The solution presented is an extension of an analytical form proposed by [1]. It uses the affinity hydration model that provides a framework for accommodating all stages of the cement hydration. The rate of hydration is expressed by the temperature-independent normalized chemical affinity model.

The affinity model incorporates four material coefficients, which have physical meaning and they can be calibrated experimentally. Alternatively, the hydration material parameters are computed using an analytical micro-scale model that accounts for the majority of underlying chemical reactions as well as the topology of the cement grains. The solution stems from [2] and it employs the discrete hydration model CEMHYD3D [3] enabling the particle size distribution of the cement, the chemical composition of the cement, the temperature and the moisture history in the concrete, etc. to be accounted for.

Concrete heat, moisture capacity and conductivity-diffusivity are predicted from the intrinsic properties of the components during hydration by several homogenization methods. Both concrete properties also depend on the degree of hydration and are updated as the solution proceeds.

The multi-scale model is validated on a series of examples. One of them deals with heat and moisture transport on a cross-section of a newly erected arch bridge in northern Bohemia. Its analysis takes into account material properties, such as the chemical composition of the cement, its fineness, or the amount in the concrete. Environmental conditions, such as the heat exchange to environment and the cooling regime complement the analysis.

The presented heat and moisture transport material model is implemented in ATENA finite element system [4]. This software, being known for advanced nonlinear analyses of RC structures, is now extended with the multiscale hydration model. Future coupling of transport problems with mechanical part is scheduled for a near future.

1

M. Cervera, J. Oliver, T. Prato, "Thermo-chemo-mechanical Model for Concrete. I: Hydration and Aging", Jour. Eng. Mech. ASCE, 125(9), 1018-1027, 1999. doi:10.1061/(ASCE)0733-9399(1999)125:9(1018)

2

V. Šmilauer, Z. Bittnar, "Microstructure-based Micromechanical Prediction of Elastic Properties in Hydrating Cement Paste", Cement and Concrete Research, 36, 1708-1718.

3

D.P. Bentz, "A 3D Cement Hydration and Microstructure Development Modelling Package", Gaithrsburg, MD, NIST Building and Fire Research Laboratory, 2005.

4

V. Cervenka, J. Cervenka, "Atena Program Documentation, Part 1 Theory", Prague, Cervenka Consl., 2000-2007.

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