Enhancing self-healing properties of engineered cementitious composites through the application of super-sulfated cement

Abstract

To date, no prior research has addressed the self-healing performance of engineered cementitious composites (ECC) prepared with super-sulfated cement (SSC), despite its potential to reduce carbon emissions compared to Portland cement (OPC). This paper addresses this significant research gap in the literature by exploring the influence of SSC on the recovery ability of pre-cracked ECC samples. In addition to the mechanical characterization at the sound state, an exhaustive investigation was undertaken to comprehensively assess the self-healing ability of flexural strengths, deflections, ultrasonic pulse velocity (UPV), and rapid chloride permeability (RCPT) of preloaded SSC-based ECCs. Furthermore, scanning electron microscopy (SEM), coupled with energy-dispersive X-ray (EDX) was employed to evaluate the microstructural changes and development of self-healing products within the microcracks of SSC mixtures prepared with various amounts of FA. The findings indicated that SSC-based ECC, while maintaining comparable mechanical and ductility properties, exhibited significant improvements in the recovery rates of ECC, reaching more than 27%, 7%, and 76% for flexural strength, UPV, and RCPT, respectively, compared to the OPC-based control ECC. The microstructural SEM-EDS results confirmed the enhanced precipitation of ettringite as a new self-healing product related to the inclusion of SSC in ECCs, along with the conventional C-S-H/C-A-S-H gels.