Potential differences between passive reinforcement segments in concrete components in dependency of binder type, aeration conditions and quality of the steel/concrete‐interface
Potential differences between passive reinforcement segments in concrete components in dependency of binder type, aeration conditions and quality of the steel/concrete‐interface
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DOI：
10.1002/maco.201608855
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发表时间：
2016-04
期刊：
影响因子：
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通讯作者：
M. Kosalla;M. Raupach
中科院分区：
文献类型：
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作者：
M. Kosalla;M. Raupach
为了探索混凝土中钢筋的氯离子阈值水平，分别在一般情况下，在被动状态下的环境和电化学条件的主动钢筋腐蚀的发病是决定性的。在实践中，对于钢筋混凝土结构，内部极化状态和由此产生的电位差的可能特性，主要是由结构中的水分偏差，是不常见的。本文介绍了四个“真实的”尺寸的板状试件和两个柱脚在氯盐溶液中循环暴露以模拟室外结构典型潮湿条件的探索。使用普通波特兰水泥（OPC，CEM I）和高炉矿渣水泥（BFSC，CEM III）。对于不同的，去耦段的钢筋电位差的确定和去极化测量进行。具有不同粘结剂类型的混凝土组合物显示出相当不同的结果。最大确定的电位差为150 mV的OPC标本和650 mV的BFSC标本。改变曝光条件的即时效果的程度也完全不同。通常，暴露（润湿）会导致电位位移到更负的值。其他影响参数并不导致明确的行为或反应模式。
For exploring the chloride threshold level of steel in concrete, respectively the onset of active reinforcement corrosion in general, the environmental and electrochemical conditions in the passive state are decisive. For reinforced concrete structures in practice, possible characteristics of the inner polarization state and the resulting potential differences, mainly forced by moisture deviations in the structure, are not commonly known. In this paper the exploration of four slab like specimens and two column bases with “real” dimensions, which are cyclically exposed to chloride solution for simulating typical moisture conditions for outdoor structures, is described. Ordinary portland cement (OPC, CEM I) and blast‐furnace slag cement (BFSC, CEM III) are used. For various, decoupled segments of the reinforcing steel potential differences are determined and depolarization measurements are performed. The concrete compositions with different binder types show considerably diverging results. The maximum of the determined potential differences is 150 mV for OPC specimens and 650 mV for BFSC specimens. The extent of instant effects of changing exposure conditions also is completely different. Generally, exposure (wetting) causes a displacement of the potential to more negative values. Other impact parameters do not lead to a clear pattern of behavior or reaction.