Samir Dirar
Department of Civil Engineering
University of Birmingham, United Kingdom
Title: Strength enhancement of existing concrete infrastructure: challenges and opportunities
Biography
Biography: Samir Dirar
Abstract
The strength enhancement of existing concrete infrastructure is an application of considerable economic importance. It has been estimated that the cost of replacing structurally deficient transport infrastructure in Europe, a significant amount of which are concrete structures, is about €400 billion. In the United States, thousands of concrete bridges have been rated as structurally deficient and $20.5 billion would need to be invested annually to eliminate the bridge deficient backlog by 2028. There is thus scope for safe, practical and economic strengthening techniques for existing concrete infrastructure. Extensive research has resulted in approved flexural strengthening methods for concrete structures. In contrast, shear strengthening of concrete members is a particular challenge due to the brittle nature of shear failure and the complex mechanics of the behaviour. The collapse of the de la Concorde Overpass in 2006 in Canada, which killed or injured eleven people, was a tragic reminder of the dire consequences of concrete shear failures. This Keynote Paper will critically review current concrete shear strengthening techniques, with a special focus on a promising method known as the deep embedment (DE), or embedded through-section (ETS), technique. The Keynote Paper will also highlight the experimental, numerical and analytical work on DE/ETS strengthening of concrete members carried out at the University of Birmingham. Topics will include development of bond models for reinforcement bars embedded into concrete, repair of corrosion-damaged beams, strengthening of large scale bridge girders, seismic strengthening of beam-column joints, nonlinear finite element modelling and development of design guidance