摘要
为在不影响美观的前提下解决木构件狭小裂缝的修复问题,以木构件裂纹为研究对象,运用湿态流动性及渗透性较好的碳纤维浆料填充注入法对其进行修复,并对裂纹损伤修复性能进行评价,探索木构件裂纹损伤修复与增强的一种新的技术手段。结果表明:木构件自然开裂裂纹顺纤维方向产生,并沿径向向内发展且裂纹开口逐渐减小。裂纹壁面外侧平滑无毛刺,里侧存在细小纤维粘连。微观图显示裂纹断口清晰平整,大多发生轴向管胞胞间层间破坏,轴向管胞本身结构相对完整。外力作用引起的断裂裂纹壁面凹凸不平,部分存在不规则木纤维断裂薄层。微观图显示裂纹横穿轴向管胞细胞壁,多数轴向管胞被强行拉断,结构破损严重,断口粗糙。裂纹创面修复后构件的断裂峰值荷载和断裂能均有提高,其中,0.5 mm碳纤维浆料修复组最为显著,其峰值荷载及断裂能相对未修复组分别提高69.62%和107.02%。锯切法预制裂纹可释放木构件部分内应力,切口断面呈梯形,外层宽内层窄。预制裂纹中碳纤维浆料填充彻底,浆料与裂纹壁面结合牢靠。浸水处理及高温热处理均未导致裂纹修复创面出现分层或结合不牢的现象,裂纹中碳纤维浆料固化密实、稳定。
In this research,we explored a new technique for repairing and reinforcing narrow cracks on wooden structures without affecting aesthetics.The cracks were repaired by injecting and filling them with carbon fiber slurry with good fluidity and permeability,and thereafter,the performance was evaluated.The results showed that the cracks occurred along the fiber direction and developed inward along the radial direction;the crack openings decreased gradually in this direction.The outer surface of the cracked wall was smooth and without burrs,and there was only slight fiber adhesion inside.The microscopic diagram showed that the crack fracture was clear and smooth,and most of the cracks occurred at the intercellular interlaminar failure,with the tracheid itself remaining relatively intact.The wall surface of the fracture crack caused by external force was rough and uneven,and there were thin,irregular layers of wood fiber fracture in some parts.As the crack crossed the tracheid cell wall,most tracheids were forced to break,and the tracheid structure was seriously damaged by the resulting rough fracture.The peak fracture load and specific fracture energy of members increased after the crack repair,and the 0.5 mm carbon fiber slurry repair group was the most significant.The peak load and specific fracture energy of the 0.5 mm carbon fiber slurry repair group were 69.62%and 107.02%higher than those of the non-repair group,respectively.Some cracks were prefabricated by the sawing method,having a trapezoidal cut section,a wide outer layer,and a thin inner layer.These cracks could release some internal stress within the wooden members.The prefabricated crack was filled thoroughly with carbon fiber slurry,and the slurry firmly adhered to the crack wall.The water immersion treatment and high temperature heat treatment of the samples did not lead to delamination or weak bonding on the repaired surface,and the carbon fiber slurry in the crack remained dense and stable.
作者
董浩然
谈永杰
杨小军
刘嘉敏
白新春
陈泽华
DONG Haoran;TAN Yongjie;YANG Xiaojun;LIU Jiamin;BAI Xinchun;CHEN Zehua(College of Materials Science and Engineering,Nanjing Forestry University,Nanjing,Jiangsu 210037,China;Jingjiang National Forestry Products Co.,Ltd.,Jingjiang,Jiangsu 214500,China)
出处
《森林与环境学报》
CSCD
北大核心
2022年第4期442-448,共7页
Journal of Forest and Environment
基金
国家自然科学基金项目“粉状碳纤维-木构件端面复合界面力学特性研究”(31300484)
江苏省泰州市双创人才项目“建筑结构材裂纹修补剂开发研究”(2020090120)。
关键词
碳纤维浆料
木构件
裂纹修复
裂纹损伤
carbon fiber slurry
wood members
crack repair
crack damage
作者简介
第一作者:董浩然(1997-),男,硕士研究生,从事木材加工与木结构建筑研究。Email:976847838@qq.com;通信作者:杨小军(1978-),男,副教授,从事木材加工与木结构建筑研究。Email:yxj5460@163.com。
