Effect of bulk density on flame resistance of rockwool in combined fire-resistant facings

Fire protection of steel structures is playing an increasingly important role nowadays. The fire protection of steel structures can be solved with intumescent paint, mortar, fire protection coating and concrete coating. Several fire tests have been performed to check these solutions. Combined structures, which consist of insulation material and fire protection panels, can be used to increase the fire resistance of steel structures. In this article, the application of combined fire protection solutions (combined use of fire protection panels and thermal insulation) was examined. In the experiments, six types of rockwool products with different densities were used as an additional insulation. As a result, the behaviour of combined insulations made with rockwool products of different densities was compared at high temperatures. Based on the laboratory measurements, a finite-element model was also created.