Comparative Study on Mortar Containing Fly Ash from Southeast Asia and Japan in Relation to Strength and Durability

Abstract

In Thailand, the utilization of fly ash as a concrete admixture has been increasing gradually. However, there are no local standards regulating the use of fly ash. Mixing of concrete usually follows standards that contain requirements, especially temperature, that are difficult or sometimes impossible to satisfy. Therefore, this research was carried out to verify the influence of temperature, hot (Thailand) and temperate (Japan) climate, on the strength and durability properties of fly ash mortar. Also, to propose an optimum range of cement replacement percentage and water-binder ratio for each kind of fly ash under Thai (simulated) and Japanese climate conditions. From this investigation, it was found that fly ash exhibited advantages in strength and durability of mortar under high temperatures. The strength activity index of both fly ash mortars were satisfied in accordance with ASTM C 618 under all temperatures considered. Furthermore, the optimum range of cement replacement and water-binder ratio became wider with increasing temperature. Thus, fly ash is recommended to be used under high temperatures.