Document Type

Conference Paper

Rights

This item is available under a Creative Commons License for non-commercial use only

Disciplines

Computer Sciences, Organic Chemistry, Civil engineering

Abstract

Hydration models are useful to predict, understand and describe the behaviour of different cementitious-based systems. They are indispensable for undertaking long-term performance and service life predictions for existing and new products for generating quantitative data in the move towards more sustainable cements while optimising natural resources. One such application is the development of cement-based thermoelectric applications.

HYDCEM is a new model to predict the phase assemblage, degree of hydration, heat release and changes in pore solution chemistry over time for cements undergoing hydration for any w/c ratio and curing temperatures up to 450C. HYDCEM, written in MATLAB, is aimed at complementing more sophisticated thermodynamic models to predict these properties over time using user-customisable inputs. A number of functions based on up to date cement hydration behaviour from the literature are hard-wired into the code along with user-changeable inputs such as the cement chemical (oxide) composition, cement phase densities, element molar mass, phase and product densities and heat of hydration enthalpies. HYDCEM uses this input to predict the cement phase and gypsum proportions, volume stoichiometries and dissolution and growth of hydration products from the silicates, aluminates and ferrites, including C-S-H, calcium hydroxide, hydrogarnet (if applicable) ettringite and monosulphate. A number of comparisons are made with published experimental and thermodynamic model results and HYDCEM predictions to assess its accuracy and usefulness.

The results show that HYDCEM can reasonably accurately predict phase assemblages in terms of volume change and behaviour for a range of cements and curing temperatures. It is proposed that HYCEM can complement more sophisticated thermodynamic models to give users a reasonable prediction of cement behaviour over time.

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