Steel-free expansion joint structure

Abstract

This invention discloses a steel-free expansion joint structure, belonging to the field of building structure technology. It includes a roadbed and an asphalt pavement layer. A continuous concrete layer is poured on the roadbed, and an expansion joint is pre-installed in the continuous concrete layer. An extruded polystyrene (XPS) board is installed within the expansion joint. Two symmetrically arranged pouring grooves are formed on the continuous concrete layer about the expansion joint. Continuous reinforcing bars extending horizontally into the pouring grooves are pre-embedded in the continuous concrete layer. Several vertical fixed reinforcing bars are provided on each pouring groove. Each fixed reinforcing bar is coaxially fitted with a top-closed sliding sleeve. The sliding sleeve moves horizontally relative to the fixed reinforcing bars, and an elastic reset structure is provided between the sliding sleeve and the fixed reinforcing bars. Resin concrete, flush with the asphalt pavement layer, is poured into each pouring groove, and the top of the XPS board is filled with sealant. The purpose is to solve the problem of easy separation between the concrete layer and the resin mortar layer in steel-free expansion joints.

Description

Technical Field

[0001] This invention belongs to the field of building structure technology, specifically relating to a steel-free expansion joint structure. Background Technology

[0002] In road engineering, expansion joints are key components connecting the superstructure and substructure of a road. Their performance directly affects the road's durability, safety, and driving comfort. Traditional concrete road expansion joint technology mainly relies on structural forms such as rubber strips, steel plates, or comb plates. By leaving gaps, the road can freely deform under temperature changes, live loads, and foundation settlement. However, with the increase in traffic flow, the number of heavy vehicles, and the frequent occurrence of extreme weather, the limitations of traditional expansion joints are becoming increasingly apparent. The steel sections in traditional steel expansion joints are prone to rust and damage, and subsequent maintenance is inconvenient.

[0003] To address the aforementioned issues, patent application number CN202111334420X discloses a steel-free expansion joint structure for continuously reinforced composite pavements. This steel-free expansion joint features a high-strength, elastic, and tough resin mortar laid on the concrete layer within the joint. This mortar exhibits good flexibility, strong resistance to deformation, and fatigue resistance, while also meeting the longitudinal expansion and contraction requirements of continuously reinforced concrete pavements. It boasts strong overall load-bearing capacity, smooth driving, and an aesthetically pleasing appearance.

[0004] However, in the aforementioned patent, the modulus of the resin mortar layer and the concrete layer are different. When the concrete layer is subjected to temperature changes, shrinkage and creep, and expansion and contraction displacement caused by load, it is easy for the concrete layer and the resin mortar layer to separate. Summary of the Invention

[0005] In view of this, the present invention discloses a steel-free expansion joint structure, the purpose of which is to solve the problem that the concrete layer and the resin mortar layer in the steel-free expansion joint are easily separated.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A steel-free expansion joint structure includes a roadbed and an asphalt pavement layer. A continuous concrete layer is poured on the roadbed, and an expansion joint is pre-installed in the continuous concrete layer. An extruded polystyrene board is installed in the expansion joint. Two pouring grooves are symmetrically arranged about the expansion joints in the continuous concrete layer. Continuous reinforcing bars extending horizontally into the pouring grooves are pre-embedded in the continuous concrete layer. Several vertical fixed reinforcing bars are provided in each pouring groove. Each fixed reinforcing bar is coaxially fitted with a sliding sleeve with a closed top. The sliding sleeve moves horizontally relative to the fixed reinforcing bars. An elastic reset structure is provided between the sliding sleeve and the fixed reinforcing bars. Resin concrete flush with the asphalt pavement layer is poured into each pouring groove, and the top of the extruded polystyrene board is filled with sealant.

