Fabricated FRP profile-concrete continuous composite beam structure and construction method thereof

Abstract

The invention discloses an assembly type FRP profile-concrete continuous composite beam which is mainly composed of an FRP profile main beam, a sagging moment area prefabricated concrete slab and a hogging moment area prefabricated laminated slab. Wherein the upper part of the hogging moment area prefabricated laminated plate is a large-strain FRP grid reinforced EGC top plate, the lower part of the hogging moment area prefabricated laminated plate is an FRP rib reinforced concrete bottom plate, and shear-resistant short steel bars are vertically arranged on the two; the beam sections of the FRP profile main beam are connected through FRP lap joint plates, U-shaped formwork-free comb-tooth-shaped wet joints are arranged between the plates, and the FRP profile main beam is connected with the upper prefabricated concrete slab and the laminated slab through detachable high-strength bolts. According to the structure, the characteristics of ultrahigh ductility, multi-seam steady-state cracking and higher tensile strength of a large-strain FRP grid reinforced EGC material are fully utilized, and meanwhile, the advantages of light dead weight, high strength and high elasticity of an FRP profile and the advantages of large rigidity, good stability, low construction cost and the like of a concrete wing plate are exerted; and the reliable and durable assembly type functional gradient composite beam is formed.

Description

Technical Field

[0001] The invention relates to an FRP profile-concrete composite beam structure, in particular to a fully assembled large-strain FRP grid / EGC-NC-FRP profile functional gradient continuous composite beam. Background Art

[0002] Steel-concrete composite bridges have the characteristics of high bearing capacity, high rigidity and small cross-sectional height, and can give full play to the respective advantages of steel and concrete. They are widely used at home and abroad. However, there are several problems in their application: (1) The durability of structures in complex environments is becoming increasingly prominent, especially in marine environments where steel corrosion is extremely severe, which will reduce the safety of the structure. The surface coating process currently used cannot fundamentally solve this problem in the long run; (2) The bridge deck in the negative bending moment area of ​​continuous beam bridges is common, which reduces the rigidity of the structure and affects its appearance and durability. The current construction techniques, such as jacking up the support points, introducing prestressing in advance, and changing the order of pouring bridge decks, are complex and technically difficult. Some studies have used ultra-high performance concrete (UHPC) with high strength and high crack resistance or engineered cementitious composite (ECC) with high ductility to replace ordinary concrete bridge decks to solve this problem. However, the two composite materials are expensive, and the large-scale use of cement brings about large carbon emissions. (3) At present, most domestic steel-concrete composite bridge structures still use the on-site casting of beams and slabs. The degree of industrial standardization is low, the construction progress is slow, and the quality is difficult to guarantee.

[0003] The invention patent application with application number 202111174838.9 discloses an assembled FRP profile-concrete composite beam, including a precast concrete slab and an FRP profile. The precast concrete slab is provided with reserved holes arranged at intervals along the length direction of the precast concrete slab, and the upper surface of the FRP profile is provided with a shear connector. The precast concrete slab is placed above the FRP profile, and UHPC is cast in the reserved holes. The FRP profile is shear-connected to the UHPC. The assembled FRP profile-concrete composite beam has the advantages of the assembled structure such as saving formwork, improving the construction environment, and improving construction efficiency. At the same time, it can have the advantages of the FRP profile-concrete composite structure such as low dead weight, high bearing capacity, and good durability. The assembled composite beam technology is to install steel bolts or FRP connectors on the FRP profile main beam, and cast UHPC and concrete wing plates at the construction site through reserved grooves on the concrete slab for shear connection. The quality of the cast-in-place process is difficult to guarantee, and the maintenance cycle is long and the efficiency is low, and the overall stress of the composite beam cannot be achieved immediately. Moreover, the structural system of the patent disclosed technology is a single-span simply supported beam, rather than a multi-span continuous beam, and does not involve the problem of cracking in the negative bending moment zone on the support top.

[0004] Therefore, in order to overcome the problems existing in the existing FRP profile-concrete composite beam bridges, ensure the construction quality and progress, and ensure the safety of the bridge, it is still necessary to upgrade and improve the existing FRP profile-concrete composite beam technology. Summary of the invention

[0005] In view of the shortcomings of the prior art, the present invention proposes an assembled FRP profile-concrete continuous composite beam structure, which can fundamentally solve the corrosion problem of steel in a coastal environment and greatly improve the durability of the composite beam structure; The present invention also proposes a construction method for the assembled FRP profile-concrete continuous composite beam, which eliminates the need for formwork time, saves time and effort; the composite beam can fully play a bearing role after the bolt connection is completed, which is efficient and convenient.

