ФОРМИРОВАНИЕ МАРШРУТА МАГИСТРАЛЬНОЙ ТРЕЩИНЫ РАЗРУШЕНИЯ В МНОГОУРОВНЕВОЙ СТРУКТУРЕ КОНГЛОМЕРАТНЫХ СТРОИТЕЛЬНЫХ КОМПОЗИТОВ

Abstract

In the publication, conglomerate building composites (concrete) are identified as heterogeneous solids with a hierarchically organized spatial-geometric structure with a characteristic dimension from 10-10 to 10-1 m, with a minimum of 5-6 scale levels and three types of substructure design that differ in scale, genesis and mechanics of properties manifestation. The first type is characteristic of the macro-, meso- and microscale levels and is taken in the form of a two-component “construction” of a spatially continuous matrix and discrete solid and gaseous (macropores) inclusions deterministically and stochastically distributed in it; the second type refers to the submicro-, ultra-micro- and nanoscale levels and is believed to be in the form of a “microscale spatial structure” of new formations of a cementitious substance from consolidated individual crystalline differences; the third type, finally, corresponds to the atomic-molecular structure of new formations of the cementing substance. Characteristics of the distinguished types of substructures are given according to the scale of their components, the peculiarities of formation, the mechanics of manifestation of properties, design criteria and means of synthesis of each substructure. The patterns of formation of the fracture route in substructures of all types and substances of each scale level are analyzed. In this case, the development of the stress-strain state of the conglomerate composite according to the principle of energy dissipation, localization and increase (concentration) of stress is realized in the direction from the macro- to the atomic-molecular level of the structure of the composite, and the destruction itself and, accordingly, the formation of the crack route in time and in space of the composite passes in the direction from the atomic-molecular level to the macrolevel in a cascade through all intermediate structural levels. Within the framework of an integrated mechano-physico-chemical approach, the place of thermofluctuation theory (fracture physics) at the stages of breaking single atomic-molecular bonds and crack mechanics at the stages of development of micro- and macrodamage is shown. The possibilities of using theoretical principles of crack route formation to formulate and solve practical problems of designing and synthesizing optimal structures of conglomerate building composites are discussed.