EC21.2 and EC41.2 provide the following models
incorporating temperature effects for the thermal properties
of normalweight concrete.
The thermal strain (expansion) of concrete ε_{c
, θ} can be determined by:
For siliceous aggregates:

(1) 
For calcareous aggregates:

(2) 
where θ_{c} is the
concrete temperature (°C).
The variation of the thermal elongation, with temperature, is shown in Figure
1.
The specific heat of dry concrete c_{c
, θ} [in J/kg •K] (i.e. moisture content
by weight u = 0%) can be determined by:
For siliceous and calcareous
aggregates:

(3) 
The variation of the specific heat with temperature
is shown in Figure
2.
Where the moisture content u is not
considered explicitly in analysis, the specific heat of concrete
may be modelled by peak value at 115°C as given below:

(4) 
The value of u = 10.0% may occur for hollow sections
filled with concrete. For other moisture contents, linear interpolation
between
the above given values is acceptable. The peak values of specific
heat are shown in Figure
2.
The variation of density of concrete ρ _{c , θ} with
temperature is influenced by free water loss and is defined as
follows:

(5) 
where ρ_{c , 20} is concrete density
at ambient temperature.
The variation of the ratio of ρ_{c , θ} to ρ_{c
, 20} with respect to temperature is shown in Figure
3.
The thermal conductivity of concrete λ_{c} [in
W/m •K] can be determined between the lower and
upper limit values as follows:

(6) 
The variation of the upper limit and
lower limit of thermal conductivity with temperature is shown
in Figure
4.
