CALCULATION OF THE CRACK RESISTANCE OF REINFORCED CONCRETE ELEMENTS WITH ALLOWANCE FOR THE LEVELS OF NORMAL CRACKS FORMATION
Journal Title: Збірник наукових праць Українського державного університету залізничного транспорту - Year 2018, Vol 181, Issue 15
Abstract
The importance of the step formation of cracks in reinforced concrete elements for the modern theory of concrete and reinforced concrete is substantiated. The separate experimental investigations results and the major drawbacks of existing methods of calculating the reinforced concrete elements crack resistance are considered in detail, taking into account the process of multilevel formation and crack opening. Based on the basic provisions of the deformation and strength model of concrete and reinforced concrete resistance, an engineering method for calculating the formation and disclosure of discrete cracks in the reinforced concrete elements and structures normal sections at the operational stages of their deformation is proposed. It is based on the determination of the active coupling of reinforcing concrete with expanded concrete, due to the known function of the average stresses of this bond. Dependences are obtained on the determination of the distances between adjacent cracks as one and different levels of their formation. The formula for determining the width of opening of normal cracks from the positions of successive accumulation of mutual displacements of reinforcement and concrete with their degree formation is proposed. The developed method for calculating the degree of formation and disclosure of normal cracks in reinforced concrete elements develops and complements the generalized strain-force model of the resistance of concrete and reinforced concrete. It is implemented on the system of generally accepted static, geometric and physical relations of a deformed solid mechanics. The proposed calculation method simplicity is due to the use of the nonlinear function of the average stresses of the reinforcement bond with concrete on the sections of the reinforced concrete element between adjacent cracks. The main advantages of the developed calculation method in comparison with others are outlined.
Authors and Affiliations
Vasyl Romashko, Olena Romashko
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