Concrete Crack Detection and Monitoring Using a Capacitive Dense Sensor Array

Abstract

Cracks in concrete structures can be indicators of important damage and may significantly affect durability. Their timely identification can be used to ensure structural safety and guide on-time maintenance operations. Structural health monitoring solutions, such as strain gauges and fiber optics systems, have been proposed for the automatic monitoring of such cracks. However, these solutions become economically difficult to deploy when the surface under investigation is very large. This paper proposes to leverage a novel sensing skin for monitoring cracks in concrete structures. This sensing skin is constituted of a flexible electronic termed soft elastomeric capacitor, which detects a change in strain through changes in measured capacitance. The SEC is a low-cost, durable, and robust sensing technology that has previously been studied for the monitoring of fatigue cracks in steel components. In this study, the sensing skin is introduced and preliminary validation results on a small-scale reinforced concrete beam are presented. The technology is verified on a full-scale post-tensioned concrete beam. Results show that the sensing skin is capable of detecting, localizing, and quantifying cracks that formed in both the reinforced and post-tensioned concrete specimens.

Large-Area Resistive Strain Sensing Sheet for Structural Health Monitoring

“…Numerical simulations and laboratory experiments have validated the use of such sensors for wind turbine blade monitoring [21]. (3) A robust and durable sensing skin based on large-area capacitor-called a soft elastomeric capacitor (SEC)-that can measure additive strain on the structure and have been characterized for static as well as dynamic sensing capabilities through laboratory experiments [22][23][24][25][26][27]. Through further numerical and laboratory experiments, the SEC-sensing skin have been demonstrated to perform damage detection and localization on a wind turbine blade.…”

Numerical Investigation of Auxetic Textured Soft Strain Gauge for Monitoring Animal Skin

“…Advantages of the capacitive-based method include (1) low energy required for interrogation, (2) high scalability and large-area monitoring, (3) high mechanical and environmental robustness, (4) high mechanical compliance enabling deployment on irregular surfaces, and (5) customization of shapes and sizes [ 14 , 15 , 16 ]. The sensor technology has been demonstrated for structural health monitoring applications, notably for the detection and quantification of cracks in concrete structures [ 17 ] and fatigue cracks on steel girders [ 18 ], in both cases on full-scale components using arrays of sensors.…”

Concentric Array of Printed Strain Sensors for Structural Health Monitoring

“…The sensing sheet was analyzed during a several-hours-long field test on a concrete bridge to measure static strains [17]. Other very promising studies on the development large-area sensing systems includes capacitive sensors [18,19], and sensor arrays incorporating Lead Zirconate Titanate (PZT) piezoelectric sensors [20,21]. Printed electronics are revealed to be a suitable technique for the manufacturing of such strain sensors arrays.…”