基于森林资源的日趋缩减与木材之间的供需矛盾,国家大力发展木质植物纤维复合材料产品,芦苇作为一种重要的生物质材料,其分布范围广泛,在涵养水源、维持生物多样性和生态平衡起到了重要作用,由于芦苇纤维具有优良的物理性能可作为木材的替代产品.本文根据目前芦苇纤维材料的研究及产业发展现状及利用方面存在的问题,阐述了芦苇作为功能性材料基材及芦苇纤维重组材的研发现状以及应用前景.

采用自然光对比不同纤维含量木纤维/聚乳酸复合材料进行光照老化试验,对比经过不同时间光照后材料的弯曲性能以及拉伸性能的变化,分析光照时间对材料力学性能的影响.结果显示,加入木纤维后,复合材料的弯曲强度和拉伸强度均出现了先下降后上升的趋势,说明加入一定量的木纤维会对复合材料体系起到一定的增强作用;在受到一定时间的自然光照射后,纯聚乳酸材料和木纤维/聚乳酸材料的弯曲性能和拉伸性能均有显著降低,含有木纤维的复合材料强度降低较少.

聚乳酸是一种强度较高的聚酯类材料,其良好的降解性能在保证了其环保优势的同时,也对其物理力学性能产生一定影响.本研究将木纤维/聚乳酸复合材料置于水环境中进行水解处理,然后测试复合材料的力学性能.结果显示,将复合材料放置在水中一段时间后,复合材料的弯曲性能和拉伸性能都显著下降,木纤维含量越高,材料性能下降越明显.这说明水环境使聚乳酸分子链发生了水解反应,使材料性能下降;同时,木纤维的吸水膨胀和干燥收缩也使材料界面薄弱点增加,使材料性能有所下降.

竹材和木材都是由微小纤维排列组成的多孔型各向异性材料,在不同的方向有不同的强度性能和胀缩特性,本文利用竹材较高的硬度和杨木轻质的特点,采用高频加热方法,研制不同厚度(18~50 mm)的竹木复合板,其中较厚板材可用于桌台面、门板等,较薄板材可用于家具板、橱柜板等.竹材和木材在纤维纹理方向的强度大于弦向和径向,湿胀干缩变化比弦向和径向小.本研究研制的竹木复合板由3层或5层纵横交错的组合结构复合而成,竹材的表层、芯部为杨木,在厚度方向上采用奇数层;通过每层材料形式、种类和厚度的变化,考察复合后板材的尺寸稳定性和形状变化.

设计两种试验方法用来计算木工字梁的抗弯刚度(EI)和剪切系数(K),一种是不同跨度组合的全跨度挠度实验方法,另一种是纯弯曲挠度和全跨度挠度组合实验方法.按照不同跨度组合的全跨度挠度实验方法进行试验,得到了木工字梁的EI和K,可以用于准确预测木工字梁的挠度.还讨论了用原材料性能推算木工字梁EI和K的方法.

采用目测和色差计两种方法,对柞木的耐光色牢度进行试验.结果表明,染色柞木的耐光色牢度等级要好于未染色的柞木;未染色木材在处理15 h之前色差变化较快,而15 h后变色趋于平衡;染色木材色差变化较未染色木材缓慢,约在处理40 h左右变色趋于平衡;色差目测结果与用△Eab*公式计算结果差别较大,但与用△E00公式计算结果较接近,△E00公式计算结果更符合目测结果.

通过分析2个结构单板层积材国家标准,简述了结构单板层积材标准框架及技术内容对比,介绍了结构单板层积材足尺检测和评价方法及尺寸效应,为新标准的实施奠定了应用基础.

我国2002年和2003年颁布实施的GB 50206-2002《木结构工程施工质量验收规范》和GB/T50329-2002《木结构试验方法标准》及GB 50005-2003《木结构设计规范》3个木结构建筑标准规范,标志着木结构建筑将在我国重新得到认可、重视和推广应用.同时也进一步促进和拉动了我国结构用木质材料生产和加工技术及性能评价方法的引进、消化和再创新及应用.

