Effects of waste engine oil and cooking oil on the chemical, rheological, and permanent deformation of bitumen and asphalt mixtures

The effects of using waste engine oil (WEO) and waste cooking oil (WCO) as rejuvenators on some engineering properties of asphalt concrete containing reclaimed asphalt pavement (RAP) have been studied. 10% (by the weight of total binder) of the rejuvenators has been added to asphalt concrete containing 25%, 50% and 75% (by the weight of aggregate) of RAP, and the Marshall properties, indirect tensile strength (ITS), permanent deformation and fatigue properties of the mixtures have been evaluated. The effect of rejuvenators on Marshall properties depends on RAP content and type of rejuvenator, with higher values for the mixtures containing WEO. The ITS of the mixtures increase with increasing RAP content, and decreases with increasing rejuvenators content. Addition of WEO results in lower accumulated strain in the mixtures than adding WCO. In addition, the accumulated strain in the mixtures containing 50% of RAP is higher than that in the mixtures containing 25% and 75% of RAP. The fatigue life of the mixtures was found to increase with increasing RAP content and decrease by addition of rejuvenator with a higher reduction for the WCO. In general, it is concluded that using the rejuvenators enables using higher RAP content in recycled asphaltic mixtures.

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.

After serving their intended purpose, traditional asphalt pavements are destroyed and dumped across the neighboring fields in Pakistan, affecting the natural environment. Only 15% of the old asphalt material has been recycled on the Motorway (M-2) near Shekhupura. Thus, the current study was intended to increase the amount of recycled asphalt, utilizing waste engine oil (WEO), waste cooking oil (WCO), and waste brown grease (WBG) as rejuvenators. Therefore, the asphalt mixture containing 50% recycled materials, rejuvenated with 5%, 10%, 15%, 20%, and 25% WEO, WCO, and WBG, respectively, were investigated. The asphalt samples for Marshall Stability, indirect tensile strength, and rut resistance were prepared and tested as per ASTM D1559, ASTM D979, and ASTMD8360, respectively. The results showed that WEO, WCO, and WBG of 15% and 20%, respectively, are best for equating the properties of recycled binder to those of neat binder, except for ductility characteristics. The results also demonstrated that, in comparison to the traditional asphalt mixture, asphalt mixes with 50% recycled materials performed significantly better in terms of Marshall stability at 15% utilization of WEO, WCO, and WBG, respectively. Additionally, it is established that recycled asphalt mixture, at WEO of 15%, displayed equivalent rut resistance to virgin asphalt mixture. The results of this study will help recycle old asphalt materials for practical engineering purposes, lowering the dependence on natural resources and benefiting the environment.

In recent years, Reclaimed Asphalt Pavement (RAP) has become very popular in pavement construction due to its benefits to the economy and the environment. The present study investigates the feasibility of employing Waste Cooking Oil (WCO) and Waste Engine Oil (WEO) as rejuvenators blended with reusable asphalt binder through physical and rheological properties at high and intermediate temperatures. Examined conventional properties of WCO-and WEO-modified bitumen include softening point, penetration, ductility and viscosity. In addition to these rheological properties, they also include Amplitude Sweep, Frequency Sweep, Multiple Stress Creep Recovery (MSCR), Linear Amplitude Sweep (LAS) and High-temperature Performance Grading (HTPG) tests carried out by Dynamic Shear Rheometer (DSR). The experimental outcomes revealed that both WCO and WEO could reduce deformation resistance and improve stiffness, workability and viscous behavior of aged bitumen. Moreover, the addition of waste oils improves the fatigue lives of rejuvenated bitumen and enhance fatigue cracking resistance, but at the cost of rutting resistance. Overall, WCO performs better in restoring stiff binder properties than WEO as per rheological testing. KEYWORDS: Dynamic shear rheometer (DSR), Reclaimed asphalt pavement (RAP), Rejuvenators, Waste cooking oil (WCO), Waste engine oil (WEO).

