【摘要】 采用化学分析方法探索了盐湖环境的Na+,K+,Mg2 +,SO42 - 和Cl- 离子在混凝土和钢筋混凝土结构中的扩散规律 ,并用XRD ,DTA TG和SEM EDAX方法研究了侵蚀性离子与混凝土之间的相互作用机理 .结果表明 ,Mg2 +和SO42 - 离子在混凝土中呈现出不同的分布规律 ,Na+,K+和Cl- 离子的扩散速度大小顺序为 :VCl- >VNa+ ≈VK+ .盐湖侵蚀性离子渗入混凝土后 ,一部分吸附于孔隙内表面 ,结晶成食盐NaCl和光卤石KCl·MgCl2 ·6H2 O ;另一部分与水化产物发生化学腐蚀 ,形成石膏CaSO4·2H2 O ,南极石CaCl2 ·6H2 O和氢氧化镁Mg(OH) 2 ;还有一部分与CSH凝胶发生 3种相互作用 :吸附于凝胶粒子表面 ,进入凝胶结构形成含水硅酸钙镁 (C1 -xMx) 1 .1 5- 1 .70 SH(x =0 .2 2～ 0 .39)和碱硅凝胶 (C1 -xNx) 1 .85- 1 .60SH(x=0 .39～ 0 .63) .更多还原

【Abstract】 Diffusion of Na +, K +, Mg 2+ , SO 4 2- and Cl -ions into concrete and reinforced concrete structures exposed to salt lake was investigated by chemical analyzing. Interaction between corrosive ions and concrete was studied by means of XRD, DTA TG and SEM EDAX method. Results show that Mg 2+ and SO 4 2- ions present different distributions in concrete, and the rate of diffusivities are in the order of V Cl - > V Na + ≈ V K + . Some of the penetrated corrosive ions are adsorbed to the inner surfaces of concrete holes, forming NaCl and KCl·MgCl 2·6H 2O; another part of the ions chemically react with cement hydration products, forming CaSO 4·2H 2O, CaCl 2·6H 2O and Mg(OH) 2. And three kinds of interactions occur between the residual penetrated corrosive ions and CSH gel, namely adsorption to surfaces of CSH gel grains, ingress into the gel forming calcium magnesium silicate hydrate (C 1- x M x ) 1.15-1.70 SH( x =0.22-0.39) or alkali silicon gel (C 1- x N x ) 1.85-1.60 SH( x =0.39-0.63).更多还原