UHPC-steel bar reinforced pier capping beam structure

Abstract

The utility model discloses a UHPC (Ultra High Performance Concrete)-steel bar reinforced pier cover beam structure, which belongs to the technical field of bridge reinforcement and comprises a plurality of transverse embedded steel bars positioned on two side surfaces of an original cover beam and arranged at intervals along the transverse direction of the original cover beam; the longitudinal embedded steel bars are located on the two end faces of the original bent cap and arranged at intervals in the longitudinal direction of the original bent cap. The transverse stress main ribs are arranged on the upper side of the original bent cap at intervals in the longitudinal direction of the original bent cap. The multiple inverted-U-shaped stirrups are arranged at intervals in the transverse direction of the original bent cap. The longitudinal embedded steel bars, the transverse embedded steel bars, the inverted-U-shaped stirrups and the transverse stress main steel bars are all connected with a main body framework of an original bent cap to form a widened part of the original bent cap. And the UHPC concrete layer is poured on the widened part of the original bent cap. As the sectional dimension of the pier capping beam is increased, the problem that the capping beam cannot meet the requirement of a new anti-seismic specification on the minimum distance from the beam end to the edge of the capping beam is solved.

Description

Technical Field

[0001] The utility model belongs to the technical field of bridge reinforcement, and specifically relates to a UHPC-steel reinforced bridge pier cap beam structure. Background Art

[0002] The pier cap beam is the link between the upper and lower structures of the bridge. The upper load is transferred to the cap beam through the support, and then distributed to the pier column and then to the pile foundation through the cap beam.

[0003] However, as the service time of bridge structures continues to increase, the bearing capacity and durability of various components have decreased to varying degrees. In addition, after the release of the "Highway Bridge Seismic Design Code" JTG / T 2231-01-2020, the width of the pier cap beams of many bridges with relatively large sub-sections and high piers in one section mostly do not meet the requirements of the first-level seismic measures of bridges (the minimum distance a from the end of the beam of the superstructure of the continuous beam bridge to the edge of the cap beam). Therefore, an effective reinforcement method and structure are urgently needed to solve the problem that the bearing capacity and durability of the bridge structure deteriorate with the increase of service time and some cap beams do not meet the requirements of the new seismic code for the minimum distance from the end of the beam to the edge of the cap beam. Utility Model Content

[0004] The main purpose of the utility model is to provide a UHPC-steel reinforced bridge pier cap beam structure to solve the problem that the prior art does not meet the minimum distance requirement in the new seismic code.

[0005] In order to achieve the above purpose, the utility model adopts the following technical solution: a UHPC-steel reinforced bridge pier cap beam structure, used to reinforce the original cap beam set on the upper side of the pier column, comprising:

[0006] A plurality of transverse embedded bars, the plurality of transverse embedded bars are located on two sides of the original cap beam, are arranged at intervals along the transverse direction of the original cap beam, and are at least partially embedded in the structure of the original cap beam;

[0007] A plurality of longitudinal embedded bars, the plurality of longitudinal embedded bars are located at both end surfaces of the original cap beam, are arranged at intervals along the longitudinal direction of the original cap beam, and are at least partially embedded in the structure of the original cap beam;

[0008] A plurality of transverse force-bearing main reinforcement bars are arranged at intervals on the upper side of the original cap beam along the longitudinal direction of the original cap beam;

[0009] A plurality of inverted U-shaped stirrups, wherein the plurality of inverted U-shaped stirrups are arranged at intervals along the transverse direction of the original cap beam; wherein the longitudinal embedded bars, the transverse embedded bars, the inverted U-shaped stirrups and the transverse force-bearing main bars are all connected to the main frame of the original cap beam to form a widened portion of the original cap beam;

[0010] The UHPC concrete layer is cast on the widened portion of the original cap beam.

[0011] Furthermore, an interface agent layer is provided between the original cap beam and the bottom layer of the UHPC concrete layer.

[0012] Furthermore, a hook is provided at the end of the transverse force-bearing main reinforcement.

[0013] Furthermore, the bending angle of the hook is 90°.

[0014] Furthermore, the transverse force-bearing main reinforcement and the inverted U-shaped stirrups are both made of HRB400, with a diameter d of 16mm-32mm.

[0015] Furthermore, the spacing between the two transverse force-bearing main reinforcements is 10 cm, and the length of the straight section of the hook is 10 d.

[0016] Furthermore, the transverse embedded steel bars and the longitudinal embedded steel bars are both made of HRB400 with a diameter of 14mm-22mm.

