A novel FRP pipe-concrete composite structure

Abstract

This invention discloses a novel FRP pipe-concrete composite structure, belonging to the technical field of beam-column joint structures. By placing reinforcing steel bars within the beam-column formwork and FRP pipes at the beam-column joints, the FRP pipes effectively resist 45° oblique shear forces. Due to the high tensile strength of the FRP pipes, they can distribute the shear stress originally borne by the concrete and reinforcing steel bars under 45° shear forces, preventing cracks, breakage, and bending at the joints caused by oblique shear forces. This ensures the structural safety when subjected to lateral forces, such as horizontal forces generated by earthquakes. With four FRP pipes distributed at the four corners, regardless of the angle from which the shear force is applied to the beam-column joint, the FRP pipes can work together to resist shear, forming a mutually supportive and coordinated shear-resistant system, thus improving the overall load-bearing capacity of the joint under oblique shear conditions at different angles.

Description

Technical Field

[0001] This invention belongs to the field of beam-column joint structure technology, specifically relating to a novel FRP pipe-concrete composite structure. Background Technology

[0002] In the field of modern construction engineering, with the continuous increase in building height, the increasing complexity of structural forms, and the continuous improvement of building performance requirements, traditional concrete structures have gradually revealed their limitations in certain aspects. As a widely used building material, concrete has high compressive strength, but relatively low tensile strength. It is prone to cracking when subjected to large tensile forces or complex stress states, which in turn affects the durability and integrity of the structure.

[0003] In critical areas such as beam-column joints, due to the complex stress distribution and significant stress concentration, traditional concrete structures often require substantial reinforcement with steel bars. This not only increases construction difficulty and cost but can also lead to problems such as incomplete concrete compaction at the joint due to improper reinforcement placement, affecting the joint's mechanical properties. At beam-column joints, 45° shear stress is often concentrated and of high value. Due to insufficient tensile strength of concrete, diagonal cracks are easily generated and propagated in the joint area. These cracks compromise the integrity of the concrete, weaken the joint's load-bearing capacity, and consequently affect the mechanical properties and stability of the entire structure. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a novel FRP pipe-concrete composite structure, which improves the shear resistance of beam-column joints by adding FRP pipes to the beam-column joints.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] The present invention includes a beam-column formwork for casting beam-column joints. The beam-column formwork is provided with a plurality of horizontally and vertically distributed steel bars. Four FRP pipes are provided in the middle of the beam-column joint, and the four FRP pipes are distributed at the four corners. A plurality of through holes are opened on the FRP pipes, and the horizontally distributed steel bars pass through the through holes.

[0007] Furthermore, it also includes a suspension frame, which includes a sleeve coaxially fixed to the top of one of the vertically distributed reinforcing bars. A vertical shaft is coaxially fixed to the sleeve, and two rotating beams are rotatably mounted on the vertical shaft. The rotating beams have grooves in their extending direction. It also includes a cylindrical vertical rod that passes vertically through the grooves. It also includes a pull rope and a stop beam. The pull rope passes through the upper end and exits from the lower end of the vertical rod. The middle end of the stop beam is fixed to the lower end of the pull rope. Three horizontal bars are distributed around the lower end of the vertical rod. The horizontal bars are threaded with stop nuts. The three horizontal bars are positioned at the upper edge of the FRP pipe. The stop nuts are positioned at the side of the FRP pipe. Pulling the pull rope up causes the two ends of the stop beams to be positioned at the lower edge of the FRP pipe. A threaded stop plate is mounted on the vertical rod, and the stop plate is positioned on the upper side of the rotating beam.

[0008] Furthermore, the top of the vertical shaft is provided with a threaded post, and the threaded post is threadedly connected to an internal threaded cylinder. A stop bar is fixed on the inner side of the top of the internal threaded cylinder. After the pull rope tightens the stop beam, it is knotted and fixed at the stop bar. The stop beam is further tightened by rotating the internal threaded cylinder.

[0009] Furthermore, the sleeve is inserted from the top of the reinforcing bar, and three locking screws are threaded around the bottom of the sleeve, with the locking screws abutting against the outside of the reinforcing bar being fixed.

[0010] Furthermore, a clamping block is slidably provided on the crossbar, and the clamping block has an obtuse-angled clamping surface on the side facing the FRP pipe. The stop nut abuts against the clamping block, so that the clamping block is clamped on the outside of the FRP pipe.

