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Prestressed laminated wood with creep resistant deformation performance, and preparation method and use thereof

A technology of deformation performance and glued wood, which is applied in the direction of wood layered products, wooden veneer joints, chemical instruments and methods, etc., to achieve the effect of not changing the cost of materials, small volume, and improving structural performance

Inactive Publication Date: 2013-05-01
NANJING UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] Aiming at the poor creep resistance of the conventional glulam beams in the above prior art under long-term loads, the cross-section of the glulam beams in the building is too large, and the wood in the compression zone cannot be fully utilized; high-strength FRP or steel bars The construction process of glulam beams reinforced by non-natural materials such as glulam is complicated, the compatibility between materials is poor, and problems such as peeling easily occur. The present invention provides prestressed glulam with creep resistance and its preparation method and application. The prestressed glulam is used in the field of glulam beams. By pre-setting the moisture content gradient in the height direction of the glulam beam, the moisture content gradient is eliminated in the later stage, and the shrinkage and swelling of the wood are affected by the moisture content. Dimensionally stable wood is constrained and cannot be freely deformed, thereby generating prestressed methods to strengthen wooden beams, which overcomes the above-mentioned shortcomings, and effectively solves the above problems in conventional glued wood beams and non-natural material reinforced wooden beams

Method used

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  • Prestressed laminated wood with creep resistant deformation performance, and preparation method and use thereof
  • Prestressed laminated wood with creep resistant deformation performance, and preparation method and use thereof
  • Prestressed laminated wood with creep resistant deformation performance, and preparation method and use thereof

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Experimental program
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Embodiment 1

[0040] Such as figure 1 It is a preparation method of prestressed glulam with creep deformation resistance, and its steps are:

[0041] (1) Wood raw material pretreatment :According to the design requirements, Douglas fir and fast-growing poplar wood are cut, split, and planed through mechanical sawing to produce specifications with a thickness of 20mm, a width of 80mm, and a length of 1000mm. Dry the size lumber to control its moisture content within 15%, and eliminate and control the inherent natural defects, decay, knots, diagonal lines, cracks, wormholes and holes of Douglas fir and fast-growing poplar wood materials, and To carry out stress classification (stress classification number mark), the stress classification generally adopts mechanical elastic modulus and mechanical stress classification. The mechanical elastic modulus grading laminate is divided into 9 grades, and the average elastic modulus performance index of each grade is shown in Table 1. The stress grading...

Embodiment 2

[0052] (1) Wood raw material pretreatment :According to the design requirements, through mechanical sawing and other processing methods, the specification lumber with a thickness of 45mm, a width of 280mm and a length of 6000mm is produced, and the specification lumber is dried to control its moisture content within the range of 25%. Natural defects, decay, knots, diagonal lines, cracks, worm holes and holes are removed and controlled. Then through stress grading and artificial drying, the moisture content of Douglas pine wood in the tension zone and compression zone of the high stress level is adjusted to 8% and 15%, respectively, and the moisture content of the masson pine wood in the low-grade shear zone is adjusted to 12%;

[0053] (2) Production of glulam laminate : Finger-joining, curing, horizontally widening and curing the wood of the same layer with the same moisture content. Finger-joining, widening and two curing processes are all operated under constant environmental...

Embodiment 3

[0058] (1) Wood raw material pretreatment :According to the design requirements, through mechanical sawing and other processing methods, the specification lumber with a thickness of 35mm, a width of 140mm and a length of 3000mm is produced, and the specification lumber is dried to control its moisture content within the range of 20%. Defects such as decay, knots, diagonal lines, cracks and wormholes should be controlled, and should be classified and numbered. Then by artificial drying, the moisture content of Douglas pine wood in the tension zone and compression zone is adjusted to 6% and 16% respectively, and the moisture content of masson pine wood in the shear zone is adjusted to 11%;

[0059] (2) Production of glulam laminate : Finger-joining, curing, horizontally widening and curing the wood of the same layer with the same moisture content. Finger-joining, widening and two curing procedures are all operated in an environmental condition that maintains a constant moisture co...

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Abstract

The invention discloses a prestressed laminated wood with creep resistant deformation performance, and a preparation method and use thereof, and belongs to the field of a structural member of architecture. The prestressed laminated wood with the creep resistant deformation performance comprises a top compressive zone, a middle shear zone, a bottom tensile zone and an adhesive layer in the height direction of a wood beam; laminates inside and among the top compressive zone, the middle shear zone and the bottom tensile zone are cohered with each other by the adhesive layers to be fixed and formed; and for the laminated wood member which comprises the top compressive zone, the middle shear zone and the bottom tensile zone, the final moisture content of the wood of the three parts is the same, that is 10-12 percent. A principle is that high stress-grade structural wood is arranged in the tensile zone and the compressive zone of a wood beam of the laminated wood; a moisture gradient is set along the wood of the three parts with the heights; after the moisture content of the wood with different moisture contents is balanced and consistent, prestress is generated when the wood cannot be freely stretched and deformed fully because water loss shrinkage and hydroscopic expansion of the wood are inhibited, so that the creep resistant deformation performance of the wood beam of the laminated wood is obviously improved under the long-term load effect, inherent and natural defects which influence the mechanical property of the wood are overcome when the member is prepared initially; and the product has the advantages of stability and reliability in structural performance, high rigidity, excellent creep resistance, and can be used as bearing beams for the timber structure architecture.

Description

technical field [0001] The invention relates to structural components for buildings, in particular to prestressed glued wood with creep deformation resistance and its preparation method and application. Background technique [0002] Due to the advantages of energy saving and environmental protection, excellent structural performance, and the size and shape are not limited by the log diameter, the glued wood structure is currently widely used in the field of foreign building structures. In recent years, due to my country's energy-saving emission reduction and green building technology policy guidance, glued wood structure buildings have also shown a momentum of rapid development in my country, so the use of advanced wood processing technology to manufacture light and high-strength glued wood materials will be It is used in the construction field and has broad development prospects and markets. [0003] In actual use, the structural beam section of conventional glulam beams is...

Claims

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Application Information

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IPC IPC(8): B27D1/04B27D1/10B27K5/00B27K1/00B27D1/08B32B21/14
Inventor 岳孔刘伟庆陆伟东刘宇霍瑞丽
Owner NANJING UNIV OF TECH
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