ABSTRACT
In this study, combined experimental and modeling works have been carried out to investigate the chemical degradation of cementitious materials in various sulfate environments. Three types of cement paste specimens were immersed in deionized water and sodium and magnesium sulfate solutions with 100 https://www.w3.org/1998/Math/MathML"> m m o l / l https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429227196/8b5c0a5d-ddea-4c88-8eea-7152f7afb008/content/eq11286.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> of https://www.w3.org/1998/Math/MathML"> S O 4 2 - https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429227196/8b5c0a5d-ddea-4c88-8eea-7152f7afb008/content/eq11287.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> concentration for 9 months. Visual observation of the exposed surface and spatial changes of solid phases, which were quantified by XRD/Rietveld analysis, were recorded at the end of exposure period, and the results are presented and discussed in here. The influence of the composition of cement paste on the resistance to calcium leaching in deionized water and external sulfate attack is discussed. A coupled physicochemical and geochemical model was used to predict experimentally determined phases changes in ordinary Portland cement paste exposed to deionized water and sodium and magnesium sulfate solutions. The mineralogical distributions observed experimentally were compared with those from the model.
