水泥和泥对聚羧酸减水剂的吸附性能研究

Adsorption Research of Polycarboxylate Superplasticizer on Cement and Clay

本文选用水泥、砂中泥和种植泥作为试验研究对象,利用紫外可见分光光度计法(UV),测定反应设定时间后的聚羧酸减水剂浓度,研究水泥和泥对聚羧酸减水剂的吸附性能。试验结果表明:聚羧酸减水剂在水泥和泥表面的吸附量随时间延长而增加,最后达到平衡;聚羧酸减水剂在泥颗粒表面的吸附存在优先选择性和亲和性,使得其在泥颗粒表面的吸附速率和吸附量大于水泥;泥种类不同,吸附量大小不同,对净浆流动度的影响程度不同;泥的掺入会大大降低水泥净浆的流动度,增大流动度经时损失量,且掺量越大影响越大,因此在工程应用中,对原材料泥含量进行控制,降低泥对聚羧酸减水剂的吸附量,对提高减水剂的减水率,保证混凝土坍落度保留值具有重要意义。

To research the adsorption of polycarboxylate superplasticizer on cement and clay,the cement、sand clay and planting clay are chosen as test subjects,and the spectrophotometry（ UV） is used to determine the concentration of polycarboxylate superplasticizer react with cement and clay after a set time.The results show that： the adsorption of polycarboxylate superplasticizer on cement and clay increases with time elapsing,and adsorption amount finally reaches equilibrium; while adsorption speed and adsorption amount of polycarboxylate superplasticizer on clay is larger than cement; different kinds of clay has different adsorption amount and different degrees of negative impact on the cement paste fluidity;clay incorporation will greatly reduce the fluidity of cement paste,increase the amount of loss fluidity with time,and the larger content of clay the larger negative impact.Therefore,in engineering applications,controll clay content of the raw materials,reduce clay adsorption amount of Polycarboxylate,are important to improve water reduction,ensure concrete slump retention.