The word 'concrete' stands in common usage for something that is solid and enduring. This is testimony to the belief in the performance of concrete as a construction material. It was therefore a shock when it became apparent that concrete could suffer from a form of internal disintegration, dubbed 'concrete cancer'. caused by the chemical reaction between alkalis in cement and the minerals in the aggregate. This book provides a sound understanding of the alkali-aggregate reaction and how it affects the design, construction and maintenance of concrete roads and bridges. it draws on examples from the UK and around the world to relate experience of damage caused by this reaction and how the problems have been investigated and treated.