Experimental study on smoldering combustion of construction products

This paper deals with the phenomenon of smoldering and smoldering fire propagation in construction products. Numerous studies on this process describe and capture the basic conditions and propagation behavior of this sensitive process for various products. The repeatability of the smoldering combustion results is strongly dependent on constant ambient and material conditions. Against the background of the European standard harmonization and building authority requirements, we are investigating the smoldering behavior of construction products. Due to the non-transferability of results from the reaction to fire tests (acc. to EN 13501-1:2010) to the smoldering process, a new standard test method is being developed. One central task of this project is to distinguish materials in an equivalent, neutral and objective way according to their smoldering behavior as well as to identify and define their reaction to smoldering initiation. The following four stages of reaction to smoldering initiation for construction materials classified A1 to E (acc. to EN 13501-1:2010) have been identified: 1. No smoldering, not self-sustaining, not progressive, instantly self-extinguishing; 2. Smoldering, not selfsustaining, not progressive, delayed self-extinguishing; 3. Smoldering, self-sustaining, progressive, self-extinguishing; 4. Smoldering, self-sustaining, progressive, not self-extinguishing. These stages are based on combinations of reactions in the materials during and after an initiation and in the course of a smoldering combustion. The initiated smoldering combustion and the course of the smoldering combustion after an initiation appear to be the situation in which a material indicates how high its inherent potential to smolder can be. It is planned to propose the reaction stages as elements for the identification of smoldering behavior of construction products in the developmental work on a harmonized European standard test.