unit according to the plate division of the cement concrete surface layer 14, and prefabricating each load-bearing unit and deformation coordination unit in the factory; 2. Constructing the pavement base layer; 3. Transporting each load-bearing unit and deformation coordination unit to the site, first installing the adjustable lifting component 6 on the pavement base layer, and then using the splicing plate 10 and the fastener 9 to fix the straight steel bar 11 on the sealing plate 1, and fix the end of the spiral steel bar hoop 12 on the sealing plate 1, and then adjusting the height of the adjustable lifting component 6 so that the longitudinal slope of the entire device is consistent with the longitudinal slope of the pavement, and try to make the central axis of the web 4 located at the interface between the asphalt concrete surface layer 15 and the cement concrete surface layer 14, and then operating the fastener 9 to tighten and straighten the straight steel bar 11 and the spiral steel bar hoop 12; 4. Constructing the cement concrete surface layer 14; 5. Constructing the asphalt concrete surface layer 16.

[0029] Preferably, in step 2, the road base adopts a semi-rigid base, i.e., cement-stabilized gravel. After the construction of the semi-rigid base, the layer thickness, compaction, flatness, and road crown cross slope are inspected. If unqualified, it is repaired and cleaned. After passing the inspection, penetrating oil is spread.

[0030] Preferably, in step 4, when constructing the cement concrete surface layer 14, first apply anti-corrosion paint to the load-bearing unit and the deformation coordination unit, then set up the formwork and support on the pavement base, and choose whether to lay the steel mesh according to the needs, and then pour the cement concrete surface layer 14, and vibrate it to make it dense, smooth it, and maintain it. Stop maintenance after the flexural strength of the cement concrete reaches the requirements.

[0031] Preferably, in step 5, when constructing the asphalt concrete surface layer 15, after checking that the flexural strength, flatness and thickness of the cement concrete surface layer 14 are qualified, firstly spread the adhesive layer oil, then lay the asphalt concrete, and then roll and compact it into shape.

[0032] Application example: A certain road section is a city trunk street light-controlled intersection, which adopts rigid-flexible composite pavement and semi-rigid base layer, heavy-load traffic, and large interlayer shear stress; 12cm thick asphalt concrete surface 15 and 24cm thick cement concrete surface layer 14 are designed; the upper wing plate 2, the lower wing plate 3 and the web 4 are welded I-beams H200mm×200mm×8mm×12mm; the shear members 5 are Φ10mm shear studs, which are welded in three rows on the top surface of the upper wing plate 2 and the bottom surface of the lower wing plate 3, with a lateral spacing of 40mm and a longitudinal spacing of 80mm; each load-bearing unit is equipped with 4 adjustable lifting components, and the upper screw 6a and the lower screw 6b are both 40# steel shafts with a nominal diameter of φ40mm and a length of 500mm, with rolled threads and matched with threaded sleeves 6c , arranged in two rows in pairs 100mm away from the end, with a horizontal spacing of 60mm, the anchor plate 8 is made of Q235 steel plate, with a size of 50mm×50mm×8mm, and 4 bolt holes are reserved, and the anchor bolt 7 is an M16 self-tapping bolt; the sealing plate 1 is made of 2 pieces of Q235 steel plates, with a size of 176×96mm, and 4 bolt holes are preset. It is welded with the upper wing plate 2, the lower wing plate 3 and the web 4 by double-sided fillet welds, and the size of the through-weld hole 13 is R20; the splicing plate 10 is made of Q235 steel plate, with a size of 176×96mm, and the fastener 9 is an M16 ordinary bolt; the straight steel bar 11 is made of 4 HRB400 threaded steel bars with a diameter of 10mm, and the two ends are rolled with rolled threads, passing through the preset bolt holes of the sealing plate 1 and the splicing plate 10, The spiral steel bar hoop 12 adopts continuous spiral hoop, HRB400 threaded steel bar, with a diameter of 6mm, a spacing of 150mm, and both ends are welded to the center of the sealing plate 1; a row of this device is arranged at an interval of 1m along the transverse direction of the road surface, and the longitudinal length of this device is the same as the designed waiting length of the intersection.

[0033] The present invention has a simple structure, strong practicality and good economy. The load-bearing unit, the deformation coordination unit, the asphalt concrete surface layer 15 and the cement concrete surface layer 14 form a combined structure to jointly bear the vehicle load, which can effectively improve the bonding strength of the asphalt concrete surface layer 15 and the cement concrete surface layer 14, significantly improve the deformation coordination ability of the two, and eliminate interlayer shear damage; wherein, most of the horizontal force and normal radiation fatigue stress generated between layers by vehicle load acceleration, deceleration, start and stop are borne by the load-bearing unit, and the asphalt concrete surface layer 15 and the cement concrete surface layer 14 bear them together under the constraint of the deformation coordination unit, and the longitudinal tensile and compressive stress is mainly transmitted to the load-bearing unit by the sealing plate 1, and the vertical compressive stress is transmitted to the pavement base via the adjustable lifting component 6. Specifically: the upper wing plate 2 is embedded in the asphalt concrete surface layer 15 and has a shear key 5 on the top surface, which can be fully connected with the asphalt concrete and can bear the horizontal shear force and variable amplitude fatigue tensile stress in the asphalt concrete surface layer 15; the lower wing plate 3 is embedded in the cement concrete surface layer 14 and has a shear key 5 on the bottom surface, which can be fully connected with the cement concrete and can bear the horizontal shear force in the cement concrete and transfer the vertical compressive stress from the asphalt concrete surface layer 15 to the cement concrete surface layer 14; the web 4 can form the upper wing plate 2, the lower wing plate 3 and the surrounding asphalt concrete and cement concrete into a whole; the sealing Plate 1 can transfer the axial stress in the surface layer to the bearing unit; the adjustable lifting assembly 6 can adjust the longitudinal slope and height of the entire device to adapt to the road surface thickness and route slope, and can transfer the stress absorbed by the bearing unit to the road surface base; the splicing plate 10 and the preloaded part 9 can splice the prefabricated bearing unit and deformation coordination unit on site; the straight steel bar 11 and the spiral steel bar hoop 12 can connect the bearing unit and the deformation coordination unit, and can transfer the force between the bearing units. The spiral steel bar hoop 12 can constrain and coordinate the deformation of the asphalt concrete surface layer 15 and the cement concrete surface layer 14.

