矿物掺合料混凝土早期氯离子扩散系数的试验  

The Study on Chloride-Ion-Diffusion-Coefficient of Concrete Mixed Mineral Admixture

作　　者：张巨松[1] 邓嫔[1] 鞠里红 张微[1] 韩自博[1] 陈苗[1] 

机构地区：[1]沈阳建筑大学材料科学与工程学院,辽宁沈阳110168 [2]沈阳市建委科技处,辽宁沈阳110013

出　　处：《沈阳建筑大学学报（自然科学版）》2009年第2期312-315,共4页Journal of Shenyang Jianzhu University：Natural Science

基　　金：建设部科技攻关项目(2007-k4-19);沈阳地铁混凝土攻关项目(SJW06-08-30)

摘　　要：目的研究掺不同矿物掺合料及Na2SO4混凝土的Cl-扩散系数变化规律,分析其对混凝土早期孔结构的影响.方法试件在标准养护条件下养护3 d、7 d、14 d、21 d,采用饱盐混凝土电导率(NEL)法测试混凝土氯离子扩散系数.结果粉煤灰、矿粉混凝土早期的Cl-扩散系数随掺量的增加而增加;粉煤灰与掺Na2SO4粉煤灰混凝土的Cl-扩散系数差值随粉煤灰掺量的增加而增加;矿粉与掺Na2SO4矿粉混凝土的Cl-扩散系数差值在3 d、7 d随矿粉掺量的增加而增加,14 d、28 d差值接近于零;粉煤灰与矿粉混凝土的Cl-扩散系数的差值随掺量增加而增加;掺Na2SO4的粉煤灰与矿粉混凝土的Cl-扩散系数差值在3 d、7 d随掺量的增加而增加,14 d、28 d随掺量增加无明显变化.结论掺合料的早期活性低于水泥,且粉煤灰低于矿粉;硫酸钠可激发掺合料的活性,但3 d、7 d矿粉混凝土的孔结构比粉煤灰密实,14 d、21 d基本相同,硫酸钠在14 d、21 d时激发作用已完成.The law of the change of the chloride-ion-diffusion-coefficient of different mineral admixture and sodium sulfate （ Na2 SO4 ） on the concrete is studied and its influence on the early pore structure is analyzed in this paper. The NEL method is applied to test the chloride-ion-diffusion-coefficient of concrete at 3 days, 7 days, 14 days and 21 days. The chloride-ion-diffusion-coefficient of early-age concrete is increasing along with the increase of the quantity of fly-ash and pulverized slag. The chloride-ion-diffusion-coefficient difference-value of fly-ash,the difference-value of fly-ash and Na2SO4-fly-ash concrete are also increasing along with the increase of the amount of mineral. The difference-value of pulverized slag and Na2SO4-pulverized slag concrete ,show the same tendency at 3 and 7 days but there is no obvious change at 14 and 21 days. The difference-value of fly-ash and pulverized slag concrete is increasing with the mineral increase. The difference-value of Na2SO4-fly-ash and Na2SO4-pulverized slag concrete show the same tendency at 3 and 7 days but there is no obvious change at 14 and 21 days. The results indicate that the activity of mineral admixture is lower than cement and fly-ash is lower than pulverized slag;Na2 SO4 can activate mineral admixture;the pore-structure of pulverized slag concrete is better than fly-ash concrete at 3 and 7 days and they approach at 14 and 21 days;the excitation of Na2SO4 is finished at 14 and 21 days.

关 键 词：粉煤灰 矿粉 硫酸钠 氯离子扩散系数 

分 类 号：TB321[一般工业技术—材料科学与工程]