Double-wall FRP-steel pipe self-compacting concrete hollow pier column
By adopting technical means such as double-wall structure, FRP shear grille, I-shaped shear groove and stiffened steel ring in FRP-steel pipe self-finished concrete hollow pier column, the problems of concrete air-removal and local buckling of FRP pipes, concrete and steel pipes while being subjected to stress are solved, and the risk of air-removal of concrete is achieved is reduced.
Patent Information
- Application Number
- CN202421477219.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-26
- Publication Date
- 2025-04-18
- Estimated Expiration
- 2034-06-26
AI Technical Summary
In the prior art, FRP pipe, concrete and steel pipes have problems of air discharge and local buckling of the inner concrete of the pipe while being subjected to force, especially during the construction of FRP-concrete-steel double-wall hollow composite columns.
The double-wall FRP-steel pipe self-contained concrete hollow pier column structure is adopted, and the outer FRP pipe is connected to the outside of the inner steel pipe through the outer FRP pipe, and the FRP shear grille is bonded in the circumferential direction to the inner wall of the outer FRP pipe, and the I-shaped shear groove is bonded between the inner space, and the opening I-shaped steel and stiffening steel ring are set up, combined with expansion agent and welding connection to form a self-contained concrete structure.
The coordinated working ability and deformation ability of FRP pipes, concrete and steel pipes are improved, the risk of concrete de-emphasis is reduced, local buckling or instability is avoided, and self-solid concrete filling is achieved without the need for construction vibration.
Smart Images
Figure CN222771738U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of concrete hollow piers, in particular to a double-wall FRP-steel tube self-compacting concrete hollow pier. Background Art
[0002] Fiber Reinforced Polymer (FRP) is a new type of high-performance material. It is widely used in the civil engineering industry due to its advantages such as high tensile strength, light weight, easy construction, good durability, similar thermal expansion coefficient to concrete, and linear elastic stress-strain relationship. FRP-concrete-steel double-wall hollow composite column is composed of an external FRP tube and an internal steel tube concrete column. It is an application of FRP derived from the steel tube concrete column. It can simultaneously play the role of FRP tube in restraining concrete and the advantage of internal steel tube in connecting components. The external FRP tube provides circumferential restraint for concrete, and the internal steel tube also provides lateral pressure for concrete. When the composite component is working, the inner-filled concrete is in a three-way compression state. The ultimate strength and ultimate strain are greatly improved compared to plain concrete, giving full play to the advantages of steel tube, FRP tube and inner-filled concrete.
[0003] The shear connection between the FRP profile and concrete composite interface is a reliable guarantee for the coordinated work of the two. Domestic and foreign scholars have developed a variety of shear connection forms suitable for the FRP profile-concrete interface based on the design ideas of steel-concrete composite structures, mainly including bonding, mechanical bite connection, FRP bolts, steel bolts, FRP shear keys and new perforated FRP plates, but there is a lack of shear connection forms for FRP-concrete-steel double-wall type. During the construction of FRP-concrete-steel double-wall hollow composite columns, when the gap between the FRP tube and the steel tube is too small, it is not convenient to vibrate and compact them. At the same time, multiple factors such as concrete shrinkage, construction technology and construction environment will cause the concrete in the steel tube to be hollow. Summary of the invention
[0004] The utility model aims to solve the deficiencies of the prior art and provides a double-wall FRP-steel tube self-compacting concrete hollow pier column to solve the problems of force coordination among FRP tubes, concrete and steel tubes and hollowing out and local buckling of concrete inside the tubes.
[0005] In order to achieve the above-mentioned purpose, the utility model adopts the following technical solutions:
[0006] A double-wall FRP-steel tube self-compacting concrete hollow pier column comprises an inner steel tube and an outer FRP tube, wherein the outer FRP tube is sleeved on the outer side of the inner steel tube, an FRP shear grid is bonded circumferentially on the inner wall of the outer FRP tube, I-shaped shear grooves are bonded at intervals in the FRP shear grid, an open I-beam is arranged on the outer side of the inner steel tube and the inner side of the outer FRP tube, the outer end of the open I-beam is bonded to the inner wall of the I-shaped shear groove, the inner end of the open I-beam is connected to the outer wall of the inner steel tube by welding, self-compacting concrete is poured in the gap between the outer side of the inner steel tube and the outer FRP tube, an expansion agent is added to the self-compacting concrete admixture, and the expansion rate is limited to 0.056%, and a stiffening steel ring is welded inside the inner steel tube.
[0007] The cross-sectional dimensions of the inner groove of the I-shaped shear groove are consistent with the cross-sectional dimensions of the open I-shaped steel beam, and the wall thickness of the I-shaped shear groove is greater than or equal to 2 cm.
[0008] The glue used to bond the open I-beam to the inner wall of the I-shaped shear groove is epoxy resin AB glue.
