TxDOT’s Fort Worth District embarked upon a recycling mission in 2001 to find a way to use baled scrap tires in highway-related engineering applications. Richard Williammee, P.E., the District’s Materials Engineer / Construction and Maintenance Recycling Coordinator, began to investigate the use of tire bales as a possible repair method for slope failures resulting from higher than normal rainfall in the area. Since tire bales had been used in other states as roadbed foundation and to prevent stream/channel erosion, the concept of using tire bales in this type of an engineering application was amenable.
Scrap Tires – An Abundant Resource in Texas and the Nation
Texas generates approximately 24 million tires annually, roughly one per person per year. At the end of 2002, an additional 66 million shredded tires were stockpiled at current and formerly registered storage sites throughout the state, plus an estimated 4.4 million whole tires remain at known illegal tire dumps. Nationwide, approximately 225 million tires are generated annually with approximately 700-800 million tires stockpiled at registered storage sites throughout the nation.
Newly generated and stockpiled tires represent a resource available for many engineering uses – whether in the form of crumb rubber, tire shreds, and even tire bales – and can yield a positive life-cycle cost-benefit ratio in many highway construction projects. During the past ten years, TxDOT has consumed the equivalent of more than ten million tires in asphalt rubber hot mix, crack seals, tire shreds, embankment fill, and miscellaneous products made from crumb rubber and whole tires.
Although TxDOT frequently purchases rubber or die-cut products for weighting bases on traffic cones, delineator posts, barrels, and other traffic control devices, TxDOT continues to explore other innovative uses of tire rubber products, such as the use being explored by this project.
About the Demonstration Project