[0006] The technical solution adopted by the present invention is: An assembled FRP profile-concrete continuous composite beam mainly comprises an FRP profile main beam (1), a precast concrete slab in a positive bending moment area (2) and a precast composite slab in a negative bending moment area (3); wherein the precast concrete slab in the positive bending moment area (2) adopts FRP bar reinforced concrete and pre-embeds nuts; the upper part of the precast composite slab in the negative bending moment area (3) is a large strain FRP mesh reinforced EGC top slab (31), and the lower part is an FRP bar reinforced concrete bottom slab (32) and pre-embeds nuts, and short shear-resistant steel bars (14) are arranged vertically between the two slabs; comb-tooth-shaped wet joints (5, 6) are arranged between the slabs; the FRP profile main beam (1) is provided with reserved bolt holes corresponding to the reserved nut positions of the slabs; the FRP profile main beam (1) is connected to the precast concrete slab in the positive bending moment area (2) and the precast composite slab in the negative bending moment area (3) by using detachable high-strength bolts (4), thereby forming a reliable and durable assembled functional gradient continuous composite beam.

[0007] In the fabricated FRP profile-concrete continuous composite beam, the negative moment zone prefabricated composite slab (3) is subjected to roughening treatment such as chiseling or notching on its upper surface after the FRP bar reinforced concrete bottom slab (32) is cast in the factory. The vertical shear-resistant short steel bars (14) extending out of the bottom slab are tied and fixed to the upper large strain FRP mesh (10), and then the EGC (11) is cast.

[0008] The assembled FRP profile-concrete continuous composite beam is roughened on the inner side of the flange, end and web of the FRP profile main beam, and then two layers of carbon fiber cloth (9) are glued vertically and one layer is glued longitudinally, and the carbon fiber cloth (9) is wrapped at the beam end.

[0009] In the assembled FRP profile-concrete continuous composite beam, the precast concrete panels (2) in the positive moment zone are connected in pairs; the precast composite panels (3) in the negative moment zone are connected in pairs; the precast concrete panels (2) in the positive moment zone and the joints between the precast concrete panels (2) in the positive moment zone and the precast composite panels (3) in the negative moment zone are connected by a J1-type formwork-free comb-tooth wet joint (5) connection method, and the precast composite panels (3) in the negative moment zone are connected by a J2-type formwork-free comb-tooth wet joint (6) connection method.

[0010] In the assembled FRP profile-concrete continuous composite beam, the flanges and webs of two adjacent FRP profile main beams are connected at the middle support by FRP lap plates (7) and then fastened by high-strength bolts; and short T-shaped FRP plates (8) are provided at the support, mid-span, and concentrated load action locations as vertical stiffening ribs.

[0011] The assembled FRP profile-concrete continuous composite beam, the J1 type formwork-free comb-tooth wet joint (5): after pouring asphalt mastic (18) to seal the bottom of the joint at the end of the concrete slab, an annular longitudinal steel bar (13) is embedded in the comb-tooth joint, transverse steel bars (15) are tied, high-grade shrinkage compensating concrete (16) is poured, and cured to form; the J2 type formwork-free comb-tooth wet joint (6) is based on the structure of the J1 type comb-tooth wet joint (5), the FRP mesh (10) extending out of the plate body on both sides of the upper part is overlapped and tied and fixed with the transverse steel bars (15), and then ultra-high performance concrete (17) is poured.

[0012] A method for constructing an assembled FRP profile-concrete continuous composite beam, comprising: firstly, manufacturing an FRP profile main beam (1) with reserved bolt holes, a positive moment zone concrete slab (2), and a negative moment zone composite slab (3) in a factory; wherein a row of rectangular notches are provided in the length direction of the joints at both ends of the two slabs to form a comb-tooth shape, and a cross section in the depth direction to form a U-shape or a broken line shape, and a large strain FRP mesh (10) on the upper part of the composite slab extends out of the slab body; Then, the FRP profile main beam (1) is hoisted to the construction site and assembled and connected using FRP lap plates (7) and fastened with high-strength bolts (4); then, the precast concrete slabs (2) in the positive bending moment area and the precast composite slabs (3) in the negative bending moment area are laid in sequence; at the same time, high-strength bolts (4) are passed through the bolt holes reserved in the FRP main beam (1) and fastened with nuts embedded in the concrete slab; finally, wet joints (5, 6) are poured between the precast slabs to connect them into a whole.