This study attempts to investigate the viability of using waste engine oil (WEO) and waste cooking oil (WCO) as rejuvenator in asphalt concrete containing reclaimed asphalt pavement (RAP). Different percentages of the waste oils, namely 0, 5, 10 and 15% (by the weight of total binder) have been added into an asphalt concrete containing, 25, 50 and 75% of RAP and the effects on creep and fatigue properties have been investigated. The rutting resistance was found to increase with adding RAP, with lower increase for adding 50% RAP than 25 and 75%, and decrease with adding WEO and WCO, with lower decrease for adding 10% than adding 5 and 15%. Stress controlled fatigue tests showed that the fatigue resistance of non-rejuvenated mixtures grows with increasing RAP content, and, in general, the increase of WEO/WCO dosage results in the decrease of fatigue life. At the same dosage of rejuvenator, WEO results in more fatigue life than WCO, indicating that higher WEO is allowed to be used in recycled mixtures.

Repurposing waste oils into cleaner aged asphalt pavement materials: A critical review

In order to explore the applicability of waste engine oil and waste cooking oil used in aged asphalt, the effect of waste engine oil and waste cooking oil on aged asphalt recycling was studied through the analysis of the improvement of its physical, chemical, and rheological properties. Six aged asphalt binders with different aging times were obtained by indoor test simulation using the Thin Film Oven Test at 163 °C. Then, waste engine oil and waste cooking oil with five different dosages were added to investigate improvement performances. The results clearly demonstrated that waste engine oil and waste cooking oil could soften and recover the work ability of aged asphalt effectively. Furthermore, the physical, chemical, and rheological performances of six aged asphalts could be improved to normal level of virgin asphalt if the content of waste engine oil or waste cooking oil was suitable. The rheological properties of aged asphalt with waste cooking oil had better improvement than that with waste engine oil. Overall, the good applicability would provide waste oil a much wider service range in asphalt pavement recycling field. It also provided a method of developing new rejuvenating agent with the two waste oils to achieve complex synergism effect. Moreover, it realized the waste cyclic utilization and environmental protection.

The depletion of natural resources has accelerated the demand for sustainable solutions in urban infrastructure, especially concerning hydrological impacts. This study explores the influence of Recycled Asphalt Pavement (RAP), in combination with rejuvenators such as Waste Cooking Oil (WCO) and Waste Engine Oil (WEO), on surface runoff and water infiltration behavior in urban environments. Aimed at restoring aged bituminous binder properties, the research involves comprehensive physical, chemical, and rheological analyses to ensure pavement durability while enhancing hydrological performance. Experimental findings show that WCO significantly improves the rheological and physical characteristics of aged asphalt binders, enhancing flexibility and reducing surface impermeability. Fourier Transform Infrared Spectroscopy (FTIR) confirms chemical compatibility between VG 30 bitumen and the rejuvenators, ensuring effective binder blending. Dynamic Shear Rheometer (DSR) tests indicate that aging increases stiffness, as evidenced by a higher complex shear modulus and lower phase angles. However, WCO rejuvenation effectively reverses this, achieving a peak shear stress of 120 kPa at 10% strain, outperforming the 80 kPa at 5% strain for WEO-modified RAP. Hydrological assessments reveal that RAP mixtures with 4% WCO improve infiltration rates by 12–15% and reduce surface runoff by approximately 10% compared to conventional pavements. These outcomes underscore the dual benefits of RAP and WCO in sustainable pavement design-enhancing structural performance while supporting urban stormwater management. The study establishes a clear linkage between environmentally conscious pavement technologies and improved urban hydrology, promoting the adoption of RAP-based pavements in climate-resilient infrastructure planning.

