FRP (Fiber Reinforce Plastic) steel pipe concrete composite beam with bolt pins

Abstract

The FRP concrete filled steel tube composite beam with the bolt pins comprises a rectangular thin-wall square tube and an FRP core tube with the same length as the rectangular thin-wall square tube, and the FRP core tube is arranged in an upper compression area in the rectangular thin-wall square tube. Inter-pipe filling materials are arranged between the FRP core pipe and the rectangular thin-wall square pipe, and the FRP core pipe is filled with core pipe concrete; steel bolts penetrating through the rectangular thin-wall square tube are evenly distributed on the top face or the side face of the rectangular thin-wall square tube in the length direction, the steel bolts penetrate through the center of the cross section of the FRP core tube, and extension sections are reserved at the positions, on the surface of the rectangular thin-wall square tube, of the two ends of each steel bolt. The FRP material has excellent tensile property, and after the FRP core pipe is arranged in the structure compression area, the concrete performance of the compression area is remarkably improved through the constraint effect provided by the FRP core pipe. By arranging the steel bolts penetrating through the whole structure, the bonding performance between the inter-pipe filling material and the inner wall of the steel pipe is improved, the interface slippage amount is reduced, and the bearing capacity and ductility of the test piece are improved. And the filling material between the pipes adopts the combination of concrete and polyurethane foam, so that the self weight of the structure can be effectively reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to civil building structure technical field especially is related to a FRP steel pipe concrete composite beam with pin bolt. BACKGROUND

[0002] Traditional steel pipe concrete composite structure is widely used in civil engineering field because of high bearing capacity, convenient construction and other advantages. However, the prior art still has significant defects: firstly, the original interface bonding force between steel pipe and concrete is insufficient, and the slippage and debonding phenomenon easily occurs, which weakens the collaborative working performance of the composite structure. Secondly, the tensile strength of the concrete in the tensile zone is low and easy to crack, which cannot effectively participate in the bearing in the actual stress process, and the material utilization rate is low. At the same time, although the fiber reinforced composite material (FRP) has the advantages of light weight, high tensile strength and corrosion resistance, its elastic modulus is only 1 / 3-1 / 4 of that of steel, and the interlayer shear strength is insufficient, which is easy to cause brittle failure of interlayer fiber when directly used in the main bearing structure, and it is difficult to meet the high stiffness requirement. In the prior art, when trying to combine FRP with steel pipe concrete, a simple wrapping form is usually adopted, and the reinforcement of the existing structure is focused on, but there is little in the structure design. In addition, the traditional steel pipe concrete beam has large self-weight, and the high density of concrete material increases the overall quality of the structure, which limits its lightweight application in large-span and high-rise buildings. SUMMARY

[0003] In view of the problems that the FRP steel pipe and the concrete interface in the steel pipe concrete beam structure in the prior art are easy to slip and debond, the collaboration is poor, and the overall structure has large self-weight, the utility model provides a FRP steel pipe concrete composite beam with pin bolt, which comprises a rectangular thin-walled square tube and a FRP core pipe equal in length to the rectangular thin-walled square tube, the FRP core pipe is arranged in the upper compression zone of the rectangular thin-walled square tube;

[0004] A pipe interfilling material is arranged between the FRP core pipe and the rectangular thin-walled square tube, the pipe interfilling material comprises a first filling material filled around the FRP core pipe and a second filling material filled in the remaining space between the pipes, the first filling material is concrete; the FRP core pipe is filled with core pipe concrete;

[0005] Steel bolts are uniformly arranged on the top surface or side surface of the rectangular thin-walled square tube along the length direction and penetrate the rectangular thin-walled square tube, the steel bolts penetrate the cross-sectional center of the FRP core pipe, and the steel bolts have elongated sections on the surface of the rectangular thin-walled square tube at both ends.

[0006] Further, the second filling material is polyurethane foam, and the thickness of the polyurethane foam is less than or equal to 1 / 3 of the height of the inner wall of the rectangular thin-walled square tube cross section.

[0007] Further, the steel bolt diameter is greater than or equal to 5mm; the length of the extension section is greater than or equal to 10mm.

