Print Email Facebook Twitter The role of hydrotalcite-like phase and monosulfate in slag cement paste during atmospheric and accelerated carbonation Title The role of hydrotalcite-like phase and monosulfate in slag cement paste during atmospheric and accelerated carbonation Author Zhang, Y. (TU Delft Materials and Environment) Copuroglu, Oguzhan (TU Delft Materials and Environment) Date 2022 Abstract This paper identified carbonation products in the slag-rich cementitious systems upon three different exposure conditions, namely, long term exposure in the field, indoor natural exposure, and accelerated carbonation testing. Overall, mineralogy of the carbonation products was found to be fundamentally similar under different exposure environments. In the fully carbonated areas, no monosulfate and calcium hydroxide was observed, and calcium carbonate, carbonated hydrotalcite-like phase and Ca–Al AFm phases were identified as the main carbonate phases. In the mildly carbonated areas, monosulfate and calcium hydroxide clusters were detected again. With the continuous supply of CO2, monosulfate appeared to be consumed at first. Despite different exposure environments, carbonated Ca–Al AFm phases bound around 5% of CO2 penetrated into the matrix. Hydrotalcite-like phase was able to absorb more than 15% CO2 initially. However, this value decreased to around 10% in the fully carbonated areas. Therefore, more than 20% CO2 entered into hydrotalcite-like phase as well as Ca–Al AFm phases at first, and the involved reactions were harmless without any detrimental effect on cement matrix. Meanwhile, hydrotalcite-like phase was able to keep intact and its Mg/Al atomic ratio did not vary significantly during carbonation. Subject Field slag concreteIndoor natural exposureAccelerated carbonation testingHydrotalcite-like phaseMonosulfateThermodynamic modelling To reference this document use: http://resolver.tudelft.nl/uuid:3ab54ebc-9a7a-4ca3-909d-e133672e1346 DOI https://doi.org/10.1016/j.cemconcomp.2022.104642 ISSN 0958-9465 Source Cement and Concrete Composites, 132 Part of collection Institutional Repository Document type journal article Rights © 2022 Y. Zhang, Oguzhan Copuroglu Files PDF 1_s2.0_S0958946522002359_main.pdf 11.83 MB Close viewer /islandora/object/uuid:3ab54ebc-9a7a-4ca3-909d-e133672e1346/datastream/OBJ/view