[0011] The beneficial effects of this invention are as follows:

[0012] This invention involves placing reinforcing steel bars within the beam-column formwork and installing FRP pipes at the beam-column joints. The FRP pipes effectively resist 45° oblique shear forces. Due to the high tensile strength of the FRP pipes, they can distribute the shear stress originally borne by the concrete and reinforcing steel bars under 45° shear forces, preventing cracks, breakage, and bending at the joints caused by oblique shear forces. This ensures the structural safety when subjected to lateral forces, such as horizontal forces generated by earthquakes. With four FRP pipes distributed at the four corners, regardless of the angle from which the shear force is applied to the beam-column joint, the FRP pipes work together to resist shear, forming a mutually supportive and coordinated shear-resistant system. This overall improvement enhances the load-bearing capacity of the joints under oblique shear conditions at different angles.

[0013] 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

[0014] To make the objectives, technical solutions, and beneficial effects of this invention clearer, the following figures are provided for illustration:

[0015] Figure 1 This is a schematic diagram of the FRP pipe distribution in the combined structure of an embodiment of the present invention;

[0016] Figure 2 This is a schematic diagram of the FRP pipe hoisting of the combined structure according to an embodiment of the present invention;

[0017] Figure 3 for Figure 2 Enlarged view of point A;

[0018] Figure 4 for Figure 2 Sectional view at point B;

[0019] Figure 5 This is a schematic diagram showing the details of FRP pipe hoisting in an embodiment of the present invention;

[0020] Figure 6 for Figure 5 Enlarged view of point C;

[0021] Figure 7 for Figure 5 Enlarged diagram of point D;

[0022] The following are marked in the attached diagram: 1. Beam and column formwork; 2. FRP pipe; 21. Through hole; 3. Suspension bracket; 31. Sleeve; 311. Locking screw; 32. Vertical shaft; 33. Turning beam; 331. Groove; 34. Vertical rod; 341. Stop plate; 35. Pull rope; 36. Stop beam; 37. Horizontal bar; 371. Stop nut; 372. Clamping block; 38. Threaded column; 39. Threaded cylinder; 391. Stop bar; 6. Reinforcing bar. Detailed Implementation

[0023] This invention discloses a novel FRP pipe-concrete composite structure, such as... Figure 1 As shown, it includes a beam-column formwork 1 for casting beam-column joints. The beam-column formwork 1 is provided with several horizontally and vertically distributed steel bars 6. Four FRP pipes 2 are provided in the middle of the beam-column joint. The four FRP pipes 2 are distributed at the four corners. Several through holes 21 are opened on the FRP pipes 2, and the horizontally distributed steel bars 6 pass through the through holes 21.

[0024] This structure, by setting steel bars 6 inside the beam-column formwork 1 and installing FRP pipes 2 at the beam-column joints, effectively resists 45° oblique shear forces. Due to the high tensile strength of the FRP pipes 2, when facing 45° shear forces, the FRP pipes 2 can share the shear stress originally borne by the concrete and steel bars 6 through their own mechanical properties, preventing cracks, breakage, and bending at the joints caused by oblique shear forces. This ensures the safety of the structure when subjected to lateral forces, such as horizontal forces generated by earthquakes. With four FRP pipes 2 distributed at the four corners, regardless of the angle from which the shear force is applied to the beam-column joint, the FRP pipes 2 can work together to resist shear, forming a mutually supportive and cooperative shear-resistant system, thus improving the overall load-bearing capacity of the joints under oblique shear conditions at different angles.

[0025] In further proposals, such as Figure 2 , Figure 3 , Figure 5 and Figure 7 As shown, it also includes a suspension frame 3, which includes a sleeve 31 coaxially fixed to the top of one of the vertically distributed reinforcing bars 6. A vertical shaft 32 is coaxially fixed to the sleeve 31. Two rotating beams 33 are rotatably mounted on the vertical shaft 32. The rotating beams 33 have grooves 331 extending in their extension direction. It also includes a cylindrical vertical rod 34 that vertically passes through the grooves 331. It also includes a pull rope 35 and a stop beam 36. The pull rope 35 passes through the upper end and exits through the lower end of the vertical rod 34. The stop beam 35... The middle end of the 6 is fixed to the lower end of the pull rope 35. Three horizontal bars 37 are distributed around the lower end of the vertical bar 34. The horizontal bars 37 are threaded with a stop nut 371. The three horizontal bars 37 are positioned at the upper edge of the FRP pipe 2. The stop nut 371 is positioned at the side of the FRP pipe 2. Pulling the pull rope 35 up causes the two ends of the stop beam 36 to be positioned at the lower edge of the FRP pipe 2. The vertical bar 34 is threaded with a stop plate 341. The stop plate 341 is positioned on the upper side of the rotating beam 33.

