In this study, a method was developed to estimate accurately the chloride threshold value for corrosion initiation in reinforced concrete. In this method, chlorides are supplied through a part of the specimen surface, and half-cell potential between the rebar and reference electrode embedded in a concrete specimen was measured in every ten minutes. A sudden drop of half-cell potential was observed as the continuation of the measurement. At that time, the specimen was broken and corrosion of rebar on its narrow surface was confirmed. The chloride threshold value can be estimated by determining the chloride concentration at the time of the potential drop. The estimated chloride threshold values for normal Portland cement concrete with cement content between 254 and 446 kg/m³ are in the range of 1.6 to 3.6 kg/m³. This paper is an English translation from the authors’ previous work [Horiguchi, K., Yamaguchi, T., Maruya, T. and Takewaka, K., (2015). “A study on the method of measuring the chloride threshold value of corrosion and on the estimation of the values.” Journal of JSCE, Ser. E2, 71(2), 107-123. (in Japanese)].

在这项研究中，开发了一种方法来准确估算钢筋混凝土中腐蚀引发的氯化物阈值。在这种方法中，氯化物通过试样表面的一部分提供，并且每十分钟测量一次钢筋和嵌入混凝土试样中的参比电极之间的半电池电位。随着测量的继续，观察到半电池电位的突然下降。那时，试样断裂，并确认了钢筋在其狭窄表面上的腐蚀。氯化物阈值可以通过确定电位下降时的氯化物浓度来估计。水泥含量在254至446 kg / m ³之间的普通波特兰水泥混凝土的估计氯离子阈值在1.6至3.6 kg / m的范围内³。本文是作者先前工作的英文翻译[Horiguchi，K.，Yamaguchi，T.，Maruya，T. and Takewaka，K.，（2015）。“关于测量腐蚀的氯化物阈值的方法和估计值的研究。” JSCE，Ser。E2，71（2），107-123。（日语）]。