Foot bridge deck slab adopting prefabricated concrete centrifugal beams
By laying precast concrete centrifugal beams on the upper surface of the bridge main beam and connecting them with Fe-SMA stranded wires, the problems of long construction period, high cost and insufficient integrity of the bridge deck in the prior art are solved, and the effects of reducing costs, improving connection strength and integrity are achieved, and the service life of the bridge deck are extended.
Patent Information
- Application Number
- CN202422104701.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-29
- Publication Date
- 2025-06-27
- Estimated Expiration
- 2034-08-29
AI Technical Summary
The existing concrete footbridge has a long construction cycle and high cost, and is prone to environmental pollution and is not strong integrity, which leads to cracking of the bridge deck paving layer, affecting the durability of the bridge.
Precast concrete centrifugal beams are used as the bridge deck panel, and Fe-SMA stranded wires are used to pass through all precast concrete centrifugal beams in sequence along the longitudinal direction of the bridge, and are fixedly connected to the bridge main beam through embedded bolts to improve the connection strength and integrity.
On the premise of ensuring the quality of the bridge deck, the cost is reduced, the connection strength and integrity are improved, the timely repairability is achieved, the service life of the bridge deck is extended, and it is in line with the national green and low-carbon construction development strategy.
Smart Images
Figure CN223033833U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of bridge engineering, and particularly relates to a pedestrian bridge deck adopting precast concrete centrifugal beams. Background Art
[0002] A pedestrian bridge is a structural form in urban bridges that mainly meets the traffic needs of pedestrians and also needs to meet the occasional vehicle passing needs. At present, the bridge decks of concrete pedestrian bridges are usually formed by in-situ construction, resulting in a long construction period, high cost, and easy environmental pollution of the bridge deck system, and should be avoided as much as possible in scenic spots and nature reserves. Moreover, general precast concrete bridge decks have deficiencies such as weak connection between plates and poor integrity, resulting in easy cracking of the bridge deck paving layer, which in turn affects the durability of the bridge. Summary of the Utility Model
[0003] The purpose of the utility model is to overcome the deficiencies existing in the prior art and provide a pedestrian bridge deck adopting precast concrete centrifugal beams. By laying multiple precast concrete centrifugal beams on the upper surface of the bridge main beam as the bridge deck and passing Fe-SMA stranded wires through all the precast concrete centrifugal beams in sequence along the longitudinal direction of the bridge, on the premise of ensuring the quality of the bridge deck, the cost is reduced, the connection strength and integrity are improved, and it has timely reparability during use, improving the service life of the bridge deck.
[0004] To achieve the above purpose, the utility model adopts the following technical solutions: A pedestrian bridge deck adopting precast concrete centrifugal beams, including a bridge main beam, precast concrete centrifugal beams laid flat on the upper surface of the bridge main beam in sequence along the longitudinal direction of the bridge, and Fe-SMA stranded wires passing through all the precast concrete centrifugal beams in sequence along the longitudinal direction of the bridge;
[0005] Each precast concrete centrifugal beam is arranged along the transverse direction of the bridge.
[0006] Further, the precast concrete centrifugal beam is fixedly connected to the bridge main beam through embedded bolts; the vertical section of the precast concrete centrifugal beam is a rectangle with a central hole; in the vertical direction, the Fe-SMA stranded wire transversely passes through the middle of the cross-section of the precast concrete centrifugal beam.
[0007] Further, a prestressed sleeve is sleeved outside the Fe-SMA stranded wire. After the two ends of the Fe-SMA stranded wire pass through the two ends of the prestressed sleeves of each centrifugal beam in sequence, they are anchored on the corresponding edge precast concrete centrifugal beams.
[0008] Furthermore, the precast concrete centrifugal beam includes a concrete main body with a through hole formed in the middle, centrifugal beam stirrups that are circumferentially tied and arranged equidistantly along the length direction of the concrete main body inside the concrete main body, and centrifugal beam longitudinal bars that are circumferentially tied equidistantly inside the centrifugal beam stirrups and arranged along the length direction of the concrete main body; the prestressed sleeves are tied to the centrifugal beam stirrups and / or centrifugal beam longitudinal bars and embedded in the concrete main body.
