Asphalt Pavement Rehabilitation Research Articles

A Comprehensive Review of Life Cycle Cost Assessment of Recycled Materials in Asphalt Pavements Rehabilitation

This paper provides a comprehensive review of the use of life cycle cost assessment (LCCA) and life cycle assessment (LCA) methods for evaluating the sustainability and costs of using recycled materials in asphalt pavement rehabilitation projects. The review begins with an introduction to pavement rehabilitation strategies and the importance of choosing techniques based on thorough engineering and economic analyses. It then explores the different types of recycled materials that can be utilized, including reclaimed asphalt pavement, recycled concrete aggregate, and recycled asphalt shingles, discussing the key characteristics and properties of these materials based on previous laboratory studies. The review also examines the various rehabilitation methods that employ recycled content, such as cold in-place recycling, hot in-place recycling, and full-depth reclamation, providing a detailed breakdown of the construction, maintenance, and rehabilitation costs considered in LCCA and analyzing the environmental benefits of recycled material usage through a review of LCA techniques and criteria like carbon footprint reduction, impacts on air and water quality, and considerations of technological factors. Software tools for conducting LCA are compared and challenges to advancing the adoption of recycled materials are reviewed along with directions for future research efforts. The unique contribution of this work is its holistic assessment of LCCA and LCA methodologies to inform the sustainable and cost-effective deployment of recycled materials in asphalt pavement rehabilitation, a topic of growing importance for transportation infrastructure management. In summary, this current work provides a valuable review of how LCCA and LCA methodologies can assess the sustainability and costs of employing recycled content in asphalt pavement rehabilitation projects.

Contribution of climate change and traffic load on asphalt pavement carbon emissions

The maintenance and rehabilitation of asphalt pavement contribute to carbon emissions, impacting climate change. The interaction between climate change and increasing traffic loads influences the frequency of maintenance for asphalt pavement infrastructure. This study assessed the combined impact of climate change and traffic growth on the performance and carbon emissions of Chinese freeway asphalt pavement, informing carbon reduction policies amid future climate change. Using climate prediction models (Representative Concentration Pathways 4.5 and 8.5), the research forecasted pavement performance under 2% and 4% traffic volume growth rates and estimates future carbon emissions based on maintenance strategies. Results indicated that both future climate change and increased traffic loads would have adverse effects on the asphalt pavement performance, particularly with a 4% annual traffic load growth. Freeway length with rut depths exceeding 25 mm may increase from 33,600 km in the 2020s to 94,950 km in the 2050s (an 182.6% increment). The interaction between climate change and traffic growth intensifies pavement deterioration, increasing maintenance frequency and carbon emissions. Under the conditions of RCP 8.5 and a 4% traffic load growth rate, the carbon emissions in the 2050s may increase by 71.9 million tons compared to the 2020s (an 180.7% increment). This underscores the need for strategic interventions and policy decisions to mitigate environmental impacts.

Calculation of the reduction of equivalent carbon dioxide (CO2e) by applying a thermostable geogrid on the example of the main project of DP IB no. section 12, Žabalj - Zrenjanin

Every asphalt pavement rehabilitation, apart from benefits in terms of safety, comfort and speed for users, also has its negative side, i.e., adverse effects on the environment. Some of these impacts, such as carbon dioxide equivalent emissions, cannot be limited to the immediate environment where the works are carried out, but are global. In order to limit the increase in the average temperature on Earth caused by increased CO2e emissions to below 2oC, and in accordance with Serbia's internationally accepted obligations, it is necessary that all industries, including construction, make their maximum contribution. When we talk about the rehabilitation of asphalt curtains, one of the possible ways to greatly reduce CO2e emissions is the application of thermostable geogrids for asphalt reinforcement. The main effect achieved by the application of geogrids for asphalt reinforcement is the extension of the durability of the new asphalt layer while reducing maintenance costs. According to the manufacturer of asphalt reinforcement nets and delaying the appearance of reflected cracks, the durability of the new asphalt layer increases 3-4 times. The paper provides a detailed analysis of the achieved carbon dioxide equivalent savings as well as the financial benefits of applying the HaTelit C 40/17 geogrid during the rehabilitation of the pavement on the project: Enhanced maintenance of state road IB no. 12, Žabalj-Zrenjanin.

