非晶态C_(12)A_7矿物对水泥早期凝结硬化的影响及作用机理  

Effect and Mechanism of Amorphous C_(12)A_7 on Cement Early Setting and Hardening

作　　者：王奕仁 王栋民[1] 张江涛[1] 李文平[1] 赵计辉[2] 

机构地区：[1]中国矿业大学(北京)化学与环境工程学院混凝土与环境材料研究所,北京100083 [2]清华大学土木工程系,北京100084

出　　处：《硅酸盐通报》2017年第5期1548-1555,共8页Bulletin of the Chinese Ceramic Society

摘　　要：非晶态C_(12)A_7具有更高的、亚稳态化学能,具有较快的水化速率,少量的存在能够加速水泥的凝结硬化。本试验研究非晶态C_(12)A_7矿物对普通硅酸盐水泥(OPC)的性能影响,重点探究了C_(12)A_7与OPC中SO3的比例在0~2.0时,对OPC的凝结时间、流动度、早期抗压强度等性能的影响,并通过灰色关联度法进行C_(12)A_7/SO3优选,对最优比例试样采用水化放热、XRD、SEM等表征手段分析其微观机理。结果表明:非晶态C_(12)A_7的掺入能够加速OPC的凝结硬化并降低其流动度;不同的C_(12)A_7/SO3对OPC胶砂早期强度的贡献程度分别不同,C_(12)A_7/SO3为0.4时能够显著优化OPC的早期性能;C_(12)A_7的掺入能够加速OPC中C3S、C2S的水解,反应生成的钙矾石、C-S-H凝胶及氢氧化钙等水化产物胶结在一起,从而起到早强作用。Since amorphous C12 A7 has higher, metastable state chemical energy, it has a faster rate of hydration. The setting and hardening of OPC can be accelerated just by the existence of small amounts of C12A7. The effect of amorphous C12A7 mineral on OPC properties were studied. The effects of 0-2.0 ratio of C12 A7/SO3 on OPC macroscopic properties including setting time, fluidity and early compressive strength were discussed. At the same time, the optimal C,2A7/SO3 ratio carried out preferably by gray related degree method, and then its microscopic mechanism was analyzed by hydration heat, XRD, SEM. The results show that： adding amorphous C12A7 can accelerate OPC coagulated and reduce its fluidity. The effect of different ratio of C12A7/SO3 on OPC mortar early strength is different respectively, which can significantly optimized OPC earlier performance when C12A7/SO3 is 0.4. CI2A7 can accelerate the hydrolysis of C3S, C2S in OPC. Reaction of hydration products including ettringite, C-S-H gel and calcium hydroxide cemente together, which play an important role in early hardening of OPC.

关 键 词：非晶态C12A7 水泥 早期性能 微观机理 

分 类 号：TU528.45[建筑科学—建筑技术科学]