[0026] In this design, the suspension frame 3 mainly consists of components such as sleeve 31, vertical shaft 32, rotating beam 33, vertical rod 34, pull rope 35, stop beam 36, crossbar 37, stop nut 371, and stop plate 341 working together. The sleeve 31 is coaxially fixed to the top of a vertically distributed reinforcing bar 6, thus providing a stable support foundation for the entire suspension frame 3. This fully utilizes the structural stability and load-bearing capacity of the existing vertical reinforcing bar 6. Two rotating beams 33 are rotatably mounted on the vertical shaft 32. The extending direction of each rotating beam 33 has a groove 331, which provides an effective guiding path for the movement of the vertical rod 34, allowing it to flexibly adjust its position within a specific trajectory range. The vertical rod 34 adopts a cylindrical design, vertically penetrating the groove 331 of the rotating beam 33, thus forming a linkage with the rotating beam 33. A pull rope 35 passes through the upper end of the vertical rod 34 and exits through the lower end. At the lower end of the vertical rod 34, the middle end of the retaining beam 36 is fixed to the pull rope 35. Three horizontal bars 37 are evenly distributed around the lower end of the vertical rod 34, and the horizontal bars 37 are fitted with retaining nuts 371 by threaded connection. In actual operation, the three horizontal bars 37 can be positioned against the upper edge of the FRP pipe 2. Then, by rotating the retaining nuts 371, the upper end of the FRP pipe 2 is clamped and positioned, ensuring that the relative position of the FRP pipe 2 on the vertical rod 34 is accurate and will not easily shift. At the same time, pulling the pull rope 35 upwards allows the two ends of the retaining beam 36 to be positioned against the lower edge of the FRP pipe 2. With the traction of the pull rope 35 and the blocking effect of the retaining beam 36, the lower end of the FRP pipe 2 is effectively fixed, thus temporarily and securely fixing the FRP pipe 2 to the end of the vertical rod 34. The threaded retainer 341 on the vertical rod 34 can be placed on the upper side of the rotating beam 33, effectively supporting and restricting the vertical movement of the vertical rod 34. This structure is easy to install, requiring no additional complex installation procedures or auxiliary support structures, reducing construction difficulty and time costs. By setting two freely rotating beams 33, the FRP pipe 2 can be easily and flexibly moved to the specified precise position in both horizontal and vertical directions, effectively improving the operational convenience and positioning accuracy during construction. After completing the perforation of two FRP pipes 2, the installed FRP pipe 2 can be removed, and then the simultaneous suspension and perforation of the other two FRP pipes 2 can be carried out quickly. The entire process is smooth and efficient, significantly improving construction efficiency and project progress.

[0027] The suspension frame 3 structure has many significant advantages. Its installation is extremely simple; the sleeve 31 is simply coaxially inserted onto the already vertically installed reinforcing steel bar 6, allowing for rapid and easy erection of the suspension frame 3. No additional complex installation procedures or auxiliary support structures are required, greatly reducing construction difficulty and time costs. Particularly noteworthy is that, by setting two freely rotating beams 33, the suspension frame 3 can simultaneously perform efficient suspension and precise positioning operations on two FRP pipes 2 requiring perforation. The two rotating beams 33 give the FRP pipes 2 a high degree of freedom in space, allowing them to easily and flexibly move to the designated precise position in both horizontal and vertical directions, effectively improving operational convenience and positioning accuracy during construction. After completing the perforation of two FRP pipes 2, the installed FRP pipes 2 can be easily removed, and then the simultaneous suspension and perforation of the other two FRP pipes 2 can be carried out quickly. The whole process is smooth and efficient, which significantly improves construction efficiency and project progress, and provides strong technical support and construction guarantee for the application of the new FRP pipe-concrete composite structure in beam-column joint construction.

[0028] In further proposals, such as Figure 4 As shown, the top end of the vertical shaft 32 is provided with a threaded post 38, and the threaded post 38 is threadedly connected to an internal threaded cylinder 39. A stop bar 391 is fixedly provided on the inner side of the top end of the internal threaded cylinder 39. After the pull rope 35 tightens the stop beam 36, it is knotted and fixed at the stop bar 391. The stop beam 36 is further tightened by rotating the internal threaded cylinder 39.

[0029] The added tension adjustment mechanism in this structure allows for more precise control of the blocking force of the retaining beam 36 on the lower end of the FRP pipe 2, ensuring that the FRP pipe 2 maintains a stable position during suspension and subsequent perforation. The use of the internally threaded cylinder 39 and the retaining rod 391 to fix the pull rope 35 increases the redundancy of the entire suspension frame 3 system. Even if the pull rope 35 becomes slack to some extent, rotating the internally threaded cylinder 39 can promptly restore the tension of the pull rope 35, ensuring the effective blocking of the FRP pipe 2 by the retaining beam 36, thereby preventing the FRP pipe 2 from accidentally slipping or shifting.

