建設材料特集 フェロニッケルスラグ細骨材を用いたコンクリートの凍結融解抵抗性に関する研究

Abstract

A total of five ferro-nickel slag fine aggregates were examined by blending natural fine aggregates to investigate the freeze-thaw resistance of concrete with these fine aggregates. The volume blending ratio of slag fine aggregates in excess of 60% resulted in poor freeze-thaw resistance of concrete when the water cement ratio exceeded 55% and the air content less than 5%. The inherent freeze-thaw resistance of slag sand particles was superior to that of natural fine aggregates. The poor resistance of concrete with slag fine aggregates couldn't be well explained by the air content and spacing factor. The major cause to impair the resistance was guessed the excess bleeding and it was found that the larger the amount of bleeding, the poorer the freeze-thaw resistance of concrete.It was concluded that the durable concrete could be produced by suppressing the bleeding less than 0.4cm3/cm2 together with the suitable air entrainment.