骨料裹浆厚度对混凝土流变性能的影响  

Effects of Paste Thickness on Coated Aggregates on Rheological Properties of Concrete

作　　者：焦登武 安晓鹏[2] 史才军[1,2] 刘豫[2] 李晃[1] 何富强[3] 

机构地区：[1]湖南大学土木工程学院,长沙410082 [2]中国建筑材料科学研究总院绿色建筑材料国家重点实验室,北京100024 [3]厦门理工学院土木工程与建筑系,福建厦门361024

出　　处：《硅酸盐学报》2017年第9期1360-1366,共7页Journal of The Chinese Ceramic Society

基　　金：国家国际科技合作专项(2015DFA50880);国家自然科学基金(U1305243;51502279)

摘　　要：基于Bingham模型,测试了不同骨料裹浆厚度时新拌混凝土的流变参数,探究了骨料裹浆厚度对新拌混凝土流变性能的影响。结果表明,改变骨料裹浆厚度能够明显影响新拌混凝土的流变性能。在保持骨料基本参数不变时,随着骨料裹浆厚度的增加,混凝土的屈服应力、塑性黏度和静态屈服应力基本呈降低趋势,坍落度逐渐升高,混凝土的流动性得到改善;当在特定水灰比、骨料裹浆厚度相对较高时,拌合物的坍落度较高,且存在轻微离析现象。通过建立流变参数随骨料裹浆厚度的变化曲线,能够确定混凝土中的最佳胶凝材料用量,进而指导混凝土的组成设计。The effect of paste thickness on coated aggregates on the rheological properties of fresh concrete was investigated based on Bingham model. The results show that the paste thickness on coated aggregates can have a significant effect on the rheological properties of concrete. The yield stress, plastic viscosity and static yield stress of concrete gradually decrease with the increase of paste thickness on coated aggregates under the fixed parameters of aggregates. The slump gradually increases, thus improving the flowability. At a specific water-to-cement ratio and a relatively high paste thickness on coated aggregates, the mixture shows a higher slump and the slight segregation appears. The optimum amount of cementitious materials can be determined by a relationship between rheological parameters and paste thickness on coated aggregates. It could be effective to guide the concrete mixture design by controlling the rheological properties of fresh concrete.

关 键 词：Bingham模型 骨料裹浆厚度 流变性能 组成设计 混凝土 

分 类 号：TQ172[化学工程—水泥工业]