[0007] In this scheme, reinforcing bars are pre-embedded or installed in the pouring trench to connect the fixed reinforcing bars to the continuous concrete layer. Then, sliding sleeves are installed on the fixed reinforcing bars. Extruded polystyrene (XPS) boards are installed, with the top of the XPS boards lower than the asphalt pavement layer. Resin concrete is poured, and after curing, sealant is injected into the top of the XPS boards. This scheme eliminates traditional expansion joint gaps, resulting in a continuous and smooth driving surface, completely eliminating vehicle bounce, bumps, and noise, improving driving comfort and safety, and reducing the impact load on the structure from vehicles. It also eliminates the need for structural steel, reducing future maintenance. Furthermore, the sliding sleeves can move relative to the fixed reinforcing bars, and in conjunction with the elastic reset structure, can adapt to temperature changes, concrete shrinkage and creep, and expansion and contraction displacement caused by loads, preventing bridge deck cracking or tensile cracking. The elastic reset structure also buffers vibrations and absorbs impacts, reducing structural fatigue damage and extending the service life of the expansion joints. In addition, the fixed reinforcing bars effectively transfer vehicle loads and structural internal forces, preventing the expansion area from becoming loose or slipping.

[0008] Furthermore, the elastic reset structure includes an annular block coaxially threaded to the inner wall of the sliding sleeve. The inner diameter of the annular block is larger than the diameter of the fixed reinforcing bar. Several grooves facing its axis are formed on the inner wall of the annular block. A base is slidably connected within each groove. The end of the base facing away from the fixed reinforcing bar is arc-shaped. An elastic reset member is fixed to the other end of the base. A sliding protrusion slidably connected to the groove is fixed to the end of the elastic reset member. The bottom of the sliding protrusion facing the fixed reinforcing bar is wedge-shaped. A receiving groove for accommodating the base is coaxially provided at the lower end of the inner wall of the sliding sleeve. A magnet for attracting the base is provided within the receiving groove. Several positioning grooves corresponding to the sliding protrusions are coaxially formed on the periphery of the fixed reinforcing bar.

[0009] In this scheme, when installing the sliding sleeve, ensure that the base is located at the upper end of the receiving groove. After the sliding sleeve is placed on the fixed steel bar, press the sliding sleeve downward. Through the wedge shape at the bottom of the sliding protrusion, the sliding protrusion moves towards the base until it is aligned with the positioning groove. At this time, the sliding protrusion is inserted into the corresponding positioning groove under the action of the elastic reset member, preventing the sliding sleeve from detaching from the fixed steel bar. At the same time, rotate the sliding sleeve forward, and the sliding sleeve moves downward relative to the annular block, so that the bottom of the sliding sleeve fits tightly with the roadbed. When the resin concrete expands or contracts due to external factors, the resin concrete compresses the elastic reset member through the sliding sleeve and the sliding protrusion, adapting to the deformation of the resin concrete. At the same time, the elastic force accumulated by the elastic reset member can help the resin concrete recover its deformation.

[0010] When maintaining the expansion joint, after removing the resin concrete, rotate the sliding sleeve in the opposite direction. The sliding sleeve moves upward relative to the annular block until the receiving groove is directly opposite the base. At this time, the base slides into the receiving groove under the attraction of the magnet, which in turn drives the sliding protrusion to disengage from the positioning groove, making it easier to maintain and replace the sliding sleeve.

[0011] Furthermore, the extruded board has several horizontally opened through slots, and a horizontal sleeve is coaxially fixed in each through slot. A force transmission rod is coaxially slidably arranged in each horizontal sleeve. An anchor plate is provided at one end of the force transmission rod, and a sealing sleeve is coaxially slidably fitted at the other end of the force transmission rod.

[0012] In this solution, by setting up a dowel bar, when the resin concrete is subjected to a vertical load, the resin concrete transfers part of the load to the resin concrete on the other side through the dowel bar, preventing the resin concrete on both sides of the extruded board from having a height difference due to uneven force, which would affect vehicle driving safety; at the same time, the cooperation between the dowel bar and the horizontal sleeve and sealing sleeve prevents the dowel bar from horizontally transmitting the force of the resin concrete, preventing the resin concrete from being pulled or cracked.