[0017] Beneficial effects:

[0018] The utility model provides a UHPC-rebar reinforced bridge pier cap beam structure, which firstly adopts longitudinal embedded reinforcement, transverse embedded reinforcement, inverted U-shaped stirrups and transverse force-bearing main reinforcement to connect with the main skeleton of the original cap beam, and then uses ultra-high performance concrete UHPC to cast the widened part. By adopting the method of putting a "jacket" on the original cap beam of the pier, the cross-sectional size of the cap beam is increased, the bearing capacity of the pier cap beam is improved, and the durability of the pier cap beam is improved by utilizing the characteristics of large self-shrinkage and small drying shrinkage of ultra-high performance concrete UHPC. At the same time, due to the increase in the cross-sectional size of the pier cap beam, the problem that the cap beam does not meet the minimum distance requirement from the beam end to the cap beam edge in the new seismic code is solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A cross-sectional view of a UHPC-reinforced bridge pier cap beam structure provided by the utility model along the transverse direction of the bridge;

[0020] Figure 2 A longitudinal and transverse reinforcement plan view of a UHPC-reinforced bridge pier cap beam structure provided by the utility model;

[0021] Figure 3 A cross-sectional view of an inverted U-shaped stirrup and a plurality of main force bars sequentially arranged along the transverse direction of the cap beam for reinforcing a bridge pier cap beam structure provided by the utility model;

[0022] Figure 4 This is a solid rendering of a UHPC-rebar reinforced bridge pier cap beam structure provided by the utility model.

[0023] In the figure: 1. Original cap beam; 2. Reinforced cap beam; 3. Ultra-high performance concrete UHPC; 4. Main stress-bearing reinforcement; 5. Inverted U-shaped stirrups; 6. Transverse embedded reinforcement; 7. Longitudinal embedded reinforcement; 8. Pier column; 9. Structural reinforcement. DETAILED DESCRIPTION

[0024] Example 1

[0025] refer to Figure 1-Figure 4 A UHPC-steel reinforced bridge pier cap beam structure is used to reinforce the original cap beam 1 arranged on the upper side of the pier column 8, comprising:

[0026] A plurality of transverse embedded steel bars 6, which are located on both sides of the original cap beam 1 and are arranged at intervals along the transverse direction of the original cap beam 1, and are at least partially embedded in the structure of the original cap beam 1;

[0027] A plurality of longitudinal embedded steel bars 7, which are located at both end surfaces of the original cap beam 1, and are arranged at intervals along the longitudinal direction of the original cap beam 1, and are at least partially embedded in the structure of the original cap beam 1;

[0028] During the specific implementation, the transverse embedded reinforcement 6 and the longitudinal embedded reinforcement 7 are embedded longitudinally and transversely in the existing cap beam in accordance with the relevant requirements of the Technical Code for Post-Anchorage of Concrete Structures JGJ145-2013 to increase the connection between the new and old cap beams.

[0029] A plurality of transverse force-bearing main reinforcement bars 4 are arranged at intervals along the longitudinal direction of the original cap beam 1 on the upper side of the original cap beam 1;

[0030] During specific implementation, the transverse force-bearing main reinforcement 4 of the cap beam mainly plays a bearing role to meet the structural force requirements.

[0031] A plurality of inverted U-shaped stirrups 5, wherein the plurality of inverted U-shaped stirrups 5 are arranged at intervals transversely along the original cap beam 1;

[0032] During specific implementation, the inverted U-shaped stirrup 5 mainly plays a role in shear resistance of the oblique section of the cap beam, and connects the main force-bearing reinforcement and the mixed reinforcement skeleton in the compression zone.

[0033] Among them, the longitudinal embedded reinforcement 7, the transverse embedded reinforcement 6, the inverted U-shaped stirrup 5 and the transverse force-bearing main reinforcement 4 are all connected to the main frame of the original cap beam 1 to form a widened part of the original cap beam 1;

[0034] The UHPC concrete layer 3 is cast on the widened portion of the original cap beam 1 .

[0035] During specific implementation, structural reinforcements 9 are provided on both sides of the widened portion to meet the structural force requirements.

[0036] In this embodiment, the raw materials of UHPC concrete include: cement, fly ash, silica fume, quartz sand, steel fiber and polycarboxylate water reducer.

[0037] In specific implementation, the tensile strength of ultra-high performance concrete UHPC is about 3 times that of ordinary concrete, and the compressive strength is more than 4 times that of ordinary concrete. In addition, the autogenous shrinkage of UHPC accounts for a large proportion of the total shrinkage, while the drying shrinkage (shrinkage caused by water loss in a dry environment after curing) is relatively small, and it has a stronger micro-crack self-healing ability. Therefore, HUPC concrete has ultra-high strength and high toughness and durability, and can effectively inhibit the appearance and development of 45° inclined cracks on the top of the reinforced cover beam and column.

