Development and application of a novel low-cost capacitive sensor for accurate rebar position detection

Influence of different design parameters on a coplanar capacitive sensor performance

“…Furthermore, the coplanar sensor requires single-sided access to the material and this is one of the most important advantages of this method, especially when accessing both sides of the specimen is restricted [6]. This method has the potential to detect corrosion under insulation (CUI) [14][15][16], rebar in concrete [10,17], water intrusion into composite structures [8,18], cracks, and delamination of the material [10], impact damage [10,19], surface defects in conductive materials [5,20] and carbon fibre composites [10]. In addition, capacitive sensor manu-facturing is relatively straightforward and there is no need to use expensive equipment or complex operating procedures to achieve sought inspection results [7].…”

Experimental Study and FEM Simulations for Detection of Rebars in Concrete Slabs by Coplanar Capacitive Sensing Technique

“…Ultrasonic techniques have been employed as an NDT method to evaluate concrete structures [ 5 ] and for inspecting the rebars through the use of a variety of transducer technologies and frequencies [ 6 ]. However, ultrasonic techniques often encounter the problem of scattering, in which, the ultrasonic wave may bypass the rebar, causing uncertainty about the measurement data [ 7 ]. Radiography is another NDT method to inspect RC structures to acquire information on the quality of concrete and its defects.…”

“…Recently, the coplanar capacitive sensing technique has been employed as an NDT method to inspect and identify rebars in concrete structures [ 12 ]. This technique is also used for the inspection of composites [ 13 ] and ceramic tiles [ 14 ] due to its low cost [ 15 ], non-contact detection, no radiation and high-efficiency level (fast and accurate response) [ 7 ]. In addition, there is no need to prepare the surface of the specimen with water or gel as a couplant to perform the inspection [ 16 ].…”

Damage Propagation Analysis in the Single Lap Shear and Single Lap Shear-Riveted CFRP Joints by Acoustic Emission and Pattern Recognition Approach

“…Several sensor types have been employed for the NDE evaluation of reinforced materials. The details about the capacitive and resistive sensors used for this purpose and their applications can be found in literatures [11,12]. The Acoustic Emission (AE) technique is rather efficient in identifying these damages, which can be attributed to its efficacy in sensing transient elastic waves [13].…”