FIBER MORTAR COMPOSITES UNDER FIRE CONDITIONS - EFFECTS OF AGING AND MOISTURE-CONTENT OF SPECIMENS

Two small scale test series were performed using the cone calorimeter heating method to detect any differences in the way various fibres aff ect the thermal properties of a standard mortar. The cone shaped heate r of the cone calorimeter produces a uniform heat flux on the sample s urface over an area of 100 x 100 mm2. The heat flux was adjusted to 50 kW m-2, which corresponds to the early stage of a fully developed fir e. The total exposure also corresponds roughly to the ISO 834 time-tem perature curve during the first 30 minutes. Short ageing of the specim ens gave very clear differences in thermal properties between fibre mo rtars. However, no such differences were observed with oven dried samp les. This shows the importance of carrying out tests in conditions as close as possible to the end use conditions of the material or product .