[0008] Further, the distance between the outer wall of the FRP core pipe and the inner wall of the rectangular thin-walled square pipe is greater than 20mm.

[0009] Further, the FRP core pipe is made of FRP pipe or FRP cloth.

[0010] Further, the core pipe concrete is any one of ordinary concrete, seawater sea sand concrete, coral aggregate concrete, and recycled concrete.

[0011] Further, the inner wall surface of the rectangular thin-walled square pipe and the outer wall surface of the FRP core pipe are provided with roughening structures for strengthening the interface bonding force.

[0012] Further, the roughening structure includes any one of surface mortar, notches, ribs, convex points, and concave points.

[0013] Compared with the prior art, the utility model has the following beneficial effects:

[0014] (1) The FRP material has superior tensile properties, and after the FRP core pipe is arranged in the compression zone of the structure, the compression zone concrete efficiency can be significantly improved, and the structure has the characteristics of high bearing capacity.

[0015] (2) By arranging the steel bolt penetrating through the whole structure, the bonding performance between the inter-pipe filling material and the inner wall of the steel pipe is increased, the interface slip amount is reduced, and the bearing capacity and ductility of the test piece are improved.

[0016] (3) The FRP core pipe not only improves the strength of the pipe concrete, but also has corrosion resistance, can effectively isolate ion erosion, and the core pipe concrete filling selection is various, and resources can be effectively utilized.

[0017] (4) Compared with the traditional steel pipe concrete composite beam, the inter-pipe filling material can adopt the combination of compression zone concrete and tensile zone polyurethane foam, and the structure combination can effectively reduce the structure weight and improve the structure ductility. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 It is a three-dimensional schematic view of the structure of the utility model arranging steel bolts on the top surface;

[0019] Figure 2 It is a three-dimensional schematic view of the structure of the utility model arranging steel bolts on the side surface;

[0020] Figure 3 It is Figure 1 the sectional view of the structure shown in the figure;

[0021] Figure 4 For Figure 2 Cross-sectional view of the structure shown in the schematic diagram;

[0022] Figure 5 For the rectangular thin-walled square tube and FRP core tube punching in the manufacturing method of the FRP steel pipe concrete composite beam with a pin bolt;

[0023] Figure 6 For the rectangular thin-walled square tube and FRP core tube combination, support base mold, and steel bolt insertion in the manufacturing method of the FRP steel pipe concrete composite beam with a pin bolt;

[0024] Figure 7 For the rectangular thin-walled square tube and FRP core tube combination, formwork erection, and steel bolt insertion in the manufacturing process of the FRP steel pipe concrete composite beam with a pin bolt;

[0025] In the figure: 1, rectangular thin-walled square tube; 2, FRP core tube; 3, inter-tube filling material; 31, first filling material; 32, second filling material; 4, core tube concrete; 5, steel bolt; 6, formwork. DETAILED DESCRIPTION

[0026] In order to enable personnel in the technical field to better understand the present application scheme, the technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative efforts should belong to the scope of protection of the present application.

[0027] It should be noted that the terms "first", "second", and the like in the specification and claims of the present application and the above-described drawings are used to distinguish similar objects, and do not necessarily have to be used to describe a specific order or sequence. The terms "up", "down", "front", "back", "top", "bottom", and the like indicate the orientation or positional relationship shown in the drawings, and are only used to facilitate the description of the present application and simplify the description, and do not indicate or imply that the devices or parts referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. It should be understood that the data thus used can be interchanged under appropriate circumstances, in order to describe the embodiments of the present application described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion.

[0028] As Figures 1-4As shown, a pin bolted FRP steel pipe concrete composite beam comprises a rectangular thin-walled square tube 1 and an FRP core tube 2 equal in length to the rectangular thin-walled square tube 1, and the FRP core tube 2 is arranged in the upper compression zone of the rectangular thin-walled square tube 1.

[0029] A tube inter-filling material 3 is arranged between the FRP core tube 2 and the rectangular thin-walled square tube 1, and the tube inter-filling material 3 comprises a first filling material 31 filled around the FRP core tube 2 and a second filling material 32 filled in the remaining space between the tubes, and the first filling material 31 is concrete; and a core tube concrete 4 is filled in the FRP core tube 2.

