2. General Characteristics of Concretes and Reinforced Concretes

The Chapter presents general characteristics of concretes and reinforced concretes, their classification, grading and designations. Definition of structure inhomogeneity in these materials and its effect on service characteristics are given. The Chapter contains typical diagrams of concrete deformation and fracture as well as nominal strength values for different concrete grades in tables. Besides strength, other important mechanical characteristics, such as fracture toughness, are of no less importance in concretes. The authors provide a summary of existing fracture toughness criteria and methods for experimental fracture toughness determination. At present, concrete science can formulate only individual aspects of a concrete strength and deformation theory. Considering concrete as a composite material with hierarchical structure (at micro, meso, and macro levels) and analyzing these structure levels, the authors propose a mathematical model enabling the establishment of quantitative relations between breaking (tensile) and compressive strength values for a porous material such as concrete.

The Chapter contains classification and mechanical properties of concrete reinforcement as well.