Asphalt mixtures are particulate composite materials consisting of uniformly distributed mineral aggregates, asphalt binder and air voids. Mixtures of asphalt binder and filler, also called mastics, are often assumed to behave as simple viscoelastic materials, where the binders are stiffened by the filler. Because the workability and performance of bituminous mixes are known to be affected by the filler-asphalt mixture (or mastic) properties, this study is intended for performing rheological tests on asphalt binder and mastics and use the results in order to estimate performance parameters of asphalt mixture.
The present work uses the PG64-22 asphalt binder test data initially to predict mastics' performance parameters - shear modulus (G*) and accumulated permanent shear strain (γ<sub>acc</sub>) and then same properties for asphalt mixtures, in order to find a correlation between the three materials. Mastics were obtained by mixing the PG64-22 asphalt with three types of filler - donna fill, limestone, and granite - in five different percentages by volume - 5, 10, 15, 20, and 30%. The asphalt mixtures contained granite aggregate, 6% air voids content and five asphalt contents - 3% through 7%. Binder and mastics were tested at three temperatures (46°, 55°, and 64°C) using a dynamic shear rheometer (DSR), while the mixtures were tested at two temperatures (55° and 64°C) using the Superpave shear tester.
Newly developed Hirsch model was used for estimating the shear moduli of asphalt mastics and mixtures, while for estimating the accumulated permanent shear strain a semi-empirical equation developed by Shenoy was used. Both estimations have been performed by using the shear modulus of the binder obtained from the DSR. The binder, mastics, and mixtures rheological data were generated using the appropriate equipment for each material, under identical conditions of measurement, thus making it possible to identify a correlation between the materials. There was a good agreement between the measured and estimated values using the two methods (Hirsch and Shenoy), with Pearson correlation parameters (R<sup>2</sup>) being over 0.90 or better.
| Identifer | oai:union.ndltd.org:LSU/oai:etd.lsu.edu:etd-08292006-121153 |
| Date | 30 August 2006 |
| Creators | Druta, Cristian |
| Contributors | Linbing Wang, George Z. Voyiadjis, Suresh Moorthy, Su-Seng Pang, Darrell Hanry |
| Publisher | LSU |
| Source Sets | Louisiana State University |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lsu.edu/docs/available/etd-08292006-121153/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached herein a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to LSU or its agents the non-exclusive license to archive and make accessible, under the conditions specified below and in appropriate University policies, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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