[0030] Steel bolts 5 are arranged on the top surface or side surface of the rectangular thin-walled square tube 1 along the length direction, and the steel bolts 5 penetrate the rectangular thin-walled square tube 1, pass through the cross-sectional center of the FRP core tube 2, and have an extended section on the surface of the rectangular thin-walled square tube 1 at both ends.

[0031] By arranging the FRP core tube in the concrete compression zone, the utilization rate of the concrete in the compression zone of the steel pipe concrete composite beam can be significantly improved due to the superior tensile performance of the FRP material and the good hoop constraint of the tube concrete under compression, and the structure has the characteristics of high bearing capacity. By arranging the steel bolts penetrating the whole joint, the bonding performance between the tube inter-filling material and the inner wall of the steel pipe is increased, and the interface slip is reduced, so that the bearing capacity and ductility of the specimen can be effectively improved.

[0032] It should be noted that the second filling material 32 can be consistent with the first filling material 31, and concrete can be used, or other high-quality materials can be used. The second filling material 32 is polyurethane foam, and the thickness of the polyurethane foam is less than or equal to 1 / 3 of the height of the inner wall of the rectangular thin-walled square tube 1.

[0033] Polyurethane foam has been applied in the current field of civil engineering and construction, and polyurethane foam has excellent qualities such as small mass and strong anti-deformation ability. By filling polyurethane foam in the lower tension zone, the self-weight of the structure can be reduced, and the ductility of the structure can be improved. In addition, polyurethane foam has the following advantages: (1) sprayed on site to form a whole without joints, reducing maintenance workload; (2) simple and fast construction, hundreds of square meters can be sprayed per day per worker; (3) simple end structure, no special treatment is required; (4) good aging resistance; (5) one-time foaming of polyurethane, high economic benefit.

[0034] In a more preferred embodiment, the diameter of the steel bolt 5 is greater than or equal to 5 mm, and the length of the extended section is greater than or equal to 10 mm. The setting of the extended section can prevent the steel bolt 5 from slipping off and falling between the rectangular thin-walled square tube 1 and the FRP core tube 2 during the construction of pouring the tube inter-filling material 3.

[0035] In order to ensure the structural strength and prevent the concrete around the FRP core pipe 2 from being damaged before the overall structure, the distance between the outer wall of the FRP core pipe 2 and the inner wall of the rectangular thin-walled square pipe 1 is greater than 20 mm.

[0036] Generally, the FRP core pipe 2 is made of FRP pipe material or FRP cloth. There are various forms of manufacturing processes for FRP pipes, and one-time pultrusion FRP pipe material can be used, or FRP cloth can be wound on a mold (such as an acrylic pipe) and then demolded to form.

[0037] Since the FRP core pipe has corrosion-resistant characteristics and can effectively isolate ion erosion, the core pipe concrete 4 can be diversified and selected, and the core pipe concrete 4 can be any one of ordinary concrete, seawater and sea sand concrete, coral aggregate concrete, and recycled concrete, which can effectively utilize resources.

[0038] The inner wall surface of the rectangular thin-walled square pipe 1 and the outer wall surface of the FRP core pipe 2 are provided with roughening structures for strengthening the interfacial bonding force. By roughening the inner wall surface of the rectangular thin-walled square pipe 1 and the outer wall surface of the FRP core pipe 2, the interfacial bonding strength between the pipe wall and the inter-pipe filling material 3 can be improved. Generally, the roughening structure includes any one of surface mortar, notches, ribs, protrusions, and recesses.

[0039] When the first filling material 31 and the second filling material 32 are both concrete, a method for manufacturing a FRP steel pipe concrete composite beam with pins is as follows:

[0040] (1) The FRP core pipe 2 is prefabricated in advance, and FRP cloth is used to wrap the prefabricated FRP core pipe 2 or FRP profiles are directly selected, spliced or cut to the same length as the rectangular thin-walled steel pipe 1;

[0041] (2) Holes are opened on the rectangular thin-walled square pipe 1 and the FRP core pipe 2 at corresponding positions (as shown in Figure 5 );

[0042] (3) The FRP core pipe 2 is vertically combined with the rectangular thin-walled square pipe 1, and a formwork 6 is erected at the bottom end of the composite beam (as shown in Figure 6 );

[0043] (4) The steel bolts 5 are inserted into the beam body in sections, and the inter-pipe filling material 3 (concrete) and the core pipe concrete 4 are filled and vibrated;

[0044] (5) Repeat step (4) for the next section upwards to the top of the beam, and remove the formwork 6 after the concrete is completely solidified.

