Performance-Based Concrete Mixtures for Durable,Long-Life Bridges

摘要

Worldwide,the state of transportation infrastructure has reached a critical stage.Aging bridges and other infrastructure assets are currently supporting the demands of increases in use far beyond the originally engineered capacity and well beyond the intended service life expectations [1-2].With this increased capacity and usage-in conjunction with increased climate change instabilities(natural or man-made)comes accelerated deterioration of bridges and the compromised safety of its users [3-6].Capital investment of new infrastructure systems is economically intensive.Transportation agencies are challenged to plan,build,and operate”sustainable”transportation systems that-in addition to achieving the important goals of mobility and safety-support a variety of asset management,environmental stewardship,climate mitigation/adaptation,and resilient infrastructure objectives.Concrete is one of the most widely used building materials in the construction of infrastructure.Approaches to help achieve higher concrete infrastructure sustainability include design and construction techniques to provide longer-lasting structures,increasing the use of supplemental cementitious materials(SCMs),and most importantly enhancing the durability and increasing the service life.Two US projects,a concrete-segmented,cable-stayed bridge and an extradosed bridge utilizing performance-based concrete mixtures to meet expedited constructability,enhance long-term durability and increase service life are discussed.