Development of Design Guidelines for Use of Shredded Tires as a Lightweight Fill in Road Subgrade and Retaining Walls

Abstract

The use of shredded tires as a lightweight fill material over weak soil deposits is gaining popularity as a means of disposing a great quantity of an undesirable waste material in a beneficial manner. This report discusses the production, past applications, and properties of shredded tires with respect to their use in lightweight fills. Shredded tires have the advantages of low bulk density, high permeability, and insensitivity to the presence or state of moisture. However, they possess a high degree of compressibility, and they exhibit a degree of rebound atypical of materials normally used in lightweight fills (e.g., woodchips). Before using shredded tires in a fill, one must consider the layer thickness of the shredded tires, the amount of overburden to be placed on the tires, the type of pavement surface, and the volume of heavy traffic expected to use the roadway. Because of the orientation of shredded tires after placement, the importance of anisotropy as a future research topic is discussed.