FRP增强结构用集成材木梁胶合性能研究

FRP增强结构用集成材木梁可有效地提升梁体的抗弯强度,FRP与结构用集成材的复合首先要解决的是FRP与木材的胶合问题。本试验对比等离子体处理及羟甲基间苯二酚HMR改性处理工艺对FRP木材界面胶合性能的影响,并用胶层剥离率、剪切强度对胶合性能加以表征。试验结果表明,FRP增强结构用集成材木梁的胶合界面优化处理工艺为：FRP表面不处理,木材表面预先以2.5 m/min的送料速度进行射频功率为400 W的等离子体处理5次,然后以150 g/m2的涂胶量涂布HMR。试材的浸渍剥离率、煮沸剥离率、干剪强度、湿剪强度及木破率均满足结构用集成材国家标准GB/T 26899-2011中关于使用环境3的要求。     

集成材及其胶粘剂市场一瞥

１　集成材概述集成材又称胶合木，是一种用板材或方材按平行于纤维方向配板，用胶粘剂沿其长度、宽度或厚度方向胶合而成的材料。集成材是近几年新兴的木材加工制品，其产品主要用于家具和建筑行业。１－１　集成材的特点（１）集成材是用短小料胶合而成的材料，因此，它可以做到小材大用、劣材优用，提高木材利用率；（２）由于集成材的原料经过了充分的干燥，因此，即使长大材，其各部分的含水率也很均一，产品不易变形、开裂；（３）在抗拉、抗压等物理力学性能方面和材料质量均匀化方面都优于实体木材，其强度性能为实体木材的１－５倍…     

落叶松集成材耐候试验分析

耐久性能是结构集成材的主要质量指标,它是由胶层的劣化和木材的腐朽、受虫害的程度等因素决定的。检验集成材的耐久性能有剥离试验和耐候试验两种试验方法,前者可在短时间内检验集成材的耐久性能,而后者是以在室内外的自然环境条件下长期暴露来检验集成材的耐久性能,因此,也是最     

马尾松防腐材胶合性能的径向变异研究

胶合性能径向变异的研究可为马尾松防腐集成材的原料选取提供重要依据。以35年生马尾松为试验用材,选用季铵铜防腐剂和间苯二酚-苯酚-甲醛树脂胶黏剂制备防腐材胶合试件,并检测其拉伸剪切强度及木破率,研究胶合性能的径向变异,从木材密度和胶黏剂渗透性能两方面分析胶合性能变化的原因。结果表明:沿髓心至树皮方向,马尾松防腐材剪切强度呈现出先增加(1～13 a)而后趋于稳定(≥14 a)的变化规律,不同部位对应的木破率均在90%以上,未表现出显著差异;木材密度(0.493～0.572 g/m~3)沿径向的变化趋势与剪切强度一致,且两者之间呈较强的线性正相关性(Pearson相关系数为0.659),而径向不同部位对应的胶黏剂平均渗透深度(76.65～88.01μm)之间无显著性差异。成熟材区域对应的马尾松防腐材的胶合性能明显优于幼龄材区域,因而在生产集成材时应优先选择14年生以上的成熟材为原料。木材密度是马尾松防腐材胶合剪切强度出现明显径向变异的重要影响因子,而胶黏剂在木材中的渗透性能对其影响较小。     

落叶松非结构集成材加工工艺的研究

以短周期工业材落叶松为原料生产非结构集成材，解决了劣材优用问题，提高了木材利用率，为家具制造和室内装修提供了理想的优质材料。     

短周期工业材集成材的胶合性能试验

短周期工业材集成材的胶合性能试验何林，李琳，马春香（黑龙江省林产工业研究所）（黑龙江省建材校）集成材是把板材或小方材平行于木材纤维沿其长、宽、厚度方向胶合而成的新型结构材料。它具有强度高、变形小、耐燃性好，可加工成任意形状和尺寸等特点。因此广泛应用于...     

