Thermodynamic modeling of cement hydration is a well-known tool capable of predicting the mineralogical and chemical composition of cementitious systems as a function of time and varying cement mixes. At present, however, composition and mineralogy cannot be adequately modeled at the interface between corroding iron and cement paste in anoxic conditions due to the lack of thermodynamic data for the Fe(0) corrosion species (Fe(II,III)) interacting with cement phases.
The anoxic corrosion of iron is an important process in ground granulated blast furnace slag cement (GGBFS). Fe released by corrosion of iron particles could be either taken up by cement phases in a manner similar to Fe(III), i.e. Fe(III) substitutes for Al(III) in cement phases, replace as Fe(II) a part of the calcium present in cement hydrates, precipitate as specific Fe(II)-bearing phase, e.g. Fe(II)-hydroxide or Fe(II)-sulfides, or adsorb onto the surface of cement phases.

Kinetic and isotherm sorption experiment with Fe(II) and Fe(III) were carried out on the most important cement phases using 55Fe as a radiotracer. The Fe(II) sorption studies were conducted in reducing conditions in the glove box ensured by the use of electrochemical cells.

EXAFS spectroscopy measurements were performed on Fe-doped cement phases in order to determine the oxidation state and coordination environment of iron in cement phases. Micro XRD, redox mapping, and XANES spectroscopy were employed to study the interaction between iron particles and cement paste in GGBFS cements having different ages and exposed to different conditions.