Mechanical Properties of Tire Bales for Highway Applications

Scrap tire bales are typically treated as discrete elements that consist of approximately one hundred (100) scrap tires compressed into a 4.5 foot by 5 foot by 2.5 foot block. The advantage of baling tires is that a volume reduction of approximately ten is achieved, and handling bales is much simpler, and therefore cheaper, than whole tire or tire shreds. The use of tire bales in highway structures, however, requires that the mechanical properties of the tire bales are known. Determining these properties is vital to the proper design and construction of the tire bale structures. A literature review indicated the lack of material properties that are available for tire bales. A laboratory testing program was designed and implemented to determine the strength and compressibility properties of the bales required for design. Field testing to determine the unit weight and permeability of the tire bale mass was also conducted. Analytical studies and cost benefit analyses highlighting the benefits of using tire bales already assembled were also conducted for a series of tire bale case histories. The following document outlines all the work conducted as part of this, as well as previous, testing programs to determine the properties needed for design of tire bales structures, as well as economical aspects of reusing the tires as opposed to throwing them away.