Textile reinforced mortar at high temperatures

Textile reinforced mortar (TRM) is a composite made by fine grained matrix and glass fabric reinforcement. The main advantages of such a material are the orientation of the reinforcement in the direction of tensile forces, no concrete cover requirement against corrosion and the capability to produce thin and light weight elements. Special attention was given by researchers to the time dependent loss in strength of AR-glass reinforcement embedded in a cement based matrix. Some research has shown durability models to calculate the amount to the strength loss related to material, humidity and temperature. Nevertheless, the behaviour of TRM when exposed to high temperature requires further investigations. A suitable experimental programme was planned to investigate the behaviour of TRM when exposed to high temperatures. Uniaxial tensile tests were performed after thermal cycle on 400 mm x 70 mm specimens 6 mm thick, reinforced with 2 layer of AR-glass fabric. Several thermal thresholds (20, 200, 400 and 600°C) were considered for the mechanical characterization in fire condition. Thermal cycles were performed in an oven considering a heating rate of 30°C/h up to the maximum temperature and by a cooling branch at 15°C/h after a stabilization phase at maximum temperature.