Investigating Permanent Deformation of Recycled Asphalt Concrete Containing Waste Oils as Rejuvenator Using Response Sur
- PDF / 2,363,780 Bytes
- 13 Pages / 595.276 x 790.866 pts Page_size
- 25 Downloads / 244 Views
RESEARCH PAPER
Investigating Permanent Deformation of Recycled Asphalt Concrete Containing Waste Oils as Rejuvenator Using Response Surface Methodology (RSM) Hasan Taherkhani1 · Farid Noorian2 Received: 18 September 2019 / Accepted: 1 October 2020 © Shiraz University 2020
Abstract In this research, the permanent deformation property of asphalt concrete containing different percentages of recycled asphalt pavement (RAP) and dosages of waste engine and cooking oil has been investigated using response surface methodology (RSM). 25, 50 and 75% of total aggregates have been replaced with RAP, and each rejuvenated with 5, 10 and 15% (by the weight of total binder) of waste engine oil (WEO) and waste cooking oil (WCO). Experiments were designed using composite central design method in RSM, and the permanent strain accumulated after applying 1000 cycles of 300 kPa vertical stress at a frequency of 1 Hz and temperature of 40 °C was measured. Using RSM in Design Expert program, a polynomial quadratic model was found to be capable for predicting the permanent strain. It was found that the significant terms for prediction of permanent strain are RAP and oil content, the squared oil content and type of oil. Results reveal that permanent strain decreases with increasing RAP content; however, for each RAP content, the lowest permanent strain is achieved at a certain level of oil content. At the same dosage of use, WEO results in lower strain than WCO. Interaction effect was found between RAP content and oil type, such that the decrease of strain with RAP content is higher with WCO than WEO. Using optimization in RSM, the content of oils to achieve a mixture with similar deformation property of control mix was obtained. Keywords RAP · Permanent strain · Waste engine oil · Waste cooking oil · Response surface method
1 Introduction Reclaimed asphalt pavement (RAP) is one of the main solid wastes, which is produced after milling distressed asphalt layers during reconstruction or rehabilitation of flexible pavements. It contains valuable materials of asphalt binder and quality aggregates which can be recycled and used in production of different types of asphalt mixtures including hot mix asphalt (HMA), cold mix asphalt (CMA) and warm mix asphalt (WMA) (Behnood 2019). Recycling of RAP materials results in reduction of energy consumption, * Hasan Taherkhani [email protected] Farid Noorian [email protected] 1
Civil Engineering Department, University of Zanjan, 45371‑38791 Zanjan, Iran
Highway and Transportation Engineering, University of Zanjan, Zanjan, Iran
2
conservation of landfills space, reduction of air pollutants, preservation of non-renewable resources, reduction of production cost and improvement of some of the mechanical properties of asphalt mixture (Behnood 2019, 2020). Due to the environmental and economic benefits, use of RAP in production of hot mix asphalt, as a replacement of virgin aggregates and asphalt binder has become a common practice worldwide. For instance, in 2016, 76.5 million tons of R
Data Loading...
