矿物掺合料对水泥与减水剂相容性的影响  

Influence of Mineral Admixture on Compatibility of Cement with Water Reducer

作　　者：陈源伟 丁华柱 陈伟 杨继鲁 文庆军 Chen Yuanwei;Ding Huazhu;Chen Wei;Yang Jilu;Wen Qingjun

机构地区：[1]重庆市庄大商品混凝土有限公司,重庆402660 [2]重庆市綦江区朝野混凝土有限公司,重庆401420 [3]中国电建集团核电工程有限公司,山东济南250131 [4]重庆欣材混凝土集团股份有限公司,重庆400021

出　　处：《重庆建筑》2020年第6期38-41,共4页Chongqing Architecture

摘　　要：减水剂与水泥容易出现相容性不良的问题,而添加适量矿物掺合料有助于改善水泥与减水剂的相容性。该文研究了三种减水剂和粉煤灰、硅灰和矿渣粉与水泥的相容性,通过测定相应时间的水泥净浆流动度表征相容性。通过改变减水剂的种类和掺量,确定了减水剂的最佳掺量(饱和点掺量),改变矿物掺合料的掺量,确定了粉煤灰、硅灰和矿渣粉的最佳掺量。采用TOC法测试了矿物掺合料对聚羧酸减水剂吸附量的影响;采用电声法测定了水泥-聚羧酸减水剂体系浆体的zeta电位,分析了矿物掺合料影响聚羧酸减水剂与水泥相容性的机理。结果表明:两种聚羧酸系高性能减水剂与水泥和粉煤灰、硅灰和矿渣粉的相容性比萘系减水剂效果好,在一定掺量范围内,粉煤灰和矿渣粉能够明显增加水泥浆体的流动度,硅灰显著降低了水泥浆体的流动性,复掺效果较好,矿物掺合料的最佳掺量为:粉煤灰15%,硅灰5%,矿渣粉10%,粉煤灰与矿渣粉有利于增加聚羧酸减水剂的有效吸附量,降低水泥-聚羧酸减水剂浆体的zeta电位,改善水泥浆体的和易性。The water reducer is prone to show poor compatibility with cement,and adding an appropriate amount of mineral admixture can help improve the compatibility of cement and water reducer.In this paper,the compatibility of three water reducers and fly ash,silica fume and slag powder with cement is studied,and the compatibility is characterized by measuring the fluidity of cement paste at the corresponding time.By changing the type and amount of water reducer,the optimal amount of water reducer(at the saturation point)was determined,and the amount of mineral admixture was changed to determine the most suitable amount of fly ash,silica fume and slag powder.The TOC method was employed to test the effect of mineral admixture on the adsorption of polycarboxylic acid water reducer.The electro-acoustic method was adopted to determine the zeta potential of the cement-polycarboxylic acid water reducer system paste,and analyze the mechanism of mineral admixture affecting the compatibility of carboxylic acid water reducer with cement.The results show that the compatibility of the two polycarboxylic acid-based high-performance water reducers with cement and fly ash,silica fume and slag powder is better than that of naphthalene-based water reducer.Within a certain mixing range,fly ash and slag powder can significantly increase the fluidity of cement paste,silica fume significantly reduces the fluidity of cement paste,and the compounding effect is better.The optimal mixing amount of mineral admixture is as below:15%of fly ash,5%of silica fume,and 10%of slag powder,fly ash and slag powder are conducive to increase the effective adsorption of polycarboxylic acid water reducer,reduce the zeta potential of the cement-polycarboxylic acid water reducer paste and improve the workability of the cement paste.

关 键 词：聚羧酸系高性能减水剂 粉煤灰 硅灰 矿渣粉 相容性 

分 类 号：TU528[建筑科学—建筑技术科学]