Use of Shredded Tires as Lightweight Backfill Material for Retaining Structures

Abstract

Each year in the United States, approximately 242 million automobile, truck and specialty tires are discarded. Almost 78% of these scrap tires wind up in overcrowded landfills, and thousands more are strewn across the country's empty lots, highways and illegal tire dumps. Used tires pose both a serious public health and an environmental threat. Therefore, economically feasible alternatives for scrap tire disposal must be found. Some of the current uses of scrap tires are tire-derived fuel, barrier reefs, and crumb rubber as an asphalt additive. However, all of the recycling, re-use and recovery practices combined only consume about 22% of the discarded tires. Thus, a need still exists for the development of additional uses for scrap tires. This paper addresses one potential use of scrap tires within the civil engineering field. Specifically, the feasibility of using shredded tires as a lightweight backfill material for retaining walls has been investigated. In this study, laboratory tests were first performed to determine the engineering properties of shredded tires. Based on sieve analyses, the shredded tires used for this study can be classified as uniformly graded material. The unit weight of shredded tires was found to range from 35 to 38 lbs ft-3 (pcf), and the hydraulic conductivity was determined to be 0.03 cm s-1. The values of shear strength parameters, cohesion and angle of internal friction, were determined to be 147 lbs ft-2 (psf) and 27 degrees, respectively. Using these properties, retaining walls of various heights were then designed using shredded tires as the backfill material. Retaining walls were also designed using conventional sand as the backfill material for comparison purposes. When comparing the overall cost for the retaining wall using shredded tires with the retaining wall using sand, a substantial cost saving was realised by the use of shredded tires. An increase in the factor of safety was also a result of using shredded tires instead of sand as backfill. The results of this study indicate that shredded tires have a definite potential to be used as a backfill material for retaining structures.

Performance of Scrap Tire Shreds as a Potential Leachate Collection Medium

“…Shredded tires obtained from scrap tires have been used as lightweight fill material for roadways, embankments and backfills behind retaining walls. The shredded tires can be used by themselves or blended with soil (Ahmed and Lovell 1993;Eldin and Senouci 1992;Humphrey and Manion 1992;Bosscher et al 1997;Humphrey et al 1998;Edil and Bosscher 1994;Cecich et al 1996;Papp et al 1997;Al-Tabbaa and Aravinthan 1998;Humphrey 1999;Lee et al 1999;ASTM 2002;Pierce and Blackwell 2003). Tire shreds have also been used as an alternative to crushed stones (gravel) as drainage media in landfill leachate collection systems (Humphrey and Manion 1992;Duffy 1995;Donovan et al 1996;Geosyntec Consultants 1998;Humphrey 1999).…”

Predicting the compressibility behaviour of tire shred samples for landfill applications

“…Shredded tires obtained from scrap tires have been used as lightweight fill materials for roadways, embankments and backfills behind retaining walls. The shredded tires can be used by themselves or blended with soil Lovell, 1992, 1993;Eldin and Senouci, 1992;Humphrey and Manion, 1992;Bosscher et al, 1993Bosscher et al, , 1997Humphrey et al, , 1998Upton and Machan, 1993;Edil and Bosscher, 1994;Cecich et al, 1996;Papp et al, 1997;Al-Tabbaa and Aravinthan, 1998;Tweedie et al, 1998;Humphrey, 1999;Lee et al, 1999;ASTM, 2002;Pierce and Blackwell, 2003). Tire shreds have also been used as an alternative to crushed stones (gravel) as drainage media in landfill leachate collection systems Duffy, 1995;Donovan et al, 1996;Geosyntec Consultants, 1998;Humphrey, 1999).…”

Evaluation of the Shear Strength Behavior of TDA Mixed with Fine and Coarse Aggregates for Backfilling around Buried Structures

“…In addition, during rainy seasons, stockpiled tires collect rainwater, which provides a breeding ground for many insects, including mosquitoes, that can transfer dangerous diseases such as encephalitis to humans. Moreover, there is a potential risk of fire from stockpiled tires [1]. Over 500 million scrap tires are discarded in the USA annually [2].…”