Bachelor

Bachelor in Building and Construction Engineering

Master

Master in Construction Materials Engineering

PhD

PhD in Civil Engineering (Pavement and Road Materials Engineering)

Head of Department [Head of Department]

Building & Construction Engineering Techniques Engineering, Technical Engineering College of Mosul, NTU, IRAQ

Consultant [Consultant of Mosul Municipality]

Consultant of Mosul Municipality, Nineveh Governorate, Iraq

Supreme Council [Member of the Supreme Council for Scientific Research]

Member of the Supreme Council for Scientific Research, Northern Technical University (NTU), Iraq

Industrial Advisory Council [Member of Industrial Advisory Council]

Member of Industrial Advisory Council, Northern Technical University (NTU), Iraq

Lecturer [Lecturer]

Lecturer (Full-time) at NTU university, Engineering Technical College of Mosul, NTU university, Iraq

Lecturer Visitor [Lecturer Visitor]

Lecturer Visitor at Al-Noor University, Mosul Iraq

Quality Control Manager [Quality Control Manager]

QC Engineer at UNESCO, Project: Reviving Mosul & Basra Old Cities, Mosul, Iraq

Civil [Civil, Safety and TVET Engineer]

Civil, Safety and TVET Engineer at UNESCO, Project: Reviving Mosul & Basra Old Cities

Bologna process [Member of Bologna process committee]

Member of Bologna process committee at NTU, (Under the supervision of UNESCO, TVET2 Project)

Advisor of International Student Society [Advisor]

Advisor of International Student Society – IRAQ / Universiti Teknologi Malaysia (UTM)

President of international student society [President of international student society]

President of international student society – IRAQ / Universiti Teknologi Malaysia (UTM)

Researcher and Engineer [Researcher and Engineer]

Researcher and Engineer at Athar innovation (NGO)

Site engineer [Site engineer]

Site engineer at Al-Rea’za group company

Self-Healable Bio-based Epoxy Resin from Epoxidized Palm Oil

Journal CHEMICAL ENGINEERING TRANSACTIONS

publisher The Italian Association of Chemical Engineering

DOI 10.3303/CET2189064

Epoxy resin is a thermoset with superior mechanical strength, thermal stability and dimensional stability, granted by the permanent crosslinking networks in the epoxy network. Despite its advantages, the rigid 3D epoxy resin precludes flow, resulting in the recycling and reprocessing of epoxy resin becomes impossible. The incorporation of covalent adaptable network (CAN) into the epoxy resin enable their network topology to be rearranged and permits recycling of epoxy resin. This project highlights the self-healing efficiency as well as mechanical and thermal properties of epoxy resin synthesized from various stoichiometric ratios (R) of curing agent (citric acid monohydrate) to epoxidized palm oil (EPO). EPO was cross-linked with citric acid monohydrate (CA) without the usage of a catalyst under specific curing condition to produce self-healable epoxy resin. Fourier-Transformed Infrared Spectroscopy (FTIR) analysis shows that the epoxide group in EPO successfully reacted with carboxylic groups in (CA) via ring-opening reaction to form β-hydroxyester networks. Thermogravimetric Analysis (TGA) analysis reveals the thermal stability of each formulation, indicating that R 0.5 possess the highest crystallinity and R 1.5 has the highest Tg (8.09 °C) among the others. Interestingly, R 1.0 which is the lowest in terms of thermal stability exhibited the best self-healing performance. To further improve the overall properties of the synthesized epoxy thermoset, reinforcement materials need to be added during the synthesis process.

A new approach to enhance the reclaimed asphalt pavement features: role of maltene as a rejuvenator

Journal Road Materials and Pavement Design

publisher Taylor & Francis

DOI 10.1080/14680629.2021.1984978

The properties of aged asphalt can be renewed using rejuvenating agents. Rejuvenators can improve the performance of reclaimed asphalt pavement (RAP) by reducing the asphaltene-to-maltene ratio back to their initial state. This study assessed the function of maltene as a rejuvenator to renew aged asphalt. Penetration, softening point, ductility and viscosity tests were performed to determine the ideal maltene content to be incorporated into RAP. The rejuvenated asphalt samples were evaluated using rolling thin film oven (RTFO), dynamic shear rheometer (DSR), bending beam rheome-ter (BBR), Fourier transform infrared (FTIR), thermogravimetric (TGA) and atomic force microscopy (AFM) measurements. The outcomes were compared with virgin and aged asphalts. Both oxygenated groups and asphal-tene content decreased by adding 12% maltene. Essentially, DSR, BBR, TGA, and AFM analyses divulged the comparable performance of rejuvenated asphalt with virgin asphalt, signifying the potency of maltene for practical applications.

