Mechanical enhancement of cement-stabilized soil by flax fibre reinforcement and extrusion processing

Cement-based materials typically exhibit low tensile strength and their behaviour is generally brittle. Fibres can be added to make composites with enhanced tensile response and toughness. This study focuses on the effects of flax fibre content, mix design and processing on the hardened product properties (density, fibre orientation, surface quality, compressive and tensile strength). Effects of fibre addition on the mechanical performance of cast and extruded flax fibre reinforced composites are compared. Microstructure observations are used to study the influence of processing on fibre-matrix bond, fibre dispersion and fibre orientation. Flax fibre dispersion and orientation are also investigated to understand their effect on mechanical behaviour. In the case of cast materials, fibres do not significantly improve the mechanical behaviour. In contrast, improvement of fibre dispersion and fibre/matrix bond quality due to an extrusion process enhances mechanical performance.