Mesoscale mechanical discrete model for cementitious composites with microfibers

Microfibers (less than 100 µm in diameter) are commonly employed in structural applications to minimize early shrinkage cracking and lower pore pressure during fires. For any application, micro fiber-reinforced concrete (FRC) structural behavior and durability must be estimated using the mechanical constitutive law. Formulating a mechanical constitutive law for FRC presents several difficulties in terms of comprehending the physical principles and employing suitable numerical techniques. A novel model called “Lattice Discrete Particle Model for micro-FRC (LDPM-MicroF)” is presented to simulate the fracture behavior of black micro-FRC. An equivalent fiber diameter coefficient has been defined to balance modeling accuracy and computational cost so that the LDPM-MicroF model can simulate the mechanical responses of engineered cementitious composites. The unimodal variation in tensile strength caused by the increase in microfiber dose is assessed and quantitatively reproduced by LDPM-MicroF predictions.