AN EXPERIMENTAL STUDY ON APPLICATION OF GRANULATED COAL ASH SLAG TO CONCRETE AGGREGATE

Aggregate test, mortar test, concrete test and manufacture test of secondary concrete products were executed in order to examine whether the coal ash slag can be used as a fine aggregate for concrete. As a result of these tests, the coal ash slag turned out to be similar to the pit sand in ingredient composition without any toxic chemicals to be eluted and after being subject to grinding process, it satisfied the quality requirements as a fine aggregate for concrete. The greater the slag substitution rate is, the greater the bleeding rate of the concrete using coal ash slag becomes. However, the concrete using coal ash slag has almost equivalent the compressive strength and tensile strength to those in which the land sand is used. Concerning the characteristics related to durability, such as the carbonation rate and freeze-thaw resistance, it did not show any difference from the concrete using the land sand. With these results, it can be concluded that the granulated coal ash slag has a quality to be applied to structural concrete.