粗骨料特性对新拌自密实混凝土流动性能的影响  

Effect of coarse aggregate properties on the performance of freshly mixed self-compacting concrete

作　　者：葛智 高天明 王思琪 盛丽艳 陈萌萌 孙柯 万田涛 袁化强 GE Zhi;GAO Tianming;WANG Siqi;SHENG Liyan;CHEN Mengmeng;SUN Ke?;WAN Tiantao;YUAN Huaqiang(School of Qilu Transportation,Shandong University,Jinan 250002,China;Binzhou Yellow River Bureau,Shandong Yellow River Bureau,Binzhou 256601,China;School of Civil and Hydraulic Engineering,Ningxia University,Yinchuan 750021,China)

机构地区：[1]山东大学齐鲁交通学院,山东济南250002 [2]山东黄河河务局滨州黄河河务局,山东滨州256601 [3]宁夏大学土木与水利工程学院,宁夏银川750021

出　　处：《混凝土》2024年第7期169-173,共5页Concrete

基　　金：国家自然科学基金面上项目(51978387)。

摘　　要：为探究粗骨料特性对自密实混凝土工作性和流变性的影响,首先采用骨料成像系统AIMS通过棱角、纹理、球度、棱角纹理等参数定量表征了4种粗骨料(碎石、鹅卵石、雨花石、玻璃珠)的颗粒形状及纹理特性;然后制备了4种不同粗骨料类型的自密实混凝土并测试了扩展度、T500、屈服应力和塑性黏度;最后定量分析了新拌自密实混凝土工作性及流变参数与粗骨料特性之间的关系。结果表明:粗骨料特性对自密实混凝土工作性和流变性影响显著,制备的4种自密实混凝土的扩展度介于596~688 mm、T500介于5.8~9.1 s、屈服应力介于66~261 Pa、塑性黏度介于45~105 Pa·s;降低粗骨料的棱角和纹理,或者提高其球度,有利于提高自密实混凝土的流动性并降低其流变参数;CAAT综合量化了粗骨料的几何形状和表面纹理,与自密实混凝土扩展度、T500、静态屈服应力和塑性黏度均呈现良好的线性关系。In order to investigate the effects of coarse aggregate characteristics on the workability and rheology of self-compacting concrete(SCC),the particle shape and texture characteristics of four types of coarse aggregates(crushed stone,cobble,rainstone,and glass beads)were first quantitatively characterized by parameters such as gradient angularity,texture,sphericity and coarse aggregate angularity texture(CAAT)using the aggregate imaging system(AIMS).Then the SCC with four different coarse aggregate types were prepared and tested for slump flow,T500,yield stress and plastic viscosity.Finally,the relationship between the workability and rheological parameters of the freshly mixed self-compacting concrete and the coarse aggregate properties was quantitatively analyzed.The results showed that the coarse aggregate characteristics had significant effects on the workability and rheology of the SCC,and the slump flow of the four prepared SCC ranged from 596 mm to 688 mm,T500 from 5.8 s to 9.1 s,yield stress from 66 Pa to 261 Pa,and plastic viscosity from 45 Pa's to 105 Pa's.Reducing the gradient angularity and texture of the coarse aggregate,or increase their sphericity,which is helpful to improve the flowability and reduce the rheological parameters of the self-compacting concrete.

关 键 词：自密实混凝土 工作性 流变性 粗骨料特性 纹理 

分 类 号：TU528.53[建筑科学—建筑技术科学]