ABSTRACT Materials and products age with time and their properties change. It is known that, for example, the mechanical strength may be deteriorated from ageing. To understand the ageing effect on the fire behaviour of materials and products is important to maintain the safety level of the construction or application. In this study, three different sandwich panels with intumescent coatings were selected for a study to evaluate the effect of accelerated ageing on reaction‐to‐fire properties. The accelerated ageing methods used were thermal exposure in 90°C and moisture exposure in 40°C and 90% RH. Samples were collected from ageing chambers after 1, 2 and 4 weeks. The reaction‐to‐fire properties were evaluated using the ISO 5660‐1 cone calorimeter and the smoke density chamber, EN ISO 5659‐2, with FTIR analysis of gas composition. The results show that ageing has an effect on the fire behaviour. Fire properties such as heat release rate and smoke production were unchanged or actually improved. Generally, the time to ignition was longer for the aged samples. The smoke density was affected as well as the smoke toxicity.
Sandinge et al. (Fri,) studied this question.