When different mineral admixtures were applied to suppress the alkali-aggregate reaction(AAR) in concrete, the water-binder ratio has some effect on it. The AAR of concrete was tested by the mortar bar method according to CECS 48:93. The mortar bars were prepared by adding mineral admixture, high efficiency water reducing agent and air entrain agent. The result shows that in case that the water-binder ratio is less than 0.50 by mass, for mineral admixture (fly ash or silica fume) alone or that with entraining agent or with super-plasticizer along with entraining agent to be added in the high performance concrete, the less the water-binder ratio, the better. However, for the case of water-binder ratio between 0.30-0.35 or greater than 0.40, the greater the water-binder ratio, the more effective to suppress the AAR by adding the mineral admixture and the super-plasticizer.
