Effect of Freeze-thaw Cycles on the Strength and Durability of Cement-stabilized Soils Mixed with Composite Recycled Materials
古川, 芹菜亀井, 健史
33 , 2016-07-31 , 宮崎大学工学部
This paper investigates the influence of freeze-thaw cycles on the unconfined compressive strength and durability of very soft clay soil stabilized with composite recycled materials based on the formation of etteringite in ground improvement applications. Recycled bassanite is mixed with coal ash and blast furnace slag in varying proportions to obtain the optimal ettringite production, based on the chemical response. This admixture was treated with as small amount furnace cement type B cement to enhance the performance of soft clay. The results of this study show that an increase in the number of freeze-thaw cycles decreases the unconfined compressive strength and durability index. The presence and increase in the composite recycled materials content in the soil mixture has a significant effect on the role of composite admixture in increasing the soil strength and durability. Based on the observation of internal structure using a scanning electron microscope (SEM), ettringite occurrence is related to the strength increase of cement-stabilized soil.Well-developed ettringite could be seen in the case of higher composite recycled materials addition ratios. In addition, the use of composite recycled materials as a stabilizer material for very soft clay achieves the acceptable durability and strength against the effects of freeze-thaw cycles.These properties make composite recycled materials useful as a construction material.