Application of pyrolized carbon black from scrap tires in pavement design (hot mix asphalt)
Various concepts and techniques have been developing for efficient and economical disposal and utilization of scrap tires. One of these is pyrolysis of scrap tires by a cooking process in order to break down the rubber into salable byproducts. Tire pyrolysis yields approximately 25% carbon black (CB) and is named pyrolized carbon black (PCB) in this study. Due to relatively high contents (75%) of carbon black in PCB, the use of PCB in asphalt pavement is expected to improve performance in terms of rutting resistance, reduction of temperature susceptibility and cracking potential. Furthermore, tire pyrolysis could be a remedy to the mass disposal problem of scrap tires.(DIAGRAM, TABLE OR GRAPHIC OMITTED...PLEASE SEE DAI)This study presents the viability of using PCB as an additive in hot mix asphalt concrete. Different ratios of PCB (5%, 10%, 15%, 20% by weight of asphalt) were blended with two grades of asphalt (AC-10 and AC-20). The complete behaviors of the PCB modified asphalt concrete were investigated by comprehensive laboratory testing and evaluation. The Marshall method was used to determine the optimum binder content, and the mechanical properties and void relationships were investigated by this method. The Gyratory Testing Machine was used to define the stress-strain relationships of the PCB mixtures. The rutting potential of PCB mixtures was investigated using the Dynamic Creep Testing. The performance of the PCB mixtures at low temperature (5$\sp\circ$C) was determined by the Indirect Tensile Testing. The strength performance of the PCB mixtures at intermediate temperatures (5$\sp\circ$C and 25$\sp\circ$C) was examined by the Resilient Modulus Test. The Hamburg Wheel Tracking Device was employed to ascertain the stripping potential of the PCB mixtures.^ The findings of this study show beneficial effects for conventional asphalt mixture. The analyses of test results show that the PCB content 10% to 15% by weight of asphalt produces a number of significant improvements. The rutting potential, the temperature susceptibility and the stripping potential can be reduced by the inclusion of PCB in the asphalt mixture. ^
Major Professor: Charles W. Lovell, Purdue University.