Numerical analysis of direct-shear behavior of HPC dry joints with different plastic damage parameters in precast concrete segmental bridges

The effectiveness of connections in precast concrete segmental bridges (PCSBs) critically depends on the prestressing forces and shear performance at joints, generating complex biaxial stresses, particularly with dry concrete joints and external prestressing. High-performance concrete (HPC), enhanced with different materials exhibits distinct fracture mechanisms, affecting its uniaxial and multiaxial mechanical behaviour. Accurate nonlinear calibration of concrete is crucial to match experimental and numerical findings. To solve this challenge, with a constitutive model proposed based on the Concrete Damaged Plasticity (CDP) theory, a parametric study is performed on finite element modelling for PCSBs with self-compacting reactive powder concrete (RPC). Results indicate that the nonlinear shear behaviour of the HPC dry joints with a smaller fracture energy is sensitive to tensile damage. The study offers recommendations for setting parameters in the CDP model, particularly for predicting direct-shear strength of keyed joints in PCSBs.