Effective non-destructive methods of evaluating quality of efficient building materials

Abstract

The research is devoted to the analysis of available and widely used conventional measures to ensure reliable operation of the in-situ reinforced concrete structures and their compliance with legal requirements. It requires using one of the research trends of the Samara school of material sciences developed by the authors some time ago. Several stages of the work have been distinguished during the process of defining methodological foundations for effective non-destructive methods. The first stage concerned the proper mathematical apparatus of the concrete deterioration under various types of external effects. The second stage is important for determining the composition of basic physical and mechanical characteristics. Finally, the third stage is the period when the most reliable existing non-destructive methods are identified and investigation on new techniques is carried out. Thus, the combination of the A.A. Griffiths energy theory and the kinetic theory of S.N. Zhurkov has led to the formation of the mathematical apparatus that is able to simulate conditions of external effects. Testing effective methods for the concrete quality control developed by authors of this paper has been performed at the construction site. The conditions under study are characterized by a large number of ambiguous factors influencing the quantitative indicators of quality control criteria.

Assessment methodology of concrete crack resistance on cement binder

“…Studies of the destruction processes of concrete carried out by the authors for a number of years [29][30][31] have shown that the nature and kinetics of concrete destruction processes are affected by two types of characteristics: the initial parameters of the concrete structure and the kinetic characteristics of the processes of its destruction. The first group includes such physical and mechanical characteristics of the structure of concrete as surface energy, modulus of elasticity, Poisson's ratio, compressive strength.…”

“…The process of destruction of concrete, from the energy point of view, has three stages [29][30][31]. All three stages, which differ significantly from each other by the energy released during cracking.…”

Complex characteristic for forecasting durability of hydraulic concrete

“…For many years, the Academy of construction and architecture of Samara state technical university has been developing operational methods for determining the values of physical and mechanical characteristics of various materials by acoustic methods [7][8][9][10][11], as well as methods and techniques for optimal design of building structures [12][13][14][15][16][17][18][19][20][21][22][23][24][25][26]. For concrete, the determination of frost resistance and water resistance are based on theoretical studies of the processes of destruction [27][28][29][30]. These theoretical studies of the energy concept and kinetic theory of fracture mechanics are based on the work of A.…”

“…A. Gifits and S. N. Zhurkova [31,33]. The developed methods of evaluation of physical and mechanical characteristics of concrete on the basis of ultrasonic studies are related to the methods of non-destructive testing [7][8][9][10][11][27][28][29][30]. The theoretical studies of the processes of concrete destruction by various types of external influences (compression, tension, bending, cyclic freezing, hydrostatic action), confirmed experimentally, have shown that the rate of concrete destruction and its durability depend on two groups of characteristics.…”