Characterisation of Cracking Resistance in Modified Hot Mix Asphalt Under Repeated Loading Using Digital Image Analysis

Journal Theoretical and Applied Fracture Mechanics

publisher Elsevier

DOI 10.1016/j.tafmec.2021.103130

Laboratory determination of fatigue characteristics of asphalt mixtures is a vital step in evaluating and designing asphalt pavement. This study aims to provide a comprehensive analysis of the fatigue resistance of the modified asphalt mixtures containing plastic waste and crumb rubber. These dry process-modified mixtures have been presented in the road construction on the basis of the basic understanding of the mechanical properties and lack of intensive studies on fracture mechanics. In this study, a controlled-stress, repeated load semi-circular bending test under two load levels with the effect of ageing and moisture condition was used to characterise the three stages of fatigue life of asphalt mixtures. The fatigue life was characterised on the basis of the crack mouth opening distance assessment and image analyses of the crack patterns on the sample surface. Digital image correlation was used to capture the strain field that forms the plastic zone of mixtures under consideration. Results show that rubberised asphalt mixture promotes crack propagation and failure stages by increasing the plastic zone, whilst plastic waste-modified asphalt mixtures function to increase the bonding properties. Consequently, the cracking initiation and propagation stages increase. The digital image analysis of the sample surface of modified asphalt mixtures indicates higher values of crack tortuosity, crack density and fractal dimension due to the increase in the cracking resistance of asphalt mixtures. The extracted strain field has successfully captured the effect of modifiers on the size of plastic zones under t

Effects of maltene on the attributes of reclaimed asphalt pavement: Performance optimisation

Journal Construction and Building Materials

publisher Elsevier

DOI 10.1016/j.conbuildmat.2021.124210

The asphalt mixtures using elevated percentages of the reclaimed asphalt pavement (RAP) are of significant interest due to its ability to address environmental issues and reduce cost of asphalt. However, utilising elevated RAP content is associated with several disadvantages. Hence, this study explores the potential application of maltene as a rejuvenator to improve the output of asphalt mixtures incorporating RAP binder. The contents of maltene were optimised according to several parameters, namely penetration, softening point, ductility, and viscosity tests. Thereafter, the specimens containing an optimum maltene percentage were assessed using maltene-to-asphaltene ratio, storage stability, Dynamic Shear Rheometer (DSR), Bending Beam Rheometer (BBR), Fourier Transform Infrared (FTIR) spectroscopy and Thermogravimetric Analysis (TGA) measurements. Subsequently, the mechanical characteristics of asphalt mixtures were analysed using Marshall Stability, moisture damage, resilient modulus (MR), and Cantabro loss tests. The results demonstrated that 8% and 16% of maltene restored the physical properties of 30% and 50% of RAP binder, respectively. In addition, the workability was improved due to the reduction of viscosity, while maltene-rejuvenator managed to compensate the light components of RAP binder that were lost during the lifespan. As a result, the high- and low-temperature performance of RAP binder were restored approximately to that of virgin asphalt (VA). The oxygenated indices of RAP binder were effectively abated by blending with maltene. The TGA exhibited that the t​h​e​r​m

