波茨坦砂岩的微观结构和碱活性快速检测方法的适应性  

MICROSTRUCTURE OF POTSDAM SANDSTONE AND APPLICABILITY OF ACCELERATED TESTS FOR ALKALI–SILICA REACTIVITY

作　　者：卢都友[1] 许仲梓[1] 吕忆农[1] 唐明述[1] FOURNIER Benoit 

机构地区：[1]南京工业大学材料科学与工程学院,南京210009 [2]International Centre for Sustainable Development of Cemen tand Concrete Natural Resources Canada,Ottawa K1A0G1,Canada

出　　处：《硅酸盐学报》2006年第4期458-464,共7页Journal of The Chinese Ceramic Society

基　　金：国家重点基础研究规划(2001CB610706);江苏省高校自然科学研究计划(05KJB430046);教育部留学回国人员科研启动基金(2005383)资助项目。

摘　　要：为研究集料微观结构对碱活性快速检测方法中对岩石适应性的影响,采用混凝土棱柱体法、快速砂浆棒法、压蒸法、中国快速砂浆棒法研究了波茨坦砂岩的膨胀行为,并研究了膨胀后试件的微观结构。结果表明:快速砂浆棒法、压蒸法、中国快速砂浆棒法均不能正确判定波茨坦砂岩的碱活性,主要是由于这些方法使用的集料中含大量粒径太小、不能反映该砂岩特殊结构特征的颗粒;对该类岩石,除活性组分的类型、数量外,岩石的微观结构特征能够显著影响碱–集料反应发生的位置和膨胀行为。在快速法中采用能够保持岩石原有结构特征的集料粒径是正确鉴定类似波茨坦砂岩微观结构岩石及其它非均质、多矿物岩石碱活性的关键。To evaluate the effect of the microstructure of aggregate on the applicability of accelerated tests of alkali - silica reactivity for rocks, the expansion behavior of Potsdam sandstone was studied using the concrete prism test and several accelerated tests： accelerated mortar bar test, Chinese autoclave method and Chinese accelerated mortar bar test. The microstructure of the mortar bars was also studied after the expansion tests. The results show that the alkali reactivity of Potsdam sandstone is not properly identified with any of these accelerated tests because the aggregate, used in the tests has too many of fine particles, and therefore it does not reflect the special microstructure characteristics of the sandstone. The results also show that, in addition to the type and amount of reactive constituent in the rock, the microstructure of the rock has a significant influence on the location where the alkali - aggregate product forms and on the expansion behavior of the rock. In order for accelerated tests to accurately predict the alkali-expansivity of Potsdam sandstone as well as other multi-mineral and heterogeneous rocks, it is critical to use aggregate particles suitable to maintain the microstructure characteristics of the rocks.

关 键 词：碱-集料反应 碱-硅酸反应 检测方法 微观结构 

分 类 号：TQ172[化学工程—水泥工业]