Multi-stage heating technology for asphalt pavement hot in-place recycling using controlled heating power

ABSTRACT Hot in-place recycling allows the rehabilitation of worn asphalt pavement with minimal resources. However, it is limited by the heating rate of asphalt pavement. Temperature field distribution was calculated and analyzed in traditional single-stage heating technology (SHT) with constant temperature heating mode. Multi-stage heating technology (MHT) was proposed to improve the heating rate by decreasing the depth to which the asphalt pavement was heated at a given time. The asphalt pavement temperature fields were calculated for SHT and MHT. The calculation results accurately described the temperature field of the asphalt pavement, and the heating rate of MHT was over half that of SHT.

Evaluation of performance characteristics of asphalt mixtures modified with renewable oils and reclaimed asphalt pavement (RAP)

Over the years, there has been a significant production of Reclaimed Asphalt Pavement (RAP) from asphalt pavement maintenance and rehabilitation processes. This material is typically thrown away and has negative impacts on the environment. However, it can be reused for pavement construction, but it is crucial to use agents that restore its original properties. This study evaluates the impact of two natural renewable oils, sunflower, and soybean, on the properties of neat asphalt and asphalt mixtures that contain RAP. The optimal amount used was 5%. The results show that sunflower and soybean oils are effective in rejuvenating aged asphalt in RAP mixtures by softening the aged binder. As a result, the modified asphalt mixtures exhibit improved resistance to low-temperature cracks, moisture susceptibility, and permanent deformation.

Stiffness assessment of cold recycled asphalt mixtures – Aspects related to filler type, stress state, viscoelasticity, and suction

Cold recycling is an advantageous technique, from economic and environmental perspectives, for asphalt pavement rehabilitation, interventions, and maintenance. Additional investigation is still needed for the widespread of the technique. Some of the issues evolve predicting the recycled material mechanical behavior and performance along its service life. Therefore, stiffness assessment (through triaxial resilient modulus and dynamic modulus tests) and suction tests were performed to better understand the cold recycled asphalt mixture (CRAM) behavior. This paper covered an investigation of the suction pressure phenomenon and its effects regarding the stiffness of emulsion-stabilized cold recycled asphalt mixtures, considering different fillers. A non-contact suction test method was proposed for CRAM compacted specimens in a way to enable total suction readings. Further theoretical analysis, key literature review, and discussions were presented. Some of the findings of the work are: (i) CRAM’s stiffness may present similar behavior of a granular material, with confining pressure dependence, and at the same time, presents a temperature/frequency dependence (as asphaltic materials); (ii) suction phenomenon may be responsible for part of the stiffness of CRAM; (iii) the filler type (even in small percentage) affects the mechanical behavior of CRAM.

Effect of aging and temperature on milling-induced stresses and cracks in Hot Mix Asphalt (HMA) pavements

The majority of the pavements in the world are surfaced with asphalt mixes. Milling is a necessary step for the removal of aged or distressed Hot Mix Asphalt (HMA) materials and recovery of Reclaimed Asphalt Pavement (RAP) for rehabilitation of asphalt pavements. The objective of this study was to predict the milling-induced stresses for two asphalt mixes. Using laboratory-measured stiffness, a three-dimensional finite element model (3-D FEM) was developed and validated with drop tower impact tests. The models were simulated at 25 °C and 60 °C, with unaged, 60 months, and 120-month aged conditions. Viscoelastic and Drucker-Prager models with the maximum principal stress failure criterion and the erosion method were utilized to predict failure. Results showed that the milling-induced stress zone increases significantly with increased stiffness/aging. Milling at 25 °C results in greater stress penetration depth than at 60 °C and leads to the formation of cracks below the milling line.

Quantitative assessment and mechanism analysis of modification approaches for cold recycled mixtures with asphalt emulsion

Cold recycled mixtures with asphalt emulsion (CRMEs) are environmentally friendly and cost-effective materials widely used in asphalt pavement maintenance and rehabilitation (M&R). However, CRMEs exhibit lower mechanical performance and durability than hot-mix asphalt. This study aims to evaluate the effects of different modification approaches on the mechanical properties and durability of CRMEs. To this end, four optimal additives, including the rejuvenation agent (RA), basalt fibres (BFs), styrene–butadiene rubber (SBR) latex, and Buton rock asphalt (BRA), were added to CRMEs during the mixing procedure. Comprehensive laboratory tests including immersion splitting and freeze–thaw splitting tests, high-temperature rutting tests, low-temperature semi-circle bending tests, and indirect tensile fatigue tests were conducted to evaluate the mechanical properties of the modified CRMEs. In addition, the radar chart method was performed to quantitatively assess the effects of the multiple modification approaches. To investigate the influence mechanisms, microscopic features of the modified CRMEs, such as the compactness of the mortar and bonding sufficiency of the interface, were detected by scanning electron microscopy. The results showed that the addition of RA, SBR latex, and BRA can improve the comprehensive performance of the modified CRMEs. Among these additives, RA had the most significant effect, followed by BRA. These findings aid in selecting modifiers to improve the performance and durability of CRMEs in practical engineering applications.

