Conformity Assessment Model for the Installation and Monitoring of Post-tensioning Systems in Concrete Structures for Nuclear Projects

Abstract

The Conformity Assessment models continue to develop and the need for such models has never been so great in recent years due to the failures and collapse of conventional structures which have unfortunately been commonplace. These incidents have led to an increased requirement for enhanced site installation control, product type testing and product traceability to allow a level of confidence for the project owner. For obvious reasons Nuclear Projects demand high levels of control during the procurement and construction phase, but there has been a drive for external conformity assessment bodies to become involved to provide this extra level of reassurance for the project owner. CARES developed a new Post Tensioning (PT) Nuclear (N) Scheme at the end of 2021, PT (N) in collaboration with the project team of a current nuclear development in the UK. The Scheme was originally developed from the current CARES PT1 Scheme for Highway structures, but needed significant enhancement in numerous areas, including on site fabrication, installations in precast members and enhancement in grout testing and ongoing quality control. Conformity assessment for such nuclear projects involves a set of processes that show the installer, the post tensioning systems they use, and any associated off-site installation or fabrication meets the requirements of a recognised specification or standard whether this be internal or external. Undergoing this additional conformity assessment process gives the client an added level of reassurance and confidence, which may be missed by those personnel who work closely within the project. This unique and comprehensive model describes the technical and assessment requirements for the conformity of post tensioning installers and the use of approved tested materials. It covers all stages in the supply chain from the supply of post tensioning systems and associated constructional steel products to the final product installation and ongoing monitoring of the same.