Impact of incorporating waste tire rubber particles into granular inclusion on reducing lateral swelling pressures of expansive soil against concrete retaining walls

• Published in: Construction & building materials 2024-12, Vol.457, Article 139462
• Main Authors: Fan, Kewei, Shen, Yang, Han, Zhong, Zou, Weilie, Liu, Sihong, Cheng, Yi Pik Helen
• Format: Article
• Language: English
• Subjects: Concrete retaining wall; Expansive soil; Granular inclusion; Lateral swelling pressure; Waste tire rubber particles
• ISSN: 0950-0618
• DOI: 10.1016/j.conbuildmat.2024.139462

Using waste tire rubber particles-sand mixture as the inclusion between concrete retaining walls and expansive soil backfills help to improve the performance of pure sand inclusion in terms of reducing the lateral swelling pressure of expansive soils upon wetting. In this study, model tests on concrete retaining walls-expansive soil system with rubber-sand mixture (abbreviated as RSM) and pure sand as inclusions to evaluate the effectiveness of the RSM inclusion in reducing lateral swelling pressures (Pex). Additionally, a method for predicting the Pex was developed and validated using the experimental data. Further analyses were performed to evaluate the effects of the RSM inclusion thickness, rubber particle content and size on the mitigation of Pex. The results indicate that the horizontal displacement induced by the RSM inclusion is higher than that of the pure sand inclusion, thereby can accommodate more swelling strain of the expansive soil backfill and significantly decrease the Pex. The thickness of the RSM inclusion and content of rubber particles remarkably influence the Pex. The thicker the RSM inclusion and the higher the rubber content, the lower the Pex. Specifically, a 40 % reduction in the Pex can be achieved by incorporating waste tire rubber particles with a particle size of 0.5–2 mm and a content of 40 % into a 0.5 m thick sand inclusion. However, the size of rubber particles exhibited a minimal impact on the reduction of the Pex. •Proposed SRM inclusion to reduce lateral swelling pressure on retaining walls.•Investigated SRM inclusion efficacy in reducing lateral swelling pressure.•Developed a method to predict reduced lateral swelling pressure.•Analyzed factors affecting lateral swelling pressure reduction by SRM inclusion.