[0009] The transverse shear bars of the FRP shear grid have a size of 500mm×20mm×10mm and a spacing of 200mm, and the longitudinal shear bars have a size of 180mm×10mm×10mm and a spacing of 40mm, which increases the connectivity between the one-way connectors, promotes the joint work of different connectors, and greatly enhances the integrity of the shear member.
[0010] The reinforcing steel ring is welded at the position on the inner side of the inner steel pipe that is prone to local buckling, which can effectively prevent the hollow pier from local buckling or instability.
[0011] The inner steel pipes between the segments are connected by welding, the bonding surfaces of the outer FRP pipes are connected with PLEXUS MA310 acrylic structural adhesive, and FRP cloth is glued to the outside of the joints.
[0012] The beneficial effects of the utility model are as follows: the FRP shear grid bonded to the inner wall of the outer FRP tube of the utility model is a bidirectional connector, which increases the connectivity between unidirectional connectors, promotes the joint work of different connectors, greatly enhances the integrity of the shear component, and improves the ultimate shear bearing capacity of the connector; the I-shaped shear groove, the FRP shear grid and the open I-beam jointly connect the FRP tube, the self-compacting concrete and the steel tube into a whole, improves the integrity and shear bearing capacity of the shear key, and increases the cooperative working ability and deformation capacity of the double-wall FRP-steel tube self-compacting concrete hollow pier; the stiffening steel ring can effectively avoid local buckling or instability of the hollow pier; the self-compacting concrete is not affected by the construction space between the FRP tube and the steel tube, and does not need to be vibrated during construction, and an appropriate amount of expansion agent is added. Under the constraints of the FRP tube and the steel tube, the generated calcium aluminate is squeezed into the capillary pores under the action of expansion energy, forming a denser internal structure, increasing the bonding force between the concrete and the tube wall, and reducing the risk of degassing. BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Figure 1 It is a three-dimensional structural schematic diagram of the utility model;
[0014] Figure 2 It is a top view of the utility model;
[0015] Figure 3 It is a 1 / 4 cross-sectional view of the utility model;
[0016] In the figure: 1-inner steel pipe; 2-outer FRP pipe; 3-I-shaped shear groove; 4-FRP shear grid; 5-open I-beam; 6-reinforced steel ring; 7-self-compacting concrete;
[0017] The following is a detailed description of the embodiments of the present invention with reference to the accompanying drawings. DETAILED DESCRIPTION
[0018] The utility model is further described below in conjunction with the accompanying drawings and embodiments:
[0019] like Figure 1-Figure 3 As shown, a double-wall FRP-steel tube self-compacting concrete hollow pier column comprises an inner steel tube 1 and an outer FRP tube 2, the outer FRP tube 2 is sleeved on the outer side of the inner steel tube 1, an FRP shear grid 4 is bonded circumferentially on the inner wall of the outer FRP tube 2, an I-shaped shear groove 3 is bonded at intervals inside the FRP shear grid 4, an open I-beam 5 is arranged on the outer side of the inner steel tube 1 and the inner side of the outer FRP tube 2, the outer side end of the open I-beam 5 is bonded to the inner wall of the I-shaped shear groove 3, and the inner side end of the open I-beam 5 is bonded to the inner steel tube 1 The outer wall is connected by welding, and the self-compacting concrete 7 is poured in the gap between the outer side of the inner steel pipe 1 and the outer FRP pipe 2. The expansion agent is added to the self-compacting concrete admixture to limit the expansion rate to 0.056%. The inner steel pipe 1 is welded with a reinforcing steel ring 6. The outer FRP pipe 2, the I-shaped shear groove 3 and the FRP shear grid 4 are all made of eight glass fibers laid in the direction of ±45° and 90°. The unsaturated polyester resin is vacuum-introduced and cured, and is cut and trimmed into the required shape and size after molding.
[0020] The inner groove cross-sectional dimension of the I-shaped shear groove 3 is consistent with the cross-sectional dimension of the open I-shaped steel 5, and the wall thickness of the I-shaped shear groove 3 is greater than or equal to 2 cm.
[0021] The glue used to bond the open I-beam 5 to the inner wall of the I-shaped shear groove 3 is epoxy resin AB glue, and the interface between the outer FRP tube 2, the I-shaped shear groove 3, and the FRP shear grid 4 is connected by PLEXUS MA310 acrylic ester structural glue.
[0022] The transverse shear bars of the FRP shear grid 4 have dimensions of 500 mm×20 mm×10 mm, with a spacing of 200 mm, and the longitudinal shear bars have dimensions of 180 mm×10 mm×10 mm, with a spacing of 40 mm.
[0023] The reinforcing steel ring 6 is welded to the position on the inner side of the inner steel pipe 1 that is prone to local buckling.
[0024] The inner steel pipes 1 between the segments are connected by welding, the bonding surfaces of the outer FRP pipes 2 are connected by PLEXUS MA310 acrylic structural adhesive, and the joints are bonded with FRP cloth.
