Cement; thermodynamic; C-S-H; supplementary cementitious materials; solubility; thermodynamic modelling
Lothenbach Barbara, Nonat André (2015), Calcium silicate hydrates: Solid and liquid phase composition, in Cement and Concrete Research
, 78, 57-70.
Rossen J. E., Lothenbach B., Scrivener K. L. (2015), Composition of C-S-H in pastes with increasing levels of silica fume addition, in CEMENT AND CONCRETE RESEARCH
, 75, 14-22.
Myers Rupert J., Myers Rupert J., L'Hôpital Emilie, Provis John L., Lothenbach Barbara (2015), Composition-solubility-structure relationships in calcium (alkali) aluminosilicate hydrate (C-(N,K-)A-S-H), in Dalton Transactions
, 44(30), 13530-13544.
Myers Rupert J., L'Hopital Emilie, Provis John L., Lothenbach Barbara (2015), Effect of temperature and aluminium on calcium (alumino)silicate hydrate chemistry under equilibrium conditions, in Cement and Concrete Research
, 68, 83-93.
Haas Jeremy, Nonat André (2015), From C–S–H to C–A–S–H: Experimental study and thermodynamic modelling, in Cement and Concrete Research
, 68, 124-138.
L'Hôpital E., Lothenbach B., Le Saout G., Kulik D., Scrivener K. (2015), Incorporation of aluminium in calcium-silicate-hydrates, in Cement and Concrete Research
, 75, 91-103.
Lothenbach B., Nied D., L'Hôpital E., Achiedo G., Dauzères A. (2015), Magnesium and calcium silicate hydrates, in Cement and Concrete Research
, 77, 60-68.
Myers Rupert J., Lothenbach Barbara, Bernal Susan A., Provis John L. (2015), Thermodynamic modelling of alkali-activated slag cements, in Applied Geochemistry
, 61, 233-247.
Churakov Sergey V., Labbez Christophe, Pegado Luis, Sulpizi Marialore (2014), Intrinsic Acidity of Surface Sites in Calcium Silicate Hydrates and Its Implication to Their Electrokinetic Properties, in JOURNAL OF PHYSICAL CHEMISTRY C
, 118(22), 11752-11762.
Pegado Luis, Labbez Christophe, Churakov Sergey V. (2014), Mechanism of aluminium incorporation into C-S-H from ab initio calculations, in JOURNAL OF MATERIALS CHEMISTRY A
, 2(10), 3477-3483.
Pegado Luis, Marsalek Ondrej, Jungwirth Pavel, Wernersson Erik (2012), Solvation and ion-pairing properties of the aqueous sulfate anion: explicit versus effective electronic polarization, in Phys. Chem. Chem. Phys.
, 14, 10248-10257.
The production of cement is responsible for 5-8% of global man-made CO2. The replacement of Portland cement by supplementary cementitious materials (SCM) offers the highest potential to reduce these CO2 emissions. The industrial application of SCMs based materials is hindered by the fact that novel, low-CO2 cementitious materials have different chemical composition and will form other hydrates than Portland cements. In the presence of silica rich SCMs, such as blast furnace slag or fly ash, calcium silicate hydrate (C-S-H) with a low Ca/Si ratio is the most important hydrate that forms. However, reliable thermodynamic models and experimental data for C-S-H with low Ca/Si ratio are not available.This project aims to investigate the solubility, structure, and composition of C(-A)-S-H gel as a function of different parameters such as Ca/Si ratio, pH, aluminum, alkali and anion content. We will develop a thermodynamic model for C(-A)-S-H, N/K-A-S-H gel in cementitious systems based on 1.the structural information and surface properties of C-(A)-S-H from atomistic simulations; 2.experimental data on solubility of C(-A)-S-H in the presence of alkali 3.experimental data on solubility of C(-A)-S-H in the presence of anionic species such as sulfate, carbonate and chlorides4.detailed spectroscopic characterization and investigation of the homogeneity of the solid phasesNewly developed modeling tools provide a solid scientific background for predictions and testing of novel environmentally friendly and cost efficient cementitious materials. These modeling tools will enable us in the future to predict the kind, amount and volume of hydration products also in silica-rich cementitious systems. The ability to calculate the porosity of a specific system is a starting-point to assess the potential of this system. In addition, the coupling of thermodynamic modeling with microstructural modeling will allow to predict mechanical and transport properties of cementitious system. The cutting edge modeling expertise and experimental knowledge required for the project success are not available within a single research group or university. Therefore we embark on interdisciplinary collaboration between world recognized experimental and modeling research groups working in the field of cement chemistry. Molecular modeling groups in PSI and ICB will closely collaborate with experimentalist in EMPA, EPFL and ICB. Atomistic scale system understanding and experimental data will back up the geochemical modeling expertise at EMPA and PSI.