摘要
本文提出了一种快速、无损、准确检测钢筋/混凝土(砂浆)体系中钢筋腐蚀速率的TR法。该法用本文设计的计算机数据采集系统,采集钢筋对阶跃电位的暂态响应,根据高斯——牛顿法编制的计算机拟合程序,拟合钢筋对阶跃电位△E=10mV的暂态响应,求得极化电阻R_p;拟合弱极化数据,求得塔费尔常数B。在加速腐蚀实验条件下,测定体系中钢筋的腐蚀量。结果表明,用TR法测得的腐蚀失重量与实际失重量较为一致。在此基础上,提出了符合体系中钢筋腐蚀的等效电路模型。通过测定砂浆中钢筋处于不同腐蚀状态时的B值发现,在整个腐蚀进程中,B值逐渐变小,并趋于一定值。
A rapid, nondestructive, and accurate monitoring method(TR method) is developed for measuring corrosion rate of steel bar in mortar or concrete in this paper. In this method, the transient response of steel bar to a step potential is acquired using the computer data acquisition system designed in this paper. The polarization resistance and Tafle constant B are then obtained using curve fitting. A good agreement is found between the calculated weight loss of steel bar from the TR method and that Obtained gravimetrically. Based on this, an equivalent circuit model of the behaviour of the steel bar/concrete(motar) system is prop0sed. The values of B under different corrosion conditions are measured, and the results show that the values of B reduce gradually and approach to a stable value.
