Influence of thermal conditioning on tensile behaviour of single basalt fibres

This article presents an experimental investigation of the effects of temperature and atmosphere on the tensile behaviour of basalt fibres. The heating conditions have been chosen in order to mimic those used in thermal recycling of polymer matrix composites. The change of properties is investigated at room temperature on fibres heat-treated for 1 h up to 600 °C in air and in inert atmosphere (argon). The loss in fibre strength was found to be affected by both temperature and atmosphere with a significant strength loss occurring under the heating conditions used for high temperature incineration of polymer composites. Scanning electron images of fibre fracture surfaces after tensile tests for different environments and temperatures confirmed that failure originated from the fibre surface. The modulus of thermally-treated basalt fibres increased with conditioning temperature and these effects have been discussed in terms of decomposition of the organic sizing and structural relaxation during thermal treatment while X-ray diffraction excluded the effect of crystallization phenomena on the strength loss of basalt fibres after thermal exposure.