Effect of wetting-drying cycles on strength properties of ground granulated blast-furnace slag and magnesium oxide-stabilized soft clay

In this study, MgO is added to GGBS as an activator and is used to stabilize kaolin clay. For the purpose of comparison, cement is used as another type of binder to stabilize kaolin clay. The effect of wetting-drying cycles on the durability of the stabilized soils is investigated. The results of unconfined compression tests show that wetting-drying cycle has more evident effect on GGBS+MgO stabilized soils. The change rules of unconfined compressive strength, pH, secant modulus, and mass loss with wetting-drying cycle and standard curing time are discussed. It is found that the values of unconfined compressive strength of GGBS+MgO-stabilized soils are 1.5 times those of cement-stabilized soils under the standard curing condition. pH of GGBS+MgO-stabilized soils is slightly lower than that of the cement-stabilized soils. Upon wetting-drying cycles, the unconfined compressive strength of GGBS+MgO-stabilized soils decreases more rapidly than that of the cement-stabilized soils. pH of both GGBS+MgO- and cement-stabilized soils decreases with the increasing wetting-drying cycles. It is found that the degree of integrity of GGBS+MgO-stabilized soils is lower than that of the cement-stabilized soils. It is concluded that compared with that of the cement-stabilized soils, the wetting-drying durability of the GGBS+MgO-stabilized clay is weaker.