摘要
为探究干湿-冻融循环作用下模袋混凝土损伤特征,基于扫描电镜(SEM),结合差分盒维数法,计算得到了其分形维数的微观损伤演化特征;又基于核磁共振试验(NMR)的T_(2)谱计算了孔隙体积的分形维数,发现孔隙结构具有分形特征,并推导了孔隙度、渗透率与分形维数之间的数学关系;进一步,结合分形理论,以相对动弹性模量为损伤指标,建立了基于小波变换回归估计的模袋混凝土干湿-冻融损伤模型.所建立的损伤模型能够很好地表征渗透率与相对动弹性模量之间的函数关系,说明分形维数能够作为损伤参量用以评估模袋混凝土的抗干湿-冻融性能.分形维数将模袋混凝土的微观特征进行了量化,建立了其微观和宏观损伤的联系,研究结果可为模袋混凝土衬砌干湿-冻融损伤定量描述提供依据.
In order to explore the damage characteristics of mold-bag concrete under dry-wet and freeze-thaw cycles,based on the scanning electron microscope(SEM)test,the fractal dimension of the damage evolution characteristics was calculated by the box-counting methods.The fractal dimension of the pore volume was calculated by the nuclear magnetic resonance(NMR)test.The mathematical relationship was established between the porosity,permeability,and the fractal dimension.Furthermore,based on the fractal theory,using relative dynamic elastic modulus as damage index,the dry-wet and freeze-thaw damage model of concrete based on wavelet transform regression estimation can characterize the functional relationship between permeability and relative dynamic elastic modulus.It shows that the fractal dimension can be used as a damage parameter to evaluate the dry-wet and freeze-thaw resistance of concrete.The fractal dimension quantifies the microscopic characteristics of concrete and establishes the relationship between micro-and macro-damage.The results can provide a basis for the quantitative description of dry-wet and freeze-thaw damage of mold-bag concrete lining.
作者
孙浩然
邹春霞
薛慧君
赵泉
武军
SUN Haoran;ZOU Chunxia;XUE Huijun;ZHAO Quan;WU Jun(Water Conservancy and Civil Engineering College,Inner Mongolia Agricultural University,Hohhot 010018,China;Urad Irrigation Management Bureau,Hetao Irrigation District,Inner Mongolia,Bayannaoer 014400,China)
出处
《建筑材料学报》
EI
CAS
CSCD
北大核心
2022年第2期124-130,共7页
Journal of Building Materials
基金
内蒙古自治区水利科研专项项目(NSK2016-S11)
内蒙古自治区自然科学基金资助项目(2020BS05008)
内蒙古农业大学引进优秀博士人才科研启动资助项目(NDYB2018-40)。
