RUBBER SOILS AS LIGHTWEIGHT GEOMATERIALS

TLDR

Shredded tires used in highway construction can reduce fill weight and back‑fill pressures, improve drainage, extend material life, and provide abundant, low‑cost, environmentally beneficial waste recycling, though concerns about leachate, fire risk, and high compressibility remain. This study investigates the feasibility of rubber soils as lightweight geomaterials by characterizing the stress–strain–strength behavior of tire chips for design and performance prediction of tire embankments and assessing long‑term environmental impacts. The authors present a literature review and laboratory results, including compaction, compressibility, and permeability tests on compacted rubber soils, and summarize conclusions on the suitability of shredded tires for highway construction.

Abstract

The literature review and laboratory testing results from an on-going research study, which investigates the feasibility of using rubber soils as lightweight geomaterial in highway construction, are presented. An overview of conventional lightweight materials; generation and disposal options for scrap tires; a summary of the various field and laboratory studies on the use of shredded tires as lightweight fill; results from compaction, compressibility, and permeability testing of compacted rubber soils samples; and the salient conclusions of this study are also presented. The use of shredded tires in highway construction offers technical, economic, and environmental benefits under certain conditions. The benefits are reduced weight of fill and backfill pressures. Shredded tires serve as a good drainage medium and have longer life. Tire chips are practically indestructible and available in abundance at practically no cost. Recycling large quantities of discarded tires has a positive impact on the environment. Potential problems are leachate of metals and hydrocarbons, fire risk, and large compressibility of tire chips. Information about stress-strain-strength behavior of tire chips for design and performance prediction of tire embankments and long-term environmental impacts of shredded tires is lacking.