MPC Research Reports
Report Details

Title:	Beneficial Use of Scrap Tire Rubber in Low-Volume Road and Bridge Construction with Expansive Soils
Authors:	J. Antonio H. Carraro, Jesse Dunham-Friel, and Micah Smidt
University:	Colorado State University
Publication Date:	Dec 2008 (Interim Report)
Report #:	MPC-08-202
Project #:	MPC-274
TRID #:	01680112
Keywords:	bridge construction, embankments, low volume roads, mechanical properties, pavement design, recycled materials, rubber, swelling soils, test sections, tires

Abstract

Untreated native soil with high swell potential has been identified by the Colorado Department of Transportation as one of the major contributing factors in the development of premature longitudinal cracking and other pavement distresses in Colorado (Ardani et al. 2003). Unique regional factors such as a semi-arid climate and widely-occurring expansive soil deposits have made cost-effective maintenance and rehabilitation of bridges and pavements a challenging task in the region. Although excessive movement of pavement and bridge structures has been reported in both rural and urban areas in Colorado, this issue represents a particular burden for local governments due to the excessive costs associated with the construction, management and operation of low-volume roads and bridges founded on expansive soils. Increasing costs of conventional (e.g. gravel, sand) and alternative (e.g. fly ash) road construction materials and heavier truck and farm equipment loads have only added up to the problem.

While waste tire rubber products have been used in many engineering applications such as highway embankments and retaining wall backfills, most of these previous works have dealt with rubber-sand mixtures (Lee et al. 1999; Yoon et al. 2006; Zornberg et al. 2004). Among the few studies that have focused on rubber-clay mixtures (e.g. Ahmed and Lovell, 1993; Edil and Bosscher, 1994; Tatlisoz et al. 1997), none of them have investigated the effect of rubber on the engineering properties of highly-expansive clays such as the ones found in rural and urban areas in Colorado.

In this study, the mechanical response of expansive soil rubber (ESR) mixtures and the beneficial use of waste tire rubber on the swell potential mitigation of local expansive soils are evaluated through a systematic and comprehensive experimental investigation. The adequacy of ESR mixtures as an alternative road construction material is evaluated through computational modeling of sections of highway embankments designed with these mixtures. A test section is being constructed in Loveland, CO with the assistance of the Department of Public Works from the City of Loveland. It is expected that the lower swell potential of engineered ESR materials tested in this study (Seda et al. 2007) will help reduce the long term maintenance and rehabilitation costs of local, low-volume roads such as the one that will be constructed during this project.