This PhD subject is focused on evaluating novel cement and mortar formulations comprising repurposed industrial slags, ashes, and lightly-processed raw minerals as more sustainable alternatives to Ordinary Portland Cement (OPC). These formulations will be optimized to facilitate the setting and strengthening of concrete via carbonation rather than hydration, which has the potential to reduce even further the emissions of concrete towards net carbon capture and storage (CCS). The carbonation mechanisms of the different formulations under different environmental conditions (temperature, relative humidity, %CO2) will be elucidated in situ using a variety of techniques including micro X-ray diffraction (XRD) and X-ray micro computed tomography (µ-CT). We will also further develop recently-introduced methods in digital pH imaging to understand the evolving chemical environment in and around the cement as it matures. Cement and mortar formulations will be characterized across a number of length and time scales utilizing microfluidic devices up to full-scale carbonation cabinets and utilizing laboratory X-ray sources up to synchrotron radiation facilities.