[0013] Furthermore, the sealing sleeve and the sliding sleeve are provided with several anchoring protrusions on their periphery.

[0014] Furthermore, the diameter of the middle part of the horizontal sleeve is larger than the diameter of its two ends.

[0015] Furthermore, the resin concrete is a mixture of epoxy resin, polyurethane resin and aggregate.

[0016] Furthermore, a sealing layer is provided at the bottom of the sliding sleeve.

[0017] Other advantages, objectives, and features of the invention will be set forth in the following description and will be apparent to those skilled in the art in some respects, or may be learned by practice of the invention. The objectives and other advantages of the invention can be realized and obtained through the following description. Attached Figure Description

[0018] To make the objectives, technical solutions, and beneficial effects of this invention clearer, the following figures are provided for illustration: Figure 1 This is a schematic diagram of the structure of an embodiment of the present invention; Figure 2 for Figure 1 Enlarged diagram of point A in the middle.

[0019] The following are the markings in the attached diagram: 1. Roadbed; 2. Asphalt pavement layer; 3. Extruded polystyrene board; 4. Continuous reinforcing steel; 5. Sliding sleeve; 6. Sealant; 7. Annular block; 8. Sliding protrusion; 9. Elastic reset element; 10. Base; 11. Magnet; 12. Horizontal sleeve; 13. Force transmission rod; 14. Anchor plate; 15. Sealing sleeve; 16. Anchor protrusion; 17. Continuous concrete layer; 18. Fixed reinforcing steel; 19. Resin concrete. Detailed Implementation

[0020] like Figures 1-2 As shown: A steel-free expansion joint structure includes a roadbed 1 and an asphalt pavement layer 2. A continuous concrete layer 17 is poured on the roadbed 1, and an expansion joint is pre-installed on the continuous concrete layer 17. An extruded polystyrene board 3 is installed in the expansion joint. Two pouring grooves are symmetrically arranged about the expansion joints on the continuous concrete layer 17. Continuous reinforcing bars 4 extending horizontally into the pouring grooves are pre-embedded on the continuous concrete layer 17. Several vertical fixed reinforcing bars 18 are provided on each pouring groove. Each fixed reinforcing bar 18 is coaxially fitted with a top-closed sliding sleeve 5. The sliding sleeve 5 moves horizontally relative to the fixed reinforcing bars 18. An elastic reset structure is provided between the sliding sleeve 5 and the fixed reinforcing bars 18. Resin concrete 19 flush with the asphalt pavement layer 2 is poured into each pouring groove. The top of the extruded polystyrene board 3 is filled with sealant 6.

[0021] In this scheme, reinforcing bars are pre-embedded or installed in the pouring trench to connect the fixed reinforcing bars 18 to the continuous concrete layer 17, and then the sliding sleeve 5 is installed on the fixed reinforcing bars 18; extruded polystyrene board 3 is installed, with the top of the extruded polystyrene board 3 lower than the asphalt pavement layer 2; resin concrete 19 is poured, and after curing, sealant 6 is injected into the top of the extruded polystyrene board 3. In this scheme, the traditional expansion joint gap is eliminated, the vehicle surface is continuously flat, completely eliminating vehicle bounce, bumps and noise, improving driving comfort and safety, and reducing the impact load of vehicles on the structure; at the same time, it saves the steel section, which can reduce the later maintenance; and the sliding sleeve 5 can move relative to the fixed reinforcing bars 18, and with the elastic reset structure, it can adapt to temperature changes, concrete shrinkage and creep and expansion displacement caused by load, avoiding bridge deck squeezing cracks or tensile cracks; at the same time, the elastic reset structure can also use to buffer vibration and absorb impact, reduce structural fatigue damage, and extend the service life of the expansion device; in addition, the fixed reinforcing bars 18 can effectively transfer vehicle load and structural internal force, and prevent the expansion area from becoming loose or detached.