[0013] The method for constructing an assembled FRP profile-concrete continuous composite beam comprises: a J1 type formwork-free comb-tooth wet joint (5) is used for connecting the precast concrete slabs (2) in the positive moment zone and between the precast concrete slabs (2) in the positive moment zone and the superimposed slabs (3) in the negative moment zone; after pouring asphalt mastic (18) at the bottom of the joint at the end of the concrete slab to seal the joint, an annular longitudinal steel bar (13) is embedded in the comb-tooth joint, transverse steel bars (15) are tied, high-grade shrinkage compensating concrete (16) is poured, and cured to form; a J2 type formwork-free comb-tooth wet joint (6) is used for connecting the superimposed slabs (3) in the negative moment zone, which is similar to the J1 type formwork-free comb-tooth wet joint (5), except that the FRP mesh (10) extending out of the slab body on both sides of the upper part is overlapped and then tied and fixed with the transverse steel bars (15), and ultra-high performance concrete (17) is poured.

[0014] Beneficial effects of the invention: 1. The fabricated FRP profile-concrete continuous composite beam of the present invention is a fiber-reinforced polymer (FRP) composite material with properties such as light weight, high strength, and corrosion resistance. FRP profiles, FRP bars, FRP meshes, etc. are used to replace the steel beams, steel bars, and steel meshes of the traditional steel-concrete composite structure, which can fundamentally solve the corrosion problem of steel in the marine environment and greatly improve the durability of the structure. The structure fully utilizes the characteristics of ultra-high ductility, multi-seam steady-state cracking, and high tensile strength of the large-strain FRP mesh-reinforced EGC material, and at the same time gives play to the advantages of light weight, high tensile strength, good elasticity of the FRP profile and high rigidity, good stability, and low engineering cost of the concrete wing plate.

[0015] 2. The assembled FRP profile-concrete continuous composite beam of the present invention adopts large-strain FRP (Large-Rupture-Strain FRP, LRS FRP for short) grid to reinforce ultra-high toughness geopolymer-based composite materials (Engineered geopolymer Composites, EGC for short) on the upper part of the prefabricated plate in the negative bending moment area of ​​the continuous beam. The large-strain FRP grid improves the tensile strength of EGC, and both have extremely high tensile ductility (the ultimate tensile strain is above 3%) and good deformation coordination ability. Under the action of negative bending moment, the crack width of the large-strain FRP grid / EGC thin plate is less than 100 microns, which can be regarded as a seamless structure in engineering, solving the safety and durability problems caused by cracking and water seepage. In addition, the EGC material uses industrial solid waste such as slag and fly ash as the geopolymer matrix, and has obvious green and low-carbon advantages.

[0016] Multi-span continuous beams inevitably involve the problem of cracking in the negative moment zone at the top of the support. The present invention proposes for the first time a new type of material, namely, a large-strain FRP grid reinforced ultra-high toughness geopolymer-based composite material (large-strain FRP grid / EGC), and for the first time proposes a structural measure of assembling a large-strain FRP grid / EGC composite layer and ordinary concrete (NC) into a composite plate after interface treatment to solve the problem of cracking in the negative moment zone at the top of the support of multi-span continuous beams.

[0017] 3. The assembled FRP profile-concrete continuous composite beam of the present invention uses FRP profiles for tension, concrete (NC) wing plates for compression, and large-strain FRP grids / EGCs only for the tension zone of the negative bending moment section of the composite beam. The combined large-strain FRP grid / EGC-NC-FRP profile composite beam gives full play to the advantages of light weight, high tensile strength, good elasticity of FRP profiles and high stiffness, good stability, and low engineering cost of concrete wing plates, as well as the characteristics of high ductility and multi-seam steady-state cracking of large-strain FRP grids / EGCs. By combining different components at different stress-bearing locations or sections, a functional gradient structural system is formed, which is more technologically advanced and economically reasonable.

