东南大学学报（自然科学版）2016，Vol.18Issue(3)：612-618,7.DOI:10.3969/j.issn.1001-0505.2016.03.026
隧道用纤维素纤维混凝土在弯拉荷载作用下的耐久性
Durability of cellulose fiber reinforced concrete under bending load in tunnel engineering
摘要
Abstract
According to the bending load conditions of tunnel lining concrete in service,the durabili-ties of cellulose fiber reinforced concrete(CFRC)unloaded and loaded to 40% four-point bending strength were studied:resistances of chloride ion permeability,carbonation,freezing-thawing and sulfate attack.These results were also compared with the durability of unloaded plain concrete with-out fibers.The micro-mechanisms of the effect of cellulose fiber on the durability of CFRC were in-vestigated as well.The results show that compared with the unloaded plain concrete,the durability of the unloaded CFRC is increased dramatically due to the effects of the special hollow microstructure and hydrophilicity of cellulose fiber on the optimized pore structures and homogeneous dispersion of cellulous fibers in hardened CFRC matrix,and the electric flux of CFRC only decreases by 25%;the carbonization depth of unloaded CFRC with different ages reduces by 0.9 to 2.5 mm.The external bending load slightly weakens the durability of CFRC compared to unloaded CFRC,e.g.the electric flux increases by 17%,and the carbonization depth increases by 0.2 to 1.3 mm.However,the du-rability of loaded CFRC is still better than that of the unloaded plain concrete,e.g.the electric flux only reduces by 12%,and the carbonization depth reduces by 0.4 to 1.2 mm.The relative dynamic elastic modulus increases by 3% after 200 times of sulfate dry-wet cycles.关键词
隧道混凝土/纤维素纤维/耐久性/微观机理Key words
tunnel concrete/cellulosic fiber/durability/micro-mechanism分类
土木建筑引用本文复制引用
郭丽萍,张文潇,孙伟,谌正凯,丁聪..隧道用纤维素纤维混凝土在弯拉荷载作用下的耐久性[J].东南大学学报（自然科学版）,2016,18(3):612-618,7.基金项目
国家自然科学基金资助项目（51378113）、水利部水科学与水工程重点实验室开放研究基金资助项目（Yk914009）． （）
