A lot of RC bridge piers are now suffering from serious damage in the Hokuriku district in Japan. The deterioration of concrete in this district is mainly due to ASR resulting from the andesite crushed stone with a high reactivity. The concrete with the andesite crushed stone successively expanded for more than 20 years, leading to the serious damage of structural member of bridge pier, for example, the peeling off of cover concrete, the reduction in compressive strength of concrete, and in the most serious case, the yielding or fracturing of steel bars. So, for bridge piers in the Noto highway in Ishikawa prefecture, which is considered to be the most serious case in Japan, the degree of deterioration of bridge pier due to ASR was investigated by both the inspection of cracking of bridge piers and the mechanical test of concrete cores taken from them. Corresponding to the classification of ASR deterioration level of each bridge pier, the strengthening techniques by the steel plate bonding or by the confining with prestressing steel wire have been adopted for some ASR-affected bridge piers on Noto highway. (a) For the covering entry of this conference, please see ITRD abstract no. 0612AR242E.
Samenvatting