In recent decades, great progress has been made in developing specifications and application technologies for durable and sustainable concrete. Performance-based specifications and durability models have been developed, and concrete has diversified into a group of innovative products, with high strength, low permeability, self compacting, with polymer and carbon fibre reinforcement, and its applications extended to extreme conditions (tropical, marine, seismic etc). For long-lasting concrete structures it is important to use a multi-step approach, so ""replace, repair and retain"" becomes increasingly important in the sustainable approach to managing structures. This issues are covered in 92 papers by leading international experts in this volume, grouped into four themes: Retaining and extending performance; Fundamental mechanisms; Replace, repair and retain; Extreme exposure conditions. Each theme starts with a keynote paper by the foremost exponents in their fields. This volume forms Volume 3 of the six-volume set of proceedings of the International Congress 'Concrete: construction's sustainable option', organised by the Concrete Technology Unit of the University of Dundee in July 2008, and available as a set, ref. EP92, ISBN 978-1-84806-043-2