混凝土中几种无机相对钢筋腐蚀的影响  

Influence of the inorganic phases present in concretes on corrosion of steel rebars

作　　者：卜劲鸿[1] 唐聿明[1] 左禹[1] 

机构地区：[1]北京化工大学材料科学与工程学院,北京100029

出　　处：《北京化工大学学报（自然科学版）》2010年第2期44-48,共5页Journal of Beijing University of Chemical Technology(Natural Science Edition)

基　　金：国家自然科学基金(50731004)

摘　　要：用CaCO3、SiO2、Al2O3和Fe2O3为原料,通过高温固相反应,分别制备了组成单一的无机相粉体C3-S2、C3-A1和C4-A1-F1,以此来模拟混凝土无机相的主要成分。这3种粉体被分别浸泡到含有氯离子的混凝土孔隙模拟溶液中。针对浸泡实验的固液共存体系,分别做了钢筋的极化曲线测试、溶液相的氯离子浓度测试以及过滤产物的XRD晶相分析。分析结果表明,无机相粉体对钢筋起到减缓腐蚀的作用;溶液相中氯离子浓度随时间的延长均呈下降趋势,其中C3-A1和C4-A1-F1粉体对自由氯离子都有很强的结合能力;C3-A1和C4-A1-F1粉体的过滤产物中均发现了Friedel盐相(Ca2Al(OH)6Cl.2H2O),而C3-S2粉体的过滤产物中没有发现含有氯离子的产物晶体相,表明C3-A1和C4-A1-F1粉体模拟的铝酸钙(C3A)通过离子交换结合氯离子,而C3-S2粉体模拟的C-S-H凝胶相则通过物理吸附结合氯离子。Inorganic powders C3-S2, C3-A1 and C4-A1-F1 were synthesized by high-temperature solid-state reactions, using CaCO3 , SiO2 , Al203 and Fe2O3 as raw materials, in order to simulate the inorganic phases present in concrete. The three inorganic powders were separately immersed in simulated concrete pore solution. Potentiodynamic polarization measurements, chloride ion concentration monitoring tests and XRD crystallography analysis were carried out. The results showed that the powders inhibited corrosion of steel rebar. In all three solid-liquid systems, the chloride ion concentrations decreased with increase of immersion time, and both C3-A1 and C4-A1-F1 powders possessed a strong capability to bind free chloride ions. Friedel＇ s salt （Ca2A1（OH）6Cl·2H2O） was found in the percolation residues of the solutions containing C3-A1 and C4-A1-F1 powders, which was the result of calcium alu- minate （C3A） binding chlorides through ion exchange, while no Friedel＇ s salt was found in the percolation residue of the solution containing C3-S2 powder. This clearly suggests that calcium aluminate, can bind chloride ions strongly through ion exchange, and C-S-H gel can only bind chloride ions weakly through physical adsorption.

关 键 词：混凝土 无机相 钢筋 氯离子 腐蚀 

分 类 号：TG174[金属学及工艺—金属表面处理]