Development of an IoT-Enabled Autonomous Crack Detection and Self-Sealing System for Concrete Structures

Abstract

Traditional concrete inspection methods are labour-intensive, time-consuming, and incapable of continuously monitoring hidden subsurface cracks. This study addresses the lack of an integrated, real-time autonomous repair system by developing an automated crack-detection and self-sealing prototype. The system integrates an HC-SR04 ultrasonic sensor for surface crack detection, an AMG8833 thermal sensor for internal defect identification, two Arduino Uno microcontrollers, an ESP32 module, a linear actuator, and a cement-spraying mechanism, managed remotely via the Blynk Internet of Things platform. Experimental testing of the laboratory prototype demonstrated that the ultrasonic sensor, positioned at a fixed distance of 3 cm, successfully detected surface cracks with measured peak depths of 1.8 cm and 1.2 cm, yielding an average depth of 1.5 cm. Under sunlight, the thermal sensor identified internal defects by recording temperature differences, with the crack area averaging 34.5°C compared to 30.3°C in the surrounding regions. The ESP32 module successfully transmitted real-time alerts to the Blynk application when temperature readings exceeded 28°C, and the linear actuator and spraying mechanism automatically sealed the detected cracks with cement. This work demonstrates the viability of combining intelligent sensing and automation to improve the maintenance efficiency of concrete infrastructure.