Iakovenko I. The deformation models of reinforced concrete constructions on the basis of fracture mechanics

It is solved the problem of crack resistance and rigidity of reinforced concrete constructions in the thesis. It is related to the definition of the true width of the disclosure and development of different types and levels of cracks, based on the finer tools of fracture mechanics. This leads to a significant change in the rigidity, caused by cracking, which is very necessary at the effective design and calculation of reinforced concrete constructions, buildings and structures. Experimentally and theoretically confirmed new features of reinforced concrete resistance and modernized existing calculation hypotheses. A new classification of discrete cracks has been constructed, which includes geometric, strength and intermediate concentration. It is adapted a functional of fracture mechanics in relation to the calculation of reinforced concrete constructions. New transformational elements are developed with different power influences, which connect the basic provisions and dependencies of fracture mechanics with the dependence of the reinforced concrete theory. The models of deformation of reinforced concrete on the main provisions of the fracture mechanics by the limit states of the second group have been developed: the models of different levels and types cracks formation, resistance of tensioned concrete between cracks, model of distance between cracks and model crack opening width of different types and levels have been developed. New approaches to determining the rigidity of reinforced concrete constructions are presented. It is devoted numerical analysis and comparative evaluation of developed deformation models with existing calculation methods and normative documents. The calculation algorithms of formation, estimation of resistance of tensioned concrete between cracks, distance and width of crack opening are presented. The results of the thesis are introduced into normative documents of Ukraine, design objects and are widely used in the educational process.