Reliability‐based design of transmission and anchorage lengths in prestressed concrete elements

Abstract This work proposes new reliability‐based formulations for the design of transmission and anchorage lengths in prestressed reinforced concrete, starting from the equations discussed and proposed by fib TG2.5 “Bond and Material Models.” To this end, an extensive experimental dataset with more than 900 results was collected from the scientific literature. Then, two deterministic models were proposed, one for the transmission and one for the anchorage length. For each, model uncertainty was evaluated, and then a probabilistic calibration of their distributions was carried out, separating the cases when sudden or gradual prestress release was applied. Then, probabilistic models were developed for transmission and anchorage length evaluation, depending on the prestress release method: from them, it was possible to evaluate suitable coefficients to target varying reliability indexes. Particularly, two design situations were considered, for transverse stresses verification at the Serviceability Limit State (SLS) and shear and anchorage verification at the Ultimate Limit State (ULS). Lastly, the reliability of current deterministic models was verified.