[0009] Furthermore, at least three prestressed sleeves are provided and arranged at equal intervals along the length direction of the centrifugal beam.
[0010] Furthermore, embedded steel plates are provided on the upper part of the precast concrete centrifugal beam, and the embedded steel plates are welded to the centrifugal beam stirrups; a cast-in-place concrete layer is poured above the precast concrete centrifugal beam, and longitudinal bridge-aligned steel bars and transverse bridge-aligned steel bars that are tied to each other are laid inside the cast-in-place concrete layer; a number of connectors arranged at equal intervals are welded on the upper surface of the embedded steel plates, and the tops of the connectors are tied or welded to the longitudinal bridge-aligned steel bars or transverse bridge-aligned steel bars; a bridge deck asphalt layer is laid above the cast-in-place concrete layer.
[0011] Furthermore, the connectors are studs or steel bars arranged vertically.
[0012] The beneficial effects of the present utility model are as follows:
[0013] 1. By laying precast concrete centrifugal beams on the upper surface of the main bridge beam as the bridge deck and successively passing Fe-SMA stranded wires through all the precast concrete centrifugal beams along the longitudinal direction of the bridge, on the premise of ensuring the quality of the bridge deck, the cost is reduced, the connection strength and integrity are improved, and it has the function of timely repair during use, improving the service life of the bridge deck, etc.; using precast concrete centrifugal beams to form the main body of the bridge deck can form factory-standardized production, improve the construction efficiency of the bridge deck, reduce the cost of the bridge deck, and at the same time can reduce carbon emissions, reduce pollution, and be environmentally friendly, meeting the national green and low-carbon construction development strategy, with good comprehensive benefits.
[0014] 2. Using stranded wires made of iron-based shape memory alloy (Fe-SMA) materials can generate prestress through the method of energizing and heating excitation, eliminating the need for on-site mechanical tensioning construction and related tensioning equipment, improving the construction convenience. At the same time, during the later operation of the bridge deck, even if prestress loss occurs in the Fe-SMA stranded wires, the prestress loss can be compensated in a timely manner by the same heating excitation method or the prestress loss can be compensated regularly by heating, preventing the upper bridge deck layer from cracking caused by the generation of gaps between components, thereby reducing the later operation and maintenance cost of the bridge deck and improving the service life of the bridge deck.
[0015] 3. The prestress of the Fe-SMA stranded wire is used to connect the discrete centrifugal beams into a whole, which can improve the integrity of the bridge deck. At the same time, studs are welded above the embedded steel plate at the top of the centrifugal beam. The connection between the studs and the longitudinal and transverse steel bars of the bridge deck steel mesh can achieve the effective connection between the cast-in-place concrete layer and the precast centrifugal beam bridge deck layer, promoting their collaborative working ability and further improving the integrity of the bridge deck. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Figure 1 is a schematic vertical sectional structure view of the present utility model;
[0017] Figure 2 is a schematic structure view of the present utility model without laying the bridge deck steel mesh;
[0018] Figure 3 is a schematic plan view of the present utility model without pouring the upper layer of concrete and asphalt layer;
[0019] Figure 4 is a schematic sectional structure view of the precast concrete centrifugal beam of the present utility model.
[0020] In the figure: 1. Prestress sleeve; 2. Fe-SMA stranded wire; 3. Bridge deck asphalt layer; 4. Embedded steel plate; 5. Connector; 6. Longitudinal steel bar along the bridge; 7. Transverse steel bar along the bridge; 8. Cast-in-place concrete layer; 9. Centrifugal beam longitudinal bar; 10. Centrifugal beam stirrup; 11. Precast concrete centrifugal beam; 12. Bridge main beam. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0021] The technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all of the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative efforts shall fall within the protection scope of the present utility model.
[0022] The directional terms mentioned in the present utility model, such as "upper", "lower", "front", "rear", "left", "right", "inner", "outer", "side", "top" and "bottom" and other words, are only references to the orientation of the accompanying drawings. The directional terms used are for explaining and understanding the present utility model, rather than for limiting the present utility model.
