What happens to steel structural members when heated?

When steel structural members are heated, they undergo thermal expansion, which causes them to elongate. This elongation can create internal pressures, especially in frameworks where members are connected to walls or other structural components. As the steel expands, it may push against adjacent walls, leading to potential structural instability or failure if the connections are unable to accommodate this movement.

The phenomenon is important in fire scenarios, where the heat can not only cause elongation but also significant loss of strength. While it is factually accurate that steel retains its non-combustibility even when heated, this does not directly relate to the implications of structural expansion during heat exposure. Therefore, the choice about steel elongating and pushing walls outward effectively captures one of the critical responses of steel in fire conditions.