核廢料處置坑道封塞用低鹼性混凝土性能研究

This research is exploring the properties of localized low-pH Self-Compacting Concrete (SCC). The proportion of the specimen is based on Swedish SKB B200 and B300. The B200 series explore the effect of cement replaced by 40%, 50% and 60% silica fume on concrete properties; B300 series explore the properties of tri-system (silica fume + fly ash replaces 50% of cement by weight) concrete. The results show that the replacement amount of silica fume reaches more than 40%, the pH value of concrete can below 11, and the pH value decreases with the increase of the replacement amount; B200 series, 40% silica fume replaces the cement, the concrete has higher compressive strength, lower drying shrinkage, better resistance to sulfate attack and chloride ion penetration. B300 series, 30% silica fume + 20% fly ash replace the cement, the compressive strength of concrete is higher. 50% silica fume replacement concrete has the smaller dry shrinkage value; 30% silica fume + 20% fly ash replacement concrete has the better performance of the resistance to sulfate attack and chloride ion penetration.