[0034] It should be understood that those skilled in the art can make improvements or changes based on the above description, and all these improvements and changes should fall within the scope of protection of the appended claims of the present invention.

Claims

1. A combined device for bonding rigid-flexible composite pavement layers, characterized in that: It includes load-bearing units and deformation coordination units which are staggeredly distributed along the longitudinal direction in the rigid-flexible composite pavement; the main body of the load-bearing unit is an I-shaped steel structure composed of an upper wing plate, a web plate and a lower wing plate, both ends of the I-shaped steel structure are fixedly connected with sealing plates, the inner sides of the sealing plates are affixed with splicing plates, the top surface of the upper wing plate and the bottom surface of the lower wing plate are distributed with shear members, the bottom surface of the lower wing plate is supported and installed on a number of adjustable lifting components, the adjustable lifting components are installed on the pavement base, the upper wing plate and the lower wing plate are respectively located in the asphalt concrete surface layer and the cement concrete surface layer; the deformation coordination unit includes a number of straight steel bars distributed in the asphalt concrete surface layer and the cement concrete surface layer and a spiral steel bar hoops which wrap and bypass all the straight steel bars, both ends of the straight steel bars pass through the sealing plates and the splicing plates and are fastened by fasteners, and both ends of the spiral steel bar hoops are fixedly connected to the sealing plates.

2. The combined device for combining rigid-flexible composite pavement layers according to claim 1, characterized in that: The adjustable lifting assembly comprises an upper screw rod, a threaded sleeve and a lower screw rod which are threadedly connected in sequence. The upper screw rod is fixedly connected to the bottom surface of the lower wing plate, and the lower screw rod is fixedly connected to the anchor plate. The anchor plate is installed on the anchor bolt of the road base.

3. The combined device for bonding rigid-flexible composite pavement layers as claimed in claim 1, characterized in that: The upper edge and the lower edge of the sealing plate are welded to the upper wing plate and the lower wing plate respectively, and the middle part of the back side of the sealing plate is welded to the web plate.

4. The combined device for bonding rigid-flexible composite pavement layers as claimed in claim 1, characterized in that: Both ends of the straight steel bar are threaded sections, and the fasteners are nuts that match the threaded sections.

5. The combined device for bonding rigid-flexible composite pavement layers as claimed in claim 1, characterized in that: In the deformation coordination unit, the straight steel bars are distributed in a rectangular shape, and the end connection points of the spiral steel bar stirrups are located at the center of the rectangle.

6. The combined device for combining rigid-flexible composite pavement layers according to claim 1, characterized in that: Welding holes are provided at the intersection of the web plate and the upper wing plate and at the intersection of the web plate and the lower wing plate on the sealing plate.

7. A construction method for a combined device for bonding rigid-flexible composite pavement layers according to any one of claims 1 to 6, characterized in that: The method comprises the following steps:

1. designing the size of each bearing unit and deformation coordination unit according to the plate division of the cement concrete surface layer, and prefabricating each bearing unit and deformation coordination unit in a factory; 2. constructing the pavement base layer; 3. transporting each bearing unit and deformation coordination unit to the site, firstly installing the adjustable lifting assembly on the pavement base layer, and then using the splicing plate and fasteners to fix the straight steel bars on the sealing plate, and fix the ends of the spiral steel bar hoops on the sealing plate, and then adjusting the height of the adjustable lifting assembly to make the longitudinal slope of the entire device consistent with the longitudinal slope of the pavement, and try to make the center axis of the web be located at the interface between the asphalt concrete surface layer and the cement concrete surface layer, and then operating the fasteners to tighten and straighten the straight steel bars and the spiral steel bar hoops; 4. constructing the cement concrete surface layer; 5. constructing the asphalt concrete surface layer.

8. The construction method of the combined device for combining rigid-flexible composite pavement layers according to claim 7, characterized in that: In step 2, the road base adopts a semi-rigid base, that is, cement-stabilized gravel. After the construction of the semi-rigid base, the layer thickness, compaction, flatness, and road crown cross slope are inspected. If unqualified, it is repaired and cleaned. After passing the inspection, the penetrating oil is spread.

9. The construction method of the combined device for combining rigid-flexible composite pavement layers according to claim 7, characterized in that: In step 4, when constructing the cement concrete surface layer, first apply anti-corrosion paint to the load-bearing unit and the deformation coordination unit, then set up the formwork and support on the pavement base, and choose whether to lay the steel mesh according to the needs, and then pour the cement concrete surface layer, vibrate it to make it dense, smooth it, and maintain it. Stop maintenance after the flexural strength of the cement concrete meets the requirements.

10. The construction method of the combined device for combining rigid-flexible composite pavement layers according to claim 7, characterized in that: In step 5, when constructing the asphalt concrete surface layer, after checking that the flexural strength, flatness and thickness of the cement concrete surface layer are qualified, first spread the adhesive layer oil, then lay the asphalt concrete, and roll it to make it dense.

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