# Temperature in the concrete

Last modified by Fredrik Lagerström on 2020/05/27 14:27

According to DS-EN 1992-1-2 (Danish annex to EN1992-1-2), Annex B2.

Modeling fire exposure for a cross-section entails treating the cross-section as being reduced, meaning the original concrete cross-section is reduced by a damaged zone at the exposed sides. The temperature in a reduced rectangular cross-section θM depends on the fire exposed sides as shown in the table below.

 δT+δB δL+δR θM δT+δB+δL+δR 1 1 0 θ2,2h(0,t) 0 1 θ2,2b(0,t) 2 2 0 θ2,h(0,t) 0 2 θ2,b(0,t) 1 1 θ2,2z(0,t) 3 2 1 θ2,z(0,t) 1 2 θ2,z(0,t) 4 2 2 θ2,z(0,t)

For a cross-section with flanges, we determine temperature θM for both the body and the flanges. The cross-section is divided during the calculation according to Section properties, into a body of width b (body width) and height h (original cross-section height) and a flange with width bf and height hf.

For cross-section with variable width or height of flange, we use the value in the middle of the cross-section. For a circular cross-section, the temperature in the reduced cross-section is