掺淤砂混凝土力学行为与微观孔结构特征研究  

Mechanical Properties and Pore Structure Characteristics of Sludge Concrete

作　　者：师现营 师苏傲特 李松 SHI Xianying;SHI Suaote;LI Song(East Henan Water Conservancy Project Management Bureau,Kaifeng 475000,China;China Water Resources and Hydropower Eleventh Engineering Bureau Co.,Ltd.,Zhengzhou 450001,China;School of Water Conservancy,North China University of Water Resources and Electric Power,Zhengzhou 450046,China)

机构地区：[1]河南省豫东水利工程管理局,河南开封475000 [2]中国电建水利水电十一局,河南郑州450001 [3]华北水利水电大学水利学院,河南郑州450046

出　　处：《人民黄河》2022年第6期139-143,共5页Yellow River

基　　金：国家重点研发计划项目(2018YFC0406803)。

摘　　要：含初始缺陷的混凝土,其孔结构具备多尺度特性,基于多尺度理论改变孔结构对增强混凝土力学性能具有重要意义。采用试验和理论分析手段,设计不同淤砂掺量的混凝土配合比方案,利用NMR、SEM检测技术及PCAS分析软件对掺淤砂混凝土力学性能和微观特征进行了分析研究。结果表明:掺淤砂混凝土抗压强度随淤砂掺量先增大后减小,淤砂有效掺量区间为10%~20%;抗压强度与总孔隙率保持良好的线性关系,对于各尺度孔隙率来说,10~100 nm孔径孔隙结构对抗压强度影响最为显著;淤砂掺量增加,凝胶孔的孔隙结构有转优的趋势,但孔隙率增大,孔洞体积变大,均匀分布的孔洞使凝胶体形成“网状结构”,胶凝效应弱化,导致混凝土的大孔径占比由大变小,强度反而降低。The pore structure size of concrete with initial defects is distributed from nanometer to millimeter,and it has multi-scale characteristics.Based on the multi-scale theory,changing the pore structure is of great significance to enhance the mechanical properties of concrete.In this paper,experimental and theoretical analysis means were adopted to design concrete mix proportion schemes with different sludge contents.The mechanical properties and microscopic characteristics of sludge concrete were analyzed and studied by using NMR and SEM detection technology and PCAS analysis software.The results show that the compressive strength of sludge concrete first increases and then decreases from the amount of sludge.The effective amount of sludge ranges from 10%to 20%.Compressive strength and total porosity maintain a good linear relationship.For porosities of various scales,the 10-100 nm-level pore structure has the most significant impact on compressive strength.With the increase of sludge content,the pore structure of the gel hole tends to be better,but with the increase of porosity,the pore volume becomes larger,and the uniformly distributed pore makes the gel form a“network structure”,which weakens the bonding effect and leads to the decrease of the pore size and the strength of concrete.

关 键 词：混凝土 孔结构 淤砂 孔隙率 力学性能 

分 类 号：TV41[水利工程—水工结构工程]