岩相法碱集料反应检测 砂浆棒法碱活性检测

本文扼要综述关于混凝土中掺入部分碱活性集料后,对后期强度和膨胀开裂影响的试验研究和长期观测结果。

In thisarticle, the cut-sections of concrete for energy spectrum ana lysisby an electron microscope has been proved correct and successful.Its method of prevention is not to use any aggregate of reducingactivity. By way of dipping the mortar specimen into an 80℃alkali-solution to get its relative deformation after 12-day is byfar the most reliable,simplest and experimental method todetermine the reducing activity of aggregate.

用电子显微镜对混凝土切片进行能谱分析 ,可准确地判定碱集料反应。其预防方法是不用具有碱活性的集料。把砂浆试件沉入80℃碱液中,测量试件经12d的相对变形值 ,以判定集料的碱活性状况 ,是可靠、简单的快速试验方法。

Thealkali-aggregate reaction (AAR) occurred in the ocean concreteproject of Beilun seaport harbor in Ningbo, Zhejiang Province, wasstudied by means of the petrography analysis, the autoclave rapidtest method, SEM/EDAX, XRDA and other techniques. It was found thatthere are a lot of reactive aggregates in the cracking concreteprojects, located at the sea water spray zone but there are fewreactive aggregates in the intact crack-free concrete projects.Although alkali content in the cement is very low,the... 显示全部

对浙江省宁波北仑港海工混凝土构件，用岩相法、扫描电镜／能谱分析、快速压蒸测长法，X－射线衍射分析等方法进行研究，发现在浪溅区凡表面开裂剥落的混凝土构件中都含有大量的活性集料，并发生了碱集料反应，而表面完整没有裂纹的混凝土构件中活性集料较少；结果表明，海工混凝土如使用碱活性集料，它与来自海水中的碱将会发生反应造成混凝土开裂；碱集料反应和钢筋锈蚀等破坏作用的相互促进，使海工混凝土构件的耐久性大大下降。