| Summary: | 碩士 === 國立中央大學 === 土木工程學系 === 101 === This research is apply Accelerated Lithium Migration Technique which use electrical drive lithium ions into concrete specimens and drive alkali out simultaneously ,the concrete specimens has alkali aggregate expansion reaction potential.
The specimens undergo 60 V constant voltage during the ALMT testing process. The anolyte and catholyte solutions consisted of 1L 1N LiOH．H2O and saturated Ca(OH)2, respectively. This research parameter conditions of testing such as the aggregate/paste ratio of concretes, the w/c ratio and the distance of electrodes of testing to find the distance of electrodes appropriately by the migration of ions relating to cumulative power. And analyze the effect on specimen length (distance between electrodes) for ion transmission, and the transmission performance. The results show that the concrete has higher water/cement ratio, it is beneficial for the migration of ions, the time of alkali to be removed is faster and the electricity consumed lesser and the the system resistance increases during the testing. The specimen of 8 cm is unbeneficial for the migration of ions, because the heat effect and precipitation of calcium carbonate on surface. When the specimen length under the 24 cm, it is beneficial for the migration of ions, and out of the alkali content is more than 80 %, and the Li/(Na+K) molar ratio were higer than the recommend value of 0.74, it is the appropriate range of distance between electrodes.
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