Thermodynamic modeling of cementitious systems using Gibbs Energy Minimization Software (GEMS) for Geochemical Modeling
Introduction of the GEMS course and cement chemistry. Review of cement production, clinker phases, cement hydration and solution chemistry. Get familiar with the GEMS by creating a new project using the hydration of C3A + CaO + CaSO4 as an example.
Short overview thermodynamic modelling using chemical equilibrium of gypsum as an example. Explanation and installation of GEMS. First tutorial calculations of single systems using hydration of C3A as an example, considering the systems with or without introducing CaO, CaCO3 and CaSO4.
This lecture shows how to model the influence of limestone or fly ash dosage on the phase assemblages of hydrated cement blends using process calculation.
The lecture covers the introduction of thermodynamic database, Cementdata18 for Portland cement and alkali-activated cement systems, and GEMS structure. Exercise on how to calculate the solubility, speciation and saturation indices using GEMS.
Introduction of Parrot and Killoh model to describe the dissolution of cement clinker phases. Use the obtained hydration degree of clinker phases to predict the phase assemblages and pores solution chemistry during cement hydration.
This lecture demonstrates how to use process calculation of GEMS to model the interaction of hydrated cements with the environments, such as when exposing the hydrated cements to sodium chloride solution, sodium sulfate solution or atmospheric condition with a predefined CO2 concentration.