Durability Phenomena of Bitumen and Bituminous Pavement Materials

Journal The Open Civil Engineering Journal

DOI 10.2174/1874149502115010279

The durability of asphaltic mixtures, in addition to traffic loading, is greatly influenced by the extremes environmental parameters. For instance, at higher temperatures, bitumen becomes soft, thereby reducing the stiffness of asphalt mixtures and making them vulnerable to rutting. On the other hand, at lower temperatures, the stiffness of bitumen is increased, reducing the flexibility of asphaltic concrete and rendering it prone to fatigue failure. Therefore, this evaluation is an extensive research study on the durability of binder and asphalt mixture with their phenomena. Besides that, this paper intends to delve into the various testing methods and measures adopted to evaluate aging and slowing it down. It also presents a critical review of these methods and proposes a future course of action to better address aging issues. According to the evaluation, the behavior of bitumen on the basis of its source varies; when it is mixed with bitumen modifiers, aggregates, and other filler materials, its behavior becomes even more complex. Hence the understanding of the phenomenon of aging is important and the significance cannot be overemphasized. Extensive research work has been done over the last seven decades to evolve the understanding of short- and long-term aging and to improve the durability of asphaltic mixtures. Generally, the aging of bitumen under the influence of both environment and traffic is irreversible as well as inevitable. Apart from entailing hefty maintenance budgets, it remains a challenge to the researchers to slow down aging.

A laboratory study of the effect of fiberglass additive on the behavioural properties of RAP asphalt mixtures

Journal Journal of Physics Conference Series

publisher IOP

DOI 10.1088/1742-6596/1973/1/012241

Effects of Waste Frying Oil and Crumb Rubber on the Characteristics of a Reclaimed Asphalt Pavement Binder

Journal Materials

publisher MDPI

DOI 10.3390/ma14133482

The reclaimed asphalt pavement (RAP) has become a moderately common practice in most countries; Hence, rejuvenating materials with RAP have earned publicity in the asphalt manufacturers, mainly due to the increasing raw material costs. In this study, the crumb rubber (CR) and waste frying oil (WFO) utilized as waste materials to restore the properties and enhance the rutting resistance of the RAP. Several physical, rheological, chemical properties of bituminous binders were tested. The result showed that the RAP bituminous binders incorporating WFO and CR decreased softening points and the increased penetration value; these translate to an increase in penetration index. Moreover, the viscosity of the WFO/CR combination reclaimed asphalt pavement binder showed better workability and stiffness, as well as a low storage stability temperature (less than 2.2 °C) with an acceptable loss upon heating. Without chemical reaction was observed between the waste-frying oil with the rubberized binder and the reclaimed asphalt pavement binder. Additionally, the WFO/CR rheological properties combined with the reclaimed asphalt pavement binder were comparable to the control sample. The incorporation of CR with WFO as a hybrid rejuvenator enhanced the rutting resistance. Therefore, the presence of WFO/CR has a considerable influence on the RAP binder properties while preserving a better environment and reducing pollution by reusing waste materials.

Behaviour of Hot Mix Asphalt Incorporating Untreated and Treated Waste Cooking Oil

Journal International Journal of Pavement Research and Technology

publisher SPRINGER

DOI 10.1007/s42947-021-00038-w

The recyclability of waste cooking oil (WCO) as rejuvenator for aged asphalt mixture improved the serviceability of pavement itself. Currently, the researcher is exploring the new potential of WCO as modifier for binder modification. However, the issue of compatibility properties in the modification of binder with WCO arises since the poor mechanical performance of asphalt mixture is globally recorded thus reflected the weakness of adhesion bonding inside the pavement material. Basically, the superior mechanical performance of asphaltic concrete exhibited good adhesion bonding between binder-aggregates interaction in bituminous mixture. In fact, the potential of high adhesiveness binding properties is affected by the chemical theory which is mostly related to the polarity factor. Therefore, it is vital to conduct the chemical analysis and microstructure observation to obtain a comprehensive understanding of the polar group behaviour for the internal structure in pavement material that influencing the adhesion performance for the structural arrangement material in the mixture. Therefore, excellent adhesion is capable of improving mechanical performance of Hot Mix Asphalt (HMA). The identification of chemical composition for polarity group determination was identified by using Gas Chromatography-Mass Spectrometry (GC–MS). Meanwhile, the adhesiveness measurement between binder-aggregate interactions in the mixture was observed with Field Emission Scanning Electron Microscope (FESEM) which physically resulting in mechanical performance by conducting resilient modulus test, dynamic creep t​e

Influence of Crumb Rubber Incorporated with Different Warm Mix Asphalt Additives on the Mechanical Performance of WMA Mixture

