Application of Decomposed Granite as Fine Aggregate for Concrete

Physical properties of decomposed granites distributed widely in Tottori prefecture were examined. Subsequently, mix proportion and manufacture of concrete with water content of 150kg/m3 and slump of 8cm using the decomposed granite from Togou Dam site origin were conducted. The problems with this mix design, and the properties of the fresh and hardened concrete with the decomposed granite also were examined and compared to that of ordinary concrete with normal sand. Test results showed that the disadvantage of concrete with the decomposed granite where (1) slump loss with time is larger, (2) bleeding becomes almost equal to zero, and (3) setting time becomes short compared to that of the ordinary concrete, could be improved to have almost the same physical properties as that of ordinary concrete with normal sand by using a retarder type of air-entraining high-range waterreducing agent.