[0038] In this embodiment, an interface agent layer is provided between the original cap beam 1 and the bottom layer of the UHPC concrete layer 3 .

[0039] In this embodiment, a hook is provided at the end of the transverse force-bearing main reinforcement 4 .

[0040] In this embodiment, the bending angle of the hook is 90°.

[0041] In this embodiment, the transverse force-bearing main reinforcement 4 and the inverted U-shaped stirrup 5 are both made of HRB400, and the diameter d is 16 mm-32 mm.

[0042] In this embodiment, the distance between the two transverse force-bearing main reinforcements 4 is 10 cm, and the length of the straight section of the hook is 10 d.

[0043] In this embodiment, both the transverse embedded steel bars 6 and the longitudinal embedded steel bars 7 are made of HRB400 with a diameter of 14 mm to 22 mm.

[0044] In specific implementation, according to Article 6.3.2 of the Technical Code for Post-anchorage of Concrete Structures JGJ 145-2013, the basic anchorage depth of the embedded reinforcement is (300-500mm), and the corresponding drilling diameter of the embedded reinforcement is the embedded reinforcement diameter (d+40)mm;

[0045] In addition, the dimension of the rear edge of the embedded reinforcement and the pre-reinforced cap beam shall not be less than 5d (70-110mm).

[0046] Example 2

[0047] This embodiment provides a reinforcement method for a UHPC-rebar reinforced bridge pier cap beam structure, using the UHPC-rebar reinforced bridge pier cap beam structure provided in Example 1, and the method includes the following steps:

[0048] S1. Set up a construction platform;

[0049] S2. Treat the original concrete surface of the cap beam, chisel off the corroded and damaged parts of the original cap beam, and use polymer mortar to repair the corroded and peeled parts;

[0050] S3, construct transverse reinforcement 6 and longitudinal reinforcement 7;

[0051] S4. Set up templates on both sides of the original cap beam 1 as needed, tie up the transverse force-bearing main reinforcement 4 and the inverted U-shaped stirrups 5, and connect them with the main frame of the original cap beam 1;

[0052] In this embodiment, the templates set up on both sides are generally steel templates.

[0053] S5, pouring ultra high performance concrete UHPC concrete layer 3;

[0054] S6. After the concrete pouring is completed, use moisturizing materials to maintain the reinforced rear cap beam 2.

[0055] The above description is only a preferred embodiment of the present invention and does not limit the technical scope of the present invention. Therefore, any slight modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A UHPC-reinforced bridge pier cap beam structure, used to reinforce the original cap beam arranged on the upper side of the pier column, characterized in that: include: A plurality of transverse embedded bars, the plurality of transverse embedded bars are located on two sides of the original cap beam, are arranged at intervals along the transverse direction of the original cap beam, and are at least partially embedded in the structure of the original cap beam; A plurality of longitudinal embedded bars, the plurality of longitudinal embedded bars are located at both end surfaces of the original cap beam, are arranged at intervals along the longitudinal direction of the original cap beam, and are at least partially embedded in the structure of the original cap beam; A plurality of transverse force-bearing main reinforcement bars are arranged at intervals on the upper side of the original cap beam along the longitudinal direction of the original cap beam; A plurality of inverted U-shaped stirrups, wherein the plurality of inverted U-shaped stirrups are arranged at intervals along the transverse direction of the original cap beam; wherein the longitudinal embedded bars, the transverse embedded bars, the inverted U-shaped stirrups and the transverse force-bearing main bars are all connected to the main frame of the original cap beam to form a widened portion of the original cap beam; The UHPC concrete layer is cast on the widened portion of the original cap beam.

2. The UHPC-reinforced bridge pier cap beam structure according to claim 1, characterized in that: An interface agent layer is provided between the original cap beam and the bottom layer of the UHPC concrete layer.

3. The UHPC-reinforced bridge pier cap structure according to claim 1, characterized in that: The end of the transverse force-bearing main reinforcement is provided with a hook.

4. The UHPC-reinforced bridge pier cap structure according to claim 3, characterized in that: The bending angle of the hook is 90°.

5. The UHPC-reinforced bridge pier cap structure according to claim 4, characterized in that: The transverse force-bearing main reinforcement and the inverted U-shaped stirrups are both made of HRB400, with a diameter d of 16mm-32mm.

6. The UHPC-reinforced bridge pier cap structure according to claim 5, characterized in that: The distance between the two transverse force-bearing main reinforcement bars is 10 cm, and the length of the straight section of the hook is 10 d.

7. The UHPC-reinforced bridge pier cap structure according to claim 1, characterized in that: The transverse embedded steel bars and the longitudinal embedded steel bars are both made of HRB400 with a diameter of 14mm-22mm.

Images