Shear

Fire Design

Active

Selects if this cross-section will also be designed against fire.

Cross-section surface

Defines if the cross-section surface is unprotected (exposed to fire on all sides) or is protected (on all sides).

Time of fire exposure t

The time of the exposure of the cross-section to fire, in minutes.

Time t_ch

The time of exposure of a protected cross-section to fire until it starts to char, in minutes.

Time t_f

The time of exposure of a protected cross-section to fire until the protection fails completely, in minutes.

Note that this is can be longer (but not shorter) than t_ch.

Factor k₂

Factor k₂ that defines the charring rate of a protected cross-section between the time it starts to char and the time the protection fails completely.

It is required when t_ch has a different value to t_f.

Theoretical charring rate β_n

The theoretical charring rate of the timber, in mm per minute.

It is required for plywood where the relevant standards do not provide a default value.