Optimization of Composition of Nanofiber Concrete in Terms of Fracture Toughness by Matrix Modifiсation

Concrete is a quasi-brittle building material that has low tensile strength. The process of its destruction under loading inhomogeneous, due to the nature concrete structure mass, consisting components with different physical and mechanical properties. Gradual deformation can be characterized as formation development microcracks. presence different-sized in makes it possible consider multi-level system. In this system, each level matrix own structural inclusions, which play both structure-forming role stress concentrators action loads. critical intensity factor good indicator crack resistance (fracture toughness) material. Nanoconcrete, from point view multilevel composite propagation inhibitors at cementing substance (carbon nanotubes are consi-dered inhibitors). fiber fibers subsequent scale levels allows us dispersed reinforcement (nanofiber concrete). paper discusses change fracture toughness (crack resistance) levels. presented for normal separation notched cubes eccentric compression determination modified carbon acting (nanoconcrete), well nanofiber fine-grained concrete. Based on experimental studies by non-equilibrium methods mechanics, compositions nanofiber-reinforced maximum concentrations several types matrices nanocarbon additives proposed paper.