On the Verification of Discontinuity Regions in Existing RC Structural Elements Using Strut and Tie Models

This chapter delves into the verification of discontinuity regions in existing reinforced concrete structures, with a particular focus on dapped ends and corbels. It explores the application of Strut and Tie Models (STMs) as recommended by Eurocode 2, highlighting the challenges posed by the existing reinforcement layouts that may not fit the theoretical STM. The authors provide practical approaches to estimate the number and percentage of resistance provided by vertical stirrups in dapped-end beams and observe the reduction in resistance as the distance of diagonal reinforcement from the external support increases. Numerical modelling and experimental validation are employed to confirm the reliability of these approaches. The chapter also discusses the structural response of corbels, revealing that the main horizontal reinforcement contributes the most to strength, while diagonal bars and stirrups play a limited role. The findings offer valuable insights for accurately estimating the resistance of existing discontinuity regions, making this chapter a crucial resource for professionals in the field.