Application of DOFS for monitoring post-tensioned anchorage zones in reinforced and fibre reinforced concrete

Abstract Prestressed concrete offers a range of benefits compared to traditional reinforced concrete, but in some markets the application of post-tensioned structures has seen a decline in recent decades. A critical aspect of post-tensioned structures is the design of anchorage zones. This study introduces and evaluates an experimental method based on Distributed Optical Fibre Sensors (DOFS) to assess the behaviour of post-tensioned anchorage zones. Moreover, the effectiveness of steel fibre reinforced concrete (SFRC) is also compared to various setups using conventional reinforcement systems. The aspects analysed include load-deformation behaviour, initial crack formation, and subsequent crack development. The research, based on six tested samples, shows that the application of DOFS in the presented setup holds great potential. Furthermore, the findings indicate that using exclusively SFRC at a volume fraction of 0.5%, without passive reinforcement is not recommended. However, combining SFRC with standard helical reinforcement around the anchorage block appears sufficient to meet desired structural performance, as evidenced by comparisons to control specimens.