CN110847495A

CN110847495A - Parabolic prestressed FRP reinforced recombined bamboo beam and manufacturing method thereof

Info

Publication number: CN110847495A
Application number: CN201810969914.7A
Authority: CN
Inventors: 王立彬; 王玉群; 石启浩; 李�昊
Original assignee: Nanjing Forestry University
Current assignee: Nanjing Forestry University
Priority date: 2018-08-21
Filing date: 2018-08-21
Publication date: 2020-02-28

Abstract

The invention discloses a parabola-shaped prestressed FRP reinforced recombined bamboo beam and a manufacturing method thereof, wherein the material comprises a recombined bamboo beam (1), prestressed FRP ribs (3) and FRP rib separation clip type anchorage devices (21); the FRP rib separation clamping piece type anchorage comprises an anchor ring (2) and a clamping piece (4); the recombined bamboo beam (1) is formed by connecting recombined bamboo module beams (7), (8) and (9) through structural adhesive, wherein the FRP ribs are parabolic and positioned inside the recombined bamboo beam. The manufacturing method comprises the following steps: pressing the recombined bamboo module beam, forming a parabolic FRP rib semicircular type pore channel groove on the recombined bamboo module beam, placing FRP ribs in the pore channel, connecting the recombined bamboo module beam with structural glue, mounting anchoring devices at two ends of the recombined bamboo beam, and tensioning the FRP ribs by adopting a post-tensioning method, thereby forming the parabolic prestressed FRP reinforced recombined bamboo beam. The invention meets the characteristic that the prestressed tendon is linear and close to a bending moment diagram, greatly improves the bearing capacity and span of the bamboo beam, and simultaneously has convenient and fast manufacturing method and full play of the performances of two materials.

Description

Parabolic prestressed FRP reinforced recombined bamboo beam and manufacturing method thereof

Technical Field

The invention relates to a recombined bamboo beam component, in particular to a combined beam component of bamboo and parabolic prestressed FRP, belonging to the field of civil construction structures.

Background

China has rich bamboo resources and various types of bamboos, and the bamboos are processed into strip bamboo stripes and bamboo filaments or crushed into bamboo tows, are dried and dipped with glue, then are dried to the required moisture content, and then are laid in a mould and are solidified under high pressure to form the recombined bamboos. Reconstituted bamboo is widely used in the manufacture of structural building elements, including reconstituted bamboo wall panels, reconstituted bamboo columns, reconstituted bamboo flooring, reconstituted beams, and the like.

The bamboo material has low elastic modulus, so that the material has low strength utilization rate, and the recombined bamboo beam has large section design, small span and poor economical efficiency. Aiming at the defects of the mechanical property of bamboo, the domestic patent compounds bamboo and different materials, and improves the strength, the bearing capacity and the like of a component. For example, chinese patent No. 201510163463.4 discloses a "laminated wood for prestressed FRP reinforced bamboo-wood structure and a method for manufacturing the same", which is to glue bamboo and wood and to use linear FRP prestressed tendons to improve the bending strength of the member, but the FRP prestressed tendons in this technique are linear and cannot reach the characteristic that the linear shape of the prestressed tendons is close to the bending moment diagram, so that it is difficult to fully exert the characteristic of the FRP tendons. For example, chinese patent No. 201220178111.8 discloses an FRP-bamboo-concrete composite beam, which is formed by combining bamboo, FRP ribs and concrete to improve the bearing capacity of the beam, but the FRP ribs related to this technique are linear and cannot fully utilize the performance of the FRP ribs. For example, chinese patent No. 201220178111.8 discloses "a FRP, concrete, hollow raw bamboo rectangular beam", which is formed by compounding a hollow raw bamboo tube, FRP, and concrete, thereby improving the rigidity and ductility of the beam, but the technique can fully utilize the performance of the FRP ribs.

In summary, the prior art can not solve the problem that the linear shape of the prestressed tendon is close to the bending moment diagram, that is, the problem that the parabolic prestressed FRP is applied to the bamboo beam.

Disclosure of Invention

The technical problem to be solved is as follows: in order to overcome the defects of the prior art, the invention provides the parabolic prestressed FRP reinforced recombined bamboo beam and the manufacturing method thereof, which can enable the linear shape of the prestressed FRP rib to be close to a bending moment diagram, and greatly improve the bearing capacity and the crack resistance of the recombined bamboo beam.

