泡沫混凝土孔结构表征及其对力学性能的影响  

Characterization of pore structure of foamed concrete and its influence on performance

作　　者：袁志颖 陈波[1,2] 陈家林 高志涵 YUAN Zhiying;CHEN Bo;CHEN Jialin;GAO Zhihan(School of Water Resources and Hydropower,Hohai University,Nanjing 210098,China;State Key Laboratory of Hydrology and Water Resources and Hydraulic Engineering,Hohai University,Nanjing 210098,China)

机构地区：[1]河海大学水利水电学院,南京210098 [2]河海大学水文水资源与水利工程科学国家重点实验室,南京210098

出　　处：《复合材料学报》2023年第7期4117-4127,共11页Acta Materiae Compositae Sinica

基　　金：国家自然科学基金面上项目(52079049);国家自然科学基金重点项目(51739003);国家重点实验室基本科研业务费(522012272)~~。

摘　　要：为研究泡沫混凝土孔结构及其对力学性能的影响,采用X射线计算机层析成像技术(X-CT)测试了3种密度等级泡沫混凝土孔结构,实现了对孔隙率、孔径分布、孔隙形态等特征参数的定量表征,并基于灰关联理论分析了不同孔结构特征参数与其力学性能的关联程度。结果表明:泡沫混凝土孔径分布特征符合非标准的对数正态分布,孔隙球形度均呈单峰分布,且与孔体积、孔径之间存在明显负相关关系;不同密度泡沫混凝土在不同方向上的孔隙率分布存在明显差异;随泡沫混凝土密度的增加,孔隙分形维数、中值尺寸和中值面积逐渐下降,孔隙球形度整体逐渐增大;泡沫混凝土力学性能与孔结构之间联系紧密,其中孔隙率对泡沫混凝土强度的影响最为明显,灰关联度达到0.859;与泡沫混凝土强度联系最为紧密的孔隙孔径主要分布在100~200μm、200~300μm两个区间内,灰关联度分别为0.832和0.847;孔隙形状越接近球状,其抗压能力越强。In order to study the pore structure of foamed concrete and its influence on mechanical properties,the pore structures of three density grades of foamed concrete were tested by X-ray computed tomography(X-CT)technology,and the quantitative characterization of characteristic parameters such as porosity,pore size distribution and pore shape was realized.Based on the grey correlation theory,the correlation degree between different pore structure characteristic parameters and their mechanical properties was analyzed.The results show that the pore size distribution of foamed concrete conforms to the non-standard lognormal distribution,and the pore sphericity has a unimodal distribution,and there is a significant negative correlation between pore volume and pore size.There are obvious differences in the porosity distribution of different densities of foamed concrete in different directions.With the increase of the foamed concrete density,the fractal dimension,median size and median area of pores gradually decrease,and the overall pore sphericity gradually increases.The mechanical properties of foamed concrete are closely related to the pore structure,of which the porosity has the most obvious influence on the strength of foamed concrete,and the grey correlation degree reaches 0.859.The pore size closely related to the strength of foamed concrete is mainly distributed in the range of 100-200μm,200-300μm,and the grey correlation degrees are 0.832 and 0.847 respectively.The closer the pore shape is to spherical shape,the stronger its compressive capacity.

关 键 词：泡沫混凝土 孔结构 X-CT 灰关联理论 力学性能 

分 类 号：TU528.44[建筑科学—建筑技术科学]