矿渣高钙灰复合水泥的水化程度研究

Research on Degree of Hydration of Blend Cement with Slag and High-calcium Fly Ash

根据水化热、化学收缩、CH生成量和强度等实验结果,分析了由30%矿渣+25%改性高钙灰+45%52.5 PⅡ水泥制备的42.5矿渣高钙灰复合水泥在不同龄期的水化程度。与普通硅酸盐水泥相比,由于高掺量的矿渣及改性高钙灰大幅度减少了熟料量,同时其火山灰反应消耗熟料的水化产物CH,水化产物组成和结构改变,水化热显著降低,早期化学收缩降低而后期化学收缩基本一致,不同龄期的CH生成量均显著降低,7 d和28 d的龄期强度接近,该复合水泥能够有效控制集中放热期的水化程度和优化水化产物组成,有利于改善耐久性。降低水胶比减少水化热、化学收缩和CH生成量,使水化度降低,但有利于水泥石结构的优化。

According to testing results of heat of hydration, chemical shrinkage, CH content and strength of hydrate, the degrees at various age of 42.5 PC cement, which made by 30 % slag, 25 % active high calcium fly ash and 45 % 52, 5 P Ⅱ cement, were analyzed in this paper. Comparing with that of 42.5 PO cement, composition and structure of 42.5 PC cement vary because high volume of slag and active high calcium fly ash degreased clinker and their pozzolanic reaction consume CH of hydrate of clinker. Heat of hydration droops significantly, early chemical shrinkage reduced and long-term one catched up with that of 42.5 PO cement. CH amount of hydrate at every age lowers a lot. Strengths at 7 d and 28 d are similar to that of 42.5 PO cement. It was shown that the blend design of this cement can effectively control the degree of hydration during the period when heat of hydration focuses, and would be benefit for structure and durability of hardened cement. Low W/C lowers degree of hydration, such as heat of hydration, chemical shrinkage and CH content of hydrate, and can optimize the structure.