The technical scheme is as follows: the parabola-shaped prestressed FRP reinforced recombined bamboo beam comprises a recombined bamboo beam, prestressed FRP ribs and FRP rib separation clip type anchorage devices; the recombined bamboo beam is formed by connecting three recombined bamboo module beams through structural adhesive; the parabolic FRP ribs are positioned in the contact surface of the recombined bamboo module beam, and the FRP ribs are tensioned by adopting a post-tensioning method; the FRP tendon separation clip type anchorage comprises an anchor ring and a clip, and the anchoring principle of the FRP tendon separation clip type anchorage is mainly characterized in that the clip exerts the pressure on a prestressed tendon to generate the clamping action.

Preferably, the recombined bamboo beams are formed by combining three recombined bamboo module beams, the contact surfaces of the three recombined bamboo module beams are connected through structural glue, one side surface of each of the two recombined bamboo module beams is provided with a parabolic pore, and the two side surfaces of the other recombined bamboo module beam are provided with parabolic pores.

Preferably, the dimensions of the recombined bamboo module beam are 2500mm × 70 × 240mm (length × width × height).

Preferably, the parabolic FRP ribs are positioned in the glue surface of the recombined bamboo module beam, and the FRP ribs are tensioned by adopting a post-tensioning method.

Preferably, the FRP ribs are anchored at two ends of the parabolic prestressed FRP reinforced recombined bamboo beam by adopting separate clip type anchorage devices.

Preferably, the size of the parabolic prestressed FRP reinforced recombined bamboo beam is 2500mm multiplied by 210mm multiplied by 240mm (length multiplied by width multiplied by height).

Preferably, the two prestressed FRP ribs are arranged on the cross section of the recombined bamboo beam in a bilateral symmetry manner.

The parabola-shaped prestressed FRP reinforced recombined bamboo beam and the manufacturing method thereof comprise the following working procedures:

and (3) bamboo strips and bamboo filaments or bamboo tows are crushed into bamboo tows, the bamboo tows are dried and dipped and dried to reach the required water content, and then the bamboo tows are laid in a mould and cured under high pressure to form the recombined bamboo module beam.

Manufacturing parabolic pore channels on contact surfaces of the three recombined bamboo module beams, placing the pretreated FRP ribs in the pore channels, coating structural glue on the contact surfaces, assembling the three recombined bamboo module beams, and maintaining after assembling. And finally, tensioning the prestressed FRP ribs and anchoring by using a separation clip type anchorage device.

Preferably, the FRP reinforcement pretreatment mainly comprises: firstly, sanding the surface of the FRP rib, and then carrying out plasma treatment on the surface of the FRP rib.

Preferably, the magnitude of the tension prestress is 25% of the ultimate tensile strength of the FRP tendon.

Has the advantages that: (1) the parabolic FRP ribs effectively improve the rigidity and the crack resistance of the recombined bamboo beam component; (2) the manufacturing method of the parabolic prestressed FRP reinforced recombined bamboo beam is simple and convenient, and the overall stability of the structure is high; (3) the linear shape of the prestressed FRP rib is close to a bending moment diagram, and the tensile strength of the FRP can be fully exerted; (4) the parabola-shaped prestressed FRP reinforced recombined bamboo beam has the advantages of light dead weight, high rigidity, large bearing capacity, large span, strong self-recovery capability and the like.

Drawings

FIG. 1 is a schematic structural view of a parabolic prestressed FRP reinforced bamboo beam provided by the present invention;

FIG. 2 is a schematic view of the contact surface of a reconstituted bamboo module beam;

FIG. 3 is a left side view of the parabolic prestressed FRP reinforced bamboo beam provided by the present invention;

wherein, 1 is a recombined bamboo beam, 2 is an anchor ring of the FRP rib separation clip type anchorage, 3 is a prestressed FRP rib, 4 is a clip of the FRP rib separation clip type anchorage, 5 is a recombined bamboo module beam contact surface, 6 is a parabola-shaped pore passage, 7, 8 and 9 are recombined bamboo module beams, and 21 is the FRP rib separation clip type anchorage.

