Examinando por Autor "Way, George"
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- PublicaciónAcceso abiertoLaboratory Evaluation of Asphalt Rubber Mixtures Using the Dynamic Modulus (E*)(Universidad San Ignacio de Loyola, 2003) Sotil Chávez, Andrés; Kaloush, Kamil; Witczak, Matthew; Way, GeorgeFor thirty years, the Arizona Department of Transportation has been adding crumb rubber to the asphalt concrete with remarkable performance. A primary objective of this study was to evaluate the laboratory performance of these mixtures by conducting the Dynamic Complex Modulus (E*) test. Field samples of two Asphalt Rubber (AR) mixtures were used: Asphalt-Rubber- Asphalt-Concrete-Gap-Graded, and Asphalt-Rubber-Asphalt-Concrete-Friction-Course-Open- Graded mixes, which utilized a common base binder grade of PG 58-22. Tests were performed unconfined and confined (three different levels), and the E* master curves were developed for each mixture and test condition.Since the performance of the AR mixtures have been remarkable in the field, the results of this study showed the importance of using confined tests when comparing the performance of open graded to dense graded mixtures.For thirty years, the Arizona Department of Transportation has been adding crumb rubber to the asphalt concrete with remarkable performance. A primary objective of this study was to evaluate the laboratory performance of these mixtures by conducting the Dynamic Complex Modulus (E*) test. Field samples of two Asphalt Rubber (AR) mixtures were used: Asphalt-Rubber- Asphalt-Concrete-Gap-Graded, and Asphalt-Rubber-Asphalt-Concrete-Friction-Course-Open- Graded mixes, which utilized a common base binder grade of PG 58-22. Tests were performed unconfined and confined (three different levels), and the E* master curves were developed for each mixture and test condition.Since the performance of the AR mixtures have been remarkable in the field, the results of this study showed the importance of using confined tests when comparing the performance of open graded to dense graded mixtures.
- PublicaciónAcceso abiertoMaterial characteristics of asphalt rubber mixtures(Rubber Pavements Association (Phoenix), 2004) Zborowski, Aleksander; Sotil Chávez, Andrés; Kaloush, Kamil; Way, GeorgeThis study focused on conducting experimental program on several Asphalt Rubber (AR) mixtures to obtain their typical engineering properties and understand their field performance. Most of the laboratory program was based on tests recommended by the National Cooperative Highway Research Program, NCHRP 9-19 Project, which dealt with recommending Simple Performance Tests (SPT) for the evaluation of asphalt mixes. The laboratory tests included: consistency binder tests, triaxial shear strength, repeated load permanent deformation, dynamic modulus, flexural beam fatigue, and indirect tensile tests. The results obtained for the AR mixtures were also compared, when possible, with results obtained for conventional mixtures. The AR mixes were those typically used in Arizona, along with an experimental mixture that was constructed by Alberta Transportation, in Canada. All laboratory test specimens were prepared using mixes that were collected during construction. The tests also included sensitivity studies of the mixtures to air voids, temperatures, and influence of confinement level. It was concluded that many parameters obtained from the above tests were successful in describing the observed good field performance of AR mixes.