[0018] 4. The assembled FRP profile-concrete continuous composite beam of the present invention is a multi-span continuous beam integral structure composed of multiple beam sections. The concrete wing plates are longitudinally connected by a new formwork-free wet joint, and the beam and slab components are vertically connected by a new detachable high-strength bolt. The FRP profile main beam, the concrete slab in the positive bending moment area, and the composite slab in the negative bending moment area are all prefabricated in the factory, with a high degree of industrial standardization. At the construction site, the beam and slab components are assembled and connected with detachable high-strength bolts and new formwork-free comb-tooth wet joints, with high construction efficiency, guaranteed process quality, and convenient later maintenance and repair. EGC uses industrial solid waste such as slag and fly ash to replace cement as the matrix material, with obvious green and low-carbon advantages; the beam and slab are prefabricated and assembled on site, with a high level of industrialization, guaranteed process quality, convenient construction, and convenient later maintenance.

[0019] The quality of the cast-in-place process is difficult to guarantee, and the maintenance period is long and the efficiency is low. The overall force of the composite beam cannot be realized immediately. The present invention adopts on-site bolt connection, which saves time and labor. After the connection is completed, the composite beam can play a full load-bearing role.

[0020] The prefabricated structure disclosed in application number 202111174838.9 has steel bolts or FRP connectors on the FRP profile main beam, and the UHPC is cast on the construction site through the reserved grooves on the concrete slab to achieve shear-resistant connection with the concrete wing plate; the present invention adopts a new type of detachable high-strength bolts and connection construction method, and the nuts embedded in the concrete slab are screwed into the reserved bolt holes on the FRP profile to realize the combined structure of the main beam and the concrete wing plate. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The figure shows the overall structure schematic diagram of the assembled FRP profile-concrete continuous composite beam of the present invention; Figure 2 The figure shows the overall view of the precast concrete slab (2) in the positive moment zone of the present invention; Figure 3 The figure shows a side view of a precast concrete slab (2) in the positive moment zone; Figure 4 The figure shows the overall view of the negative moment zone prefabricated composite plate (3) of the present invention; Figure 5 The figure shows a side view of the prefabricated composite slab (3) in the negative moment zone; Figure 6 Shown is a detail of a J1 type wet joint (5); Figure 7 Shown is a detail of a J2 type wet joint (6); Figure 8 The figure shows the internal interface details of the precast composite slab (3) in the negative moment zone. DETAILED DESCRIPTION

[0022] In order to make the technical concept and advantages of the present invention more clearly understood, the technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings. It should be understood that the following embodiments are only used to explain and illustrate the preferred implementation methods of the present invention, and should not be regarded as and do not constitute a limitation on the scope of patent protection claimed by the present invention. Example 1

[0023] See also Figure 1-Figure 5 The present invention provides an assembled FRP profile-concrete continuous composite beam, which is mainly composed of an FRP profile main beam 1, a precast concrete slab 2 in a positive moment zone, and a precast composite slab 3 in a negative moment zone; wherein the precast concrete slab 2 in the positive moment zone is reinforced with FRP bars and pre-embedded with nuts; the upper part of the precast composite slab 3 in the negative moment zone is a large strain FRP mesh reinforced EGC top layer 31, and the lower part is an FRP bar reinforced concrete bottom layer 32 and pre-embedded with nuts, and both are vertically provided with short shear steel bars 14; comb-shaped wet joints are provided between each plate; the FRP profile main beam 1 is provided with reserved bolt holes corresponding to the reserved nut positions of each plate, and the FRP profile main beam 1 is connected with the precast concrete slab 2 in the positive moment zone and the precast composite slab 3 in the negative moment zone by detachable high-strength bolts 4, thereby forming a reliable and durable assembled functional gradient continuous composite beam. Number 12 in the figure is an FRP bar.

[0024] The FRP profile main beam 1 can be a glass fiber (GFRP) profile, a carbon fiber (CFRP) profile, a basalt fiber (BFRP) profile, an aramid fiber (AFRP) profile, or a box-shaped, square tube-shaped, I-shaped, T-shaped or multi-cavity profile made of two or three mixed fiber composite materials among them.

