Aging mechanism and effective recycling ratio of SBS modified asphalt

Abstract With the increase of road service life, SBS (styrene–butadiene–styrene block copolymers) modified asphalt waste materials are being discarded. Taking advantage of these waste pavement surfacing materials will not only reduce the pollution of the environment, but also save resources. This paper analyzes the aging mechanism of SBS modified asphalt through macroscopic examination and microcosmic analysis using conventional performance indicators: SHRP performance index, component analysis, Gel Permeation Chromatography (GPC), Infrared Spectrum Analysis (IR), etc. The recycling effectiveness was evaluated through the indicator of effective recycling ratio which is put forward by laboratory test. The results illustrated that the aging of SBS modified asphalt was formed by both aging of matrix asphalt and aging of SBS modifier. SBS modifier degradation could slow down the aging reaction of matrix asphalt because SBS modifier would degrade to small molecules in the process of aging. In addition, the matrix asphalt could also play a role in the protection of the SBS modifier. Therefore, the mutual protection of both makes the anti-aging performance of the modified asphalt significantly better than that of matrix asphalt. We also evaluated the recycling effectiveness of aged SBS modified asphalt under the presence or absence of rejuvenating agent, different mixing time and temperature. The presence of rejuvenating agent as well as appropriately increasing mixing temperature and time are proved to be able to improve the recycling effectiveness.

[1]  Jia-Chong Du,et al.  Application of Gray Relational Analysis to Evaluate HMA with Reclaimed Building Materials , 2005 .

[2]  Trenton M Clark,et al.  Case Studies on Processes Involved in the Production and Placement of High RAP Asphalt Concrete Mixes in 2007 on Selected Routes in Virginia , 2009 .

[3]  Haifang Wen,et al.  Influence of Recycled Asphalt Pavement Content on Air Void Distribution, Permeability, and Modulus of Base Layer , 2012 .

[4]  Adriana Martínez,et al.  Experimental study of recycled asphalt mixtures with high percentages of reclaimed asphalt pavement (RAP) , 2011 .

[5]  Fariborz Gahvari,et al.  Effects of Thermoplastic Block Copolymers on Rheology of Asphalt , 1997 .

[6]  Fan Yang,et al.  Performance of the heavy fraction of pyrolysis oil derived from waste printed circuit boards in modifying asphalt. , 2013, Journal of environmental management.

[7]  Tseng-Hsing Hsu,et al.  Life cycle assessment on using recycled materials for rehabilitating asphalt pavements , 2008 .

[8]  S. Ranji Ranjithan,et al.  Quantifying the Greenhouse Gas Emission Reductions Associated with Recycling Hot Mix Asphalt , 2011 .

[9]  R M Anderson,et al.  Recommended use of reclaimed asphalt pavement in the Superpave mix design method: technician's manual. , 2000 .

[10]  William G. Buttlar,et al.  Understanding Asphalt Mastic Behavior Through Micromechanics , 1999 .

[11]  T. Ma,et al.  Laboratory Investigation of Recycling for Aged SBS Modified Asphalt Cement , 2011 .

[12]  D F Rogge,et al.  USE OF ASPHALT EMULSIONS FOR IN-PLACE RECYCLING: OREGON EXPERIENCE , 1992 .

[13]  A. B. Ngowi,et al.  Creating competitive advantage by using environment-friendly building processes , 2001 .

[14]  C. Daranga,et al.  Characterization of aged polymer modified asphalt cements for recycling purposes , 2005 .

[15]  M. L. Antunes,et al.  Mechanical Performance and Economic Evaluation of Warm Mix Recycling Asphalt , 2012 .

[16]  Paulo A. A. Pereira,et al.  Effect of different production conditions on the quality of hot recycled asphalt mixtures , 2012 .

[17]  Bernard Brûlé,et al.  Polymer-Modified Asphalt Cements Used in the Road Construction Industry: Basic Principles , 1996 .