Analysis of relationship between component changes and performance degradation of Waste-Oil-Rejuvenated asphalt

Characterization of waste cooking oil and waste engine oil on physical properties of aged bitumen

Mechanical performance evaluation of crumb rubber enriched rejuvenator modified RAP mixtures

Sustainable pavement construction is an extensively researched subject within the field of pavement engineering. Due to its environmental and commercial advantages, the construction of pavements utilizing recycled asphalt pavement (RAP) is progressively gaining popularity worldwide. Owing to the aging process, binder extracted from RAP is inherently harder than virgin binder and requires rejuvenation for application in high RAP blends. This paper investigates the performance characteristics of Waste Cooking Oil (WCO) and Waste Engine Oil (WEO) as rejuvenators in RAP-incorporated asphalt mixtures to assess their suitability for pavement use. The optimal rejuvenator content is determined based on the performance of physical properties. The study indicates that asphalt mixes rejuvenated with Waste Cooking Oil (WCO) demonstrate higher Marshall Stability values compared to mixes rejuvenated with Waste Engine Oil (WEO) at both 30% and 60% Recycled Asphalt Pavement (RAP) levels. Additionally, mixes incorporating WCO exhibit increased flow values. Furthermore, WCO outperforms WEO in Tensile Strength Ratio (TSR) at 30% RAP, with a slight decrease at 60% RAP. Results from Marshall and Indirect Tensile Strength (ITS) tests suggest that both WEO and WCO are effective rejuvenators, playing a critical role in aligning the properties of RAP-inclusive asphalt mixes with those of virgin mixes.

To make full use of the regenerative value of waste cooking oil, and to solve the environmental pollution and food security issues caused by waste cooking oil, waste cooking oil was suggested for use in asphalt. Waste cooking oil was used to adjust the performance of virgin and aged asphalt. This review article summarizes research progress on the performance of asphalt and asphalt mixture with waste cooking oil. The results showed that a moderate dosage of waste cooking oil will improved the low-temperature performance and construction workability of petroleum asphalt and aged asphalt. The mixing and compaction temperature of asphalt mixture with waste cooking oil are reduced by up to 15 °C. The rutting resistance and fatigue resistance of modified asphalt and modified asphalt mixture with waste cooking oil are damaged. After the addition of waste cooking oil in aged asphalt, the high-temperature performance and shear rheologic property of aged asphalt will be recovered. The regeneration effect of waste cooking oil on aged asphalt and aged asphalt mixture is close to that of a traditional regeneration agent, and the partial performance of asphalt or asphalt mixture with waste cooking oil is better. There is no chemical reaction between waste cooking oil and asphalt, but the asphalt component and absorption peak intensity of partial functional groups are changed. The light components content of asphalt binder is usually increased. Further research regarding the engineering application of asphalt mixture with waste cooking oil should be conducted. The method for improving the performance of asphalt and asphalt mixture with waste cooking oil will be mainly researched.

In spite of many environmental and economical advantages of using reclaimed asphalt pavement (RAP) in the production of asphalt mixtures, many technical issues remain not very well understood and require further investigation, including the interactions between RAP content, rejuvenator type and rejuvenator content, and their combined effects on engineering properties of the resultant asphalt mixtures. In this study, statistical modeling tools were utilized to gain greater insight into the aforementioned interactions. The indirect tensile strength (ITS), an important engineering property which is related to the resistance against cracking and rutting of asphalt mixtures, has been selected as the primary engineering characterization tool in this investigation. The ITS of asphalt concrete mixes containing RAP (at 25, 50 and 75% by weight of total aggregates) and incorporating waste engine oil (WEO) and waste cooking oil (WCO) as rejuvenating agents (at 5, 10 and 15% by weight of total binder) was investigated using response surface methodology (RSM). As expected, the ITS was found to increase with increasing RAP content and to decreases with increasing oil content. Results also revealed that incorporating WEO resulted in higher ITS of the asphalt mixes compared to WCO. Interaction plots of test results show that the increase of ITS with increasing RAP content depends on the oil content, with higher rate for mixtures with lower oil content, and is independent of oil type. Optimization of ITS in RSM reveals that using 75% of RAP and 5% of WEO results in the highest indirect tensile strength of the mixture.

Investigation of waste oils as rejuvenators of aged bitumen for sustainable pavement