Rheological behavior of asphalt binders and fatigue resistance of SMA mixtures modified with nano-silica containing RAP materials under the effect of mixture conditioning

Due to the environmentally associated issues regarding the construction or rehabilitation of asphalt pavements with merely virgin materials, researchers have proposed the re-utilization of the reclaimed asphalt pavement (RAP) materials. However, their adoption in asphalt pavements is detrimental to the fatigue performance of asphalt pavements. For this, modifying asphalt binders with nanoparticles has been one of the successful choices among researchers. In this study, different compounds of asphalt binders and stone matrix asphalt (SMA) mixtures containing 20%, 30%, 40%, and 50% RAP materials modified with 2%, 4%, and 6% nano-silica were prepared. Moreover, the rheological behavior of each mix was evaluated using several tests, including rotational viscosity (RV) considering the flow activation energy (FAE) method, frequency sweep, Multiple Stress Creep Recovery (MSCR), Linear Amplitude Sweep (LAS), and Bending Beam Rheometer (BBR). Besides, the fatigue performance of aged SMA mixtures was investigated using the four-point beam fatigue (4 PB) test. The results indicated that the temperature susceptibility of binders was decreased by the addition of nano-silica and RAP binder. Also, according to the MSCR and frequency sweep tests results, the rutting resistance of modified binders with the RAP binder was superior to that of the base binder. Besides, due to the establishment of a network by nano-silica within the structure of the asphalt binder in which the functional groups of asphalt binder interact with nanoparticles, the modified binders with RAP binder outperformed their unmodified counterparts regarding the fatigue life. Also, aging had a less detrimental impact on the fatigue life of the RAP contained SMA mixtures. However, the low-temperature performance of binders was degraded by the addition of nano-silica.

Review on structural damage rehabilitation and performance assessment of asphalt pavements

Abstract Asphalt pavements have been extensively used in highway system. However, a great number of asphalt pavements suffer from early distresses after servicing for about 2–3 years, which leads to frequent rehabilitation and increased maintenance cost. To understand the damage propagation principle and the correlated rehabilitation measure, the progress of pavement distress rehabilitation, structural performance, and damage assessment of asphalt pavements has been explored in the perspectives of materials and structures. The current advance on the parameters for describing the cracking and rutting of asphalt pavements has been introduced. The development tendency for the damage self-healing and rehabilitation, and structural assessment has also been discussed. The study can provide a scientific guidance for understanding the generally used structural damage rehabilitation measure and performance assessment methods of asphalt pavements.

Rehabilitation of Asphalt Pavement to Improvement the Mechanical and Environmental Properties of Asphalt Concrete by Using of Nano Particles

Dealing with the pollution released into the air by vehicles is a major concern for many countries around the world. There is an increasing trend toward environmental considerations as well as road logistics issues, resulting in doing experiments on new materials, which can help reducing the amount of pollutants in the atmosphere. In this research, the photo catalytic properties of Nano TiO2/SiO2 used over the asphalt roads in order to absorb the pollution substances from the atmosphere are investigated. The above mentioned compound reacts with UV light and oxidizes the pollutant particles including nitrogen oxides (NOx) as well as volatile organic compounds (VOC). In this method, the sol-gel technique was used to produce photo catalyst based on TiO2/SiO2. One purpose of this research is to examine the photo catalytic properties of the compound when it is used in a hot mix asphalt (HMA). Another aim of the study is to find and describe both rheological and mechanical characteristics of the hot mix asphalt (HMA) as well as the Nano modified agents. The resulting asphalt would have the advantages of HMA, including lower energy requirements and less emission during production, while having photo catalytic characteristics of TiO2/SiO2 to absorb and decompose the organic and inorganic air pollutants. The outcomes of the tests showed that adding the Nano TiO2/SiO2 modifier to the asphalt binder effectively removed NOx particles from the air and enhanced the rheological properties of bitumen. It also enhanced the hardness and viscosity of the pavement, while reducing its penetration and fatigue life. When TiO2/SiO2 was sprayed as a water based coating, the efficiency of NOx reduction ranged between 41 and 63%.