[0030] In further proposals, such as Figure 6 As shown, the sleeve 31 is inserted from the upper end of the reinforcing bar 6, and three locking screws 311 are threaded around the bottom end of the sleeve 31. The locking screws 311 abut against the outside of the reinforcing bar 6 that is being fixed.

[0031] This structure, by adjusting the screw depth and tightness of the locking screw 311, can tightly fix the sleeve 31 to the steel bars 6 of different specifications, preventing the vertical shaft 32 from shaking due to various vibrations, impacts and forces in different directions, and providing a stable and reliable support foundation for the suspension and construction operation of the FRP pipe 2.

[0032] In further proposals, such as Figure 3 As shown, a clamping block 372 is also slidably provided on the crossbar 37. The clamping block 372 has an obtuse-angled clamping surface on the side facing the FRP pipe 2. The stop nut 371 abuts against the clamping block 372, so that the clamping block 372 is clamped on the outside of the FRP pipe 2.

[0033] The obtuse-angled clamping surface design of clamping block 372 provides a more stable and uniform clamping force. When faced with different dimensional deviations or uneven surfaces of FRP pipe 2, the obtuse-angled clamping surface can better adapt to and fit FRP pipe 2, effectively dispersing clamping pressure and avoiding damage to FRP pipe 2 due to local stress concentration. This ensures the integrity and stability of FRP pipe 2 during suspension, preventing swaying, displacement, or detachment during construction, and ensuring that subsequent construction operations can be carried out accurately and smoothly.

[0034] 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 novel FRP pipe-concrete composite structure, characterized in that: The system includes a beam-column formwork (1) for casting beam-column joints, wherein the formwork (1) contains several horizontally and vertically distributed reinforcing bars (6), and four FRP pipes (2) are provided in the middle of the beam-column joint, with the four FRP pipes (2) distributed at the four corners. Several through holes (21) are opened on the FRP pipes (2), through which the horizontally distributed reinforcing bars (6) pass. The system also includes a suspension frame (3), which includes a sleeve (31) coaxially fixed to the top of one of the vertically distributed reinforcing bars (6), and a vertical shaft (32) coaxially fixed to the sleeve (31). Two rotating beams (33) are rotatably provided on the vertical shaft (32), and grooves (331) are opened in the extension direction of the rotating beams (33). The system also includes a cylindrical vertical rod (34), which vertically passes through the formwork. The groove (331) also includes a pull rope (35) and a stop beam (36). The pull rope (35) passes through the upper end of the vertical rod (34) and exits through the lower end. The middle end of the stop beam (36) is fixed to the lower end of the pull rope (35). Three horizontal bars (37) are distributed around the lower end of the vertical rod (34). The horizontal bars (37) are threaded with a stop nut (371). The three horizontal bars (37) are blocked at the upper edge of the FRP pipe (2). The stop nut (371) is blocked at the side of the FRP pipe (2). Pulling the pull rope (35) up makes the two ends of the stop beam (36) block at the lower edge of the FRP pipe (2). The vertical rod (34) has a threaded stop plate (341). The stop plate (341) is blocked on the upper side of the rotating beam (33).

2. The novel FRP pipe-concrete composite structure according to claim 1, characterized in that: The top of the vertical shaft (32) is provided with a threaded post (38), and the threaded post (38) is threadedly connected to an internal threaded cylinder (39). A stop bar (391) is fixedly provided on the inner side of the top of the internal threaded cylinder (39). After the pull rope (35) tightens the stop beam (36), it is knotted and fixed at the stop bar (391). The stop beam (36) is further tightened by rotating the internal threaded cylinder (39).

3. The novel FRP pipe-concrete composite structure according to claim 2, characterized in that: The sleeve (31) is inserted from the upper end of the reinforcing bar (6), and three locking screws (311) are threaded around the bottom end of the sleeve (31), with the locking screws (311) abutting against the outside of the reinforcing bar (6) being fixed.

4. The novel FRP pipe-concrete composite structure according to claim 3, characterized in that: A clamping block (372) is also slidably provided on the crossbar (37). The clamping block (372) has an obtuse angle clamping surface on the side facing the FRP pipe (2). The stop nut (371) abuts against the clamping block (372) so that the clamping block (372) is clamped on the outside of the FRP pipe (2).

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