Performance of High Content Reclaimed Asphalt Pavement (RAP) in Asphaltic Mix with Crumb Rubber Modifier and Waste Engine Oil as Rejuvenator

Md Zahid Hossain Khan,Mohd Rasdan Ibrahim,Obada Asqool,Herda Yati Binti Katman,Suhana Koting,Ali Mohammed Babalghaith

doi:10.3390/app11115226

Md Zahid Hossain Khan, Mohd Rasdan Ibrahim + Show 4 more

Open Access

https://doi.org/10.3390/app11115226

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Abstract

The utilisation of reclaimed asphalt pavement (RAP) as a suitable substitute for natural aggregate and binder offers an energy-saving and cost-effective approach to enhance the performance of asphalt mix. Realising the potential use of RAP as a promising recycling technique, many countries are seeking to recycle RAP as part of the global effort to address the rising challenge of climate change and contribute to a sustainable environment. This study aimed to develop an integrated approach to determine the amount of RAP to be used in an asphaltic concrete wearing course with 14 mm nominal maximum aggregate size (ACW14). The RAP was incorporated with two waste materials comprising waste engine oil (WEO) as a rejuvenator and Crumb Rubber (CRM) as a binder modifier. A total of five different mixes, which include R0 (control mix), R30, R50, R70, and R100 (replacement of 30%, 50%, 70%, and 100% of RAP aggregates in the mix, respectively) were evaluated. The Marshall parameters, resilient modulus (MR), indirect tensile fatigue, moisture susceptibility, and mass loss (ML) tests were conducted to investigate the performance of each mix. Finally, an arbitrary scale was developed to optimise the RAP content. The results showed that the Marshall parameters, moisture susceptibility, and ML values of the RAP mixes met the criteria outlined in the standard. According to the MR performance, the R50, R70, and R100 mixes were more resilient than the R0. In terms of fatigue resistance, the R30, R50, and R70 mixes showed better performance than the R0. Overall, the collective performance of all RAP mixes was above the R0 and it increased with the increment of RAP content. Therefore, it was possible to design ACW14 mixes with up to 100% RAP in combination with WEO and CRM.

Highlights

The use of reclaimed asphalt pavement (RAP) is referred to as the recycling of aged asphalt pavement since RAP is a suitable substitute for natural aggregate and binder
For RAP mixes were lower than that of R0 in which the optimum binder content (OBC) of RAP mixes gradually decreased as the RAP content increased
Since the fatigue value of all RAP mixes was close to or higher than that of the R0 value, this study suggested that the integration of waste engine oil (WEO) and Crumb Rubber (CRM)

Summary

Introduction

The use of reclaimed asphalt pavement (RAP) is referred to as the recycling of aged asphalt pavement since RAP is a suitable substitute for natural aggregate and binder. The utilisation of RAP could reduce energy consumption, mineral usages, relevant pollution, and costs [1,2,3,4,5,6,7,8]. The use of RAP could reduce gas emissions and production costs by as much as 35% and 70%, respectively [8,9,10]. The application of RAP remains limited in many countries due to the lack of awareness and non-standard recycling requirements [10,11,12]. The use of 30% RAP in HMA was reported to cause little or no complications at all [13,14,15,16]

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