Journal Journal of Rehabilitation in Civil Engineering

DOI 10.22075/JRCE.2021.22347.1474

The compacting and mixing processes involving hot mix asphalt during asphalt production can lead to air pollution as a result of a high volatile organic compound. An alternative solution that can reduce greenhouse gas emissions is by using warm mix asphalt (WMA). A proper application of additives to the WMA can improve the asphalt mixture's strength, durability, and workability. In this study, a 60/70 grade asphalt binder was added with 5% of crumb rubber (CR) and three different WMA additives at the recommended dosages, namely Sasobit, Cecabase, and Rediset. The wet method was used to blend the additives with virgin asphalt binders. The mixing and compacting temperatures were set at 135°C and 125°C, respectively, to mix the asphalt mixture. Mechanical performance tests were performed to evaluate the impact of WAM additives with CR on asphalt mixture. Based on the results, all the modified asphalt mixtures showed a better mechanical performance than the virgin asphalt mixture in terms of indirect tensile strength, moisture resistance, permanent deformation, and stiffness. Among all the WMA additives, Sasobit with CR showed the most significant impact on the asphalt mixture's performance.

Performance of Aged Asphalt Binder Treated with Various Types of Rejuvenators

Journal Civil Engineering Journal

DOI 10.28991/cej-2021-03091669

High demand for asphalt binders in road construction verifies the need of finding alternative materials through asphalt pavement recycling. This paper investigated the impact of different rejuvenators on the performance of an aged asphalt binder. Virgin Olive oil, virgin cooking oil, waste cooking oil, virgin engine oil, and waste engine oil were added to a 30/40 penetration grade aged asphalt binder at a fixed oil content of 4% for all types. The wet method was used to blend the rejuvenators and aged asphalt binder. The physical, rheological, and chemical properties of the rejuvenated asphalt binder were evaluated using several laboratory tests which include penetration, softening point, bleeding, loss on heating, storage stability, penetration index, ductility, viscosity, dynamic shear rheometer, and Fourier transform infrared spectroscopy. The outcomes of the physical properties showed that the olive, waste, and virgin cooking rejuvenators can restore the aged asphalt binder to a penetration grade of 60/70. In contrast, the virgin and waste engine oil required a more quantity of oil to rejuvenate the aged asphalt binder. A sufficient amount of rejuvenator could regenerate the (G*/sin δ), (δ°), and (G*) for the aged asphalt binder. The addition of virgin olive and cooking oils in aged asphalt led to a rutting issue. No chemical reactions were observed with the addition of rejuvenators but they give an impact on reducing the oxidation level of the aged asphalt binder. As a result, further research should be performed on waste cooking oil given that it is inexpensive and provides excellent performance results.

Impacts of Maltene on the Wettability and Adhesion Properties of Rejuvenated Asphalt Binder

Journal Arabian Journal for Science and Engineering

publisher SPRINGER

DOI 10.1088/1757-899X/713/1/012014

In recent years, the use of reclaimed asphalt pavement (RAP) has gained much attention and is widely accepted. However, the rejuvenating agents which are usually used to reduce the rigidity of the aged asphalt are subjected to diverse climate circumstances. The present work used maltene as a rejuvenator to investigate several measurements regarding stripping failure. The evaluation of wettability and work of adhesion (WA) was assessed using the sessile drop method. Meanwhile, asphalt and asphalt-water aggregate systems were tested for acid and water resistance using chemical and water immersion tests. Next, atomic force microscopy (AFM) was used to evaluate the changes in the microstructures of the asphalt binders. The experimental results revealed that the ideal percentages of maltene which should be added to 30% and 50% aged asphalt were 8% and 16%, respectively. Meanwhile, the wettability, WA and resistance to stripping differed depending on the percentage of aged asphalt in the blend. However, the inclusion of maltene has improved samples containing high percentages of aged asphalt. On the other hand, the resistance to boiling water containing acid decreased slightly with the addition of maltene. Nevertheless, all the rejuvenated samples exhibited better results than virgin asphalt. Moreover, the AFM results were in line with the observations, suggesting the suitability of maltene for the functional application of pavement.

Performance of nano kaolin clay modified bitumen under aging through the viscosity

Journal IOP Conference Series Earth and Environmental Science

publisher IOP

DOI 10.1088/1755-1315/682/1/012064

Increasing traffic volumes and rising cost of bitumen making it necessary to improve the performance of binder through bitumen modification. Nano particle have emerged as the potential solution to greatly enhance the properties of binder. This study explores the potential application of nano kaolin clay (NKC) as a modifier to improve the performance of bitumen incorporating different percentages of NKC. The performance of NKC modified bitumen was assessed using a viscosity and ageing test. The average size of NKC used was 57.7 nm. Then, 0% (control), 3%, 5%, 7% and 9% NKC by weight of bitumen PEN 60/70 was added. Generally, the results reveal that bitumen binder including nano kaolin clay is more effective in improvement the viscosity properties of asphalt before and after aged.

