可溶性碱对掺不同类型聚羧酸系减水剂水泥水化进程的影响  

Influence of Soluble Alkali on Process of Cement Hydration by Adding Different Types of Polycarboxylate Superplasticizer

作　　者：陆兵兵[1] 刘瑾 

机构地区：[1]安徽建筑大学材料与化学工程学院,合肥230022 [2]安徽省先进建筑材料重点试验室,合肥230022

出　　处：《混凝土与水泥制品》2015年第5期1-6,共6页China Concrete and Cement Products

基　　金：国家自然基金项目(21171004);国家科技支撑项目(2011BAJ03B04;2013BAJ01B05)

摘　　要：研究了可溶性碱(K2CO3)对掺聚醚型聚羧酸减水剂(PC-1)和聚酯型聚羧酸减水剂(PC-2)的水泥水化热、凝结时间的影响,并对水化产物进行了X-射线衍射分析。结果表明,在掺PC-1或PC-2的水泥中,适当增加可溶性碱含量能降低水化放热速率以及放热量,能明显缩短单硫型水化硫铝酸钙(AFm相)的形成时间,加快水泥的水化进程。当PC-1掺量较低时,少量的可溶性碱对浆体有缓凝效应,过量(大于0.12%)则表现为促凝效应。当PC-1掺量较高(大于0.30%)时,可溶性碱对浆体表现出促凝效应;而对掺PC-2的浆体而言,增加可溶性碱含量能很大程度缩短浆体凝结时间。掺PC-1能使Ca(OH)2(CH相)含量明显增多,可溶性碱则能进一步促进C3S和C2S的深度水化;而在掺PC-2的水泥中,增加可溶性碱含量则会减缓水泥后期水化。The influence of soluble alkali on hydration heat and setting time of the cement mixing the polyether type polycarboxylate-based superplasticizer （PC-l） and the polyester type polycarboxylate-based superplasticizer （PC-2） have been investigated, and the hydration products are examined with X-ray diffraction analysis. The results show that appropri- ate increase soluble alkali can reduce the hydration exothermic rate and heat, shorten the formation time of AFro phase, and accelerate the hydration process of cement. When PC-I dosage is low, a spot of soluble alkali have retarding effect on paste, but overdose resulted in accelerating its setting. When PC-1 dosage is high, soluble alkali can accelerate setting of paste, but for the paste mixed with PC-2, increasing soluble alkali content can shorten the paste setting time greatly. CH phase content increased significantly when the cement mixed with PC-l, and soluble alkali can further promote the depth hydration of C3S and C2S. However, when the cement mixed with PC-2, increasing soluble alkali content can slow down the late hydration of cement.

关 键 词：聚羧酸系减水剂 可溶性碱 水化热 凝结时间 水化进程 

分 类 号：TU528.042[建筑科学—建筑技术科学]