| Summary: | 碩士 === 國立中央大學 === 應用地質研究所 === 89 === A series of alkali-aggregate reaction tests including chemical test (ASTM C289), mortar bar test (ASTM C227), accelerated mortar bar test (STM C1260) and concrete prism test (ASTM C1293) for determining the alkali reactivity of aggregates in Western Taiwan rivers and Northern Taiwan andesites.
The results of ASTM C227 and ASTM C289 tests showed that the aggregates in the Western Taiwan rivers were innocuous. Furthermore in ASTM C1260 test,they were all classed as deleterious .The results of ASTM C1293 test showed that they were innocuous except the aggregates from Dah-An river, Dah-Chia river and Zuo-Sweh rivers.
The results of ASTM C227 and ASTM C1293 showed that the Northern Taiwan andesites were innocuous,when the alkali content was in the level of 1.2%(Na2Oeq.). But the alkali content in the two levels of 1.5% and 2%(Na2Oeq.), the alkali-aggregate reaction happened. So the Northern Taiwan andesites will be deleterious in high alkali content.
Compare ASTM C1260 results with ASTM C1293 results, we can find the results of these two tests will be identical in high alkali content. The results of ASTM C227 agreed with ASTM C1260 in high alkali content.
The results of the pessimum effect of Northern Taiwan andesites were non-available, when in low alkali content. When keeping increasing the alkali content, the pessimum effect was happened. The pessimum proportion of Northern Taiwan andesites was between 40% and 60%.The pessimum proportion was increased when the alkali content was increased.
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