水曲柳含水率对集成材胶接性能的影响

在现代木材加工工业生产中，对胶粘剂的依赖性不断增强，胶接质量已越来越成为影响木制品质量的一个重要因素。影响木材胶接性能的因素很多，有木材密度、树种等木材固有的因素，也有被胶接木材的含水率、表面粗糙度等加工过程中所产生的因素。本文从木材的干燥质量，主要是木材的含水率入手，对于不同树种满足集成材胶接对含水率的要求做了初步探索，并给出了相应的干燥工艺，这对于实际生产有着一定的指导意义。     

新型木材指接设备

新型木材指接设备郝金城（黑龙江省林产工业研究所）指接是把短木接长的有效办法，它可以提高木材利用率，减少木材资源的浪费。指接材可作为室内装修和家具制作的非结构部件用材，也可作为结构承重部件用材。特别是包括指接工序的集成材制造的家具和指接地板，其材质优良...     

集成材产品质量的控制

集成材产品应用广泛，相应对集成材产品的质量要求较高。本文从木材含水率、基材加工质量及胶拼加工等方面对集成材产品的质量加以控制。     

不同胶黏剂不同树种结构用集成材胶合性能的研究

分别采用LX1-1、KR-134、S309和RF-C05 4种胶黏剂依次胶合欧洲云杉、欧洲赤松、兴安落叶松木材层板,制备成对应的结构用集成材。再依照GB/T26899—2011《结构用集成材》和GB/T 50005—2003《木结构设计规范》国家标准对制得的试样进行检测。实验结果表明,4种胶黏剂的胶合性能存在较大的差异:1)剥离率:4种胶黏剂在胶合欧洲云杉、赤松2种集成材时,浸渍剥离率均满足国标要求,但KR-134和RF-C05在第二次煮沸剥离率均未能满足国标。在胶合落叶松集成材时,LX1-1、KR-134在浸渍时剥离能满足国标要求,煮沸剥离未能满足国标要求,S309和RF-C05 2种剥离率均不满足国标。2)剪切强度和木破率:除S309落叶松集成材的湿剪强度和木破率均未能达到标准要求外,LX1-1、KR-134和RFC05胶合欧洲云杉、欧洲赤松和落叶松结构用集成材试样的湿剪强度均在3.9MPa以上,干剪强度均在5.9MPa以上,且木破率均大于75%,满足国标相关要求。3)LX1-1型异氰酸酯胶黏剂在胶合性能上优于其他3种胶黏剂,且兴安落叶松相比较其他2种木材,更加难以被胶粘。     

Strength properties of glued laminated timber made from edge-glued laminae II: bending,tensile, and compressive strength of glued laminated timber

The purpose of this study was to investigate the strength properties of glued laminated timber composed of edge-glued laminae and to investigate the influence of edge gluing on the strength properties. Glued laminated timber composed of multiple-grade laminae (symmetrical composition, strength grade E95-F270, 10 laminations) was produced from karamatsu (Larix kaempferi) edge-glued laminae according to the Japanese Agricultural Standard. The bending, tensile, and compressive strengths of the glued laminated timber were measured. The average bending, tensile, and compressive strengths were 33.4, 24.5, and 35.9 MPa, respectively, and these values are almost equal to those of glued laminated timber composed of karamatsu single-piece laminae. It was determined that finger-joints and knots in the edge-glued laminae played a significant role in the failure of specimens. However, the use of glued edge-joints did not appear to affect the failure of specimens.     

胶合木国产化生产线关键设备

简述了胶合木的基本概念,根据胶合木生产工艺流程介绍了目前国产化生产线及其关键设备。对胶合木生产线的发展及应用前景进行了分析与展望。     

Mechanical behaviour of finger joints at elevated temperatures

Finger joints are commonly used to produce engineered wood products like glued laminated timber beams. Although comprehensive research has been conducted on the structural behaviour of finger joints at ambient temperature, there is very little information about the structural behaviour at elevated temperature. A comprehensive research project on the fire resistance of bonded timber elements is currently ongoing at the ETH Zurich. The aim of the research project is the development of simplified design models for the fire resistance of bonded structural timber elements taking into account the behaviour of the adhesive used at elevated temperature. The paper presents the results of a first series of tensile and bending tests on specimens with finger joints pre-heated in an oven. The tests were carried out with different adhesives that fulfil current approval criteria for the use in load-bearing timber components. The results showed substantial differences in temperature dependant strength reduction and failure between the different adhesives tested. Thus, the structural behaviour of finger joints at elevated temperature is strongly influenced by the behaviour of the adhesive used for bonding and may govern the fire design of engineered wood products like glued laminated timber beams.     