[0025] The precast concrete slabs 2 in the positive bending moment area are connected in pairs in sequence; the precast composite slabs 3 in the negative bending moment area are connected in pairs in sequence; the precast concrete slabs 2 in the positive bending moment area and the joints between the precast concrete slabs 2 in the positive bending moment area and the precast composite slabs 3 in the negative bending moment area are connected by J1 type formwork-free comb-tooth wet joints 5, and the precast composite slabs 3 in the negative bending moment area are connected by J2 type formwork-free comb-tooth wet joints 6.

[0026] like Figure 1 As shown, in the assembled FRP profile-concrete continuous composite beam of the present invention, the flanges and webs of two adjacent sections of FRP profile main beams are connected at the middle support by FRP lap plates 7 and then fastened by high-strength bolts; and short T-shaped FRP plates 8 are arranged as vertical stiffening ribs at the support, mid-span, and concentrated load action locations. Example 2

[0027] See also Figure 4 , Figure 5The assembled FRP profile-concrete continuous composite beam of this embodiment is different from that of Embodiment 1 in that: the negative moment zone prefabricated composite slab 3 is roughened by chiseling or notching the upper surface after the FRP bar reinforced concrete bottom slab 32 is cast in the factory, and then the vertical shear short steel bars 14 extending out of the bottom slab are tied and fixed to the upper large strain FRP grid 10, and finally the EGC (number 11 in the figure) is cast.

[0028] Figure 8 Shown is a detailed view of the internal interface of the precast composite slab 3 in the negative moment zone.

[0029] The large strain FRP mesh 10 may be an FRP mesh or a fiber braided mesh composited with polyethylene naphthalene (PEN) or polyethylene terephthalate (PET) and an appropriate amount of epoxy resin.

[0030] The assembled FRP profile-concrete continuous composite beam is roughened on the inner side of the flange, end and web of the FRP profile main beam, and then two layers of carbon fiber cloth 9 are vertically pasted and one layer of carbon fiber cloth 9 is longitudinally pasted, and the end of the beam is wrapped with the carbon fiber cloth 9. The carbon fiber cloth can be one of PAN-based carbon fiber cloth, viscose-based carbon fiber cloth, and asphalt-based carbon fiber cloth, and the weaving method can be one of woven carbon fiber, knitted carbon fiber, braided carbon fiber, carbon fiber prepreg, and carbon fiber non-woven. Example 3

[0031] The assembled FRP profile-concrete continuous composite beam of this embodiment is different from that of Embodiment 1 or Embodiment 2 in that: Figure 6 As shown, the J1 type formwork-free comb-shaped wet joint 5: after pouring asphalt mastic 18 to seal the joint at the bottom of the concrete slab end joint, annular longitudinal steel bars 13 are embedded in the comb-tooth joint, transverse steel bars 15 are tied, high-grade shrinkage compensating concrete 16 is poured, and cured to form; Figure 7 As shown, the J2 type formwork-free comb-tooth wet joint 6 is based on the J1 type comb-tooth wet joint 5 structure. The FRP meshes 10 extending out of the plate body on both sides of the upper part are overlapped and tied and fixed with transverse steel bars 15, and then ultra-high performance concrete 17 is poured. Example 4

[0032] This embodiment is a construction method of the assembled FRP profile-concrete continuous composite beam as described above, and the process is as follows: First, an FRP profile main beam 1 with reserved bolt holes, a concrete slab 2 in the positive moment zone, and a composite slab 3 in the negative moment zone are manufactured in the factory; wherein, a row of rectangular notches in the length direction of the joints at both ends of the two slabs must be opened to form a comb-tooth shape, and the cross section in the depth direction is U-shaped or broken line-shaped, and the large strain FRP mesh 10 in the upper part of the composite slab extends out of the slab body; Then, the FRP profile main beam 1 is hoisted to the construction site and assembled and connected with the FRP lap plate 7, and fastened with high-strength bolts 4; then, the precast concrete slab 2 in the positive bending moment area and the precast composite slab 3 in the negative bending moment area are laid in sequence; at the same time, high-strength bolts 4 are used to pass through the bolt holes reserved in the FRP main beam 1 and fasten with the nuts embedded in the concrete slab; Finally, the precast panels are connected into a whole by pouring wet joints.

