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Impact of Fischer-Tropsch Wax on Ethylene Vinyl Acetate/Waste Crumb Rubber Modified Bitumen: An Energy-Sustainability Nexus

Authors: Keith D. Nare, Mohau J. Phiri, James Carson, Chris D. Woolard, Shanganyane P. Hlangothi


In an energy-intensive world, minimizing energy consumption is paramount to cost saving and reducing the carbon footprint. Improving mixture procedures utilizing warm mix additive Fischer-Tropsch (FT) wax in ethylene vinyl acetate (EVA) and modified bitumen highlights a greener and sustainable approach to modified bitumen. In this study, the impact of FT wax on optimized EVA/waste crumb rubber modified bitumen is assayed with a maximum loading of 2.5%. The rationale of the FT wax loading is to maintain the original maximum loading of EVA in the optimized mixture. The phase change abilities of FT wax enable EVA co-crystallization with the support of the elastomeric backbone of crumb rubber. Less than 1% loading of FT wax worked in the EVA/crumb rubber modified bitumen energy-sustainability nexus. Response surface methodology approach to the mixture design is implemented amongst the different loadings of FT wax, EVA for a consistent amount of crumb rubber and bitumen. Rheological parameters (complex shear modulus, phase angle and rutting parameter) were the factors used as performance indicators of the different optimized mixtures. The low temperature chemistry of the optimized mixtures is analyzed using elementary beam theory and the elastic-viscoelastic correspondence principle. Master curves and black space diagrams are developed and used to predict age-induced cracking of the different long term aged mixtures. Modified binder rheology reveals that the strain response is not linear and that there is substantial re-arrangement of polymer chains as stress is increased, this is based on the age state of the mixture and the FT wax and EVA loadings. Dominance of individual effects is evident over effects of synergy in co-interaction of EVA and FT wax. All-inclusive FT wax and EVA formulations were best optimized in mixture 4 with mixture 7 reflecting increase in ease of workability. Findings show that interaction chemistry of bitumen, crumb rubber EVA, and FT wax is first and second order in all cases involving individual contributions and co-interaction amongst the components of the mixture.

Keywords: Bitumen, crumb rubber, ethylene vinyl acetate, FT wax.

