硝酸银显色法测量混凝土氯离子表观扩散系数  

MEASUREMENT OF CHLORIDE APPARENT DIFFUSION COEFFICIENT IN CONCRETE USING AgNO_3 COLORIMETRIC METHOD

作　　者：何富强[1] 史才军[2] 安晓鹏[2] 

机构地区：[1]中南大学土木建筑学院,长沙410075 [2]湖南大学土木工程学院,长沙410082

出　　处：《硅酸盐学报》2010年第11期2178-2184,共7页Journal of The Chinese Ceramic Society

摘　　要：研究了硝酸银显色法快速测量混凝土中氯离子表观扩散系数。将14组混凝土试件分别在16.5%与3.5%NaCl溶液中浸泡90d和300d,用AgNO_3显色法及NT Build 443法测量其氯离子表观扩散系数(D_A和D_N)。结果表明:用浸泡液浓度为表面氯离子浓度情况下,当表层氯离子浓度与浸泡液氯离子浓度相近时,D_A与D_N值相近;浸泡90 d时,一部分D_A与D_N值相近;浸泡300 d时,所有的D_A与D_N均十分相近。测量的表层氯离子浓度作为表面氯离子浓度时,所有D_A和D_N均十分接近。因此,合理确定表面氯离子浓度后,硝酸银显色法可以快速且较为精确地测量混凝土氯离子表观扩散系数。A quick method for measurement of chloride apparent diffusion coefficient in concrete using AgNO_3 colorimetric method was investigated.14 batches of concrete specimens were respectively immersed in 16.5%and 3.5%NaCl solutions for 90 and 300 d. Their apparent Cl^-diffusion coefficients were measured by the AgNO_3 colorimetric method and NT Build 443 method（named as D_A and D_N）.In the case of taking chloride concentration in the immersion solution as surface chloride concentration（c_s）,when chloride concentrations in the surface layer and the immersion solution were similar,D_A and D_N,values were almost the same.After 90 d of immersion,part of D_A and D_N values were almost the same.After 300 d of immersion,all of D_A and D_N values were almost the same. When taking chloride concentration in the surface layer as the c_s,all of D_A and D_N values were almost the same.Therefore,after determination of c_s,the apparent diffusion coefficients can be measured rapidly and relatively accurately by the AgNO_3 colorimetric method.

关 键 词：氯离子表观扩散系数 硝酸银显色法 变色深度 变色边界氯离子浓度 混凝土 

分 类 号：TU528.01[建筑科学—建筑技术科学]