Reaction of door constructions made of cellular wood material to fire

Abstract

Cellular wood materials (hereinafter CJVM) better known as Dendrolight® with their physical and mechanical properties are suitable for production of construction elements. A significant cost reduction, therefore, in transportation and mounting of the finished goods, as well as new and innovative modes of application based on the unique structure and lightness of the material, can all be achieved by developing the necessary technological and functional solutions. One of the possible building construction solutions are doors, including fire-resistant doors. This can be achieved by developing composites made of CJVM and other materials that would meet the requirements set by building standards in terms of reaction to fire performance, fire resistance, and acoustics and developing CJVM interconnection and fitting fastener solutions. The unique cellular structure ensures not only a reduced mass, but also a considerably better form stability under changing relative air humidity and temperature compared to materials used previously. During the research, initial tests were made to improve the reaction to fire properties of CWM by gluing it with some other materials. The results of the research showed that by gluing a CJVM reference sample with 7 mm thick pine solid wood (longitudinal fiber direction) the charring and burn-through rates are the lowest compared to the other materials investigated. By reaction to fire performance specification, CJVM with 7 mm thick pine solid wood, 4 mm thick MDF, or 6 mm thick MDF, gluing could be graded as class D in reaction to the fire classification system. The charring rate allows predictions of the potential fire resistance limit of door elements to be made. Assuming that the weakest spot in the construction is precisely the door elements, and of the materials tested, a 6 mm thick MDF or 6 mm thick magnesite panel was applied to both sides, CJVM could be used to achieve El 30 minutes fire resistance class limits.