Investigation of Bursting Stress and Spalling Stress in Post-tensioned Anchorage Zones

Over the past decades, considerable efforts have been made to quantify the bursting forces in the post-tensioned anchorage zones based on the simplified model or fitting formulas, however reproducing the transverse stress distribution is still a challenging topic, which is also important to detail the reinforcing details in the anchorage zones, especially for cracking control. To address this issue, this paper is devoted to seeking an elasticity solution for transverse stresses in the anchorage zones, and providing a more rational equation for transverse distribution in anchorage zones. The sum function of normal stresses is employed to solve the stresses filed in the anchorage zones with concentric load and two eccentric loads. The bursting stresses in the concentric anchorage zones and spalling stresses in the eccentric anchorage zones are verified by the photoelastic tests. The transverse stresses along the symmetry axis of the eccentric anchorage zones can be handled as a concentric single anchorage zone with equivalent bearing plate width. Moreover, according to the concept of force stream tube, the profiles of isostatic line of compression (ILCs) are determined and validated, which confirms the existence of ILCs.