Improving the fire resistance of wooden structures by a combined method

Abstract

The flammability of wood largely limits the use of wooden structures in modern construction. Therefore, there is a need to protect the wooden structures of buildings and structures from fire danger. Ammophos-A, ammonium sulfate, expanded perliteб and epoxy were used to develop the fire-retardant surface coating. The experiments were carried out by changing the amount of one of these components in the composition, leaving the others constant. At the same time, fire hazard indicators were controlled parameters. In this way, the optimal ratios of the components of the flame-retardant composition were established, which were: 15:15:10:50 (wt.%), respectively, ammophos-A, ammonium sulfate, expanded perlite, epoxy resin, further designated flame retardant AS-143. The test parameters of structural samples treated with this flame retardant at a consumption of 400–500 g/m2 were: weight loss 4.0–5.0 %, flame burning time 11–18 s, flameless 19–23 s. The effectiveness of the flame retardant AS-143 was established in comparison with flame retardant No. 13, which, according to the weight loss of the samples, was 43.2 %. The essence of the results is explained by the correct selection of chemical compounds and their component ratio in the fire-retardant composition, which exhibit a synergistic character during the combustion of wooden structures. At the next stage, in addition to surface treatment of wooden structures, they were faced with fire-resistant plasterboard sheets. Fire tests were carried out under field conditions for 30 minutes, the results of which were: the length of flame propagation over the surface of the samples was 456–678 mm; flame propagation speed 0.015–0.023 m/min. The data indicate that wooden structures treated in a combined way belong to group I of fire protection efficiency. These structures can be safely used in buildings and structures, especially with enclosing, attic, or attic types