Fiberglass pultrusion profile

The behaviour of fiberglass pultrusion profile exposed to fire

The behaviour of fiberglass pultrusion profile exposed to fire:

Fibre reinforced polymer (FRP) materials are being increasingly used in civil engineering applications due to their several advantages when compared to traditional materials, namely, the lightness, strength, good insulation properties, low maintenance and durability.

At the same time, new design issues and challenges are inevitably encountered, among which are the legitimate concerns regarding their performance when exposed to fire, especially in building applications.

Construction materials used in buildings are required to have adequate fire reaction behaviour, avoiding fire ignition, flame spreading and excessive smoke production and spreading. Additionally, structural elements are also expected to present sufficient fire resistance, in order to prevent structural collapse under fire.

frp grating

However, when FRP materials are exposed to high temperatures (300–500 C), the organic matrix decomposes, releasing heat, smoke, soot and toxic volatiles. Also when heated to moderate temperatures (100–200 C), FRP materials often, creep and distort, and such degradation of the mechanical properties often leads to buckling failure mechanisms of load-bearing composite structures .

In spite of such unfavourable properties, FRP materials present other attributes that are advantageous in a fire situation. In contrast with other traditional materials, such as steel, composites are very good heat insulators, and this feature is important for slowing the spread of fire from room to room. Also when compared to steel, composites present better burn-through resistance,providing an effective barrier against flame, heat, smoke and toxic fumes.

Furthermore, several measures can be applied to improve the fire performance of FRP materials.In contrast to the fire reaction behaviour e.g., and the post-fire behaviour, for which numerous investigations have been carried out and a good level of understanding was already achieved, few studies were conducted on the fire resistance properties of FRP materials, especially regarding the structural behaviour of moderately-sized elements under load.

On the compressive strength of FRP pultruded profiles channel elements at elevated temperatures showed noticeable strength reductions already at 60 C and 90 C, with compressive strengths at those temperatures being 63% and 31%, respectively, of the ambient temperature strength.