Extending the Service Life of Existing Concrete Structures to Last Beyond 100 Years

Abstract

New bridges and other concrete structures are being built using the design concepts presented in SHRP2 R19A (Bridges for Service Life Beyond 100 Years: Innovative Systems, Subsystems, and Components) and FIB Bulletin 34 (Model Code for Service Life Design) to achieve 100+ year service life. Existing concrete structures may not have been built with a specific design service life in mind but the principles of SHRP2 R19A can be used to maintain and extend the service life of existing concrete structures. Application of these principles and methods can extend service life by mitigating corrosion of embedded reinforcing steel by over 80%. Extending the service life of existing reinforced concrete structures provides many benefits to structure owners and society. Direct benefits include cost savings for owners and a general reduction in disruption to the public caused by repair and replacement. Extending service life also provides many indirect benefits including; reduction in the use of materials, reduction in the generation of demolition waste, reduction of environmental emissions, and the protection of sensitive habitat and existing ecosystems. This paper presents case studies which illustrate how the SHRP2 R19A protocol was used to design durable repairs to extend service life of existing concrete structures and the direct and indirect benefits which were achieved. Service life extension of existing reinforced concrete structures is a sustainable practice and should be encouraged.