风积沙混凝土的气泡参数对其强度的影响  

Influence of Air Void Parameters of Aeolian Sand Concrete on Its Strength

作　　者：董瑞鑫 申向东[2] 薛慧君[2] 刘倩 维利思 慕儒 DONG Ruixin;SHEN Xiangdong;XUE Huijun;LIU Qian;WEI Lisi;MU Ru(School of Civil and Transportation Engineering,Hebei University of Technology,Tianjin 300401,China;Water Conservancy and Civil Engineering College,Inner Mongolia Agricultural University,Hohhot 010018,China;Civil Engineering and Architecture,Southwest University of Science and Technology,Mianyang 621010,Sichuan,China)

机构地区：[1]河北工业大学土木与交通学院,天津300401 [2]内蒙古农业大学水利与土木建筑工程学院,呼和浩特010018 [3]西南科技大学土木工程与建筑学院,四川绵阳621010

出　　处：《材料导报》2022年第12期101-105,共5页Materials Reports

基　　金：国家自然科学基金(51878239,51769025)。

摘　　要：选取内蒙古自治区乌兰布和沙漠的风积沙作为细骨料,用质量分数为40%的风积沙替代部分河砂,采用气泡间距系数测定仪和核磁共振技术对风积沙混凝土孔结构特征进行测试,采用扫描电子显微镜观测风积沙混凝土龄期28 d内的微观形貌,探究风积沙混凝土气泡参数和盒维数对其强度的影响。结果表明,随着风积沙混凝土强度的增加,含气量先减小后增大,含气量与气泡比表面积呈正相关,与气泡间距系数呈负相关;风积沙混凝土ASC20、ASC30、ASC40组10~160μm的气孔占比分别为75.9%、84.3%和91.5%,大于500μm的气泡均不超过5.2%;灰熵理论下气泡的平均弦长对28 d抗压强度影响最大,气泡间距系数的影响最小;风积沙混凝土孔隙的分形维数为3.514~4.015,相关系数R^(2)均大于0.937,ASC40组的孔体积分形维数递增趋势较为明显。Aeolian sand from the Ulan Buh desert in the Inner Mongolia Autonomous Region was selected as the fine aggregate,and part of the river sand was replaced by aeolian sand with the mass fraction of 40%.The air void spacing meter and nuclear magnetic resonance technology were used to test the pore structure characteristics of the aeolian sand concrete,scanning electron microscope used to observe the micro morphology within the age of 28 d,and the influence of aeolian sand concrete air void parameters and box dimensions on its strength was explored.The results show that the air content decreases and then increases with the increase of the strength of aeolian sand concrete,and the air content is positively correlated with the specific surface area of bubbles but negatively correlated with the bubble spacing coefficient;the percentage of 10-160μm pores in ASC20,ASC30 and ASC40 groups of aeolian sand concrete is 75.9%,84.3%and 91.5%,respectively,and the bubbles larger than 500μm do not exceed 5.2%;the average chord length of bubbles under the grey entropy theory has the greatest influence on the 28 d compressive strength,and the bubble spacing coefficient has the least influence;the fractal dimension of pores of aeolian sand concrete ranges from 3.514 to 4.015,the correlation coefficient R^(2) is greater than 0.937,and the increasing trend of fractal dimension of pore volume is more obvious in ASC40 group.

关 键 词：风积沙混凝土 抗压强度 气泡参数 孔结构 灰色关联度 分形理论 

分 类 号：TU528[建筑科学—建筑技术科学]