The Influence of PelletRAP™ Rejuvenator on the Mechanical Properties of Reclaimed Asphalt Pavement

Journal IOP Conference Series Earth and Environmental Science

publisher IOP

DOI 10.1088/1755-1315/682/1/012071

In the last decade, the use of reclaimed asphalt pavement (RAP) resulted from asphalt milling process has been widely increased for economic and environmental reasons. However, RAP mixtures have undesired characteristics, such as higher stiffness and low flexibility. In this case, the rejuvenators should be used for restoring the properties of RAP which were lost during service life. In the present research, the mechanical properties of 100% RAP incorporating various percentages of PelletRAP TM rejuvenator were evaluated via stability, flow, stiffness, indirect tensile strength (ITS), moisture damage and Cantabro loss measurements. The results showed that the rejuvenated mixtures containing 4% of PelletRAP TM exhibited better performance in terms of stability, cracking and moisture damage resistance, as well as durability, compared with virgin mixtures. Thus, it can be concluded that 100% RAP can be renovated and re-used in the pavement if it is mixed with an appropriate prescription of PelletRAP TM. The proposed of incorporating PelletRAP TM with RAP is beneficial in the improvement of sustainability and cost-efficiency of the asphalt mixtures industry.

Volumetric Properties and Abrasion Resistance of Stone Mastic Asphalt Incorporating Eggshell Powder

Journal IOP Conference Series Earth and Environmental Science

publisher IOP

DOI 10.1088/1755-1315/682/1/012058

Stone Mastic Asphalt (SMA) is designed to improve durability and life span of road pavement through the use of a stable stone-on-stone skeleton held together by a rich mixture of asphalt. However, over time the structure is subjected to damage from cracking, rutting, stripping and rapid aging under the effects of repeated vehicle loading, hot climates and heavy rainfall. Previous studies proved that eggshell is capable to enhance the strength and durability of concrete. Thus, the aim of this study is to evaluate the performance of these stone mastic asphalt mixtures with the eggshell powder and overcome the issue that is related to SMA. A mixture contains varying percentages of eggshell powder were assessed to check which samples gives the best performance as per the requirement by using laboratory tests which are LA Abrasion and volumetric properties. Results indicated that eggshell powder can effectively recover and enhance abrasion resistance of asphalt and increases the marshal stability of SMA. SMA mixtures modified with eggshell powder produce the performance enhancement of SMA as a road surfacing material. It is concluded that the asphalt mixtures containing eggshell powder could be increases the stability and strength of the mix.

The influence of nano kaolin clay as alternative binder on the penetration properties

Journal IOP Conference Series Earth and Environmental Science

publisher IOP

DOI 10.1088/1755-1315/682/1/012063

Determining Fracture Energy in Asphalt Mixture: A Review

Journal IOP Conference Series Earth and Environmental Science

publisher IOP

DOI 10.1088/1757-899X/713/1/012014

One of the most common pavement distresses is related to surface cracking. Therefore, identifying and characterizing fracture properties of asphalt mixtures are significant towards a better pavement design. This study reviews four experimental methods used to determine the fracture energy in asphalt mixture. These methods include circular bending test (SCB), disc shape compact tension test, single-edge notched beam, and indirect tensile test. Each experimental method has its characteristics and advantages. These experimental methods are reviewed on the basis of their features, efficiency, and parameters measured. The coefficient of variation (COV) for the fracture tests reflects the result reliability of the test methods. Results with low COV value reflect low variance in the fracture test, whereas high COV indicates high variance. The review indicates that the SCB test is commonly used for determining the fracture energy in asphalt mixtures due to its simplicity and data reliability.

