External Prestressing of Concrete in Flyover Construction & Repair
Dr. J. M. Chandra Kishen, Professor, Dept. of Civil Engineering, Indian Institute of Science, Bengaluru, presents a case study on the Replacement of Cables in Externally Prestressed, Dry Jointed Superstructure of 4.5 km long Nelamangala Flyover in Bengaluru.
An externally post-tensioned concrete is considered to be superior to the conventional reinforced concrete in view of reduced cracking and deformation and improved load carrying capacity of the structure. However, one of the major challenges with externally post-tensioned structures is the possibility of corrosion of tendons when compared with internally prestressed structures. This article presents the process followed in the rehabilitation of an externally post-tensioned segmental box girder flyover located at Goraguntepalya on Bengaluru – Nelamangala expressway which had undergone loss of several post tensioned cables due to corrosion.
