1. Reference problem#

1.1. Geometry#

_images/Object_1.svg

1.2. Material properties#

The material has the following thermal characteristics:

Thermal conductivity: \({k}_{s}=6\mathrm{kJ}/h/m/°K\)

enthalpy volume change: \(\Delta H=2.4105\mathrm{kJ}/{m}^{3}\),

and the following characteristics relating to moisturizing behavior:

Heat by hydration level: \({Q}_{0}=1.4904105\mathrm{kJ}/{m}^{3}\)

Arrhenius constant: \(\mathrm{Ar}=4000/°K\).

Note:

The Arrhenius constant is always expressed in degrees Kelvin. Temperatures are expressed in \(°C\).

Affinity as a function of hydration:

Degree of hydration \(h\)

Affinity \(A(h)(1/h)\)

0

6510

0.008

6360

0.016

2485

0.019

2460

0.038

9520

0.047

21800

0.08

37600

0.138

51600

0.232

51400

0.351

28200

0.44

16100

0.5

11700

0.63

5570

0.73

4240

0.81

1780

0.88

302

0.97

50

1.00

0

1.3. Boundary conditions and loads#

A zero heat flux is imposed on all faces of the solid. Charging is only initiated by a heat source dependent on hydration \(\Delta Q={Q}_{0}\Delta h\).

1.4. Initial conditions#

The initial temperature is \(20.9°C\)

1.5. Discretization in time#

The explicit integration of hydration requires fine temporal discretization until the end of the hydration phenomenon:

From \(t=0\) to \(t=\mathrm{20h}\), \(\Delta t=\mathrm{7,5}\mathrm{min}\) is 160 steps.

From \(t=\mathrm{20h}\) to \(t=\mathrm{60h}\), \(\Delta t=1h\) is 40 steps.