STRUCTURAL REHABILITATION OF DETERIORATED UNDERGROUND CONCRETE VAULTS USING EXTERNALLY BONDED CFRP SHEETS
Oral Presentation
Paper ID : 1190-ICASGE
Authors
1Department of Civil Engineering, University of Calgary
2University of Calgary-Department of Civil Engineering
Abstract
Aging infrastructure worldwide, including Canada’s concrete structures, face significant deterioration due to structural degradation and changes in usage, necessitating urgent rehabilitation. Calgary’s downtown underground core network, comprising approximately 2,735 manholes and 476 transformer vaults, exhibits severe deterioration caused by decades of corrosion and construction defects, such as misaligned reinforcing steel. While replacement is impractical, strengthening these structures using Externally Bonded Carbon Fibre Reinforced Polymer (EB-CFRP) sheets offers a viable solution and a promising alternative to traditional strengthening systems and materials, providing high-strength, lightweight, and corrosion-resistant solutions for structural retrofitting This study evaluates the effectiveness of EB-CFRP sheets in restoring flexural capacity by testing three deteriorated specimens under flexural loading—two strengthened with EB-CFRP sheets and one unstrengthened control. The results showed that EB-CFRP strengthening significantly improved the flexural performance of the deteriorated specimens and enhanced strength, stiffness, and load-bearing capacity, with strengthened specimens exhibiting delayed crack initiation, reduced deflections, and up to a 243% increase in ultimate load capacity. These findings highlight EB-CFRP sheets as an effective rehabilitation and strengthening method to extend service life and improve structural safety. The system is a viable solution for rehabilitating damaged underground RC structures, providing an effective alternative to costly and disruptive full replacements.
Keywords