Dynamic Modulus Predictive Models for In-Service Asphalt Layers in Hot Climate Areas

Dynamic modulus of asphalt mixtures is one of the most important input parameters in design and rehabilitation of asphalt pavements. Dynamic modulus predictive models are alternative methods for laboratory determination of this parameter. These models were developed based on laboratory data. Due to sophisticated and laborious laboratory testing methods, there is a need to develop new models to determine dynamic moduli of in-service asphalt layers. In this study, nine different asphalt pavement sites were selected in two southern provinces of Iran. Falling weight deflectometer (FWD) testing was performed at each site and core samples were taken from the asphalt layers for volumetric analysis. Using the results, dynamic moduli of asphalt layers were determined using six predictive models, including Witczak, modified Witczak, Hirsch, Al-Khateeb, global, and simplified global models. Predicted dynamic moduli were compared with those determined from back-calculation analysis of FWD data. Existing predictive models were calibrated and new models were developed for the prediction of in situ dynamic modulus of asphalt layers in hot climate areas. Performance evaluation and validation of the new models showed high prediction accuracy and low prediction bias with very good correlations between the predicted and back-calculated values (R2=0.96).

Investigation of the Effects of Evaporation Methods on the High-Temperature Rheological and Fatigue Performances of Emulsified Asphalt Residues

Cold recycling technology is a widely applied asphalt pavement rehabilitation technology. The properties of emulsified asphalt residues after water evaporates play an important role in the performance of the asphalt pavement. This paper investigates the rheological and fatigue properties of emulsified asphalt residues under different evaporation methods. Two different matrix asphalt binders and emulsifiers were selected to prepare the emulsified asphalt. Moreover, the direct heating method (DHM) and the EN13074 and ASTM D7497-09 evaporation methods were used to obtain emulsified asphalt residues. Furthermore, the linear viscoelasticity, the permanent deformation resistance, and the fatigue resistance were evaluated by the temperature sweep and frequency sweep tests, the multiple stress creep recovery (MSCR) test, and the linear amplitude sweep (LAS) test, respectively. The test results show that under the three evaporation conditions, the growth amplitude order of the rutting factor, recovery percent, complex modulus, and fatigue life of emulsified asphalt residues is ASTM D7497-09 > EN13074 > DHM, and as is the attenuation amplitude order of the nonrecoverable creep compliance and phase angle. The results reveal that the evaporation process leads to oxidation and hardening of the residues. The hardening degree of the ASTM D7497-09 evaporation method is higher than that of the EN13074 evaporation method, and the hardening degree of the EN13074 evaporation method is higher than that of the direct heating method. The rheological and fatigue performances of the emulsified asphalt residues depend on the matrix asphalt. Moreover, the residue that was prepared from 70# asphalt has good high-temperature and fatigue properties, but it has higher temperature sensitivity and stress sensitivity.

Life cycle assessment of asphalt pavement maintenance and rehabilitation techniques: a study for the City of St. John’s

Although pavement maintenance and rehabilitation (M&R) techniques are usually examined in economic terms, there is a growing need to address their environmental footprints. The objective of this study is to assess the environmental impacts of M&R techniques. Life cycle assessment (LCA) can help in the decision-making process of selecting suitable maintenance techniques based on their environmental impacts. This study investigates: patching, rout & sealing, hot in-place recycling, and cold in-place recycling. Global warming potential (GWP), acidification potential, human health particulate, eutrophication potential, ozone depletion potential, and smog potential are estimated as environmental impacts for each maintenance activity. Materials, equipment use (for construction and M&R), and transportation were the main elements considered. A sensitivity test is performed to identify the significant factors for the LCA. The study concluded that GWP was the most important impact category. Rout & sealing and cold in-place recycling produced the lowest GWP emissions. Notably, pavement patching and hot in-place recycling showed significant detrimental environmental impacts.

Performance and Microstructure of Cold Recycled Mixes Using Asphalt Emulsion with Different Contents of Cement.

