A STUDY ON EVALUATION OF ALKALI-SILICA REACTIVITY OF RECYCLED AGGREGATE CONCRETE AND PROPOSAL FOR MITIGATION OF ASR

Abstract

In the Kashima Bridge constructed in 1978, about 40 % of stirrup steel bars of pillow beam fractured due to the excessive ASR expansion. For this reason, the pillow beam was completely reconstructed by removing all the concrete. In order to recycle concrete rubbles obtained from the Kashima Bridge, the residual ASR reactivity of recycled aggregate concrete was examined in the expansion test under accelerated curing conditions. From the results, it was found out that ASR expansion behavior of recycled aggregate concrete was almost similar to that of concrete with original andesite stone, and that the 15% fly ash replacement or B-type blastfurnace slag cement was not effective in controlling ASR expansion.