Localization of cracks in cementitious materials under uniaxial tension with electrical resistance tomography

This paper explores the feasibility of using electrical resistance tomography (ERT) for detecting damages or cracks on the engineered cementitious composites (ECC) under monotonic uniaxial tension loading. Two types of electrode arrays, unilateral planar electrodes array (UPEA) and bilateral edge electrodes array (BEEA) were developed and equipped in ERT system for ECC specimens and an electrode switching module (EMS) was designed to enforce the adjacent driver pattern of sixteen electrodes attached to the surface of ECC specimens. A constant and low frequency electric current (1 μa, 1.5 kHz) is applied onto the ECC specimen via some electrode pairs, and AC voltages were measured synchronously using the rest of electrode pairs. All these data were input into the inverse program to analyze and obtain the internal resistance distribution in the studied specimens. The capabilities of difference ERT to locate the cracks in ECC was estimated using (1) finite element models with given single crack and multiple cracks for image reconstruction, and (2) image reconstruction of real cracks in ECC plates under uniaxial tensile loading. The results showed that difference ERT could be used to detect the position and approximate range of the cracks produced in ECC and the performance of BEEA was better than that of UPEA.