萘系和聚羧酸系高效减水剂对混凝土性能的影响比较.pdfVIP

学兔兔 2011年第7期 混凝 土与水 泥制 品 2011 No7 7月 CHINA C0NCRETE AND CEMENT PRODUCTS July 萘 系和 聚羧酸系高效减水剂对 混凝土性能的影响比较 张海亚 ，张 斌 (1．江苏城市职业学院，南京210036；2．南京栖霞建筑材料中心实验室210038) 摘 要：通过试验对萘系高效减水剂和聚羧酸系高效减水{fI1的减水效果以及对混凝土性能的影响进行了对比。 试验结果表明：聚羧酸系高效减水剂的减水效果更好；聚羧酸系高效减水剂提高混凝土的抗压强度、抗渗性和抗碳 化性能的效果更为显著，而提高抗冻性的效果与萘系高效减水剂相当；聚羧酸系高效减水剂能减小混凝土的收缩 值，而萘系高效减水剂对减少收缩没有作用，后期甚至有负面影响。 关键词：高效减水剂；减水率；混凝土；性能 Abstract：A comparison between the effects of naphthalene series superplasticizer and polycarboxylate series super— plasticizer on the concrete’S performances is made by experiments．The results show that polycarboxylate series superplas— ticizer is better in reducing water and more effective in increasing the concrete’S compressive strength，permeability resis· tance as well as carbonation resistance；but it is as effective as naphthalene series superplastieizer in increasing the con— crete’s frost resistance．In addition，polycarboxylate series superplasticizer is able to reduce the shrinkage of concrete， while naphthalene series superplasticizer is unable，and even has negative effect in the later age of concrete． Key words：Superplastieizer；Water—reducing ratio；Concrete；Perform ances 中图分类号：TU528 文献标识码：A 文章编号：1OOO一4637(2O11)07-1O一04 0 前言 掺合料：磨细二级粉煤灰，密度2．1Og／em ，比表 混凝土减水剂是最常用的外加剂之一。早在20 面积375m2／kg，细度801~m筛余2．8％。 世纪4O年代，木质素系减水剂和具有同等效果的 集料：碎石，粒径5～25mm，表观密度2740kg／ 各种减水剂的开发和研究工作就已发展起来，6O年 m ，含水率1．0％；中砂，细度模数2．6，表观密度