Effects of Additive Materials on Indirect Tensile Strength and Moisture Sensitivity of Recycled Asphalt Pavement (RAP)

Abstract = 78 times | PDF = 35 times

Main Article Content

Soz Mohammed Ebrahim Hardy Kamal Karim


Using reclaimed asphalt pavement with additives as part of new road construction has economic and environmental advantages. As an attempt to preserve aggregate resources and save money, and knowing the effects of the selected additive materials, this study was done in Sulaimani City. The samples of the RAP were selected from the Sulaimani municipality stockpiles. The ignition and centrifuge testing machines were used to separate the aggregate and binder of the RAP. Based on the standard deviation of the obtained asphalt content, the blend was decided to be 40% RAP and 60% new material. The aggregate tests were conducted to evaluate the characteristics of the PAR aggregate. The performance grade test was done for the reclaimed asphalt binder. Three types of additives, which were Styrene Butadiene-Styrene (SBS), Crumb Rubber (CR), and Polypropylene (PP), mixed with the reclaimed asphalt binder with three different percentages of the binder which were 3%, 5%, and 7%. Indirect Tensile Strength (ITS) test was performed to the conditioned and unconditioned mixtures. To evaluate the effects of additives on the moisture sensitivity of the reclaimed mixtures, ITS Ratios were obtained. Most of the percentages of additives decreased the ITS of the conditioned and unconditioned samples. The only percentage of the additive material increased the ITS was 5% of PP in conditioned case. However, additives did not benefit the ITS, they benefited the ITSR greatly. The best obtained ITSR for each additive material was 7% SBS, 3% CR, and 5% PP that had 99.71%, 97.1%, and 90.7%, respectively.


RAP, Styrene Butadiene–Styrene (SBS), Crumb Rubber (CR), Recycled Atactic Polypropylene (PP), Performance Grade (PG), Indirect Tensile Strength, Moisture Sensitivity.


Download data is not yet available.

