Kinetics of oxygen diffusion in hardened cement pastes
Kinetics of oxygen diffusion in hardened cement pastes
复制标题
硬化水泥浆体中氧扩散动力学
DOI：
10.1007/bf01103534
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发表时间：
1987
影响因子：
4.5
通讯作者：
Paul Lambert
中科院分区：
文献类型：
--
作者：
C. Page;Paul Lambert
设计了一种用于测量氧在饱和水的水泥浆体中的有效扩散系数的电化学池。应用该技术研究了矿物组成恒定、水灰比不同的硅酸盐水泥浆体在15~35℃温度范围内的氧扩散动力学。得到的有效扩散系数和活化能的值与以前发表的离子在类似材料中扩散的动力学数据进行了比较。还研究了嵌入水饱和水泥基质中的钢的电化学行为，特别是关于氧供应的极限条件的预测，该极限条件控制着从以稳定的Fe_2O_3膜为特征的钝化状态向与稳定的碱溶物种Fe(OH)_3−相关的一般溶解状态的转变。
An electrochemical cell has been devised for measurement of the effective diffusivity of oxygen in water-saturated hardened cement pastes. The technique has been applied to investigate oxygen diffusion kinetics over the temperature range 15 to 35° C for Portland cement pastes of constant mineralogy but variable water-cement ratio. The values obtained for effective diffusivity and activation energy have been compared with previously published kinetic data for ionic diffusion in similar materials. Implications regarding the electrochemical behaviour of steel embedded in water-saturated cement matrices have also been examined with particular reference to prediction of limiting conditions of oxygen supply governing the transition from a state of passivity, characterized by a stable film of Fe2O3, to one of general dissolution, associated with a stable alkali-soluble species, Fe(OH)3−.