[0023] Embodiment:
[0024] As Figures 1-4As shown in the figure, a pedestrian bridge deck using precast concrete centrifugal beams includes a bridge main beam 12, precast concrete centrifugal beams 11 laid flat on the upper surface of the bridge main beam 12 in sequence along the longitudinal direction of the bridge, and Fe-SMA strands 2 passing through all the precast concrete centrifugal beams 11 in sequence along the longitudinal direction of the bridge;
[0025] Each precast concrete centrifugal beam 11 is arranged along the transverse direction of the bridge.
[0026] By laying precast concrete centrifugal beams 11 on the upper surface of the bridge main beam 12 as the bridge deck and using Fe-SMA strands 2 to pass through all the precast concrete centrifugal beams 11 in sequence along the longitudinal direction of the bridge, the cost is reduced, the connection strength and integrity are improved, and the bridge life is further extended while ensuring the quality of the bridge deck.
[0027] Precast concrete centrifugal beams are prefabricated and produced in the factory. The components are formed and compacted by the centrifugal force during high-speed rotation, with the advantages of reliable quality, convenient transportation and hoisting, environmental protection in construction, short construction period, and low cost, overcoming the problems of long construction period and large pollution of the traditional cast-in-place construction method.
[0028] Iron-based shape memory alloy (Fe-SMA) is a kind of intelligent metal material with shape memory effect. When its shape memory effect occurs, a recovery stress is generated inside by restricting its deformation, and this stress can generate a pre-compressive stress on the restraint body. The generation of its pre-compressive stress does not require on-site mechanical tensioning, only temperature rise excitation is needed, so it is called self-prestressing. Due to the function of providing self-prestressing by simply raising the temperature, for the prestress loss generated during the service period of the structure, timely compensation can be realized, avoiding or delaying the cracking and extension of the structure caused by the prestress loss, and then improving the whole life cycle of the structure.
[0029] To further practice the national concept of green and low-carbon development and jointly promote high-quality development such as carbon reduction, pollution reduction, and growth in engineering construction, for this kind of bridge with relatively small dynamic load on the bridge deck, its bridge deck structure can consider using products such as precast concrete centrifugal beams with low cost, low-carbon energy conservation and environmental protection to replace the existing bridge deck structure, and using iron-based shape memory alloy (Fe-SMA) to enhance the integrity and timely reparability of the bridge deck, and then improve the whole life cycle of the bridge deck.
[0030] The precast concrete centrifugal beam 11 is fixedly connected to the bridge main beam 12 through embedded bolts; the vertical section of the precast concrete centrifugal beam 11 along the longitudinal direction of the bridge is a rectangle with a central opening; in the vertical direction, the Fe-SMA strand 2 passes horizontally through the middle of the cross-section of the precast concrete centrifugal beam 11.
[0031] A prestressed sleeve 1 is sleeved outside the Fe-SMA stranded wire 2. The prestressed sleeve 1 passes through all the precast concrete centrifugal beams 11. The inner diameter of the prestressed sleeve 1 is larger than the diameter of the Fe-SMA stranded wire 2. Both ends of the Fe-SMA stranded wire 2 pass through both ends of the prestressed sleeve 1 respectively and are anchored to the corresponding precast concrete centrifugal beams 11.
[0032] The precast concrete centrifugal beam 11 includes a concrete main body with a through hole opened in the middle, centrifugal beam stirrups 10 that are circumferentially tied and arranged equidistantly along the length direction of the concrete main body inside the concrete main body, and centrifugal beam longitudinal bars 9 that are circumferentially tied equidistantly inside the centrifugal beam stirrups 10 and arranged along the length direction of the concrete main body.
[0033] At least three prestressed sleeves 1 are provided and arranged equidistantly along the transverse direction of the bridge.
