STRENGTH AND DURABILITY OF CONCRETE USING ARTIFICIAL HIGH STRENGTH LIGHT WEIGHT AGGREGATE MADE FROM COAL ASH AND EXPANDING SHALE POWDER

This study focused newly developed artificial high strength light-weight aggregates consisting of coal ashes and shale fine powders which enable us effectively to consum a large amount of the former in concrete.This research involves an experimental examination of strength characteristic and durability of concrete incorpotating the developed aggregates.As a result, the compressive strength of concrete with water to cement ratio of 30% showed an excellent strength characteristic of 84.6-89.4N/mm2 at the 91day age. The compressive strength of the concrete air-cured in 20°C•60% humidity condition form three day age following sealed curing showed almost the same value as the strength in water cured. This appears the developed aggregates enhanced long term cement hydration due to those absorbed water. Futhermore, drying shrinkage and carbonation depth of the concrete showed smaller than normal concrete. Freezing-thawing resistance of the concrete was also improved by dry curing before this test.