超细粉体和减水剂对超高性能混凝土新拌性能的影响  

Effect of Ultra-fine Powder and Superplasticizer on Fresh Performance of Ultra-high Performance Concrete

作　　者：余雪娟 郑晓博 刘建忠[2] 韩方玉[2] 沙建芳[2] 方若全 YU Xuejuan;ZHENG Xiaobo;LIU Jianzhong;HAN Fangyu;SHA Jianfang;FANG Ruoquan(Jiangsu Transportation Engineering Construction Bureau,Nanjing 210001,China;Jiangsu Research Institute of Building Science Co.,Ltd.,Nanjing 210008,China)

机构地区：[1]江苏省交通工程建设局,南京210001 [2]江苏省建筑科学研究院有限公司,南京210008

出　　处：《材料导报》2025年第10期101-106,共6页Materials Reports

基　　金：国家自然科学基金重点项目(52130806);国家自然科学基金重大项目(52293432)。

摘　　要：通过建立出浆时间判定与测试方法,研究了超细粉体和减水剂对超高性能混凝土(UHPC)拌和过程的影响,采用减水剂吸附量、颗粒堆积密实度以及水膜层厚度测试,基于颗粒堆积行为揭示了UHPC出浆时间作用机制。结果表明:UHPC在搅拌过程中经历湿颗粒形成期、湿颗粒生长期、团聚临界状态(出浆状态),之后迅速形成团聚体并转变为浆体,提出了出浆状态判据与出浆时间测试方法。相对于超细粉体,减水剂对UHPC出浆时间的影响较小。微米颗粒体系的出浆时间明显小于纳米颗粒体系,球形颗粒体系的出浆时间明显小于不规则颗粒体系。颗粒堆积密实度和水膜层厚度是控制出浆时间的关键,水膜层厚度决定了出浆时间的总体范围,而颗粒堆积密实度和水膜层厚度决定了出浆时间的变化规律。By establishing a method for determining and testing the pulping time,the impact of ultra-fine powder and superplasticizer on the mixing process of ultra-high performance concrete(UHPC)was investigated.The adsorption amount of superplasticizer,particle packing density and water film thickness were tested to reveal the mechanism of pulping time based on particle packing behavior.The results show that UHPC during the mixing process undergoes a wet particle formation period,a wet particle growth period,and a critical state of coacervate(pulping state),and then quickly forms agglomerates and transforms into a paste.The criteria for the pulping state and the pulping time test methods are proposed.Compared with ultra-fine powder,the superplasticizer has less impact on pulping time of UHPC.The pulping time of micron particle system is significantly shorter than that of nanoparticle system,and the pulping time of spherical particle system is significantly shorter than that of irregular particle system.The particle packing density and the water film thickness are the keys to controlling the pulping time,among these,the water film thickness determines the base and range of the pulping time,and the particle packing density and the water film thickness determine the variation pattern of the pulping time.

关 键 词：超高性能混凝土 超细粉体 减水剂 新拌性能 堆积密实度 水膜层厚度 

分 类 号：TU528[建筑科学—建筑技术科学]