[0045] When the first filling material 31 is concrete and the second filling material 32 is polyurethane foam, a method for manufacturing a FRP steel pipe concrete composite beam with pins is as follows:

[0046] (1) FRP core pipe 2 is pre-prepared, FRP cloth is used to wrap pre-prepared FRP core pipe 2 or FRP section is directly selected, and is spliced or cut to the same length as rectangular thin-walled steel pipe 1;

[0047] (2) the corresponding position on rectangular thin-walled square pipe 1 and FRP core pipe 2 is holed (as shown in Figure 5 );

[0048] (3) FRP core pipe 2 is combined vertically with rectangular thin-walled square pipe 1, the position of second filling material 32 (polyurethane foam) is reserved, and formwork 6 is respectively erected and fixed in the combined beam and one end of the beam (as shown in Figure 7 );

[0049] (4) steel bolt 5 is inserted in the segmented beam body, and first filling material 31 (concrete) and core pipe concrete 4 are filled and vibrated;

[0050] (5) the step (4) is repeated to the top of the beam for the next section, and the formwork is removed after the complete solidification of the concrete.

[0051] (6) polyurethane foaming agent is sprayed in the reserved position, and second filling material 32 (polyurethane foam) is formed after solidification.

[0052] The above only is the preferred embodiment of the present application, and does not limit the implementation range of the present application. It should be noted that, for ordinary technicians in the technical field, under the premise of not departing from the technical principles of the present application, a number of improvements and modifications can be made, and these improvements and modifications should be covered in the protection range of the present application.

Claims

1. A FRP (fiberglass reinforced plastic) steel-concrete composite beam with pins, characterized in that, It includes a rectangular thin-walled square tube (1) and an FRP core tube (2) of the same length, wherein the FRP core tube (2) is disposed in the upper pressure zone inside the rectangular thin-walled square tube (1); The FRP core tube (2) and the rectangular thin-walled square tube (1) are provided with inter-tube filling material (3). The inter-tube filling material (3) includes a first filling material (31) filling around the FRP core tube (2) and a second filling material (32) filling the remaining space between the tubes. The first filling material (31) is concrete. The FRP core tube (2) is filled with core tube concrete (4). The top or side surface of the rectangular thin-walled square tube (1) is uniformly provided with steel bolts (5) that penetrate the rectangular thin-walled square tube (1) along the length direction. The steel bolts (5) pass through the center of the cross-section of the FRP core tube (2), and both ends of the steel bolts (5) have extension sections on the surface of the rectangular thin-walled square tube (1).

2. The FRP steel-concrete composite beam with pins according to claim 1, characterized in that, The second filler material (32) is polyurethane foam, and the thickness of the polyurethane foam is less than or equal to 1 / 3 of the height of the inner wall of the cross section of the rectangular thin-walled square tube (1).

3. The FRP steel-concrete composite beam with pins according to claim 1, characterized in that, The diameter of the steel bolt (5) is greater than or equal to 5 mm; the length of the extension section is greater than or equal to 10 mm.

4. The FRP steel-concrete composite beam with pins according to claim 1, characterized in that, The distance between the outer wall of the FRP core tube (2) and the inner wall of the rectangular thin-walled square tube (1) is greater than 20 mm.

5. A FRP steel-concrete composite beam with pins according to claim 1, characterized in that, The FRP core tube (2) is made of FRP pipe or FRP cloth.

6. The FRP steel-concrete composite beam with pins according to claim 1, characterized in that, The inner wall surface of the rectangular thin-walled square tube (1) and the outer wall surface of the FRP core tube (2) are provided with a roughening structure to enhance the interfacial adhesion.

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