Abstract
Granulated coal ash is the alternative sea sand. That is manufactured by mixing coal fly ash powder with a small amount of cement and adequate amount of water. GCA consists of particles that ranged from coarse sand to gravel. The mean diameter of GCA is approximately 20mm. Moreover, the particles is a porous material which has a small specific gravity. It is expected that the environmental loads resulting from industrial wastes will be reduced if GCA was used. The purpose of this study is to evaluate of change of chemical composition of GCA utilized alternative sea sand in coastal area. At first, The five kinds of alternative sea sand in different mixing ratio of fly ash and cement were prepared. These materials were cured for 30 months prior to use in the experiments. The changes of the chemical composition of alternative sea sand were analyzed by XRF, XRD, and SEM observation. Moreover, the materials were analyzed to investigate the difference in specific surface by Gas Adsorption. Second, the standard GCA samples were immersed in sea water for three years. And, Divers collected the GCA layer sample which was used for 13 years in bottom sediment of coastal area. These sample materials were evaluated by XRF, XRD. From our findings, it is clarified that the change of the chemical composition of alternative sea sand, which was cured for 30 months and used for long term in coastal area.
