改性硅酸盐水泥的水化动力学研究  

Study on Hydration Dynamics of Modified Composite Portland Cement

作　　者：任书霞[1] 张光磊[1] 要秉文[1] 李仕群[2] 

机构地区：[1]石家庄铁道学院材料科学与工程分院,石家庄050043 [2]济南大学材料科学与工程学院,济南250022

出　　处：《硅酸盐通报》2008年第3期444-450,共7页Bulletin of the Chinese Ceramic Society

基　　金：国家重点基础研究发展规划(973)2001CB610700

摘　　要：将磷铝酸盐水泥熟料掺入到硅酸盐水泥中制备改性水泥,从水化动力学的角度研究其水化情况,并与硅酸盐水泥的相应行为进行了对比。首先通过测定水化放热速率、新拌水泥浆体中的Ca2+和SiO44-离子浓度、电导率及pH值研究了改性硅酸盐水泥的水化历程,并求得了水化动力学方程。其次,测定了改性硅酸盐水泥的净浆与砂浆的强度,并用XRD等分析方法初步探讨论了改性水泥的水化机理。研究发现,改性硅酸盐水泥的水化历程与硅酸盐水泥相似,也经历初始期、诱导期、加速期、减速期和稳定期,但水化放热速率明显提高;在加速期,两者的水化反应均主要由自动催化反应控制,在减速期,均主要由扩散过程控制,但反应速率常数前者明显高于后者。无论是砂浆强度,还是净浆强度,前者也均高于后者,且凝结时间相对缩短。XRD图谱显示,前者的C3S/C2S衍射峰强度的降低率高于相应龄期的硅酸盐水泥。上述结果均意味着改性硅酸盐水泥的水化速度明显高于硅酸盐水泥;水化加速的机理为磷铝酸盐熟料水化吸收了水化浆体中OH-离子,使水化体系的OH-离子浓度减少,从而加速了C3S、C2S的水化反应。The modified composite portland cement was prepared by adding phosphoaluminate cement clinker into portland cement. The hydration behaviors of it were studied from the angle of hydration dynamics here, and the comparison was conducted between modified cement and grade 42.5 portland cement. Firstly, the hydration processes of two cement samples were researched by measuring the rate of heat liberation during hydration, Ca^2＋ and SiO4^4- ions concentration, conductivity and pH values; Meanwhile , hydration dynamics formulas of them were built too. Secondly, the strength of paste and mortar were determined, and the hydration mechanism were discussed by XRD. The results show that the hydration processes of the modified .composite portland cement are very similar with that of portland cement, including five stages which are preinduction period, induction period, accelerating period, decelerating period and stable period, but the rate of heat liberation during hydration of the former is higher than that of the later. In the third stage, the reaction Of them both are catalysis controlled, in the fifth stage, the reaction both ：are controlled by diffusion, While the hydration rate of the former hasbeen increased largely comparing with the later. The strength of the paste and mortar the former is higher than that of the later in the same hydration age, and the initial and final setting time for the paste of the former are shorter than that of the later too. The falling rate of peak strength for C3S/C2S in patterns XRD is higher than that of the later. The above results suggests that the hydration rate of modified cement is higher than that of portland cement; Mechanism of hydration accelerating is that OH＂ ions concentration of the modified cement hydration system are decline because of absorbing by the hydration of phosphoaluminate cement clinker, which lead to the rapid hydration of C3S and C2S.

关 键 词：改性硅酸盐水泥 水化动力学 水化历程 水化机理 

分 类 号：TQ172.7[化学工程—水泥工业]