Experimental Study on Full-scale Girders Strengthened with Prestressed NSM Tendons

摘要

Various techniques have been developed and applied to strengthen deteriorated RC (Reinforced Concrete) structures such as the EBR (Externally Bonded Reinforcements) and NSM (Near Surface Mounted) systems. However, NSM still suffers premature failure like EBR. Recent research tried to prestress the NSM but the prestressed NSM needs a special prestressing system. Accordingly, this study develops a new prestressing system for NSM using CFRP tendons. The field-applicability of the developed prestressing system is evaluated through an application on a full-scale PC girder of 20 m with the objective of improving the girder's performance by 30%. The girder is strengthened using 5 NSM CFRP tendons with the introduction of a prestressing force of 100 kN in each of them. The test results demonstrated the applicability of the new prestressing system since the flexural capacity of the girder was successfully increased by 30%.