Article Details


[1] D. Newcomb, E.R. Brown, and J. A. Epps, Quality Improvement Series 124: Designing HMA Mixtures with High RAP Content: A Practical Guide, National Asphalt Pavement Association, Lanham, MD, 2007.
[2] N. Taylor, “Life expectancy of recycled asphalt paving. Recycling of bituminous pavements”. (L. E. Wood, Ed.), ASTM STP 662, 3–15, 1997.
[3] J. Sullivan, “Pavement recycling executive summary and report”. Report FHWA-SA-95-060 from the Federal Highway Administration. Washington, D.C.,1996.
[4] O. R. Ortiz, A. Berardinelli, Carvajal-Munoz, L.G Fuentes, “Evaluation of ‘Hot Mix Asphalt Mixtures with Replacement of Aggregates by Reclaimed Asphalt Pavement (RAP) Material”., 2012.
[5] T. Bennert, W. J. Papp Jr, A. Maher, &N. Gucunski, “Utilization of Construction and Demolition Debris under Traffic-Type Loading in Base and Subbase Applications”. Transportation research record, 1714(1), 33-39, 2000.
[6] G. Dondi, F. Mazzotta, A. Simone, V. Vignali, C. Sangiorgi, C. Lantieri, “Evaluation of different short-term aging procedures with neat, warm and modified binders, Constr. Build. Mater. 106282–289, 2016.
[7] L. H. Lewandowski, “Polymer Modification of Paving Asphalt Binders”. Rubber Chemistry and Technology, 67(3): 447, July-August, 1994.
[8] L. N. Mohammad, I. I. Negulescu, Z. Wu, C. Daranga, W. H. Daly, and C. Abadie., “Investigation of the Use of Recycled Polymer-modified Asphalt Binder in Asphalt Concrete Pavements”. Journal of the Association of Asphalt Paving Technologists, pp. 551–594., Vol. 72, 2003.
[9] B. G. Li Huang, D. Vukosavljevic, X. Shu, and B. K. Egan. “Laboratory Investigation of Mixing Hot-Mix Asphalt with Reclaimed Asphalt Pavement”. In Transportation Research Record: Journal of the Transportation Research Board, No. 1929, Transportation Research Board of the National Academies, Washington D.C., pp. 37–45, 2005.
[10] B. V. Kök, & H. Çolak, “Laboratory Comparison of the Crumb-Rubber and SBS Modified Bitumen and Hot Mix Asphalt”. Construction and Building Materials, 25(8), 3204-3212, 2011.‏
[11] FJ. Navarro, P. Partal, F. Martínez-Boza, C. Gallegos “Thermo-Rheological Behavior and Storage Stability of Ground Tire Rubber-Modified Bitumen Fuel”, 83:2041–9, 2004.
[12] W. Cao, “Study on Properties of Recycled Tire Rubber Modified Asphalt Mixtures Using Dry Process”. Construct Build Mater, 21:1011–5, 2007.
[13] F. Xiao, S.N. Amirkhanian, J. Shen, B. Putman “Influences of Crumb Rubber Size and Type on Reclaimed Asphalt Aavement (RAP) Mixtures”. Construct Build Mater, 23:1028–34, 2009.
[14] JWH. Oliver “Rutting and Fatigue Properties of Crumb Rubber Hot Mix Asphalts”. In: Proceedings of the asphalt rubber 2000 conference, Vilamoura, Portugal, p. 221–40, 2000.
[15] M. Zahedi, R. Bayat, & M. N. Jalal, ''The most appropriate mixing method of polypropylene fiber with aggregates and bitumen based on binder mix design''. International Journal of Engineering & Technology, 3(3), 333, 2014.
[16] A. Yazdani, S. Pourjafar, & A. Rahimpour, “Optimization of asphalt binder modified with PP/SBS/Nano clay nan composite using Taguchi method”., In Proceedings of World Academy of Science, Engineering and Technology (No. 67). World Academy of Science, Engineering and Technology, July 2012.
[17] B. J. Putman, J. Aune, & S. N. Amirkhanian, "Recycled Asphalt Pavement (RAP) Used in Superpave Mixes Made with Rubberized Asphalt". In Mairepav 4th International Symposium, Maintenance and Rehabilitation of Pavements and Technological Control, iSMARTi, Belfast, Northern Ireland, 2005.‏
[18] S. Kim, G. A. Sholar, T. Byron, & J. Kim, “Performance of Polymer-Modified Asphalt Mixture with Reclaimed Asphalt Pavement”. Transportation research record, 2126 (1), 109-114, 2009.‏
[19] N. G. Ahmed, & H. A. Qasim, “Fatigue and Moisture Sustainability Characterization of Reclaimed Asphalt Pavement Mixtures in Iraq”. Journal of Engineering and Sustainable Development, 21 (1), 178-192, 2017.
[20] Y. Yan, R. Roque, C. Cocconcelli, M. Bekoe, & G. Lopp, , “Evaluation of cracking performance for polymer-modified asphalt mixtures with high RAP content”. Road Materials and Pavement Design, 18(sup1), 450-470, 2017.‏
[21] J. Wang, W. Zeng, Y. Qin, S. Huang, &J. Xu, “Laboratory Evaluation of Rejuvenating Agent on Reclaimed SBS Modified Asphalt Pavement”. Applied Sciences, 7(7), 743, 2017.‏
[22] J. Wang, W. Zeng, Y. Qin, Y. Zhang, S. Huang, &J. Xu, “Properties of Mixtures with High Percentages of Reclaimed SBS–Modified Asphalt Pavement”. Journal of Materials in Civil Engineering, 31(1), 04018354, 2018.‏
[23] D. Singh, P. K. Ashish, &S. F. Chitragar, ''Laboratory performance of Recycled Asphalt Mixes containing wax and chemical based Warm Mix Additives using Semi Circular Bending and Tensile Strength Ratio tests''. Construction and Building Materials, 158, 1003-1014, 2018.
[24] New Jersey Department of Transportation. “Recycled asphalt pavement in HMA mix”. NJDOT Bureau of Research Quarterly Progress Report, 2009.