Evaluating the Performance of Reclaimed Asphalt Pavement Incorporating PelletRAP as a Rejuvenator

Journal IOP Conference Series Earth and Environmental Science

publisher IOP

DOI 10.1088/1757-899X/713/1/012014

Issue 682

Volume 1

In the recent years, the use of reclaimed asphalt pavement (RAP) in the pavement has become inevitable for economic and environmental reasons. However, the brittleness property of aged asphalt in the RAP restrict its usage in a high percentage. Nevertheless, the rejuvenators are introduced into the mixtures to reverse the effect of ageing processes, decrease the stiffness and increase the workability of RAP mixture. In the present research, various percentages of PelletRAP rejuvenator were added to 100% of RAP mixtures. The performance characteristics of rejuvenated mixtures were investigated via resilient modulus (M R), dynamic creep, and wheel tracking tests. The results showed that when the PelletRAP was included into the mixture, the M R values and the creep stiffness modulus (CSM) decreased, while the permanent creep, the creep strain slope (CSS) and the rutting depth increased. However, all the rejuvenated mixtures exhibited better results than that of virgin mixture. Such a trend of findings suggested that PelletRAP can be used as a rejuvenator without a negative effect on the high-temperature performance of asphalt mixtures.

Physical, rheological and chemical features of recycled asphalt embraced with a hybrid rejuvenating agent

Journal International Journal of Pavement Engineering

publisher Taylor & Francis

DOI 10.1080/10298436.2021.1878517

Issue 23

Volume 3

Rejuvenating agents are considered desirable options in rejuvenating recycled asphalt's properties. Hence, the capability of integrating waste engine oil (WEO) and maltene to rejuvenate the traits of recycled asphalt was investigated. The penetration, softening point, ductility and viscosity were measured to determine an ideal amount of hybrid rejuvenating agent. Then, the rejuvenated asphalt was evaluated against different samples through maltene to asphaltene ratio, rolling thin film oven (RTFO), storage stability, dynamic shear rheometer (DSR) and bend beam rheometer (BBR) tests. Later, the Fourier Transform Infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA) and contact angle were employed. Based on the physical tests and the statistical analysis, the properties of recycled samples were restored approximately to that of the virgin asphalt by adding appropriate doses of hybrid rejuvenating agent. Meanwhile, the DSR and BBR results reported comparable performance between the rejuvenated and virgin samples. The hybrid rejuvenating agent has reduced the chemical ageing index and asphaltene content of the recycled asphalt. Moreover, TGA exhibited that the rejuvenated samples became more sensitive to temperature compared to recycled asphalt. In conclusion, 5% and 10% of the hybrid rejuvenating agent can renovate recycled asphalt for subsequent reuse in pavements depending on the characteristics of recycled asphalt.

Read Publication

A review on the usage of waste engine oil with aged asphalt as a rejuvenating agent

Journal Materials Today Proceedings

publisher Elsevier

DOI 10.1016/j.matpr.2020.12.330

The use of reclaimed asphalt pavement (RAP) has been becoming one of the best solutions to preserve natural resources in the construction sector. However, the stiffness property of aged asphalt resulted from the RAP is considered as the main obstacle in the field application. Nevertheless, waste engine oil (WEO), as one of the most common rejuvenating agent, has been used for renovating the characteristics of aged asphalt. This paper presents a review of the previous research works conducted on the rejuvenating of aged asphalt using WEO, including its benefits, drawbacks and its adverse side effect. It was observed that the inclusion of WEO as a rejuvenating agent gives positives and negatives influences on the attributes of aged asphalt. Therefore, an integration of WEO with other modifiers might be beneficial for renovating the performance of aged asphalt at both low and high temperatures. The results of this review can be used to predict future challenges in the renovation of aged asphalt using WEO.

A comparative assessment of the physical and microstructural properties of waste garnet generated from automated and manual blasting process