[0033] The J1 type formwork-free comb-tooth wet joint 5 connection method is adopted between the precast concrete slabs 2 in the positive bending moment area and between the precast concrete slabs 2 in the positive bending moment area and the precast composite slabs 3 in the negative bending moment area. After the asphalt mastic 18 is poured at the bottom of the joint at the end of the concrete slab to seal the joint, the annular longitudinal steel bars 13 are buried in the comb-tooth joints to tie the transverse steel bars 15, and high-grade shrinkage compensating concrete 16 is poured and cured to form. The J2 type formwork-free comb-tooth wet joint 6 connection method is adopted between the precast composite slabs 3 in the negative bending moment area, which is similar to the J1 type formwork-free comb-tooth wet joint 5, but the difference is that the FRP grids 10 extending out of the plate body on both sides of the upper part are overlapped and tied and fixed with the transverse steel bars 15, and then the ultra-high performance concrete 17 is poured. Example 5

[0034] like Figures 1 to 5 As shown, an assembled FRP profile-concrete continuous composite beam includes an FRP profile main beam 1; a precast concrete slab in a positive moment zone 2; a precast composite slab in a negative moment zone 3; a detachable high-strength bolt 4; a formwork-free comb-shaped wet joint (J1 type) 5; a formwork-free comb-shaped wet joint (J2 type) 6; an FRP lap plate 7; a short T-shaped FRP stiffening rib 8; a carbon fiber cloth 9; a large strain FRP grid 10; an ultra-high toughness geopolymer-based composite material (EGC) 11; an FRP bar 12; an annular steel bar 13; a shear-resistant short steel bar 14; a transverse steel bar 15; a high-grade shrinkage compensating concrete 16; an ultra-high performance concrete (UHPC) 17; asphalt mastic (18); a large strain FRP grid reinforced EGC top plate (31); and an FRP bar reinforced concrete bottom plate (32). The FRP profile main beam 1 can be a glass fiber (GFRP) profile, a carbon fiber (CFRP) profile, a basalt fiber (BFRP) profile, an aramid fiber (AFRP) profile, or a box-shaped, square tube-shaped, I-shaped, T-shaped or multi-cavity profile made of two or three mixed fiber composite materials among them.

[0035] The large strain FRP mesh 11 may be an FRP mesh or a fiber braided mesh composited with polyethylene naphthalene (PEN) or polyethylene terephthalate (PET) and an appropriate amount of epoxy resin.

[0036] Example: A two-span continuous composite beam bridge, single span 12m, total length 24m, total width 16.775m; the length of the precast panels along the bridge is 2.6m, the width of the wet joint (J1 or J2 type) is 400mm; each main beam is 12m long and connected at one point with double lap plates. The beam height is 1.4m, and the height-to-span ratio is 1 / 21; Bolt size and spacing: The removable bolts are M8.8 grade high-strength bolts, model ∅16x70, and the nuts are hexagonal nuts with an inner diameter of 16mm and a length of 60mm. Double-row high-strength bolts, the bolts are spaced 800mm longitudinally and 200mm transversely along the composite beam. The plate thickness is 30cm, the upper EGC layer of the composite plate is 5cm, and the lower concrete layer is 25cm. Example 6

[0037] A construction method of an assembled FRP profile-concrete continuous composite beam, the process of which is as follows: First, the FRP profile main beam and three prefabricated panels are made in the factory. The cross-section of the main beam can be box-shaped, square tube-shaped, I-shaped, T-shaped, etc. Short T-shaped FRP plates are set as vertical stiffeners at the designed supports, mid-span, concentrated load action locations, etc. The T-shaped plates are connected to the main beam with a mixture of steel bolts and epoxy resin glue. After roughening the inner side of the main beam flange, the end and the web, 2 layers of carbon cloth are pasted vertically and 1 layer is pasted longitudinally, and the end of the beam is wrapped with carbon cloth; Formwork is supported, FRP bars are tied, nuts matching the removable bolts are embedded according to the designed arrangement, and then concrete is poured to form the positive moment area concrete (NC) precast slab; in the same way, the FRP bars of the lower half of the negative moment area composite slab are tied according to the preset size, and the concrete bottom slab is poured after being tied and connected with the vertical short steel bars extending out of the slab, and then the high-strain FRP grid is tied and fixed with the vertical short steel bars, and the ultra-high toughness geopolymer-based composite material (EGC) is poured. Finally, a row of rectangular notches are opened in the length direction of the joints at both ends of the slab to form a comb-like shape, and the cross-section in the depth direction is U-shaped or broken line-shaped, and the high-strain FRP grids in the upper part of the composite slab must extend out of the slab.