[0022] Furthermore, the elastic reset structure includes an annular block 7 coaxially threaded to the inner wall of the sliding sleeve 5. The inner diameter of the annular block 7 is larger than the diameter of the fixed reinforcing bar 18. Several grooves facing its axis are formed on the inner wall of the annular block 7. A base 10 is slidably connected in each groove. The end of the base 10 away from the fixed reinforcing bar 18 is arc-shaped. An elastic reset member 9 is fixed to the other end of the base 10. A sliding protrusion 8 slidably connected to the groove is fixed to the end of the elastic reset member 9. The bottom of the sliding protrusion 8 facing the fixed reinforcing bar 18 is wedge-shaped. A receiving groove for accommodating the base 10 is coaxially provided at the lower end of the inner wall of the sliding sleeve 5. A magnet for adsorbing the base 10 is provided in the receiving groove. Several positioning grooves corresponding to the sliding protrusion 8 are coaxially formed on the periphery of the fixed reinforcing bar 18.

[0023] In this scheme, when installing the sliding sleeve 5, ensure that the base 10 is located at the upper end of the receiving groove. After the sliding sleeve 5 is placed on the fixed steel bar 18, press the sliding sleeve 5 downward. Through the wedge shape at the bottom of the sliding protrusion 8, the sliding protrusion 8 moves towards the base 10 until the sliding protrusion 8 is directly opposite the positioning groove. At this time, the sliding protrusion 8 is inserted into the corresponding positioning groove under the action of the elastic reset member 9, preventing the sliding sleeve 5 from detaching from the fixed steel bar 18. At the same time, rotate the sliding sleeve 5 in the forward direction. The sliding sleeve 5 moves downward relative to the annular block 7, so that the bottom of the sliding sleeve 5 is tightly fitted with the roadbed 1. When the resin concrete 19 expands and contracts due to external factors, the resin concrete 19 squeezes the elastic reset member 9 through the sliding sleeve 5 and the sliding protrusion 8 to adapt to the deformation of the resin concrete 19. At the same time, the elastic force accumulated by the elastic reset member 9 can help the resin concrete 19 recover its deformation.

[0024] When maintaining the expansion joint, after removing the resin concrete 19, rotate the sliding sleeve 5 in the opposite direction. The sliding sleeve 5 moves upward relative to the annular block 7 until the receiving groove is directly opposite the base 10. At this time, the base 10 slides into the receiving groove under the attraction of the magnet, thereby driving the sliding protrusion 8 to disengage from the positioning groove, which facilitates the maintenance and replacement of the sliding sleeve 5.

[0025] Furthermore, the extruded board 3 has several horizontally opened through grooves, and a horizontal sleeve 12 is coaxially fixed in the through groove. A force transmission rod 13 is coaxially slidably arranged in each of the horizontal sleeves 12. An anchor plate 14 is provided at one end of the force transmission rod 13, and a sealing sleeve 15 is coaxially slidably fitted at the other end of the force transmission rod 13.

[0026] In this design, by setting up a force transmission rod 13, when the resin concrete 19 is subjected to a vertical load, the resin concrete 19 transfers part of the load to the resin concrete 19 on the other side through the force transmission rod 13, preventing the resin concrete 19 on both sides of the extruded board 3 from having a height difference due to uneven force, which would affect vehicle driving safety; at the same time, the cooperation between the force transmission rod 13 and the horizontal sleeve 12 and the sealing sleeve 15 prevents the force transmission rod 13 from horizontally transmitting the force of the resin concrete 19, and prevents the resin concrete 19 from being pulled or cracked.

[0027] Furthermore, the sealing sleeve 15 and the sliding sleeve 5 are provided with a number of anchoring protrusions 16 around their periphery.

