Monitoring of Reinforced Concrete for Decision Support in Maintenance Management Systems
Abstract
The goal of this study is to collect and validate relevant information on the degradation of reinforced concrete exposed to aggressive environments, such as chlorides or sulfates, for later incorporation in maintenance management systems compatible with the BIM methodology (Building Information Modeling). To achieve this, two simultaneous monitoring systems were used, one that allows measuring the ionic resistivity of the concrete and another that measures the corrosion potential and polarization resistance of the reinforcement. With the first monitoring system, it is intended to monitor the changes occurring in the concrete at the level of its ionic conductivity during the contamination process. The second system allows, at a later stage of the concrete degradation process, to detect signs of corrosion of the reinforcement inserted therein. Both systems provide readings at 10mm and 30 mm depth measured from the face exposed to the action of the degradation agents. The results obtained for chloride contamination show that the ionic resistivity of the concrete tends to decrease with the progression of the chlorides in depth, leading at a later stage to the corrosion of the reinforcement, which can be detected by the reduction of corrosion potential. Also, the polarization resistance of the reinforcement has been reduced when corrosion phenomena begin to develop in the reinforcement. The results related to the sulfate attack suggest a mechanism that leads to the formation of a barrier that prevents the progression of the attack in depth. The consequence of this phenomenon is a reduction of the ionic mobility of the concrete, leading to the increase of resistivity. This mechanism associated with the absence of mechanical actions that force the progression of sulfates in depth inhibits the development of corrosion processes of the reinforcement.
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