Sistema de monitoramento térmico para hidratação de argamassa

Abstract

This work presents the development, implementation, and evaluation of a low-cost thermal monitoring system designed to track the initial hydration stage of mortar. Considering that cement hydration is an exothermic reaction directly influenced by temperature conditions, continuous thermal monitoring becomes an essential resource for the technological control of cementitious materials such as concrete and mortar. For this purpose, a prototype was built consisting of an Arduino Uno microcontroller, a type-K thermocouple inserted into a copper tube to ensure greater thermal conductivity and sensor protection, and a digital reading module responsible for data conversion and transmission. To ensure stable measurement conditions and reduce the influence of the external environment, an insulating capsule made of expanded polystyrene (EPS) was developed, initially modeled in CAD software and later manually manufactured. The internal structure was designed to house two specimens and to allow proper installation of the sensor at the thermal center of the sample, ensuring repeatability and reliability of the tests. During the experiments, fresh mortar specimens were molded and monitored throughout the initial hydration period during the first 24 hours, enabling the recording of the characteristic exothermic peak of the cement reaction, followed by its gradual stabilization. The readings obtained were consistent with the expected theoretical behavior, demonstrating that the system provides satisfactory accuracy, good stability, and performance compatible with experimental and educational applications. It is concluded that the developed prototype constitutes a viable, functional, and economically accessible alternative for studies related to mortar curing, thermal monitoring, and technological control of construction materials during the initial hydration stage, also showing potential for future extensions such as the integration of new sensors and advanced automation.