EFFECTIVENESS OF MINERAL ADMIXTURES IN PREVENTING EXCESSIVE EXPANSION OF CONCRETE DUE TO ALKALI-AGGREGATE REACTION

摘要: Abstract : Twenty materials, representing eight different classes of mineral admixtures, were evaluated, using both chemical and mortar-bar test methods, for their effectiveness in preventing excessive expansion concrete due to alkali-aggregate reaction. The criteria the tests are examined, results compared with results. All those obtained by two other laboratories. It was found that cannot be used reliance evaluate effectiveness, procedure needs improvement increase its precision. Each replacement materials evaluated will prevent if a sufficient quantity is used. Correlations between and: fineness, dissolved silica, percentage alkali retained reaction product. Calculations made suggest minimum each material required effective prevention ranged from 10% synthetic silica glass 45% one slags. By groups these calculated percentages were: calcined shales, 19 29; uncalcined diatomite, 22; volcanic glasses, 32 36; slags, 39 45; fly ashes, 40 44.