3D finite element performance-based study of RC interface stiffness

Abstract

Although the importance of concrete-reinforcement interaction for reinforced concrete mechanics is well recognized, its intrinsic complexity needs in-depth meso-scales investigation. The contact zone between concrete and reinforcement was investigated in this study using RC ties that were short enough not to crack. The rib-scale simulation was carried out using a three-dimensional finite element technique using a simplified rib shape in the reinforcing bar. The contact between the concrete and steel was modeled using a friction cohesive zone model. An analysis was conducted to explore the impact of various contact zone parameters, suggesting numerical attributes for both normal and tangential stiffness while considering diverse rebar diameters. Concrete strain distribution and propagation of smeared splitting cracks in prisms were investigated. Additionally, a relationship between the interface's normal stiffness and rebar diameter was established through an exponential equation: K nn = 2,53 ∙ 10 16 ∙ D − 7,5 [ MN / m 3 ] . The stiffness parameters proposed were utilized to forecast the steel strain profiles of RC ties at various load levels.