Study on Reducing ASR Expansion in Concrete Prepared with Iron Ore Tailings Sand

Iron ore tailings, wastes of mining industry, have been widely used as manufactured sand in concrete with absence of the natural sand. In present paper, the ASR reactivity of iron ore tailings sand was assessed with rapid mortar bar method (GB/T 14684-2001). Result of a preliminary study on ASR resistance was reported. The replacement of cement by 30% Fly ash (FA), 50% ground granulated blast-furnace slag (GGBFS), 10% metakaolin (MK) and replacement of sand by 15% ground iron ore tailings (GIOT) led to the ASR-expansion to below 0.10%. Compared with replacement of cement, replacement of sand led to better performance. Further more, the fine particles less than 75 mu m in iron ore tailings sand are beneficial to the reduction of expansion induced by ASR.