ASR-Deteriorated Bridges and Rock Type of Reactive Aggregate on Noto Expressway
Toshihiko MINATO and Kazuyuki TORII
Abstract:There exist large numbers of ASR-deteriorated bridges on the Noto expressway through the center of Noto peninsula in Ishikawa Prefecture. In some serious cases, a very severe deterioration which appears to directly be related with the reduction in load carrying capacity of structures has occurred; the significant decrease in compressive strength of concrete, the loss in bonding strength around steel reinforcement, and the fracture of steel reinforcement at the bent and so on. This study aims at investigating both the mix proportions of concrete and the rock type of reactive aggregates used in ASR-deteriorated bridges. Furthermore, the relationships between mechanical properties of cores taken from various portions of bridge pier and ASR degradation ranks classified by the various inspection were discussed for the purpose of the diagnosis and maintenance procedures of these bridges. Key Words:Alkali-silica reaction, Crushed andesites, Rock and mineralogical propertiesCFracture of steel reinforcement, Classified ASR-degradation level