不同密度等级泡沫混凝土的性能和孔结构  

Properties and pore structure of foam concrete with different density

作　　者：张亚梅[1,2] 孙超 王申 朱玉 孙国星 ZHANG Yamei;SUN Chao;WANG Shen;ZHU Yu;SUN Guoxing(School of Materials Science and Engineering,Southeast University,Nanjing 211189,P.R.China;Jiangsu Key Laboratory of Construction Materials,Southeast University,Nanjing 211189,P.R.China;Institute of Applied Physics and Materials Engineering,University of Macao,Macao 999078,P.R.China;MOE Joint Key Laboratory by the MOE Key Laboratory of Bioinorganic and Synthetic Chemistry of Sun Yat-Sen University and Institute of Applied Physics and Materials Engineering of the University of Macao,University of Macao,Macao 999078,P.R.China)

机构地区：[1]东南大学材料科学与工程学院,南京211189 [2]东南大学江苏省土木工程材料重点实验室,南京211189 [3]澳门大学应用物理及材料工程研究院,澳门999078 [4]澳门大学中山大学生物无机与合成化学教育部重点实验室与澳门大学应用物理及材料工程研究院联合重点实验室,澳门999078

出　　处：《重庆大学学报（自然科学版）》2020年第8期54-63,共10页Journal of Chongqing University

基　　金：南京长江大桥维修改造工程研究项目资助项目(201727002),澳门科学技术发展基金资助项目(FDCT-078/2017/A2)。

摘　　要：泡沫混凝土的密度等级对其性能有显著影响。笔者制备了干密度在300~1000kg/m^3范围内的泡沫混凝土,对其浆体流动度、抗压强度、吸水率和干燥收缩进行了测试,利用X射线计算机断层扫描成像(X-ray computed tomography,X-CT)对试件的孔结构进行表征。结果显示:随着泡沫混凝土密度等级增加,其浆体流动度先增大后减小,密度为600kg/m^3时流动度最大;抗压强度随密度等级增加而逐渐增大,并与密度等级之间存在指数关系;干燥收缩和吸水率均随密度等级增加逐渐减小,这是由于其内部孔隙率降低、封闭孔增多所致。X-CT分析结果显示,密度低于600kg/m^3的泡沫混凝土内部孔隙分布不均,试件表面的大孔较多,这是由于浆体与泡沫的体积比过低、浆体无法均匀地包裹在泡沫表面所致。Density of foam concrete has a significant impact on its performance.In this study,foam concrete with dry density of 300kg/m^3 to 1000kg/m^3 was prepared to test the slurry fluidity,compressive strength,water absorption,and drying shrinkage;and pore structures of the specimens were characterized by X-CT(X-ray computed tomography).The results showed that the fluidity of the slurry firstly increased and then decreased with the increase of the foam concrete density,and reached a maximum at 600kg/m^3.The compressive strength of the foam concrete increased gradually and there was an exponential relationship between it and the density grade.The drying shrinkage and water absorption were all gradually reduced with the increase of the density due to the decrease of internal porosity and the increase of closed pores.XCT analysis showed that the pores in the foamed concrete with a density less than 600kg/m^3 were unevenly distributed,and there were more large pores on the surface of the specimen compared with the bulk.It is presumed that the volume ratio of the cement paste to the foam is too low for the paste to uniformly wrap the bubbles on the surface of the foam concrete.

关 键 词：泡沫混凝土 密度等级 性能 孔结构 

分 类 号：TQ178[化学工程—硅酸盐工业]