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[1] M. O. Hamzah, A. Jamshidi, and Z. Shahadan, “Evaluation of the potential of Sasobit® to reduce required heat energy and CO2 emission in the asphalt industry,” J. Clean. Prod., vol. 18, no. 18, pp. 1859–1865, 2010.
[2] Department Of Enviromental Affairs and Tourism and South Africa, “South Africa Country Report: Fourteenth Session of The United Nations Commission on Sustainable Development,” pp. 1–38, 2005.
[3] Deparment of Energy Republic of South Africa, “South African Energy Sector,” pp. 1–12, 2013.
[4] SABITA (South African Bitumen Association), “Best practice guideline for warm mix asphalt,” no. Manual 32, 2011.
[5] M. E. Abdullah, K. A. Zamhari, R. Buhari, S. K. A. Bakar, N. H. M. Kamaruddin, N. Nayan, M. R. Hainin, N. A. Hassan, S. A. Hassan, and N. I. M. Yusoff, “Warm Mix Asphalt Technology : A Review,” J. Teknol. Sciences Eng., vol. 71, no. 3, pp. 39–52, 2014.
[6] SABITA (South African Bitumen Association), "Best practice guideline for warm asphalt," no. Manual 32, 2011.
[7] A. H. Greyling, "Development of a Standard Test Method for Determining the Bitumen Bond Strength of Emulsions-A South African Perspective," Master’s thesis, December, 2012
[8] N. Saboo and P. Kumar, "Optimum Blending Requirements for EVA Modified Binder," Int. J Pavement Res. Technol., vol. 88, no. 33, pp. 172-178, 1997.
[9] S. Saoula, S. Haddadi, and K. A. Mokhtar, " The Study of the Improvement of Mechanical Performance of Asphalt Modified by the Optimization of Mixing Time of EVA Bitumen," 2011, pp. 262-267.
[10] B. Sengoz and G. Isikyakar, Evaluation of the properties and microstructure of SBS and EVA polymer modified bitumen," Constr. Build. Mater., vol. 22, no. 9, pp. 1897-1905, 2008.
[11] D. Lesueur, "The colloidal structure of bitumen: Consequences on the rheology and on the mechanisms of bitumen modification," Adv. Colloid Interface Sci., vol.145, no. 1-2, pp.42-82, 2009.
[12] L. M. B. Costa, H. M. R. D. Silva, J. R. M. Oliveira, and S. R. M. Fernandes, "Incorporation of Waste Plastic in Asphalt Binders to Improve their Performance in the Pavement," Int. J. Pavement Res. Technol., vol. 66, no. 457, pp. 457-464, 1996.
[13] M. Singh, P. Kumar, and M. R. Maurya, "Effect of aggregate types on the performance of neat and EVA-modified asphalt mixtures," Int. J. Pavement Eng., vol. 15, no.2, pp. 163-173, 2014.
[14] G. J. Zhao and P. Guo, “Workability of Sasobit® warm mixture asphalt,” Energy Procedia, vol. 16, no. Part B, pp. 1230–1236, 2011.
[15] B. D. Hurley, G.C. and Prowell, “Evaluation of SASOBIT® for use in warm mix asphalt. NCAT report,” 2005.
[16] H. Fazaeli, A. A. Amini, F. M. Nejad, and H. Behbahani, “Rheological properties of bitumen modified with a combination of FT paraffin wax (Sasobit®?) and other additives,” J. Civ. Eng. Manag., vol. 22, no. 2, pp. 135–145, 2016.
[17] M. C. Rubio, G. Martínez, L. Baena, and F. Moreno, “Warm Mix Asphalt: An overview,” J. Clean. Prod., vol. 24, pp. 76–84, 2012.
[18] A. Button, J. W., Estakhri, C., and Wimsatt, A., “Synthesis of warm mix asphalt,” Texas, 2007.
[19] B. D. Hurley and G. C. Prowell, "Evaluation of SASOBIT for use in warm mix asphalt. NCAT report," 2005.
[20] B. Kheradmand, R. Muniandy, L. T. Hua, R. B. Yunus, and A. Solouki, "An overview of the emerging warm mix asphalt technology," International Journal of Pavement Engineering, vol. 15, no. 1, pp. 79-94, 2014.
[21] G. van der Laan and A. Beenackers, "Kinetics and Selectivity of the Fischer-Tropsch Synthesis: A Literature," Catal. Rev. Sci. Eng., no, 41:3-4, pp, 255-318, 1999.
[22] G. J. Zhao and P. Guo, "Workability of sasobit warm mixture asphalt," Energy Procedia, vol. 16, no. Part B, pp. 1230-1236, 2011.
[23] A. Jamshidi, B. Golchin, M. O. Hamzah, and P. Turner, “Selection of type of warm mix asphalt additive based on the rheological properties of asphalt binders,” J. Clean. Prod., vol. 100, pp. 89–106, 2015.
[24] C. K. Akisetty, S. J. Lee, and S. N. Amirkhanian, “High temperature properties of rubberized binders containing warm asphalt additives,” Constr. Build. Mater. vol. 23, no. 1, pp. 565–573, 2009.
[25] H. Yu, Z. Leng, F. Xiao, and Z. Gao, “Rheological and chemical characteristics of rubberized binders with non-foaming warm mix additives,” Constr. Build. Mater., vol. 111, pp. 671–678, 2016.
[26] A. M. Rodríguez-Alloza, J. Gallego, and I. Pérez, “Study of the effect of four warm mix asphalt additives on bitumen modified with 15% crumb rubber,” Constr. Build. Mater., vol. 43, pp. 300–308, 2013.
[27] D. Pagel, “Where the rubber meets the road,” Institute of Municipal Engineering of Southern Africa, pp. 6–7, Aug-2015.
[28] H. Marais and J. Muller, “Shelf-life and Performance Properties of Bitumen-Rubber,” Rubberized Asphalt Foundation, 2014.
[29] P. A. Gonzalez V, Martinez-Boza FJ, Navarro FJ, Gallegos C, Perez-Lepe A, “Thermomechanical properties of bitumen modified with crumb tire rubber and polymeric additives.,” Fuel Process. Technol., vol. 91, no. 9, pp. 1033–9, 2010.
[30] A. Jamshidi, M. O. Hamzah, and Z. You, "Performance of Warm Mix Asphalt containing Sasobit®: State of the art," Constr. Build. Mater., vol. 38, pp. 530-553, 2013.
[31] P. M. Mamohanoe, “Influence of the presence and amount of metal nanoparticles on the thermal and mechanical properties of iPP/soft paraffin wax phase change materials for thermal energy storage,” MSc Thesis, 2014.
[32] A. Khodaii, E. S. Mousavi, M. Khedmati, and A. Iranitalab, “Identification of Dominant Parameters for Stripping Potential in Warm Mix Asphalt using Response Surface Methodology,” Mater. Struct., vol. 49, no. 6, pp. 2425–2437, 2016.
[33] D. C. Montgomery, Design and Analysis of Experiments, vol. 2. 2012.
[34] T. G. Mezger, The Rheology Handbook : For users of rotational and oscillatory rheometers, 4th ed. Hanover: Vincent Network, 2014.
[35] N. Saboo and P. Kumar, “Optimum Blending Requirements for EVA Modified Binder,” ISSN Int. J. Pavement Res. Technol. Int. J. Pavement Res. Technol., vol. 88, no. 33, pp. 172–178, 1997.
[36] K.-D. Jeong, S.-J. Lee, S. N. Amirkhanian, and K. W. Kim, “Interaction effects of crumb rubber modified asphalt binders,” Constr. Build. Mater., 2010.
[37] M. R. Ibrahim, H. Y. Katman, M. R. Karim, S. Koting, and N. S. Mashaan, “A Review on the Effect of Crumb Rubber Addition to the Rheology of Crumb Rubber Modified Bitumen,” Adv. Mater. Sci. Eng., 2013.
[38] D. Lo Presti, G. Airey, and P. Partal, “Manufacturing terminal and field bitumen-tyre rubber blends: the importance of processing conditions,” Procedia - Soc. Behav. Sci., vol. 53, pp. 485–494, 2012.
[39] H. Wang, Z. Dang, Z. You, and D. Cao, “Effect of warm mixture asphalt (WMA) additives on high failure temperature properties for crumb rubber modified (CRM) binders,” Constr. Build. Mater., vol. 35, pp. 281–288, 2012.
[40] P. Hajikarimi, M. Rahi, and F. M. Nejad, “Comparing different rutting specification parameters using high temperature characteristics of rubber-modified asphalt binders,” Road Mater. Pavement Des., vol. 6, no. 29, pp. 1–17, 2015.
[41] M. Ameri, A. Mansourian, and A. Hossein Sheikhmotevali, “Laboratory evaluation of ethylene vinyl acetate modified bitumens and mixtures based upon performance related parameters,” Constr. Build. Mater., vol. 40, pp. 438–447, 2013.