Effect of Wetting-drying Cycles on Physical and Mechanical Properties of Stabilized Slurry with Super-absorbent Polymer

The modification of waste slurry as roadbed fill not only reduces the corresponding environmental impact, but also reuses waste materials, and thus has important engineering significance and environmental effect. To investigate the durability of stabilized soil with super-absorbent polymer (SAP) under wetting-drying cycles, a series of wetting-drying cycle tests was performed on stabilized soil. The variation in SAP content, the liquid limit of the slurry, and the presence of kaolin clay was studied. The experimental results show that the presence of SAP significantly enhances the unconfined compressive strength (<j) of stabilized soil after wetting-drying cycles. Further, there existed a threshold value of the SAP content, corresponding to the highest value of qn. With an increase in the liquid limit of slurry, q of the stabilized soil after wetting-drying cycles gradually decreased. However, enhancement of q with the presence of SAP became more significant with an increase in the liquid limit of slurry. The relationship between qu and mass loss after wetting-drying cycles can be divided into two stages: during cycles 1-4, qu of the stabilized soil with SAP increased with increasing mass. After the 4th cycle, the integrity of the specimen gradually decreased, and qu showed a power function decreasing trend with the mass loss. Moreover, the addition of kaolin can significantly improve qu of stabilized soil with SAP. However, the resistance to the wetting-drying cycle degraded accordingly. Hence, to meet both the strength and durability requirements in real projects, the SAP content in soil can be increased and materials constituting kaolinitc should be added, which also improve the resistance of stabilized slurry subjected to wetting-drying cycles. © 2023 Xi'an Highway University. All rights reserved.