[0034] Embedded steel plates 4 are arranged on the upper part of the precast concrete centrifugal beam 11. The embedded steel plates 4 are welded to the centrifugal beam stirrups 10. A concrete cast-in-place layer 8 is poured above the precast concrete centrifugal beam 11. Longitudinal bridge-aligned steel bars 6 and transverse bridge-aligned steel bars 7 that are tied to each other are laid inside the concrete cast-in-place layer 8; a number of connectors 5 arranged at equal intervals are welded on the upper surface of the embedded steel plates 4, and the tops of the connectors 5 are tied or welded to the longitudinal bridge-aligned steel bars 6 or the transverse bridge-aligned steel bars 7; a bridge deck asphalt layer 3 is laid above the concrete cast-in-place layer 8.
[0035] A number of embedded steel plates 4 are arranged along the length direction inside each concrete main body, and adjacent embedded steel plates 4 are arranged at a certain distance interval.
[0036] The connectors 5 are vertical studs or short steel bars.
[0037] The Fe-SMA stranded wire 2 is prepared from an iron-based shape memory alloy.
[0038] The construction process of the pedestrian bridge deck using precast concrete centrifugal beams includes the following steps:
[0039] 1) Prefabrication and production of the precast concrete centrifugal beam 11: Tie the centrifugal beam longitudinal bars 9 and the centrifugal beam stirrups 10 of the precast concrete centrifugal beam 11 to form a steel cage skeleton; horizontally and equidistantly embed prestressed sleeves 1 along the length direction (i.e., the transverse direction of the bridge) at positions such as the ends, mid-span, and quarter points of the steel cage skeleton. Each prestressed sleeve 1 is arranged along the longitudinal direction of the bridge. The prestressed sleeve 1 is located at the center of the cross-sectional height of the precast concrete centrifugal beam 11 and is tied and fixed to the steel cage skeleton. The prestressed sleeve 1 can be a plastic corrugated pipe; the prestressed sleeves 1 at corresponding positions of each precast concrete centrifugal beam 11 need to be accurately positioned to facilitate the smooth passing of the later Fe-SMA stranded wire 2 during strand threading;
[0040] At the top of the steel reinforcement cage, a pre-embedded steel plate 4 is welded every 1 m along the length. The width of the pre-embedded steel plate 4 is the same as the side length of the precast concrete centrifugal beam 11. The length of the pre-embedded steel plate 4 is 0.3 m, and the thickness of the pre-embedded steel plate 4 is the concrete protection layer thickness of the precast concrete centrifugal beam 11. After the corresponding processes of binding the steel reinforcement cage are completed, the formwork installation and concrete placement can be completed according to the conventional construction of the precast concrete centrifugal beam 11, and the component forming, curing, demoulding and other subsequent processes are carried out by the centrifugal compaction process to form the precast concrete centrifugal beam body.
[0041] 2) Forming of the precast bridge deck: After arranging multiple precast concrete centrifugal beams 11 horizontally side by side above the bridge main beam 12, the Fe-SMA stranded wire 2 made of iron-based shape memory alloy (Fe-SMA) is transversely passed through the prestressed sleeves 1 reserved at the corresponding positions of each centrifugal beam. The prestressed sleeve 1 generally adopts a plastic corrugated pipe, and high-temperature-resistant mortar is pressed into the plastic corrugated pipe. Then, the two ends of the Fe-SMA stranded wire are anchored on the outer end faces of the precast concrete centrifugal beams 11 with anchors. Finally, the Fe-SMA stranded wire 2 is heated and excited by applying an external current at the end of the Fe-SMA stranded wire 2. After it cools down, a transverse prestress is generated on the component, and multiple precast concrete centrifugal beams 11 are formed into a plate body with strong integrity.
[0042] The preparation of the stranded wire 2 with iron-based shape memory alloy (Fe-SMA) has the characteristics of no need for prestress tensioning equipment and short construction time and convenient construction. During the later operation of the bridge deck, even if prestress loss occurs in the Fe-SMA stranded wire, the prestress loss can be regularly compensated by the same heating method, which can prevent the upper bridge deck layer from cracking caused by the gaps between components, thereby reducing the later operation and maintenance cost of the bridge deck and improving the service life of the bridge deck.
