Physical approach for reinforced-concrete (PARC) membrane elements

A method is proposed for the analysis of the nonlinear behavior up to failure of reinforced-concrete membrane elements. The approach considers a linear elastic behavior for concrete before cracking; after cracking, the cracks are assumed as having a fixed direction and uniform spacing and cracked reinforced concrete is modeled as an orthotropic material. The basic element of cracked reinforced-concrete membrane is defined and the related stiffness matrix is proposed. The quantities that govern the problem are the opening and the sliding of the crack lips, as well as the strain of the concrete struts that are located between cracks. Applied to a local analysis of cracked reinforced concrete, the above variables allow for the effective modeling of compatibility and equilibrium conditions and take into account phenomena such as aggregate interlock, tension stiffening, and dowel action. To verify the reliability and capability of the proposed method, some comparisons with experimental observations of relevant tests are made.