丹江口大坝混凝土芯样的微观测试与分析  

Microscopic Tests and Analysis on Concrete Core Samples from Danjiangkou Dam

作　　者：李珍[1,2] 肖靓[1] 汪在芹[1,2] 

机构地区：[1]长江科学院材料与结构研究所,武汉430010 [2]水利部水工程安全与病害防治工程技术研究中心,武汉430010

出　　处：《长江科学院院报》2011年第5期59-62,共4页Journal of Changjiang River Scientific Research Institute

基　　金：水利部公益性行业专项项目(200801057)

摘　　要：丹江口大坝初期工程混凝土中含有一定量活性骨料——燧石,使得大坝混凝土存在碱骨料反应发生的风险。为此,对大坝混凝土进行了取芯研究,重点对原始芯样与养护后芯样采用扫描电镜(SEM)、能谱仪(EDS)进行了微观测试与分析,以准确判断大坝混凝土碱骨料反应发生情况。分析结果表明:由于建设初期采取的措施得当,运行40余年的大坝混凝土没有任何碱骨料反应发生;但是当混凝土芯样在一定的养护条件下,即同时具有活性骨料、碱和水3个必要条件时,仍会发生显著的碱骨料反应。由此得出:为了保证含有碱活性骨料的大坝混凝土能够长期安全运行,加高工程混凝土除采取适当的抑制措施以外,还应该加强整个大坝的防渗保护。During the initial construction stage of Danjiangkou Dam,a certain number of reactive aggregates（flints） were found in the concrete and hence posed potential risks caused by possible Alkali-Aggregate Reaction（AAR）.In this paper,microscopic tests on the original core samples and cured core samples are carried out to judge the status of AAR accurately.The test methods include Scanning Electron Microscope Analysis（SEMA） and Energy Dispersive Spectrometry Analysis（EDSA）.The analysis results show that AAR deterioration hasn＇t been found since 40 years of dam operation due to proper preventive measures.Nonetheless,AAR is still likely to occur if three indispensable elements exist,namely certain number of reactive aggregates,available alkalis,and water.It is concluded that besides taking proper control measures to the concrete of heightened part,the impermeability of the whole dam should be enhanced for long-term durability and safety of the dam containing alkali reactive aggregates.

关 键 词：大坝安全 碱活性 碱骨料反应(AAR) 微观测试 

分 类 号：TV431[水利工程—水工结构工程]