Monitoramento da temperatura e de deformações relativas induzidas por corrosão em uma viga de concreto armado

Abstract

The pathological manifestations in reinforced concrete structures represent the vulnerability that a given work has, either due to external and unforeseen factors in the project or because it has reached the end of its useful life. Among the agents that deteriorate reinforced concrete, one can emphatically mention corrosion, responsible for reinforcement wear and other damage to the structure. In face of this problem, methods to verify structural integrity and damage diagnosis have become relevant in the understanding and adoption of corrective measures, as is the case of Structural Health Monitoring (SHM) methods. This work aims to develop the prototype of a low-cost monitoring system capable of measuring the corrosion of the reinforcement of a reinforced concrete beam. The system was composed of temperature sensors, strain sensors and microcontrollers, and was applied to a beam built in the laboratory, subjected to wetting and drying cycles with a 10% NaCl solution in order to cause reinforcement corrosion. Through the temperature data and relative deformations, collected by the sensors, the prototype's operation was verified and a diagnosis of the beam's condition was elaborated. Through the diagnosis it was possible to quantitatively identify the reinforcement expansion caused by corrosion, however, it was not possible to eliminate the temperature effect from the strain data, even though it was possible to verify the system's operation. Furthermore, the visual analysis contributed to identify the presence of corrosion in the reinforcement.