Abstract:
The problem of non-failure work of elements of structures, buildings and constructions is especially important for their designing and operation. In the real conditions reinforced concrete structures in service are weighted by reloading, which are qualitatively change the character of the stress-strain state of the structure. At the same time the majority of the pressures that are not multiply-repeated and contain short-term variable component for a few cycles of repetition. Under these low-cycle loads may be relatively used high levels of stress, when the nonlinear properties of concrete are seen. The design processes are implemented consistently loading and unloading, which lead to the transformation of the stress-strain state of elements and accumulation of residual strains and injuries, that affect the durability of structures. The results of testing of structures and facilities survey showed a significant effect especially low-cycle loading on the fracture toughness and stiffness of structures that in some cases makes it necessary to repair. This is due to the fact that in today's standards specialty of the low-cycle loads are not considered.