摘要
采用电化学快速腐蚀法研究了碳纳米管掺量（0.1%~0.5%）对钢筋混凝土在5%氯盐环境下的电流强度、变形开裂特征及钢筋质量损失率的影响.结果表明：少量碳纳米管会在混凝土中形成微细电容器,降低钢筋混凝土的导电性,保护钢筋防止钢筋腐蚀;而掺量较多时会形成导电通路,增加混凝土的导电性,提高钢筋混凝土的腐蚀电流强度.变形性能测试结果表明：0.1%~0.3%碳纳米管使得混凝土开裂破坏时间延长11%~32%;掺量较多时,会提高钢筋混凝土开裂破坏速度,钢筋混凝土开裂时间比普通混凝土提早了27.8%.钢筋质量损失率测试结果表明：在混凝土中掺入0.1%~0.3%碳纳米管使得钢筋质量损失率比普通混凝土低30%~81%.扫描电镜测试结果表明：腐蚀后,普通混凝土保护层中存在大量的针柱状腐蚀针体,并且还可以观察到脆性裂缝,而碳纳米管改性混凝土中的裂缝较小,碳纳米管束缚针状晶体并相互交缠.
The research study presented herein evaluates the corrosion behavior of steel bar in concretes with different CNTs content（0.1%~0.5%）,which were are exposed to 5% NaCl solution.The corrosion process was followed by monitoring of open-circuit current,micro-strain and mass loss of steel bar.Electrochemical measurements show that the addition of 0.1%~0.3% CNTs enhances the corrosion resistance of reinforced concrete exposed to Na Cl solution,however the concrete with 0.5% CNTs shows a higher corrosion rates.According to the test results,the addition of 0.1~0.3% CNTs delays the cracking time of concrete cover by about 11%~32% over the unmodified concrete,while the addition of 0.5% CNTs accelerates the time by 27.8%.Moreover,the mass loss of steel rebar embedded in concrete containing 0.1%~0.3% CNTs is about 30%~81% lower than that of PCC.SEM results show that a lot of needle-like crystals and cracks can be observed in both PCC and CNTs modified concrete,however,the crack width of PCC was much larger than that of CNTs modified concrete.
作者
李庚英
王中坤
Li Gengying1,2 ,Wang Zhongkun1(1 College of Water Conservancy and Civil Engineering, South China Agricultural University, Guangzhou 510642, China; 2 Department of Civil Engineering, Shantou University, Shantou 515063, Guangdong Chin)
出处
《华中科技大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2018年第3期103-107,共5页
Journal of Huazhong University of Science and Technology(Natural Science Edition)
基金
国家自然科学基金资助项目(51378303)
广东省科技计划资助项目(2015A010105029)
关键词
碳纳米管
腐蚀性能
混凝土
电化学快速测试
质量损失
carbon nanotubes
corrosion performance
concrete
electrochemical measurements
mass loss