[0038] The above-mentioned FRP profile main beams are hoisted to the construction site for assembly. The flanges and webs of the two main beams are connected at the middle support with FRP lap plates and then fastened with high-strength bolts. Next, according to the calculated moment envelope diagram and the pre-divided moment sections, the precast concrete slabs in the positive moment section are laid first, and then the precast composite slabs in the negative moment section are laid. At the same time, high-strength bolts are passed through the reserved holes in the flanges of the FRP main beams and fastened with the nuts embedded in the concrete slabs. Finally, wet joints are cast between the precast slabs to connect them into a whole. There are two types of wet joints: J1 type is used for connection between precast concrete slabs in the positive moment area and between precast concrete slabs in the positive moment area and precast composite slabs in the negative moment area, and J2 type is used for connection between precast composite slabs in the negative moment area. J1 type formwork-free comb-tooth wet joint: after pouring asphalt mastic to seal the bottom of the joint at the end of the concrete slab, annular longitudinal steel bars are embedded in the comb-tooth joint, and transverse steel bars are tied, high-grade shrinkage compensating concrete is poured, and cured to form; the J2 type formwork-free comb-tooth wet joint is similar to the J1 type comb-tooth wet joint, but the difference is that the FRP mesh extending out of the slab on both sides of the upper part needs to be overlapped and then tied and fixed with the transverse steel bars, and ultra-high performance concrete is poured.

[0039] The fabricated FRP profile-concrete continuous composite beam of the present invention has the properties of light weight, high strength, corrosion resistance, etc., and uses FRP profiles, FRP bars, FRP meshes, etc. to replace the steel beams, steel bars, and steel meshes of the traditional steel-concrete composite structure, which can fundamentally solve the corrosion problem of steel in the marine environment and greatly improve the durability of the structure. The structure fully utilizes the characteristics of ultra-high ductility, multi-seam steady-state cracking, and high tensile strength of the large-strain FRP mesh-reinforced EGC material, and at the same time gives play to the advantages of light weight, high tensile strength, good elasticity of the FRP profile and high rigidity, good stability, and low engineering cost of the concrete wing plate.

[0040] The above description is only a preferred embodiment of the present invention and does not constitute a limitation of the present invention. Under the guidance of the prior art, those skilled in the art can make other modifications to the implementation of the present invention without creative work. Any modification made within the spirit and principle of the present invention or simple replacement or equivalent replacement, improvement, etc. made by conventional technical means in the field should be included in the protection scope of the present invention.

Claims

1. An assembled FRP profile-concrete continuous composite beam, characterized in that: The composite beam is mainly composed of an FRP profile main beam (1), a precast concrete slab in a positive bending moment area (2), and a precast composite slab in a negative bending moment area (3); wherein the precast concrete slab in the positive bending moment area (2) is reinforced with FRP bars and has pre-embedded nuts; the upper portion of the precast composite slab in the negative bending moment area (3) is a large strain FRP mesh reinforced EGC top slab (31), and the lower portion is an FRP bar reinforced concrete bottom slab (32) and has pre-embedded nuts, and short shear-resistant steel bars (14) are arranged vertically between the two slabs; comb-tooth-shaped wet joints (5, 6) are arranged between the slabs; the FRP profile main beam (1) is provided with reserved bolt holes corresponding to the reserved nut positions of the slabs, and the FRP profile main beam (1) is connected to the precast concrete slab in the positive bending moment area (2) and the precast composite slab in the negative bending moment area (3) by using detachable high-strength bolts (4).

2. The assembled FRP profile-concrete continuous composite beam according to claim 1 is characterized in that: After the FRP bar reinforced concrete bottom plate (32) is cast in the factory, the upper surface of the negative moment zone prefabricated composite plate (3) is first roughened, and then the vertical shear short steel bars (14) extending out of the bottom plate are tied and fixed to the upper large strain FRP grid (10), and then the EGC (11) is cast.

3. The assembled FRP profile-concrete continuous composite beam according to claim 1 is characterized in that: After roughening the inner side of the flange, the end and the web of the FRP profile main beam, two layers of carbon fiber cloth (9) are glued vertically and one layer is glued longitudinally, and the carbon fiber cloth (9) is wrapped at the beam end.

