Effect of waste tire rubber crumb on impermeability of cement-stabilized soil

To alleviate the application limitations of cement-stabilized soil in impermeable engineering and promote the recycling of waste rubber tires, crumb rubber produced from waste rubber tires was used to improve the engineering properties of the soil. The effect of crumb rubber on the permeability of the soil under different conditions was investigated using compression, compaction, and permeability tests. Crumb rubber can effectively improve the impermeability of cement-stabilized soil. The impermeability efficiency of crumb rubber is between 11% and 45%. Cleaning crumb rubber with water and Na₂CO₃ solution can reduce the hydraulic conductivity of rubberized cement-stabilized soil (RCSS) by 7.9%-63.6%. This, in turn, increases the unconfined compressive strength by 4.1%-25.5%. The hydraulic conductivity of the RCSS decreases with an increase in the cement content, curing duration, and void ratio. A crumb rubber concentration of 10%-20% is suitable for enhancing the impermeability of the RCSS and satisfying its strength requirements. The NOF of the equation used to predict the hydraulic conductivity of the RCSS by the rubber content, cement content, and curing duration is less than 0.35. The linear correlation between the predicted and measured values of hydraulic conductivity was determined to be 0.995 from the k-q_uc correlation model. The results show that the hydraulic conductivity of RCSS can be estimated reliably based on the mix ratio and compressive strength.