加速腐朽环境下重组竹力学及耐腐性能研究  

Research on mechanical properties and decay resistance mechanism of bamboo scrimber under accelerated decay environment

作　　者：储炜 徐明[1] 许琪 李婷[1] 崔兆彦 CHU Wei;XU Ming;XU Qi;LI Ting;CUI Zhaoyan(Key Laboratory of C&PC Structures,Ministry of Education,Southeast University,Nanjing 211189,Jiangsu,China;National-provincial Joint Engineering Research Center of Electromechanical Product Packaging,Nanjing Forestry University,Nanjing 210037,Jiangsu,China)

机构地区：[1]东南大学混凝土及预应力混凝土结构教育部重点实验室,江苏南京211189 [2]南京林业大学机电产品包装生物质材料国家地方联合工程研究中心,江苏南京210037

出　　处：《建筑科学与工程学报》2023年第3期30-39,共10页Journal of Architecture and Civil Engineering

基　　金：国家重点研发计划项目(2017YFC0703503)。

摘　　要：重组竹作为一种新型工程材料,有着良好的力学性能,为了对重组竹的耐腐性能展开定量评价,利用目测分析、失重率分析、力学性能分析以及扫描电镜分析等方法,进行重组竹耐腐性试验研究。结果表明:重组竹在褐腐菌与白腐菌84 d的作用下,仅表面有轻微腐朽,褐腐菌和白腐菌腐朽试件失重率相差不大,且均小于10%,表明重组竹属于Ⅰ级耐腐;褐腐菌试样的抗弯弹性模量M_(E)、抗弯强度M_(R)分别下降5.17%、8.17%,而抗压强度U基本不变,白腐菌试样的M_(E)、M_(R)、U下降幅度分别为10.56%、13%、0.45%,远小于木材;通过扫描电镜分析,相比毛竹在经历84 d腐朽后,其薄壁细胞中布满菌丝,细胞壁上出现大量孔洞,重组竹表面下2 mm以内的薄壁细胞中仅有少量菌丝,并且在84 d试验内均未造成细胞壁的破坏;竹材内部可以满足木腐菌生存的条件,但在疏解、炭化、浸胶、重组的过程中,吸水性能降低,限制了真菌生长的水分条件,阻碍了木腐菌侵入重组竹内部,另外酚醛树脂具有一定的抑菌性,使得重组竹成为耐腐性强的材料。Bamboo scrimber is a new type of engineering material,which has good mechanical properties.To quantitatively evaluate the decay resistance of the bamboo scrimber,methods including visual analysis,weight loss rate analysis,mechanical property analysis,and scanning electron microscopy analysis were used in the study of the decay resistance of the bamboo scrimber.The results show that after the 84 d corrosion of the brown-rot fungi and white-rot fungi,only slight decay on the surface of the bamboo scrimber samples occurred.The brown-rot and white-rot have little difference in weight loss rate,and both are less than 10%,which shows that the bamboo scrimber belong to gradeⅠdecay resistance.The elastic modulus of bending M_(E) and bending strength M_(R) of brown-rot specimens decrease by 5.17%and 8.17%respectively,while the compressive strength U remains basically unchanged.By contrast,the M_(E),M_(R) and U of the white-rot specimens decrease 10.56%、13%and 0.45%respectively,which is far less than that of wood.Scanning electron microscopy analysis shows that after 84 d decay,the thin-walled cells of moso bamboo are filled with hyphae and numerous pores appeared on the cell walls,while only a small amount of hyphae present in the thin-walled cells within 2 mm of the surface of the bamboo scrimber,and no damage to the cell walls occurs during the 84 d experiment.Although the conditions for survival of wood-decaying fungi can be met inside bamboo,the reduction in water absorption during processing such as disintegration,carbonization,impregnation,and reconstitution limits the moisture required for fungal growth,hindering the invasion of wood-decaying fungi into the bamboo scrimber.Additionally,phenolic resins exhibit some antibacterial properties,making bamboo scrimber a durable material with high decay resistance.

关 键 词：重组竹 失重率 力学性能 扫描电镜 耐腐性 

分 类 号：TU531.3[建筑科学—建筑技术科学]