Road bridges constructed during the period of rapid economic growth from 1955 to 1973 account for about 40% of all the bridges in Japan. Therefore,bridge aging will progress very rapidly. Damage to reinforced concrete slabs, fatigue cracks in steel bridges, and problems of chloride damage and ASR in concrete bridges have recently been reported. And seismic strengthening against large-scale earthquakes has become an urgent problem. To address these problems, the Ministry of Land, Infrastructure and Transport is developing a new bridge inspection system and bridge management data sheets. Under the inspection system, periodic inspections of bridges will be conducted once every five years, and the necessity of measures will be decided. The inspection results are recorded in bridge management sheets with such information as structural and environmental characteristics, and the history of repairs and strengthening of the bridges. The new inspection system and the management data sheets make proper bridge repair and extendingthe life expectancy of bridges possible. And it will be possible to equalize renewal periods for the bridges built during the period of rapid economic growth. For the covering abstract see ITRD E139491.
Abstract