[0043] 3) Completing the construction of each layer of the upper bridge deck: On the upper surface of the pre-embedded steel plate 4 exposed at the top of each precast concrete centrifugal beam 11, a vertical stud or short steel bar 5 with a diameter of 10 mm is welded every 0.1 m; then the steel bar mesh of the cast-in-place concrete layer 8 is bound; the steel bar mesh includes transverse steel bars 7 along the bridge and longitudinal steel bars 6 along the bridge; the transverse steel bars 7 along the bridge and / or the longitudinal steel bars 6 along the bridge are connected to the vertical stud or short steel bar 5 by binding or welding to strengthen the common force bearing of the precast bridge deck and the cast-in-place concrete layer 8; then the concrete cast-in-place layer 8 with a thickness of 6 - 8 mm is poured over the entire bridge deck area. After curing to a certain strength, the bridge deck waterproof layer can be laid, and finally the construction of the bridge deck asphalt layer 3 is completed according to the conventional method.
[0044] The above is only used to illustrate the technical solution of the present invention rather than to limit it. Other modifications or equivalent replacements made by those of ordinary skill in the art to the technical solution of the present invention should be covered within the scope of the claims of the present invention as long as they do not depart from the spirit and scope of the technical solution of the present invention.
Claims
1. A pedestrian bridge deck using precast concrete centrifugal beams, characterized in that: It comprises a bridge main beam (12), precast concrete centrifugal beams (11) sequentially laid on the upper surface of the bridge main beam (12) along the longitudinal direction of the bridge, and Fe-SMA strands (2) sequentially passing through all the precast concrete centrifugal beams (11) along the longitudinal direction of the bridge; Each of the precast concrete centrifugal beams (11) is arranged along the transverse direction of the bridge.
2. The pedestrian bridge deck using precast concrete centrifugal beams according to claim 1, characterized in that: The precast concrete centrifugal beam (11) is fixedly connected to the bridge main beam (12) by means of embedded bolts; the vertical cross-section of the precast concrete centrifugal beam (11) is a rectangle with a central opening; in the vertical direction, the Fe-SMA strand (2) passes through the middle of the precast concrete centrifugal beam (11).
3. The pedestrian bridge deck using precast concrete centrifugal beams according to claim 1, characterized in that: The outer side of the Fe-SMA strand (2) is sheathed with a prestressed sleeve (1), and two ends of the Fe-SMA strand (2) respectively pass through two ends of the prestressed sleeve (1) and are then anchored to the corresponding precast concrete centrifugal beam (11).
4. The pedestrian bridge deck using precast concrete centrifugal beams according to claim 3, characterized in that: The precast concrete centrifugal beam (11) comprises a concrete body with a through hole in the middle, centrifugal beam stirrups (10) tied circumferentially and arranged equidistantly inside the concrete body along the length direction of the concrete body, and centrifugal beam longitudinal bars (9) tied circumferentially and equidistantly inside the centrifugal beam stirrups (10) and arranged along the length direction of the concrete body; the prestressed sleeve (1) is tied to the centrifugal beam stirrups (10) and / or the centrifugal beam longitudinal bars (9) and pre-buried in the concrete body.
5. The pedestrian bridge deck using precast concrete centrifugal beams according to claim 3, characterized in that: At least three prestressed sleeves (1) are provided and are arranged at equal intervals in the transverse direction of the bridge.
6. The pedestrian bridge deck using precast concrete centrifugal beams according to claim 4, characterized in that: An embedded steel plate (4) is arranged on the upper part of the precast concrete centrifugal beam (11), and the embedded steel plate (4) is welded to the centrifugal beam stirrups (10); a cast-in-place concrete layer (8) is poured on the upper part of the precast concrete centrifugal beam (11), and longitudinal steel bars (6) and transverse steel bars (7) along the bridge that are tied to each other are laid inside the cast-in-place concrete layer (8); a plurality of connectors (5) arranged at equal intervals are welded to the upper surface of the embedded steel plate (4), and the top of the connector (5) is tied or welded to the longitudinal steel bars (6) along the bridge or the transverse steel bars (7) along the bridge; and a bridge deck asphalt layer (3) is laid above the cast-in-place concrete layer (8).
7. The pedestrian bridge deck using precast concrete centrifugal beams according to claim 6, characterized in that: The connecting piece (5) is a vertically arranged welding nail or steel bar.