Controlling fracture toughness of matrix with mica flake inclusions to design pseudo-ductile fibre reinforced cementitious composites

High-performance fibre reinforced cementitious composites (FRCC) are usually designed by using high-performance fibres and matrix of high bond strength to enhance fibre debonding mechanism. The crack formation in high-strength matrices results in considerable strain-energy release. In such a case, fibres may not be able to effectively bridge the initial crack and failure due to propagation of the crack is relatively brittle. An approach is proposed in which artificial microcracks are smeared in the matrix to optimize fracture toughness while preserving sufficient bond strength. Mica flakes were introduced into the composite mixture as source of microcracks, and showed promising capabilities for controlling ductility of the composite material. Key parameters to control ductility were identified and procedures for mixture optimization are under development.