Monitoring method for the chloride ion penetration in mortar by a thin-film sensor reacting to chloride ion

作者：Park Won Jun; Lee Hyun Seok; Joh Sung Hyung; Lee Han Seung

来源：Construction and Building Materials, 2014, 53: 403-410.

DOI：10.1016/j.conbuildmat.2013.11.095

• Monitoring method
• Mortar
• Chloride ion penetration
• Sensor
• Electrical resistance

The depth of chloride ion permeation from a concrete surface can be monitored in reinforced concrete structures. The purpose of this study is to develop and apply a thin-film sensor based on the measurement of changes in electrical resistance of the sensing elements in order to follow the chloride ion penetration in mortar. The proposed thin-film sensors were placed in mortar specimens intrinsically containing chlorides, and mortar specimens impregnated with chloride solutions then subjected to accelerated corrosion in a NaCl solution. For making a film sensor, a screen printer machine was used. Silver (Ag) paste and iron (Fe) powder were coated on the thin-film sensor that reacts to chloride ion in mortar. As a result of experimental testing, the appropriate ratio of Ag to Fe was >1:2. The electrical resistance of the sensors increased with the degree of corrosion behavior of thin-film sensor. The time to the first change in electrical resistance decreased along with the degree of corrosion as the distance from the mortar surface decreased. The proposed thin-film sensors are thus confirmed to be capable of monitoring the depth of chloride permeation in mortar with sufficient accuracy.

• 出版日期2014-2-28