粉煤灰-偏高岭土-石粉对混凝土微结构及早期收缩的影响研究

以偏高岭土、粉煤灰和石粉作为复合掺和料,结合混凝土孔结构、界面过渡区(ITZ)及水化热等表征研究多元复合掺合料对混凝土抗压强度及早期收缩性能的影响.研究结果表明:粉煤灰-偏高岭土-石灰石粉多元复合掺和料对混凝土抗压强度有促进作用,其28 d龄期强度增长10%以上,降低孔隙率,减少混凝土试样200 h收缩率13%~23%,且收缩率随着石粉含量增加和偏高岭土含量增加而降低.偏高岭土复合掺和料加速了水泥水化反应过程,促进了CSH凝胶的快速形成,密实了界面过渡区.

Effects of Component Admixtures Based on Fly Ash,Metakaolin and Limestone Powder on Microstructure and Early Age Shrinkage of Concrete

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 .