Detailed Description

The following examples further illustrate the present invention but are not to be construed as limiting the invention. Modifications and substitutions to methods, procedures, or conditions of the invention may be made without departing from the spirit and substance of the invention. Unless otherwise specified, the technical means used in the examples are conventional means well known to those skilled in the art.

Example 1

As shown in fig. 1 to 3, the parabolic prestressed FRP reinforced recombined bamboo beam is composed of a recombined bamboo beam (1), prestressed FRP ribs (3) and FRP rib separating clip type anchorage devices (21). The FRP rib separation clamping piece type anchorage comprises an anchor ring (2) and a clamping piece (4);

the recombined bamboo beam (1) is formed by combining recombined bamboo module beams (7), (8) and (9), the contact surfaces of the recombined bamboo module beams (7), (8) and (9) are connected through structural adhesive, a parabolic duct (6) is manufactured on one side surface of the recombined bamboo module beams (7) and (9), and a parabolic duct (6) is manufactured on two side surfaces of the recombined bamboo module beams (8). And placing the pretreated FRP ribs in the pore channels, then coating structural adhesive on the contact surface (5), assembling the recombined bamboo module beams (7), (8) and (9), and maintaining after assembling. And then tensioning the FRP ribs at two ends of the parabolic prestressed FRP reinforced recombined bamboo beam and anchoring the FRP ribs by using a separation clip type anchorage device. The anchor principle of the separated clamping piece type anchor is mainly characterized in that the clamping action is generated by the pressure exerted on a prestressed tendon by a clamping piece. Its advantages are flexible design, convenient construction and high exchangeability.

The parabolic FRP ribs are positioned in the module beam cementing surface, the FRP ribs are stretched by adopting a post-tensioning method, and the two prestressed FRP ribs are symmetrically arranged on the left and right of the section of the recombined bamboo beam.

The size of the parabola-shaped prestressed FRP reinforced recombined bamboo beam is 2500mm multiplied by 210mm multiplied by 240mm (length multiplied by width multiplied by height).

The manufacturing method comprises the following steps: the method comprises the steps of pressing the recombined bamboo module beam, manufacturing an FRP rib hole channel on the recombined bamboo module beam, placing FRP ribs in the hole channel, connecting the recombined bamboo module beam by structural adhesive, and installing anchoring devices at two ends of the recombined bamboo beam, so that the parabolic prestressed FRP reinforced recombined bamboo beam is formed. The invention satisfies the characteristic of the prestressed tendon linear approaching bending moment diagram, greatly improves the bearing capacity and the crack resistance of the member, and simultaneously has convenient and fast manufacturing method and fully exerts the performances of two materials.

Claims

1. Parabola-shaped prestress FRP reinforced recombined bamboo beam, which is characterized by comprising: the bamboo beam (1), the prestressed FRP rib (3) and the FRP rib separation clip type anchorage device (21).

2. The parabolic prestressed FRP reinforced recombined bamboo beam as claimed in claim 1, wherein the recombined bamboo beam (1) is composed of recombined bamboo module beams (7), (8) and (9), wherein the recombined bamboo module beams (7), (8) and (9) are provided with tunnel grooves on the side surfaces, the tunnel grooves are parabolic along the longitudinal direction and have semicircular cross sections.

3. The parabolic prestressed FRP reinforced bamboo beam as claimed in claim 1, wherein the longitudinal form of the prestressed FRP reinforcement is parabolic.

4. A parabolic prestressed FRP reinforced bamboo beam as claimed in any one of claims 1 to 3 and a method for manufacturing the same, comprising the steps of: the method comprises the steps of pressing the recombined bamboo module beam, forming a FRP rib semicircular channel on the inner sides of the recombined bamboo module beams (7) and (9), forming two FRP rib semicircular channel on the recombined bamboo module beam (8), placing FRP ribs in the channels, connecting the recombined bamboo module beams (7) (8) (9) by structural glue to form the recombined bamboo beam (1), mounting anchoring devices at two ends of the recombined bamboo beam, and tensioning the FRP ribs by adopting a post-tensioning method.

5. The method of claim 4, wherein the magnitude of the pre-tension stress is 25% of the ultimate tensile strength of the FRP tendon.