TAN Kiang Hwee

External Prestressing

This refers to the case where prestressing tendons are placed outside the concrete section and the prestressing force is transferred to a structural member through end anchorages or deviators. Advantages of external prestressing include the possibility of monitoring and replacing tendons, ease in concreting and hence better concrete quality and the use of narrower webs. External prestressing is being increasingly used in the construction of new bridges and is a primary method for the strengthening and rehabilitation of existing structures.

At NUS, a three-year project on the application of external prestressing in structural strengthening has been completed, and this has resulted in design charts being developed for such applications.  Works were also carried out on the use of fibre-reinforced polymer (FRP) reinforcement as external tendons in both simply supported and continuous beams.

Recently Completed Projects:

Behaviour of RC beams partially strengthened with external tendons

Strengthening of negative-moment regions with external tendons

External prestressing in continuous beams