关键词: 偏高岭土;复合掺和料;强度;抗压收缩;孔结构

Abstract: Effects of component admixtures based on metakaolin , fly ash and limestone powder on compressive strength and early age shrinkage of concrete by combination with pore structure , Interfacial Transition Zone ( ITZ) and hydration heat were investigated .The experimental results show that the multi component admixtures improve the compressive strength of concrete and increase more than 10%at 28 d. Pore structure has been refined .The drying shrinkage has been reduced by 13%-23%at 200 h and the shrinkage decreases with the increasing oflimestone powder and metakaolin content . Component admixtures accelerate the hydration of cement , improve the formation of CSH gels and make the interfacial transition zone denser .

Key words: metakaolin;compound admixture;compressive strength;shrinkage;pore structure