基于核磁共振的粉煤灰混凝土水和气体渗透性与孔结构的研究  

Relationship between pore structure and water/gas permeability of fly ash concrete based on nuclear magnetic resonance method

作　　者：张俊芝[1,2] 吕萌 方赵峰 章玉容 王建东 ZHANG Junzhi;LV Meng;FANG Zhaofeng;ZHANG Yurong;WANG Jiandong(College of Civil Engineering and Architecture,Zhejiang University of Technology,Hangzhou 310014,China;Key Laboratory of Civil Engineering Structure&Disaster Prevention and Mitigation Technology of Zhejiang Province,Hangzhou 310014,China)

机构地区：[1]浙江工业大学建筑工程学院,浙江杭州310014 [2]浙江省工程结构与防灾减灾技术研究重点实验室,浙江杭州310014

出　　处：《南昌工程学院学报》2018年第6期63-70,共8页Journal of Nanchang Institute of Technology

基　　金：国家自然科学基金资助项目(51279181);浙江省自然科学基金资助项目(LY17E090007,LY13E090008,LQ18G010007)

摘　　要：以自主设计加工的一种试验装置,测定了粉煤灰混凝土的水和气体渗透系数;同时,以核磁共振(NMR)技术测试了试验混凝土的孔隙率及其孔径分布等微观结构参数。分析了粉煤灰掺量对混凝土的水、气体渗透性及微观结构参数的影响,以及粉煤灰混凝土水和气体渗透性与其微观结构参数之间的关系。试验结果表明掺量在40%以内时,混凝土的水和气渗透系数均随粉煤灰的掺量增加有较明显的降低,但降低混凝土气体和水渗透性的最佳掺量分别是30%和40%;不同的粉煤灰掺量导致混凝土内孔径分布的变化,主要体现在不同孔径大于10 nm孔的分布;相较于总孔隙率,混凝土中不同孔径的贡献孔隙率可以更直观地反映微毛细孔(10～100 nm)和大毛细孔(100～1000 nm)对粉煤灰混凝土的水和气体渗透性的不同影响;混凝土中的微毛细孔和大毛细孔的贡献孔隙率与其气体渗透系数之间关系,比其与水渗透性之间的关系更加紧密。A self-designed device was used to measure the water and gas permeability coefficients of fly ash concrete.Meanwhile,the porosity and pore size distribution of fly ash concrete were measured with the nuclear magnetic resonance(NMR)method.The effect of fly ash on the water and gas permeability and the microstructure parameters of concrete,and their interrelation were investigated.The results indicate that when the addition of fly ash is less than 40%,the water and gas permeability coefficients decrease with the increasing of fly ash.However,the optimal replacement of fly ash is 30%and 40%for the gas and water permeability,respectively.Besides,the addition of fly ash has a significant influence on the pore size distribution of pore size larger than 10 nm.Compared with the total porosity,the contributive porosity with different pore diameters can reflect the influence of medium capillary pores(10 nm<d<100 nm),large capillary pores(100 nm<d<1000 nm)on the water and gas permeability more intuitively.Moreover,the contributive porosity is more relevant to the gas permeability than the water permeability.

关 键 词：粉煤灰 混凝土 渗透性 微观结构 核磁共振 

分 类 号：TU528.36[建筑科学—建筑技术科学]