Crack resistance of bar reinforced concrete elements during construction and reconstruction

Abstract

The consequence of the well-established idea of the crack resistance of reinforced concrete structures are two types of engineering calculations: for the formation of cracks and for limiting their opening width. Such a view is based on certain assumptions, simplifying the calculation to the possibility of its implementation “manually” and neglecting some real physical processes occurring in reinforced concrete under load. Seven of the most significant assumptions are considered in the article. For each of them, an analysis was carried out to determine whether they correspond to reality throughout the entire life cycle of the structure. It was proposed to use only one single calculation at the level of standards to assess the crack resistance of structures - according to the crack opening width, acrc. At the same time, the calculations already available in the design codes for limiting permeability and the safety of reinforcement will still remain in demand. The compressed algorithm is proposed for the possible consideration of the effect of cracks at all scale levels of the concrete structure, the key for which is the normalization of the statistical parameters of the distribution of discontinuities by diameters, lengths, openings, depths, directions, distances between discontinuities, etc.