American Society of Civil Engineering (ASCE) Online News called “SOURCE” recently posted a paper abstract titled “Reclaimed Asphalt Pavement as a Substitution to Natural Coarse Aggregate for the Production of Sustainable Pervious Concrete Pavement Mixes”. The paper is written by Surya Kant Sahdeo, Research Scholar; Gondaimei Ransinchung, Ph.D., Associate Professor; K. L. Rahul, Postgraduate Student; and Solomon Debbarma, S.M. ASCE, Research Scholar; all from the Department of Civil Engineering, Indian Institute of Technology Roorkee-Uttarakhand, and published in the Journal of Materials in Civil Engineering. The paper explores using reclaimed asphalt pavement as a substitute to natural coarse aggregate in the production of sustainable pervious concrete pavement (PCP) mixes.
According to James Mack, Director, Market Development-CEMEX, “The problem with asphalt is that there is more to recycle than the industry can use.”
Conventional concrete pavement traditionally has a lower life-cycle cost (LCC), but is directly responsible for increased carbon dioxide emissions, urban heat islands, and is inefficient in managing stormwater runoff. According to the paper, utilizing coarse reclaimed asphalt pavement (RAP) aggregates for pervious concrete pavement (PCP) mixes. Pervious concrete pavement with permeable layers is a greener and cleaner option. Mack stated, “Here is a potential long-term solution that solves two problems.”
ABSTRACT:
This study discusses the effect of utilizing coarse reclaimed asphalt pavement (RAP) aggregates as a replacement to natural coarse aggregates (NCAs) for the production of pervious concrete pavement (PCP) mixes. Coarse RAP (RC) aggregates were utilized in proportions of 0%, 25%, 50%, 75%, and 100%, respectively. It was observed that the porosity and permeability coefficient of the PCP mixes increases considerably as the RAP replacement level increases. Meanwhile, the incorporation of RC was also found to negatively affect the mechanical properties of the PCP mixes. However, the compressive and flexural strength values were noted to be well within the prescribed limits (5–25 MPa and 1–3.2 MPa) required for a PCP mixture. On the other hand, the incorporation of RC was observed to reduce the hardened density, resistance to abrasion, and resistance against aggressive environment of chlorides and sulfates. Therefore, in order to prepare a PCP mixture such that there exists a fine balance in various properties, it is recommended that RC up to 50% may be utilized as a replacement to NCA. In view of achieving maximum sustainability, RC up to 100% may be completely utilized for the production of PCP mixes provided a binary gradation is adopted. Utilization of RAP in preparation of pervious concrete pavement mix will not only resolve the issues related to clearance of an enormous amount of RAP dumps, but would go a long way in dealing with various other environmental and ecological impacts.
For the abstract on the ASCE webpage, please go to: https://source.asce.org/using-reclaimed-asphalt-for-pervious-concrete-pavement-mixes/
To read the recommendations and download the full text on the ASCE Library webpage, please go to: https://ascelibrary.org/doi/10.1061/%28ASCE%29MT.1943-5533.0003555
Journal of Materials in Civil Engineering:
February 2021 | Volume 33, Issue 2ISSN (print): 0899-1561
ISSN (online): 1943-5533: https://ascelibrary.org/toc/jmcee7/33/2