Optimization of tubular trusses using intumescent coating in fire

In steel structures, the cost of fire protection can be significant. They are typically designed to resist loads at room temperature after which the fire protection is considered. This widely used approach may result in expensive and unpractical solutions. On the other hand, automatic design systems utilizing optimization allow taking fire design aspects into account simultaneously. In this research, these two approaches are compared in a tubular roof truss case where intumescent coating is used as fire protection. The results show clearly the benefits of combined structural and fire engineering design. Design with Finnish national and ETA approvals of intumescent coating are compared for 30 and 60 minutes resistance to standard fire. It is shown, that ETA-approved rules indicate increased costs to tubular structures for 60 minutes fire. For 30 minutes the difference between the two approval systems were less significant.