Sensitivity of solidification hydration model in estimating carbonation of fly ash cement system

Abstract

Abstract The system containing ordinary Portland cement and fly ash (FA) tends to be vulnerable against carbonation, where hydration estimation is crucial for assessing the carbonation resistance of the system. To date, few available models targeting FA-cement hydration are free from empirical or epistemic parameters, leading to unresolved issues of model sensitivity in estimating carbonation. In this study, a well-acclaimed hydration model is coupled with chemophysical modelling to numerically interpret the time-dependent mechanisms of system decay under carbonation. Furthermore, leveraging the power of extended support vector regression method, a robust and efficient framework is proposed for the investigation of hydration model sensitivity in carbonation assessment. The developed method is extensively validated against experimental studies and a carefully crafted benchmark test. Through sensitivity analyses, key findings on the propagation of hydration model sensitivity as well as the detailed levels of impact from respective model parameters are unravelled.