[0025] When the utility model is working, an expansion agent is added to the concrete admixture of the self-compacting concrete 7, and the expansion rate is limited to 0.056%. The mix ratio in Table 1 can be used.
[0026] Table 1 Self-compacting concrete mix proportion
[0027]
[0028] The specific construction methods are as follows:
[0029] 1) The outer FRP tube 2 is transported to the designated position of the foundation by hoisting, and the surface of the outer FRP tube 2, the I-shaped shear groove 3, and the FRP shear grid 4 are wiped with anhydrous ethanol to remove the ash on the surface of the profile, and then the surface is polished with sandpaper to enhance the friction at the bonding interface and ensure its cleanliness;
[0030] 2) After the anhydrous ethanol on the surface of the outer FRP tube 2, the I-shaped shear groove 3, and the FRP shear grid 4 has completely evaporated, PLEXUS MA310 acrylic structural adhesive is applied to the inner surface of the outer FRP tube 2, and then the I-shaped shear groove 3 and the FRP shear grid 4 are pasted on the inner surface of the outer FRP tube 2 according to the designed spacing;
[0031] 3) Grind one end of the open I-beam 5 and apply epoxy resin AB glue, then put the open I-beam 5 into the I-shaped shear groove 3, and use a steel pipe to temporarily support the midpoint of the open I-beam 5;
[0032] 4) Weld the other end of the open I-beam 5 to the inner steel pipe 1, and remove the temporary support after the welding is firm;
[0033] 5) Weld the stiffening steel ring 6 to the inner steel pipe 1, hoist it to the center of the outer FRP pipe 2, and then weld the inner end of the open I-beam 5 to the inner steel pipe 1;
[0034] 6) Prepare concrete according to the mix ratio requirements in Table 1 and pour it between the inner steel pipe 1 and the outer FRP pipe 2.
[0035] 7) Repeat steps 1-4 to complete the assembly of the next segment. The inner steel pipe 1 is connected by welding, and the outer FRP pipe 2 is connected by PLEXUS MA310 acrylic structural adhesive. FRP cloth is glued to the outside of the joint. After the connection between the segments is completed, the second stage of concrete is poured.
[0036] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.
[0037] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present utility model, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.
[0038] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.
[0039] The utility model is described above by way of example in conjunction with the accompanying drawings. It is obvious that the specific implementation of the utility model is not limited to the above-mentioned method. As long as various improvements are made using the method concept and technical solution of the utility model, or are directly applied to other occasions without improvement, they are all within the protection scope of the utility model.
Claims
1. A double-wall FRP-steel tube self-compacting concrete hollow pier column, characterized in that: The invention comprises an inner steel pipe (1) and an outer FRP pipe (2), wherein the outer FRP pipe (2) is sleeved on the outer side of the inner steel pipe (1), an FRP shear grid (4) is bonded to the inner wall of the outer FRP pipe (2) along the circumferential direction, an I-shaped shear groove (3) is bonded to the inner side of the FRP shear grid (4), an open I-shaped steel beam (5) is arranged on the outer side of the inner steel pipe (1) and the inner side of the outer FRP pipe (2), the outer side end of the open I-shaped steel beam (5) is bonded to the inner wall of the I-shaped shear groove (3), the inner side end of the open I-shaped steel beam (5) is welded to the outer wall of the inner steel pipe (1), self-compacting concrete (7) is poured in the gap between the outer side of the inner steel pipe (1) and the outer FRP pipe (2), and a stiffening steel ring (6) is welded inside the inner steel pipe (1).
2. A double-wall FRP-steel tube self-compacting concrete hollow pier column according to claim 1, characterized in that: The cross-sectional dimensions of the inner groove of the I-shaped shear groove (3) are consistent with the cross-sectional dimensions of the open I-shaped steel (5), and the wall thickness of the I-shaped shear groove (3) is greater than or equal to 2 cm.
3. A double-wall FRP-steel tube self-compacting concrete hollow pier column according to claim 2, characterized in that: The glue used to bond the open I-beam (5) and the inner wall of the I-shaped shear groove (3) is epoxy resin AB glue.
4. A double-wall FRP-steel tube self-compacting concrete hollow pier column according to claim 3, characterized in that: The transverse shear bars of the FRP shear grid (4) have dimensions of 500 mm×20 mm×10 mm, with a spacing of 200 mm, and the longitudinal shear bars have dimensions of 180 mm×10 mm×10 mm, with a spacing of 40 mm.
5. A double-wall FRP-steel tube self-compacting concrete hollow pier column according to claim 4, characterized in that: The reinforcing steel ring (6) is welded to a position on the inner side of the inner steel pipe (1) that is prone to local buckling.
6. A double-wall FRP-steel tube self-compacting concrete hollow pier column according to claim 5, characterized in that: The inner steel pipes (1) between the segments are connected by welding, the bonding surfaces of the outer FRP pipes (2) are connected by PLEXUS MA310 acrylic structural adhesive, and the joints are bonded with FRP cloth.