Experimental investigation of the fire resistance of ultra-lightweight foam concrete

The general response of the ultra-lightweight foam concrete under fire is investigated in this paper. Different formulae of fillers have been investigated to obtain the required lightweight concrete densities and mechanical properties, using diverse components, such as a plasticizer, lightweight aggregates, foaming agents, and mineral admixtures. It was shown that the behavior of ultra-lightweight concrete in fire depends on its mix proportions and constituents. Based on the results, the fire resistance and thermal conductivity increase as the density of the concrete increases. The fire resistance of ultra-lightweight concrete with the density of 400 kg/m3 was more than three times higher than the samples with the density of 150 kg/m3. The thermal conductivity increases approximately 2.6 times by increasing the density from 150 kg/m3 to 500 kg/m3. It is recommended that ultra-lightweight concretes should be designed with a density greater than 250 kg/m3, to have sufficient fire resistance.