Cold recycled mixes using asphalt emulsion (CRME) is an economical and environmentally-friendly technology for asphalt pavement maintenance and rehabilitation. In order to determine the optimum range of cement contents, the complex interaction between cement and asphalt emulsion and the effects of cement on performance of CRME were investigated with different contents of cement. The microstructure and chemical composition of the fracture surface of CRME with different contents of cement were analyzed in this paper as well. Results show that the high-temperature stability and moisture susceptibility of CRME increased with the contents of cement increasing. The low-temperature crack resistance ability gradually increased when the content of cement is increased from 0% to 1.5%. However, it gradually decreased when the content of cement is increased from 1.5% to 4%. Cold recycled mixes had better low-temperature cracking resistance when the contents of cement were in the range from 1% to 2%. The results of microstructure and energy spectrum analysis show that the composite structure is formed by hydration products and asphalt emulsion. The study will be significant to better know the effects of cement and promote the development of CRME.

Experimental Investigation on Fatigue and Low Temperature Properties of Asphalt Mixtures Designed with Reclaimed Asphalt Pavement and Taconite Aggregate

Using reclaimed asphalt material for rehabilitation and construction of new asphalt pavements is currently a common practice not only in view of the economic benefits associated with this process but also because of the reduced exploitation of natural resources. For this reason, road authorities have implemented recommendations and guidelines to regulate the use of reclaimed asphalt pavement (RAP) and other recycled materials such as industrial by-products. Nevertheless, the combined use of different recycled materials is not commonly addressed. In this paper, the effect of adding RAP and taconite (a mining by-product) on fatigue and low temperature properties of asphalt mixture was investigated with two different testing geometries: indirect tensile (IDT) and semi-circular bending (SCB). Fatigue behavior, creep stiffness, relaxation modulus, low temperature fracture energy, and fracture toughness were also evaluated, computed, and then compared. A more brittle behavior was observed for mixture prepared with RAP material, however, the mechanical performance was not significantly different for mixtures containing 20% RAP alone and in combination with 50% taconite compared with conventional asphalt mixtures designed with virgin material. This was not the case when RAP content was increased up to 50%, showing a substantially poorer response both in terms of fatigue and low temperature characteristics and suggesting the RAP had a dominant effect. The present exploratory research seems to support the idea of combining RAP and different industry by-products, such as taconite, as long as the RAP content is kept below a specific threshold.

EXPERIENCE ON IMPLEMENTATION OF HOT IN-PLACE RECYCLING OF ASPHALT CONCRETE IN UKRAINE

Rehabilitation of asphalt concrete layers of road pavements using HIR technologies enables effective elimination of surface defects (rutting, cracking, raveling, bleeding (flushing)) including defects caused by the non-conformity of asphalt concrete to the standard specifications. Due to the economical and ecological advantages, HIR technologies belong to the present-day effective alternative methods of rehabilitation of asphalt concrete pavements. In Ukraine, HIR technologies were first applied on intermediate repair works on an area of the international road I-01 “Kyiv-Chernihiv-Novyye Yarylovichi” in the 2013. Now, HIR technologies have been applied on repair works on numerical objects including areas on such state motor roads as I-01, I-06, N-09, R-10, R-67. The presented paper analyzes the results of monitoring of materials and technologies which was aimed on HIR performance investigation supported by State Road Agency of Ukraine (Ukravtodor) throughout 2014-2018. The results of monitoring of HIR technologies including laboratory evaluation of materials and also field testing of the rehabilitated pavements led to the conclusions fitted by the world-wide experience on implementation of HIR technologies. 1. Being applied to the structurally sound pavements, HIR provides effective elimination of surface defects of flexible pavement to a depth of (50-60) mm including defects caused by the non-conformity of asphalt concrete to the standard specifications. However, HIR is not suitable for existing asphalt pavements which have too much variation in asphalt concrete composition and thickness within the project limits. 2. The efficiency of asphalt pavement rehabilitation using HIR technologies largely depends on precise engineering consideration which determines the efficiency of preparatory (repair) works including some special works such as: – correction of cracks in case of cracking that extends below the depth of hot recycling; – re-compaction of an unbound base layer(s) in case of the insufficient compaction causing “alligatored” network-like cracking of asphalt pavement. 3. Proper technical and working conditions of the rehabilitated pavement during the nominal life cycle could be maintained by overlaying the surface treatment using bituminous emulsion materials or by single-pass overlaying a new hot-mixed asphalt concrete layer. Investigations accomplished during the implementation of HIR technologies allow enhance quality of recycled materials and also promote the entire adaptation of HIR technologies to the Ukrainian standards. Keywords: asphalt pavement rehabilitation, hot in-place recycling, recycled asphalt concrete, field testing, road pavement strength measurement, rutting measurement.

