Bond Behavior of Plain Round Bars Embedded in Concrete Subjected to Biaxial Lateral Tensile-Compressive Stresses

Abstract

Owing to its importance to the assessment and design of reinforced concrete structures, the bond behavior of steel bars in concrete has been extensively studied. This paper presents an experimental investigation into the bond behavior of plain round bars embedded in concrete subjected to biaxial orthogonal lateral tensile-compressive stresses. A total of 174 pull-out specimens with different strengths of concrete, bar diameters, and combinations of lateral stresses were tested. The experimental results showed that, for a given lateral compressive stress, the bond strength decreases, but the slip at the peak bond stress increases as the lateral tensile stress increases. For a given lateral tensile stress, the bond strength increases, but the slip at the peak bond stress decreases with an increase in lateral compressive stress. Based on the experimental results, an empirical bond stress-slip relationship is proposed. It is shown that, for different strengths of concrete, bar diameters, and combinations of lateral stresses, the empirical bond stress-slip relationship is in good agreement with the experimental results.