[0028] By setting anchoring protrusions 16, the connection stability between sealing sleeve 15, sliding sleeve 5 and resin concrete 19 is enhanced.

[0029] Furthermore, the diameter of the middle part of the horizontal sleeve 12 is larger than the diameter of its two ends.

[0030] The diameter of the middle part of the horizontal sleeve 12 is larger than the diameter of its two ends, so that the force transmission rod 13 can move a small vertical distance relative to the extruded board 3 when transmitting the vertical load of the resin concrete 19, preventing the force transmission rod 13 from squeezing the extruded board 3 and causing the extruded board 3 to deform.

[0031] Furthermore, the resin concrete 19 is a mixture of epoxy resin, polyurethane resin and aggregate.

[0032] The strength of resin concrete 19 is improved by using a mixture of epoxy resin, polyurethane resin and aggregate.

[0033] Furthermore, a sealing layer is provided at the bottom of the sliding sleeve 5.

[0034] By setting a sealing layer, it is prevented that resin concrete 19 will enter the interior of the sliding sleeve 5 during pouring.

[0035] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made to it in form and detail without departing from the scope defined by the claims of the present invention.

Claims

1. A steel-free expansion joint structure, characterized in that: The system includes a roadbed and an asphalt pavement layer. A continuous concrete layer is poured on the roadbed, and expansion joints are pre-installed in the continuous concrete layer. Extruded polystyrene (XPS) boards are installed in the expansion joints. Two pouring grooves are symmetrically arranged about the expansion joints in the continuous concrete layer. Continuous reinforcing bars extending horizontally into the pouring grooves are pre-embedded in the continuous concrete layer. Several vertical fixed reinforcing bars are installed in each pouring groove. Each fixed reinforcing bar is coaxially fitted with a sliding sleeve with a closed top. The sliding sleeve moves horizontally relative to the fixed reinforcing bars. An elastic reset structure is provided between the sliding sleeve and the fixed reinforcing bars. Resin concrete flush with the asphalt pavement layer is poured into each pouring groove, and the top of the XPS board is filled with sealant.

2. The steel-free expansion joint structure according to claim 1, characterized in that: The elastic reset structure includes an annular block coaxially threaded to the inner wall of a sliding sleeve. The inner diameter of the annular block is larger than the diameter of the fixed reinforcing bar. Several grooves facing the axis of the annular block are formed on its inner wall. A base is slidably connected to each groove. The end of the base facing away from the fixed reinforcing bar is arc-shaped. An elastic reset component is fixed to the other end of the base. A sliding protrusion slidably connected to the groove is fixed to the end of the elastic reset component. The bottom of the sliding protrusion facing the fixed reinforcing bar is wedge-shaped. A receiving groove for accommodating the base is coaxially provided at the lower end of the inner wall of the sliding sleeve. A magnet for attracting the base is provided in the receiving groove. Several positioning grooves corresponding to the sliding protrusions are coaxially formed on the periphery of the fixed reinforcing bar.

3. The steel-free expansion joint structure according to claim 2, characterized in that: The extruded board has several horizontal slots, and a horizontal sleeve is coaxially fixed in each slot. A force transmission rod is slidably arranged coaxially in each horizontal sleeve. An anchor plate is provided at one end of the force transmission rod, and a sealing sleeve is slidably arranged coaxially at the other end of the force transmission rod.

4. The steel-free expansion joint structure according to claim 3, characterized in that: The sealing sleeve and sliding sleeve are provided with several anchoring protrusions on their periphery.

5. A steel-free expansion joint structure according to claim 4, characterized in that: The diameter of the middle part of the horizontal sleeve is larger than the diameters of its two ends.

6. A steel-free expansion joint structure according to claim 5, characterized in that: The resin concrete is a mixture of epoxy resin, polyurethane resin and aggregate.

7. A steel-free expansion joint structure according to claim 6, characterized in that: A sealing layer is provided at the bottom of the sliding sleeve.

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