Abstract
This study investigates the effects of organic matter on lime and cement stabilized Ariake clays with emphasis on their mechanical properties and microstructure. The study also focuses on the effect of humic acid, which is a part of organic matter, on the strength development of stabilized clays. The results show that the strength and the yield stress of lime stabilized clay with high humic acid are low due to the obstruction of the pozzolanic reaction. Consequently, the cementing products are not visible in the micrographs. The humic acid has a greater effect on the strength reduction of lime stabilized clay than that of cement stabilized clay. The effect of humic acid on strength of stabilized clays decreased with increasing salt concentration because the humic acid becomes inactive at higher salt concentration.
