摘要：Effects of multilevel modification of concrete structure with complex nanomodifier at nano- and microlevel and polypropylene fiber at macro- and mesolevel on mechanical properties and impact resistance of concrete are presented. Nanomodification with complex nanomodifier, which consists of polycarboxylate ether superplasticizer, ultra- and nanofine mineral additives, provides early structure formation, higher strength at early and later ages. The increasing of the static hardness according to Brinell and Mayer of the nanomodified concrete was indicated the high energy of the bond between the structural elements in the surface layer of nanomodified concrete, as well as the ability of the structure to withstand elastic and plastic deformations under uneven compression load. Incorporating of polypropylene fibre to concrete was increased the impact resistance according to parameter of first crack strength and failure energy and changed the failure pattern from brittle to ductile mode.
