碳酸盐反应活性的新快速鉴定方法

A new accelerated method for determining the alkali reactivity of carbonate aggregate

系统研究了大量具有不同化学组成、结构和地质特征的碳酸盐集料 ,并选择加拿大Kingston的碱活性碳酸盐集料作为标准进行对比试验。研究内容涉及集料的化学组成、矿物分析和岩相检验 ,集料不同颗粒大小的碱碳酸盐反应动力学 ,探讨并否定了 80℃下晶体热致膨胀因素的影响。根据试验结果提出了一种新的评价碳酸盐集料碱活性的方法。方法的主要试验参数为 :集料尺寸 5～ 10mm、水泥中碱质量分数 1.5 0 % (等当量Na2 O)、水灰比0 .3的小混凝土试件在 80℃、1mol/L的NaOH养护溶液中养护 14d的试件膨胀率大于 0 .10 %。

Many kinds of carbonate aggregates with different chemical compositions,structures,geological characteristics have been studied systematically, and the Kingston aggregate was also worked as a standard one. This research deals with chemical components and mineral analysis, petrographic examination, the dynamics of alkali carbonate reaction with different particle sizes, negating to affection of coarse crystal thermo expansion. A new method for evaluating the potential ACR has been proposed according to the results, in which the major test factors include 1.5% Na 2O eq. of alkali content, 1 mol/L NaOH solution, w/c =0.3, 5～10 mm particle size and 14 d of test period at 80 ℃.