Full‐scale testing and numerical modeling of tri‐segment precast concrete T‐girders with internally bonded tendons

Precast concrete segmental bridges (PCSBs) have become a widely adopted solution in bridge construction due to their construction efficiency and reduced on‐site time. This study investigates the structural behavior of tri‐segment precast concrete T‐girders (TCTGs) with internally bonded tendons, combining full‐scale experimental testing and numerical modeling. Experimental results showed that the TCTG exhibited localized deformation at the joint, with a 23‐mm‐wide major crack forming at 1880 kN. The cracking loads were 720 and 760 kN for the segmental girder, compared to 950 kN for the monolithic one, representing a reduction of approximately 20%–24%. Finite element model (FEM) revealed that the mid‐span section of the TCTG exhibited enhanced flexural capacity due to the contribution of ordinary steel reinforcement, with moment capacity increasing from 13,676 to 15,949 kN·m, representing a 16.6% improvement. Grouted (bonded) conditions significantly improved joint flexural performance: the ultimate load increased from 1484 kN (unbonded) to 1974 kN (bonded), reflecting a 33% improvement. Effective prestress had limited influence on ultimate flexural capacity but significantly increased cracking loads. When the prestress level was varied from 600 to 1400 MPa, the maximum difference in ultimate moment at the joint was only 0.6%. The amount of ordinary steel reinforcement had minimal effect on flexural capacity near the joints, whereas under mid‐span loading, flexural capacity increased with higher reinforcement ratios. Increasing girder height led to a near‐linear increase in flexural capacity for both joint and mid‐span loading conditions. Comparison with AASHTO 2020 provisions showed that FEM‐predicted capacities consistently exceeded code‐based predictions, indicating a conservative bias in the current design specifications. This study provides valuable insights for improving the design and analysis of segmental concrete bridge girders.