Fire Behaviour of Treated Insulation Fibreboards and Predictions of its Future Development Based on Natural Aging Simulation

Abstract

Wood-based composite materials represent a major fire safety risk. The application of water-based fire retardants (FR) can improve their fire performance. However, it is important to investigate the performance and stability of this protective system over time, as the ageing of materials and their exposure to climatic conditions can change their properties. The aim of this research work was to evaluate the effect of long-term aging on the combustibility of low-density insulation fibreboards (IFs) treated with a water-soluble flame retardant (FR) based on inorganic salts. Both natural and accelerated aging simulations were conducted. The accelerated aging simulation was performed using climate chambers. The FR efficiency was evaluated by the mass loss rate of the tested specimen. As expected, the FR formulation used significantly enhanced the fire properties of the boards, reaching maximum efficiency 6 months after its application onto the fibreboards. Markedly, after 4 years the efficiency of the investigated FR additive was considerably decreased with weight loss values comparable with the values of the untreated samples. Markedly, besides the apparent protection of wood fibers, the retardant did not prevent the gradual increase in mass loss rate of samples, it just slowed down the process. The main result of the study is to determine the effectiveness of the investigated FR on IFs during their natural ageing. The development of accurate datasets on the thermal behaviour of IFs is critical for their proper utilisation in building and construction applications.