Fracture mechanics is a branch of solid mechanics which deals with the behavior of

the material and conditions in the vicinity of a crack and at the crack tip. While the

concept of linear elastic fracture mechanics has been well developed for more than

past 40 years and successfully applied to metallic structures, several civil engineering

materials such as cementitious materials, rocks, and fiber-reinforced composites

commonly known as quasibrittle need a different fracture mechanics approach to

model the fracture process. Cementitious materials can be modeled at various scales

like the nano-, micro-, meso-, and macrolevels. At mesolevel, they can be considered

as a two-phase particulate composite, i.e., the matrix and the reinforcement.

In the cement pastes, mortar, and concrete, the matrices can be considered as the

hydrated cement gels, cement paste, and mortar, respectively, whereas the reinforcements

in the corresponding materials can be taken as unhydrated cement particles,

fine aggregates, and coarse aggregates.