A Proposal for the Mitigation and Maintenance Procedure Based on the Survey on Actual Condition of ASR-affected Bridges in Toyama Prefecture

Abstract

This paper describes the results of the survey on actual condition of 27 ASR-affected bridges in Toyama Prefecture ,where it has been carried out twice in 1990 and 2006 in order to verify the effectiveness of repair and strengthening method applied to them. Especially, by examining the mineralogical feature and alkali-silica reactivity of river sands and gravels used in concrete, the progress of deterioration of concrete with time due to ASR was investigated based on the regional classification of river systems in Toyama Prefecture. Furthermore, the practical ASR mitigation and maintenance procedure in this district was proposed by taking characteristics of reactive aggregates into considerations.