Investigations on bond behavior of tendons during bridge dismantling – Fiber optic strain measurements in the D-regions during the severing of tendons. For practical reasons, in some cases the dismantling of prestressed concrete bridges is carried out in the direction of construction. As a result, the separation joints for the deconstruction sections are not located at the existing coupling joints and the tendons have to be anchored through the bond. It cannot be assumed with certainty that the tendons will be completely re-anchored immediately after severing. However, the design of the dismantling states requires an accurate assumption of the bond length. Moreover, it would be beneficial to conduct a thorough examination of the actual splitting tensile forces in the bond anchorage. There are several theoretical approaches that have not yet been fully investigated experimentally. Consequently, a series of fiber-optic sensor measurements were conducted during the dismantling of a viaduct with the objective of providing information on strain changes when severing a tendon. The bond length and the stress distributions in the discontinuity region can be determined as a result. The approaches for design from the literature could be partially confirmed. It was determined that global and local effects must be considered in the design, as the bond length is greater for components exhibiting cracking. Furthermore, the fiber-optic measurement layouts presented are also suitable for verifying the calculated anchorage lengths and for reducing uncertainties during dismantling.