[01] Saad Issa Sarsam, Department of Civil Engineering, College of Engineering, University of Baghdad, Baghdad, Iraq. [02] Mostafa Shaker Mahdi, Department of Civil Engineering, College of Engineering, University of Baghdad, Baghdad, Iraq.

Recycling of aged asphalt concrete pavement is considered as one of the major requirements for sustainability. It can reserve the aggregate and binder resources. An attempt has been made in this investigation to prepare a suitable rejuvenator in the laboratory for recycling of an aged pavement. Two types of additives namely carbon black and styrene-butadiene-rubber (SBR) have been implemented and each one was mixed with asphalt cement to form the rejuvenator. Three percentages of additives (0.5, 1, and 1.5)% by weight of asphalt cement and two percentages of asphalt cement (1 and 2)% have been implemented as rejuvenator and mixed with the aged asphalt concrete. Recycled Asphalt concrete specimens were prepared and tested using the Marshall compaction. It was concluded that highest Marshal stability was achieved when 1.5% of carbon black or SBR were added with 1% of asphalt cement. The addition of 2% asphalt cement with carbon black or SBR exhibits higher flow value than that of 1% asphalt binder with additives. SBR additive exhibits higher voids content, VMA, and higher percentage of voids filled with asphalt as compared to carbon black regardless of the asphalt content. Indirect tensile strength ITS decreases by (34 and 43)%. Temperature susceptibility decreases by (50 and 86)%, while the punching shear strength decreases by (21 and 41)%. The resistance to moisture damage increases by (109 and 121)% after recycling with carbon black- asphalt and SBR-Asphalt rejuvenators respectively.

Recycling, Rejuvenate, Durability, Moisture Damage, SBR, Carbon Black

[01] Al-Qadi, I., Elseifi, M., and Carpenter, S., (2007) “Reclaimed Asphalt Pavement—A Literature Review”, Report No. FHWA-ICT-07-001, Illinois Center for Transportation, Rantoul, IL. http://hdl.handle.net/2142/46007. [02] Mazzoni G., Bocci E., Canestrari F. (2018) “Influence of rejuvenators on bitumen ageing in hot recycled asphalt mixtures”, Journal of traffic and transportation engineering (English edition); 5 (3): 157 -168. Doi: 10.1016/j.jtte.2018.01.001. [03] Sarsam S. I., (2007) “A Study on Aging and Recycling of Asphalt Concrete Pavement”, University of Sharjah Journal of Pure & Applied Sciences, Vol. 4, No. 2, pp. 79-96. [04] Sarsam S. I. and AL-Janabi E., (2014) “Assessing Shear and Compressive Strength of Reclaimed Asphalt Concrete”, International Journal of Scientific Research in Knowledge, 2 (8), pp. 352-361. DOI: 10.12983/ijsrk-2014-p0352-0361. [05] Sarsam S. I. and Saleem M., (2018) “Prospects of Using Liquid Asphalt as Rejuvenation Agent for Asphalt Pavement Recycling”, Advancements in Materials, ITS, Vol. 2 No. 2, 2018. pp 64-74. [06] Sarsam S. and AL-Shujairy A., (2015) “Assessing Tensile and Shear Properties of Recycled Sustainable Asphalt Pavement”, Journal of Engineering, Number 6, Volume 21. Pp. 146-161. [07] Sarsam S. and AL-Shujairy A., (2014) “Fatigue Potential after Rutting of Sustainable Asphalt Concrete”, International Journal of Scientific Research in Knowledge, 2 (12), pp. 549-55. [08] Noferinia L., Simonea A., Sangiorgia C., Mazzotta F. (2017) “Investigation on performances of asphalt mixtures made with Reclaimed Asphalt Pavement: Effects of interaction between virgin and RAP bitumen”. International journal of pavement research and technology 10, pp. 322-332. www.sciencedirect.com. (http://creativecommons.org/licenses/by-nc-nd/4.0/). [09] Shunyashree S., Bhavimane T., Archana M., Amarnath M. (2013) “Effect of use of recycled materials on indirect tensile strength of asphalt concrete mixes”. IJRET: International Journal of Research in Engineering and Technology, DOI: 10.15623/ijret.2013.0213040. [10] Mamun, A. A., & Al-Abdul Wahhab, H. I. (2018) “Comparative laboratory evaluation of waste cooking oil rejuvenated asphalt concrete mixtures for high contents of reclaimed asphalt pavement”. International Journal of Pavement Engineering, 1–12. Doi: 10.1080/10298436.2018.1539486. [11] Elkashef, M., Williams, R. C., & Cochran, E. (2018) “Investigation of fatigue and thermal cracking behavior of rejuvenated reclaimed asphalt pavement binders and mixtures”. International Journal of Fatigue, 108, 90–95. Doi: 10.1016/j.ij fatigue. 2017.11.013. [12] Sarsam S., and AL-Zubaidi, (2014) “Assessing Tensile and Shear Properties of Aged and Recycled Sustainable Pavement”, IJSR Publication, Vol. 2 No. 9, DOI: 10.12983/ijsrk-2014-p0444-0452. [13] Zaumanis M., and Mallick R. (2015) “Review of very high-content reclaimed asphalt use in plant-produced pavements: state of the art”, International Journal of Pavement Engineering, 16: 1, pp. 39-55, Doi: 10.1080/10298436.2014.893331. [14] McDaniel R., Kowalski K., and Shah A. (2012) “Evaluation of Reclaimed Asphalt Pavement for Surface Mixtures”, Indiana Department of Transportation and Purdue University FHWA/IN/JTRP 06. DOI: 10.5703/1288284314665. [15] AASHTO. (2015) “Standard specification for transportation materials and methods of sampling and testing”. American Association of State Highway and Transportation Officials, 14th Edition, Part II, Washington, D. C. USA. [16] SCRB. (2003) “General Specification for Roads and Bridges”, Section R/9 Hot-Mix Asphalt Concrete Pavement, Revised Edition, State Commission for Roads and Bridges, Ministry of Housing and Construction, Republic of Iraq. [17] ASTM, (2009) “Road and Paving Materials, Annual Book of ASTM Standards”, Volume 04.03, American Society for Testing and Materials, USA.