电化学除盐对混凝土微观结构的影响

设计了一套钢筋混凝土的电化学除盐循环装置,研究了用0.001 mol/L Li2B4O7 氢氧化钙饱和溶液、氢氧化钙溶液以及蒸馏水作电解液的除盐效率,并用SEM和EDS等方法进行微观结构分析,结果表明:用0.001 mol/L Li2B4O7 氢氧化钙饱和溶液作电解液最有利于混凝土中Cl-的排除,并且经电化学除盐处理后混凝土水化产物中C-S-H凝胶分解,Ca(OH)2增多,并在孔壁形成沉淀,堵塞毛细孔,使表层混凝土孔隙率降低,而钢筋与混凝土界面Ca/Si增大。

Influence of Electrochemical Chloride Extraction on the Microstructure of Desalinated Pastes of Concrete

A set of installation is designed for electrochemical chloride extracting circularly on reinforced concrete.The removal efficiency is discussed using saturated Ca(OH)2 solution,saturated Ca(OH)2 0.001 mol/L Li2B4O7 solution and distilled water as electrolyte,respectively.And the microstructure of cement paste is analyzed by scanning electron microscopy(SEM) and energy dispersive X-ray spectroscopy(EDS).The results prove that using saturated Ca(OH)2 0.001 mol/L Li2B4O7 solution as electrolyte is more favorable to removing chloride in concrete.Treated by electrochemical desalination,the hydrated product C-S-H resolves and Ca(OH)2 in the concrete increases,too.It deposites on the wall of pores and fills in pores,and then causes the porosity to decrease,while the ratio of Ca /Si of C-S-H increases in the interface between the steel and the concrete.