Features of Nonlinear Deformation of Concrete

In most studies, when the problem of determining a nonlinear model of deformation of structural concrete in normal environment, or experienced a variety of destructive (aggressive, temperature, etc.) exposure, using individual mathematical apparatus and software. The main criterion in these works for the construction of the deformation model of concrete was a unique relationship "strength - modulus of elasticity". Apply the developed model for another type of concrete or experienced a destructive impact was erroneous. However, not all features of concrete deformation in the construction of models were taken into account. In particular, the gentle nature of deformation in the initial stage of loading was not taken into account. Similarly, models of nonlinear deformation of concrete in normative materials of different countries are constructed. Especially there are problems in the inspection of structures operated for along time. It is not rational to create individual models based on the algorithm created earlier. In recent studies, a number of works have noted the need to take into account the features of the initial stage ofloading of concrete and the fact that concrete from the beginning ofloading has macro and micro cracks and structural defects. But even in these works the possibility of creating a nonlinear deformation model based on experimentally obtained data when testing prototypes of generalized model was not considered. This article discusses the possibility of constructing a concrete extracted from the structure. The possibility of replacing the individual deformation models with the proposed one is shown. In the generalized model of deformation "strength and modulus of elasticity" may not coincide with the normative characteristics and it can serve as a basis for determining the stress state in the survey of operated structures and, if necessary, for the design of new ones.