4. The assembled FRP profile-concrete continuous composite beam according to claim 1, 2 or 3, characterized in that: The precast concrete slabs (2) in the positive bending moment area are connected in pairs in sequence; the precast composite slabs (3) in the negative bending moment area are connected in pairs in sequence; the precast concrete slabs (2) in the positive bending moment area and the joints between the precast concrete slabs (2) in the positive bending moment area and the precast composite slabs (3) in the negative bending moment area are connected by J1 type formwork-free comb-tooth-shaped wet joints (5); and the precast composite slabs (3) in the negative bending moment area are connected by J2 type formwork-free comb-tooth-shaped wet joints (6).

5. The assembled FRP profile-concrete continuous composite beam according to claim 1, 2 or 3, characterized in that: The flanges and webs of two adjacent FRP profile main beams are connected by FRP lap plates (7) and then fastened by high-strength bolts; Short T-shaped FRP plates (8) are provided at the supports, mid-span, and concentrated load action locations as vertical stiffeners.

6. The assembled FRP profile-concrete continuous composite beam according to claim 4, characterized in that: The flanges and webs of two adjacent FRP profile main beams are connected at the middle support by using FRP lap plates (7) and then fastened by using high-strength bolts; Short T-shaped FRP plates (8) are provided at the supports, mid-span, and concentrated load action locations as vertical stiffeners.

7. The assembled FRP profile-concrete continuous composite beam according to claim 1, 2, 3 or 6, characterized in that: The J1 type formwork-free comb-tooth wet joint (5) is: after pouring asphalt mastic (18) to seal the bottom of the joint at the end of the concrete slab, an annular longitudinal steel bar (13) is embedded in the comb-tooth joint, transverse steel bars (15) are tied, high-grade shrinkage compensating concrete (16) is poured, and cured to form; the J2 type formwork-free comb-tooth wet joint (6) is based on the structure of the J1 type comb-tooth wet joint (5), and the FRP mesh (10) extending out of the plate body on both sides of the upper part is overlapped and tied to the transverse steel bars (15), and then the ultra-high performance concrete (17) is poured.

8. A method for constructing an assembled FRP profile-concrete continuous composite beam according to any one of claims 1 to 7, characterized in that: First, an FRP profile main beam (1) with reserved bolt holes, a positive bending moment area concrete slab (2), and a negative bending moment area prefabricated composite slab (3) are manufactured in a factory; wherein a row of rectangular notches are provided in the length direction of the joints at both ends of the two slabs to form a comb-tooth shape, and the cross-section in the depth direction is U-shaped or broken line-shaped, and the large strain FRP mesh (10) in the upper part of the composite slab extends out of the slab body; then, the FRP profile main beam (1) is hoisted to the construction site, assembled and connected using an FRP lap plate (7), and fastened with high-strength bolts (4); then, the positive bending moment area prefabricated concrete slab (2) and the negative bending moment area prefabricated composite slab (3) are laid in sequence; at the same time, high-strength bolts (4) are used to pass through the reserved bolt holes of the FRP main beam (1) and fasten with nuts pre-buried in the concrete slab; finally, wet joints (5, 6) are poured between the prefabricated slabs to form a whole.

9. The method for constructing an assembled FRP profile-concrete continuous composite beam according to claim 8, characterized in that: The precast concrete slabs (2) in the positive moment zone and the precast concrete slabs (2) in the positive moment zone and the precast composite slabs (3) in the negative moment zone are connected by a J1 type formwork-free comb-tooth wet joint (5). After the bottom of the joint at the end of the concrete slab is sealed by pouring asphalt mastic (18), an annular longitudinal steel bar (13) is embedded in the comb-tooth joint, transverse steel bars (15) are tied, and high-grade shrinkage compensating concrete (16) is poured and cured to form. The composite slabs (3) in the negative moment zone are connected by a J2 type formwork-free comb-tooth wet joint (6). Based on the J1 type formwork-free comb-tooth wet joint (5) structure, the FRP mesh (10) extending out of the slab body on both sides of the upper part is overlapped and tied and fixed with the transverse steel bars (15), and then the ultra-high performance concrete (17) is poured.

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