竹集成材办公家具可拆装化设计研究

以竹集成材为基材,办公家具为载体,开展竹集成材办公家具可拆装化设计。从材料属性、家具模块、结构形态等方面,分析了竹集成材在可拆装化设计中的优势和合理性,旨在为竹集成材办公家具产品设计提供参考。     

结构用竹集成材物理力学性能研究

测定结构用竹集成材及其竹指接集成材的主要物理力学性能,并将测试结果与几种人工林单板层积材以及常见建筑用材种的相关性能进行比较.结果表明:竹集成材的水平剪切强度、静曲强度以及弹性模量等力学性能非常优越,浸渍剥离性能较差.     

ACQ防腐处理对马尾松木材胶合强度的影响研究

采用铜氨(胺)季铵盐(ACQ-D)防腐剂处理马尾松木材,以水性高分子异氰酸酯(API)、聚氨酯(PUR)和间苯二酚-苯酚-甲醛树脂(RPF)为胶黏剂制备防腐材胶合试样,研究胶黏剂种类和防腐剂处理浓度对马尾松胶合强度的影响。结果表明:API、PUR、RPF适用于ACQ处理马尾松的胶合,平均剪切强度和木破率均达到GB/T 26899—2011《结构用集成材》要求。胶黏剂种类对防腐材胶合强度有显著影响,表现为PUR和RPF的剪切强度优于API。与未处理材相比,ACQ处理对API胶合有负面影响,对PUR胶合有增强效应,对RPF胶合没有显著影响。在ACQ浓度为0.1%～1.0%范围内,胶合强度没有显著变化。     

Withdrawal capacity of washers in bolted timber connections

Abstract

The European yield model (EYM) has been accepted to determine the load-carrying capacity of structural timber connections. However, experiments of bolted connections are still not in agreement with the EYM unless the additional bearing capacity offered by the washers is taken into account. This bearing capacity is depending on the compressive strength perpendicular to grain of the structural timber. Tests results carried out with M16 and M24 washers on solid and glued laminated timber are used to verify the reliability of three strength capacity predicting models, one of which is an analytical model while the other two are empirical. It was concluded that the analytical model is the superior one. This model should be incorporated in all new structural timber design code revisions.     

Shear behaviour of bond lines in glued laminated timber beams at high temperatures

A comprehensive research project has been carried out at the Swiss Federal Institute of Technology (ETH) on the fire behaviour of timber-concrete composite slabs (Frangi and Fontana 2000). The glued laminated timber beams used for the fire tests were bonded with a one-component polyurethane (1-K-PUR) adhesive. As one fire test on a slab showed an unexpected shear failure of a glued laminated timber beam, a series of tests was carried out to study the shear behaviour of different types of adhesives at high temperatures. The first part of the paper describes the results of the shear tests at elevated temperatures, in the second part the shear test results are compared to the fire test on a slab.     

Compressive and tensile properties of a butt-jointed lamination model

A study was undertaken to evaluate the effect of glue application and placement of butt-joints on the compressive and tensile properties in a butt-jointed lamination. The aim was to provide background information for producing butt-jointed, glued, laminated timber. Three butt-jointed lamination models were prepared from spruce-pine-fir (S-P-F) dimension lumber with glued and nonglued butt joints, with different placements of the butt joints in the models. The axial stiffness and strength properties were assessed using both compressive and tensile tests. The results of the study indicated that for the compressive lamination model the application of glue at the butt joint gave more stiffness than the nonglued butt joint. Neither glue application nor placement of the joint had a statistically significant effect on the compressive strength. There were no significant differences between the glued and nonglued butt joint for either tensile strength or stiffness.     

胶合木桥的设计、制备及其结构性能试验研究

在做出设计方案,包括技术条件、设计规范、材料参数及桥梁选型等的基础上,利用通用有限元软件MIDAS／Gen对木桥进行了结构分析,主要的计算工况包括全跨活荷载、半跨活荷载及人致振动等。分析结果表明,该桥的应力水平及结构刚度等均满足承载能力及正常使用要求。同时简要介绍了胶合木加工工艺及木桥的装配过程,并且通过静力堆我试验对整桥进行了结构性能测试,试验结果与有限元分析结果吻合较好。