<正>不同种类的木材或同一块木材的不同部位,如边芯材,其光泽和颜色不尽相同,人们为了获得更好的视觉效果,有时需要对木材进行染色处理。通常,经过染色处理的木材颜色更美丽,纹理更为赏心悦目,更突出木材原有的视觉效果和装饰特质。另外,木材通过染色,还能模仿珍贵树种的颜色,提高木材的装饰作用和产品价值。

According to the evaluation methods and standards of ASTM D5456 Standard Specification for Evaluation of Structural Composite Lumber Products and APA PRL-501 LVL Performance Standard,inspection and evaluation analysis of the mechanical properties of domestic poplar LVL is conducted.Through good-of-fitness tests,it is found that the mechanical properties of poplar LVL fit lognormal distribution very well.The study of the characteristic values of the mechanical properties of poplar LVL provides a reference for the methods for determining the characteristic values of China's structural LVL.

The test methods for determining the connection performance of dowel type fasteners in wood structures in Europe and America are introduced,mainly including withdrawal test,lateral load test,pull-through resistance and dowel-bearing strength of dowel type fasteners,with the aim to promote relevant research related to wood structures in China.

The construction technology of nailed joint in timberwork used larch in the northeast of China have been studied. The result showed that when nailed joint used Larix gmelini, pre - drilled diameter was around 85 percent of the nail diameter and pre - drilled depth should exceed the into deep of nails. The nail was not too thick at the end of the nailed joint, test determined or adopt corresponding technical measures had to ensure that the connection performance.

The common production technology,the main points and the key technology were discussed.Several solutions were explored for resolving the problems that usually happen during production.This paper provided technical support for the production and quality of three-layer parquet.

This article describes the principles and technical requirements for wood I-joists used in structural applications.This newly developed Chinese standard explains and illustrates all major technical parameters including material selection,load-carrying properties,test methods,and quality control.

单板层积材（Laminated Veneer Lumber，LVL）作为结构复合木材产品之一，与单板条层积材（Parallel Strand Lumber，PSL）、木条定向层积材（Laminated Strand Lumber，LSL）和定向刨花方材（Oriented Strand Lumber，OSL）等产品已经成为北美重要的木质工程材料，广泛应用于民用和商业木结构建筑。

The manufacturing technology and characteristics of I-joist used for light wood structures are introduced in brief.The requirements for quality and performance of I-joist in North America as well as relevant test items,principles,characteristic value calculation and evaluation methods are introduced.

The formula derivation, test, calculation,verification and analysis of the deflection of wood I-beam are conducted. The results show that considering shearing deformation,the measured deflection value is very close to the predicted deflection value while there is a big difference between measured value and predicted value when ignoring shear deformation. Theory and real measurement show that shear deformation can＇t be ignored when calculating the deflection of wood Z-beam. Such values as EI and K of wood I-beam can be obtained through the test, and those values can be used for the accurate prediction of the deflection of wood I-beam, which provides a comparatively simple method for calculating and predicting the deflection of wood Z-beam.

Nailed joint is a common manner in timber structure.Wire nail is the major material of the nailed joint in timber structure.The mechanical properties and dimension of the wire nail from different factories in American or in our country were tested.It was found that the dimension and mechanical properties of the wire nail from American or our country is very close.The import wire nail can be replaced by the one that made in our country,and used in modern timber structure buildings.

The nail joint is a common connection used in timber structures.This paper focuses on nailed joint performance of larch lumber,a common species in northeast China.The authors introduced the test methods for American nailed joints and how to develop the design values for wood structures with domestic wood species. The results could be used to develop design values of larch in this area.

Several practical surface-color treating methods for three-layer parquets were discussed.These methods included the stain coloration, chemical coloration, and physical coloration methods.The features of different coloration methods were analyzed and compared.