Differential Thermal Contraction of Asphalt Components
Large differences between the coefficient of thermal contraction of mineral aggregate and binder has been associated with localised damage at the aggregate-binder interface at low temperatures. In this work, the coefficients of thermal contraction of different binders, aggregates and asphalt mixtures have been determined. Binder specimens were first produced by pouring hot bitumen into 200 x 50 x 50 mm3 moulds. The specimens were conditioned at various temperatures ranging from 10 to -20 0C. The change in length was then measured to determine thermal strains as a result of cooling. It was found that linear coefficients of thermal contraction varied between 115 and 175 x 10− 6 mm/mm/0C depending on grade and type of binder. Coefficient of thermal contraction of different aggregates was also determined. Rock specimens of the same dimension as the binder specimens were cut from large rock cores. The specimens were then conditioned at different temperatures and their change in length was measured. Three types of rocks namely limestone, granite and greywacke typically used in asphalt mixtures were employed. It was found that CTC of the aggregates varied between 7 and 10 x 10− 6 mm/mm/0C, thus, 10 to 25 times lower than those of the binders. The coefficient of thermal contraction of various asphalt mixtures was determined using a volumetric and a composite model. Furthermore, predicted values were compared with those determined experimentally using beam shaped asphalt specimens cut from roller compacted slabs manufactured in the laboratory.
KeywordsAsphalt Mixture Asphalt Concrete Thermal Contraction Bituminous Binder Porous Asphalt
Unable to display preview. Download preview PDF.
- 2.Mukhopadhyay, A.K., Neekhra, S., Zollinger, D.G.: FHWA/TX-05/0-1700-5, Texas Transportation Institute. The Texas A&M University System, Texas (2007)Google Scholar
- 3.Bouldin, M.G., Dongre, R., Rowe, G.M., Sharrock, M.J., Anderson, D.A.: J. Assoc. Asphalt Pav. 69, 497–539 (2000)Google Scholar
- 4.Kim, S.S., Sargand, S., Wargo, A.: FHWA/OH-2009/5, Ohio Research Institute for Transportation and Environment. Ohio University, Ohio (2009)Google Scholar
- 5.Ojo, J.O., Fratta, D., Bahia, H.U., Daranga, C., Marasteanu, M.: Pavement Cracking. In: Al-Qadi, Scarpas, Loizos (eds.) Proceedings of the 6th RILEM International Conference on Cracking in Pavements, Chicago, USA, pp. 469–479. Taylor and Francis Group, London (2008)Google Scholar
- 7.Marasteanu, M., et al.: MN/RC 2007-43, National Pooled Fund Study 776, Department of Civil Engineering. University of Minnesota, Minneapolis (2007)Google Scholar
- 8.Hirsch, T.J.: ACI J. 59(3), 427–451 (1962)Google Scholar
- 9.Artamendi, I., Ward, C., Allen, B., Phillips, P.: In: Paper accepted 7th RILEM International Conference on Cracking in Pavements, The Netherlands, Delft (2012)Google Scholar