粉煤灰对混凝土抗氯盐侵蚀性能的影响  

Influence of fly ash on concrete's ability to resist chloride ion penetration

作　　者：谭业文 王曙光[1] 刘伟庆[1] 韩建德[1] 杜东升[1] 徐锋[1] 李威威[1] 

机构地区：[1]南京工业大学土木工程学院,江苏南京211816

出　　处：《混凝土》2017年第7期144-148,共5页Concrete

基　　金：国家自然科学基金(51308290);江苏省自然科学基金(BK20130947);教育部博士点基金新教师类(20133221120004)

摘　　要：利用电通量法、快速迁移法和压汞法试验分析了不同粉煤灰掺量(0、10%、20%、30%、40%)以及不同养护龄期(28、56、90 d)对强度为C55混凝土的电通量、氯离子扩散系数及孔结构的影响;研究了平均孔径与粉煤灰掺量、养护龄期的关系,并以平均孔径为中间变量,得到了氯离子扩散系数和粉煤灰掺量、养护龄期的关系式。研究表明,粉煤灰的掺入可以较好地改善混凝土的抗氯离子扩散性能,该效应在较长养护龄期的情况下尤为明显;对于强度为C55的混凝土,当粉煤灰掺量为30%时,混凝土抗氯盐侵蚀性能最好;粉煤灰的掺入可明显改善混凝土孔结构的分布,增加无害孔和少害孔所占的比例;减小平均孔径和最可几孔径,当粉煤灰掺量在30%时,混凝土具有更优的孔隙结构;氯离子扩散系数的实测值与计算值变化趋势基本相同。The influence of different fly ash content（0,10%,20%,30%,40%）and different curing age（28,56,90 d）on concrete electric flux,chloride ion diffusion coefficient and pore structure were analyzed using electric flux method,the rapid transition method and mercury intrusion porosimetry.The relationship among fly ash content,curing age and chloride diffusion coefficient is obtained with average pore diameter as the intermediate variable.Researches show that using fly ash can significantly improve resistance to chloride ion diffusion properties of concrete,especially in the case of a longer curing period.For concrete with strength of C55,when the content of fly ash is 30%,concrete can obtain the best performance of chloride corrosion resistance.Fly ash can significantly improve the distribution of the pore structure of concrete.When the content of fly ash is 30%,concrete has better pore structure.The trends of the measured value and calculated value of the chloride ion diffusion coefficient are similar.

关 键 词：混凝土耐久性 粉煤灰 电通量 氯离子扩散系数 孔结构 

分 类 号：TU528.041[建筑科学—建筑技术科学]