Best practice in the management and protection of concrete assets

Abstract

While reinforced concrete construction has boomed over the past 70 years, forensic analysis of failures shows that many structures have not achieved the design service life due to poor durability. This can primarily be attributed to a lack of understanding about durability design, poor construction practices and poor life-cycle maintenance, resulting in unexpected deterioration and damage that requires intervention. Exposure to chloride ions continues to present the construction industry with the greatest challenges. In Europe, EN 206 sets durability performance criteria for reinforced concrete under normal exposure environments, supplemented by national recommendations. Increasingly, infrastructure is being built either in environments that are so hostile to reinforced concrete or with service design lives that are so long, that they are outside the scope of European standards. For design in hostile environments, both within Europe and around the world, performance-related durability methods have been adopted, using predictive ingress models over extended service lives. However, even then, the fundamental risk remains as to whether what the designer intended, through the various cement and cover combinations, will be achieved in practice by the contractor’s workforce and site practices. This paper explores the lessons from durability failures of reinforced concrete and examines how performance can be modelled and enhanced in extreme environments and assured by effective corrosion monitoring and management strategies.