矿物掺合料对氯离子扩散系数的影响  

Effects of mineral admixtures on the chloride ion diffusion coefficient

作　　者：张程强 王曙光[1] 韩建德[1] 

机构地区：[1]南京工业大学土木工程学院,南京211816

出　　处：《中国科技论文》2017年第1期46-50,共5页China Sciencepaper

基　　金：国家自然科学基金资助项目(51308290);江苏省自然科学基金资助项目(BK20130947);高等学校博士学科点专项科研基金资助项目(20133221120004)

摘　　要：采用宏观试验和微观试验相结合的方法,研究了矿物掺合料对混凝土氯离子侵蚀的影响。采用氯离子含量快速测定仪测试混凝土中自由氯离子和总氯离子质量分数分布,通过电通量法和RCM法测定氯离子扩散系数,利用压汞法测试分析掺合料混凝土孔结构的演变规律。结果表明:氯离子侵蚀初期,混凝土内部氯离子质量分数增长较快,侵蚀后期增长变得缓慢;单掺18%矿渣、单掺15%粉煤灰以及双掺15%粉煤灰与18%矿渣都有效地降低了混凝土内部自由氯离子质量分数和总氯离子质量分数;不掺粉煤灰与矿渣、单掺粉煤灰、单掺矿渣和双掺粉煤灰与矿渣4种混凝土的电通量与其扩散系数符合由大到小的顺序,即4种混凝土的扩散性能依次递减;氯离子侵蚀对混凝土孔结构的影响较小,相比较而言,双掺粉煤灰与矿渣的混凝土孔结构最好,单掺矿渣次之,而不掺粉煤灰与矿渣则最差。A combination of macro and micro test methods were used to evaluate the influence of the mineral admixture on concrete chloride ion erosion.Chlorine ion content detector was used to test the distribution of free chlorine and total chlorine ion mass fraction.Chloride ion diffusion coefficients were evaluated by electric flux method and RCM method.The evolution of pore structure of different admixtures concrete were analyzed by mercury testing.The results showed that the chloride ion mass fraction grew rapidly at the early stage of erosion and later it became slower.Single-doped fly ash（15%）,slag（18%）or double mixed fly ash（15%）and slag（18%）reduced the free chlorine and total chlorine ion mass fraction.The order of diffusion from large to small is that no fly ash and slag concrete,single-doped fly ash（15%）concrete,single-doped slag（18%）concrete,double-doped fly ash（15%）and slag（18%）concrete.Chloride ion erosion has a little influence on the pore structure.The pore structure of double-doped fly ash and slag concrete is best and the concrete without mixing fly ash and slag is the worst.

关 键 词：矿物掺合料 氯离子扩散系数 耐久性 浓度分布 孔隙率 压汞法 电通量法 RCM法 

分 类 号：TU528[建筑科学—建筑技术科学]