摘要
运用压汞测孔法(MIP)和电镜扫描(SEM)分析方法对影响电化学再碱化混凝土的微观结构主次因素进行试验研究。试验结果表明,电流密度的影响最大,其次是再碱化时间和电解质溶液浓度。该试验最优电化学再碱化组合是电流密度为3A/m2,采用1mol/L的Na2CO3电解质溶液,再碱化时间为14d。标准养护、实验室加速完全碳化以及实施再碱化修复试件的混凝土孔隙率的测定结果表明,再碱化对混凝土的总孔隙率和孔径分布的影响都很大。再碱化后混凝土的累积孔隙体积有所减少,孔径分布偏向于凝胶孔,微观结构均匀密实,说明再碱化可以改善混凝土的孔结构,提高混凝土的耐久性能。
The primary and secondary factors of influencing the microstructure of concrete after electrochemical realkalization were investigated by MIP and SEM. The results show that current density has the largest effect, that the secondary influence factors are the electrify time and concentration of solution. When the electrolyte composed of lmol/L Na2CO3 solution, electrify time of 14 days and electrical current density of 3A/m^2 were adopted, the best efficiency can be achieved. Experimental measurements of porosity in standard specimens, completely carbonated specimens and realkalization specimens indicate that： realkalization has considerable impact on the pore size distribution and porosity of concrete. After realkalization the total pore volume is decreased, gel pores cover the majority of the total, and the concrete microstructure becomes very compact. It indicated that realkalization could improve the microstructure and durability of concrete.
出处
《工程力学》
EI
CSCD
北大核心
2009年第7期117-124,共8页
Engineering Mechanics
基金
国家自然科学基金项目(50678127)
国家重点基础研究发展计划项目(2009CB623204)
十一五国家科技支撑项目(2006BAJ03A07-04)
关键词
混凝土桥梁
碳化
再碱化
微观结构
压汞试验和电镜分析
RC bridge
carbonation
realkalization
microstructure
mercury intrusion porosimetry （MIP） and scan electronic microscope
