粉煤灰掺量对氯盐环境下高性能混凝土服役寿命的影响  

Effect of Fly Ash Content on Service Life of High Performance Concrete in Chloride Environment

作　　者：蒋琼明[1,2] 杨绿峰[2] 陈正[2] JIANG Qiong-ming;YANG Lü-feng;CHEN Zheng(College of Architecture and Engineering,Qinzhou University,Qinzhou 535011,China;Key Laboratory of Disaster Prevention and Structural Safety of China Ministry of Education,School of Civil Engineering and Architecture,Guangxi University,Nanning 530004,China)

机构地区：[1]钦州学院建筑工程学院,钦州535011 [2]广西大学土木建筑工程学院工程防灾与结构安全教育部重点实验室,南宁530004

出　　处：《科学技术与工程》2018年第24期133-138,共6页Science Technology and Engineering

基　　金：国家自然科学基金(51468004);钦州学院高层次人才科研启动项目(2017KYQD121);广西高校中青年教师基础能力提升项目(2018KY0608)资助

摘　　要：鉴于粉煤灰掺量对混凝土的抗氯离子侵蚀及服役寿命有显著影响,开展了粉煤灰混凝土的氯离子快速扩散实验和解析研究,分析了粉煤灰掺量对混凝土的扩散系数、氯离子结合能力,进而得到对混凝土服役寿命的影响规律。通过建立敏感系数模型,开展了混凝土结构服役寿命对氯离子Freundlich等温结合模型的敏感性分析。据此研究粉煤灰掺量对混凝土服役寿命的影响机理。实验结果表明,粉煤灰掺量为50%时混凝土氯离子扩散系数最小,粉煤灰掺量为30%时氯离子结合能力达到最大。模型计算和分析进一步表明:尽管粉煤灰掺量既可以通过混凝土扩散系数,也可以通过氯离子结合能力对混凝土服役寿命产生影响,但前者的影响更显著。通过对Freundlich等温结合模型的敏感性分析发现,较之于混凝土的初始结合能力,混凝土对氯离子的远期结合能力对混凝土结构服役寿命的影响更大,但随着粉煤灰掺量的增加,该影响会不断下降。In view of the significant influence of the amount of fly ash on the corrosion resistance and service life of concrete,the rapid diffusion experiment and analytical study of chloride in fly ash concrete were carried out.The influence of the volume of fly ash on the diffusion coefficient of concrete and the binding capacity of the chloride,and the service life of the concrete is analyzed.The sensitivity analysis of service life of concrete structures to the chloride Freundlich isothermal bonding model was carried out by establishing the sensitivity coefficient model.Based on this,the influence mechanism of fly ash content on the service life of concrete is studied.The experimental results show that the chloride diffusion coefficient of concrete is the smallest when the fly ash content is 50%,and the chloride binding capacity reaches the maximum when the fly ash content is 30%.The calculation and analysis of the model further show that,although the amount of fly ash can not only pass through the diffusivity of concrete,it can also influence the service life of concrete,but the effect of the former is more significant.Through the sensitivity analysis of the Freundlich isothermal binding model,it is found that the effect of the long-term binding capacity of concrete on the service life of concrete is greater than the initial binding capacity of concrete,but the effect will decrease with the increase of the amount of fly ash.

关 键 词：氯离子结合性能 高性能混凝土 服役寿命 敏感性分析 

分 类 号：TU528.043[建筑科学—建筑技术科学]