Localized nonlinearity and size-dependent mechanics of in-plane RC element in shear

Structural nonlinearity and stress-carrying mechanics of reinforced concrete are greatly associated with local kinematics at crack planes and non-uniform stress fields in un-cracked concrete regions mobilized in the vicinity of cracks, especially when much less and/or highly anisotropic amounts of reinforcement are placed in space. An exact local stress field approach is implemented to in-plane reinforced concrete elements for deriving size-independent/dependent spatial averaged stress–strain relation, stress carrying mechanics and their interaction of high complexity. Much attention is directed to size sensitivity of overall responses involving transient tension softening–stiffening, interlock shear hardening–softening and average yield strength of reinforcing bars, which were previously formulated based on mere superimposition of these constituent mechanics under uniaxial stresses. Single crack localization and transitory phase of lightly reinforced concrete in-plane elements are chiefly investigated since those are out of scope of non-localized stress field approach with smeared crack concept.