ACCOUNT OF DISCRETE ARRANGEMENT OF REINFORCEMENT IN CALCULATION OF REINFORCED CONCRETE ELEMENTS

摘要

This study reviews an alternative of reinforced concrete finite element model as a system, where physical conditions for system components are recorded independently and in addition, conditions for interaction of system components on their contact are also introduced. In this case, we are able to take into account all specific features of reinforcement, to trace the history of loading and destruction for each rebar. Rebars and concrete tangent stress/shear ratio is accepted as per the model of M.M.Kholmyansky or Model Code 90. A basic specific feature of reviewed problems ascertains the necessity to use a non-linear stress-strain ratio in reinforced concrete with consideration of specific features of reinforced concrete activity after cracking. Naturally, functional dependence describing this ratio varies along with the progress of rebar corrosion. Corrosion of rebars is the key reason for a time-dependent quality degrading of reinforced concrete structures. This problem is of urgent concern with respect to structures in seismic sensitive zones since such corrosion of rebars leads to deviations of the structure's rigidity characteristics and in turn, it may lead to an increase of seismic inertia forces and simultaneous reduction of bearing capability in certain elements or to an increase of structural strain capacity to intolerable high values.