A Cost-Effective and Objective Full-Depth Patching Identification Method using 3D Sensing Technology with Automated Crack Detection and Classification

Full-depth patching is one of the commonly used asphalt pavement maintenance and rehabilitation methods in which deteriorated base and surface layers are repaired to restore strength and improve ride quality. During resurfacing projects, areas requiring full-depth patching are identified and quantified as construction priorities because of the high costs associated with the labor and materials for the procedure. Currently, the manual surveys conducted to identify these locations are time-consuming and labor-intensive. Thus, large projects often cannot easily quantify the full-depth patching need because of the significant labor that would be required. This paper proposes a method that uses emerging 3D laser technology to identify the full-depth patching need by processing and analyzing the pavement distresses automatically extracted from 3D laser images. The proposed method consists of five steps: (1) 3D data acquisition, calibration, and validation, (2) crack detection, (3) crack classification, (4) rutting detection and measurement, and (5) determination of image-based patching need using the established decision tree. A case study of one mile of 3D pavement images, collected from US 80/S.R. 26, was conducted to demonstrate the use and feasibility of the proposed method. Results show the proposed method is capable of correctly classifying 95.4% of the images that show pavements requiring patching and 84.2% of the images showing pavements not requiring patching for a combined accuracy of 94.1%. The method shows promise for identifying patch locations in a cost-effective manner and will save money and time for transportation agencies.

Comparative eco-efficiency analysis on asphalt pavement rehabilitation alternatives: Hot in-place recycling and milling-and-filling

With the ever-increasing road mileages worldwide, the focus of pavement construction has been shifted from new pavement construction to pavement maintenance and rehabilitation (M&R). The corresponding huge environmental burdens and capital consumptions posed big challenges in achieving the target of sustainable development. In this study, an eco-efficiency analysis (EEA) framework was developed and applied to compare two common asphalt pavement rehabilitation techniques: hot-in-place recycling (HIRP) and milling-and-filling (M&F), by integrating the life cycle assessment (LCA) and life cycle costing analysis (LCCA), which followed by a sensitivity analysis to investigate the eco-efficiency performances of the two alternatives under different life extension scenarios. The eco-efficiency portfolio positions of hot-in-place recycling and milling-and-filling provided by the eco-efficiency analysis clearly indicated that hot-in-place recycling was more eco-efficient than milling-and-filling under the same assumed service life (15 years) for the cases studied. Hot-in-place recycling could save 5% cost and reduce 16% overall environmental impacts than milling-and-filling, while milling-and-filling saved 7% energy consumption than hot-in-place recycling. When the life extension ratio of the two alternatives reaches 12/15 (HIPR/M&F), milling-and-filling starts to show its advantages in both environmental and economic aspects in the long-term perspective. These findings indicated that if the hot-in-place recycling technique could ensure its treatment effectiveness. Its wider adoption would be championed for more sustainable transportation infrastructure development. The method and results of this study were expected to serve as a reference for decision-makers to make well-informed project decisions on the optimum rehabilitation alternative from the view of eco-efficiency.

Enhancement the Performance of Asphalt Pavement Using Fly Ash Wastes in Saudi Arabia

Saudi Arabia is the largest Arab country and is one of the most prolific producers of oil and energy consumption. The Kingdom uses heavy oil and diesel to generate electricity and desalinate seawater. This produces large amounts of ash, a toxic substance that is disposed of by landfill and may cause many environmental problems and contribute to pollution of groundwater, which is one of the most important sources of drinking water. This paper presents the possibility of using fly ash by-product waste from electric power generation plants to improve the properties of asphalt mixtures. This study investigates the use of two types of fly ash namely; class C and class F was used as a filler in two types of bitumen and asphalt material known as AC 40/50 and AC 60/70. The rheological performance of asphalt with different percentages of fly ash filler ranging from 0% to 10% with an increment of 2% was tested. The rheological properties of both asphalts modified using both types of ash were determined. The rutting factors of the modified asphalt with fly ash content were calculated using the rheological properties. The result indicates that rutting resistance of asphalt could be improved by both types of fly ash which can be lead to reduces the costs of repairing and rehabilitation of asphalt pavement and reduce environmental impacts of a significant amount of toxic waste fly ash. Class F fly ash shows higher rutting factor than class C. Also AC 60/70 asphalt possess higher rutting factor than AC 40/50 asphalt at both low and high temperature.