中文摘要：

为探究石灰石微粉（LS）与偏高岭土（MK）在水泥中的复合效应,研究了两者以不同质量比复合对水泥砂浆强度的影响,并采用X射线衍射和热重分析研究了三元体系的水化产物。结果表明：LS与MK以1：1复合取代20%的水泥砂浆强度除3 d略低于水泥参比样外,7 d和28 d强度略高于或与参比样相当;复合取代量为30%时,LS与MK以2：1复合与以1：2比例复合,两体系3 d和7 d的强度相当,28 d时,高MK体系（LS/MK质量比为1：2）强度与参比样相当,而高LS体系（LS/MK质量比2：1）强度低于高MK体系约6 MPa;LS与MK以3：1复合取代量为40%时,体系在所研究各龄期的强度均显著降低,3、7 d和28 d强度分别为参比样的54%、55%和75%。LS与MK复合提高了水泥水化程度,强化了CaCO_3与铝质组分反应生成碳铝酸盐的化学效应,碳铝酸盐的衍射强度随龄期延长和复合体系LS的比例增加而增加。两者以适宜比例复合,可强化碳铝酸盐形成并实现与MK火山灰效应的复合,促进复合水泥不同龄期强度发展。

英文摘要：

To clarify the synergistic effect of limestone powder （LS） and metakaolin （MK） in cement, the strength of cement mortars blended with LS and MK at different mass ratios was investigated. The hydration products of ternary blend cement were examined by X-ray diffraction and thermogravimetry. The results indicate that when LS and MK are combined at a mass ratio of 1 ： 1 and replaces 20% of cement, the mortar strength is slightly lower than that of blank sample at 3 d, but comparable or slight higher at 7 d and 28 d, respectively. At the replacement level of 30% and LS and MK combined at mass ratios of 1：2 and 2：1, two blend cement mortars give the similar strength at 3 d and 7 d, however, blend cement with a higher MK content （i.e., LS/MK mass ratio of 1：2） develops a comparable strength to the blank at 28 d, which is 6 MPa greater than that with a higher LS content （i.e., LS/MK mass ratio of 1：2）. The incorporation of 40% of a combined LS and MK at a mass ratio of 3：1, the compressive strength decreases throughout the testing period, and the strength is only 54%, 55% and 75% of the strength of blank sample at 3, 7 d and 28 d, respectively. The combination of LS and MK can improve the hydration degree of cement and strengthen the reaction between CaCO3 and A1 components to form carboaluminate. The diffraction intensity of carboaluminate increases with the increases of the proportion of LS in blend cement and the curing period. An appropriate proportion of LS and MK can optimize the strengthening effect of carboaluminate formation and the pozzolanic reaction of MK, and promote the mortar strength development at different ages.