Carbonation rate of alkali-activated concretes and high-volume SCM concretes: a literature data analysis by RILEM TC 281-CCC

Abstract The current understanding of the carbonation and prediction rate alkali-activated concretes is complicated inter alia by wide range binder chemistries used testing conditions adopted. To overcome some limitations individual studies to identify general correlations between mix design parameters resistance, RILEM TC 281-CCC ‘Carbonation Concrete with Supplementary Cementitious Materials’ Working Group 6 compiled analysed data for mortars from literature. For comparison purposes, blended Portland cement-based a high percentage SCMs (≥ 66% binder) were also included in database. analysis indicates that water/CaO ratio water/binder exert an influence on resistance concretes; however, these are not good indicators when considered individually. A better indicator under approximating natural appears be their water/(CaO + MgO eq Na 2 O K ) ratio, where subscript ‘eq’ equivalent amount based molar masses. Nevertheless, this can serve as approximate at best, other affect concretes. In addition, database points peculiarities accelerated tests using elevated CO concentrations low-Ca concretes, indicating even relatively modest concentration 1% , may lead inaccurate predictions exposure conditions.