Capillary water absorption and strength of solidified marine soft soil

Abstract

In order to reveal the capillary water absorption properties and durability of soft soil solidified with industrial wastes, soda residue (SR), ground granulated blast furnace slag (GGBS), and carbide slag (CS) were used as solidifiers to solidify marine soil. The effects of solidifier content and water absorption path on capillary water absorption properties, strength, and microscopic mechanism were investigated through capillary water absorption, unconfined compressive strength (UCS), X-ray diffraction, and nuclear magnetic resonance tests. And the properties were compared with cement solidified soil. Results showed that capillary absorption parameters, including sorptivity coefficient, capillary coefficient, and diffusion coefficient, decreased with solidifier content and increased with water absorption times. The capillary absorption parameters of SR-GGBS-CS solidified soil were lower than those of cement solidified soil. For samples with 28d-UCS greater than 1390.9 kPa, the UCS after capillary absorption tended to increase up to 1.28 times. With increasing water absorption time, NaCl migrated upward and accumulated, accompanied by the change of hydrated products such as calcium chloroaluminate hydrate and ettringite, which contributed to a decrease in the strength of solidified soil. The carbon emission index of cement solidified soil was approximately 41 times that of SR-GGBS-CS solidified soil, and the soil with SR, GGBS, and CS content of 25%, 10%, and 4% respectively had the lowest carbon emission index.