Self-Healing Characterization of Engineered Cementitious Composite Materials

Abstract

This research investigates the self-healing behavior of engineered cementitious composite (ECC) materials. Crack characteristics, resonant frequency (RF) recovery, and the effect of wet-dry conditioning cycles were studied. Characterization of the self-healing products in ECC materials was carried out with an environmental scanning electron microscope-energy dispersive spectroscopy system (ESEM-EDS), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). According to the experimental results, wet-dry conditioning cycles aid self-healing, most of which occurs before four to five cycles. The products of self-healing were identified as mainly C-S-H and calcite. These products almost completely bridge cracks less than 50µm wide. Overall, the self-controlled tight crack width (CW) of ECC materials tailored for high-tensile ductility encourages robust self-healing behavior in both young and mature (3- and 90-day-old) ECC specimens, respectively.