抄録
Consolidation of cement-treated high-water content clays during their initial curing stages is a rarely considered factor in design practice, due to the assumption that cement hydration progresses much faster than consolidation in clays under typical circumstances. Certain situations, however, seem to point to importance of early-age effective stress developments in treated ground when its interim and eventual shear strengths are evaluated. This study experimentally investigated manners in which cement-treated clays develop its yield stress and shear strength through interactions between bonding and densification when subjected to effective stress changes prematurely before the hydration processes are complete. The investigation involved a suite of undrained triaxial tests on cement-treated specimens that were cured under different isotropic stresses, supplemented by K0 compression tests. The results suggested that apparently opposite consequences could be observed depending on the cement doses; reductions in undrained shear strength were observed when early-age consolidation occurred in clay treated with a larger cement dose, while the opposite was true for a smaller cement dose. These apparently complex effects seem to be only explained by kinematic development of a state bounding surface, which adjusts itself to a consolidation stress regime during curing.