Journal Case Studies in Construction Materials

publisher Elsevier

DOI https://doi.org/10.1016/j.cscm.2020.e00474

Cold mix asphalt (CMA) is an eco-friendly sustainable asphalt mixture, mostly for asphalt surface treatments (ASTs). However, material compatibility and poor adhesion leading to high voids, moisture damage susceptibility, and weak early strength remain challenging. Efforts to solve this limitation is beamed towards binder improvement and modification with modifiers, adhesion promoters, or polymers. Other forms of AST mixture improvement entail supplementary cementitious reinforcing or pozzolanic agents in the form of by-products. In this study, the physio-mechanical and microstructural desirability of spent garnet for use as fine aggregate in CMAwas explored. Spent garnet is a by-product of abrasive blasting, often produced in large quantities and disposed of in landfills. Often, spent garnet waste gets contaminated with toxic elements either during usage or in landfills. This study aimed to investigate the properties of Automatically (AG) and Manually generated (MG) spent garnet grades. The physio-mechanical, morphologic, and chemical parameters of spent garnet were assessed to achieve this aim. The result compared with relevant specifications on cold mixtures plus Jabatan Kerja Raya (JKR) requirement. Moreover, crystallinity and composition were studied using Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), and X-ray Fluorescence (XRF). The presence of toxic heavy metals that often contaminate spent garnet deposits in landfills was evaluated too. Results suggested that both AG and MG’s high sand equivalent and least water absorption of 98 %, 89 %, and 0.14 %, 0​.​2

The tailored traits of reclaimed asphalt pavement incorporating maltene: performance analyses

Journal International Journal of Pavement Engineering

DOI 10.1080/10298436.2020.1824294

Environmental issues and fluctuations in the price of asphalt binders have increased the demand in usage of reclaimed asphalt pavement (RAP) material for asphalt mixtures. The RAP binder, nevertheless, is often highly aged and has several drawbacks, for instance, low cracking resistance, low workability, and low fatigue in the resulting mixtures. These issues can be resolved by using rejuvenators. As such, this research work assessed the engineering properties of reclaimed hot-mix asphalt (HMA) mixture rejuvenated by maltene-derived asphalt. The tests examined Marshall properties, moisture damage, resilient modulus (M R), dynamic creep, Cantabro loss, and rutting resistance, including the stripping and coating tests. The results showed that maltene had been effective in mitigating the aging effect of RAP asphalt, while the rejuvenated mixture exhibited considerable enhancement, especially when compared to the virgin and RAP mixtures without maltene. A simple cost analysis revealed that maltene was cost-effective as it compensated for the adverse effects of RAP, hence can be used to raise the content of RAP in asphalt mixture.

The influence of nano-carbon from coconut shell ash as modifier on the properties of bitumen

Journal Road Materials and Pavement Design

DOI 10.1080/14680629.2020.1809502

Nanomaterials are small-sized materials between 1 and 100 nm which produce a greater surface area than common size materials. Coconut shell is one of the potential agricultural wastes to be used as nanomaterial due to its high strength and hardness. However, poor adhesion bonding was the problem of using this agricultural waste material as a modifier in the bitumen matrix. Therefore, in this study nanocarbon from coconut shell ash (NCA) was produced as bitumen modifier. NCA was produced and characterised using various techniques prior to be utilised at 0.0%, 1.5%, 3.0%, 4.5%, 6.0% and 7.5% by weight of bitumen PEN 60/70. The rheological test, using a dynamic shear rheometer (DSR), was performed on the unaged, rolling thin film oven and pressure ageing vessel samples. Subsequently, X-ray diffraction and atomic force microscopy were performed on the unaged samples. The DSR results revealed that NCA improved the rutting and fatigue cracking parameter of the bitumen. Also, the observations from microstructure properties showed that NCA delayed the ageing of the bitumen, produced a homogenous structure and increased the cohesion and adhesion properties of the bitumen. As a result, a strong bonding between the NCA and bitumen was formed and the properties of bitumen were altered.

Evaluating the Chemical and Rheological Attributes of Aged Asphalt: Synergistic Effects of Maltene and Waste Engine Oil Rejuvenators

Journal Arabian Journal for Science and Engineering

DOI 10.1007/s13369-020-04842-7

The service life of road pavement reduces as it ages and loses its properties due to the exposure to varying traffic loads and climatic conditions. This study explores the potential rejuvenation of the aged asphalt properties to enable it to be reused in pavement by adding hybrid rejuvenator (WEO-MLT). The WEO-MLT is composed of waste engine oil and maltene (MLT). Four types of binders, namely virgin asphalt, aged asphalt, 40% aged asphalt and rejuvenated asphalt, were prepared and evaluated via rheological and chemical tests [e.g. storage stability, asphaltene-to-MLT ratio, dynamic shear rheometer, bending beam rheometer, Fourier transform infrared (FTIR), thermogravimetric analysis and stripping resistance tests]. The results revealed that the WEO-MLT markedly enhanced the properties of aged asphalt at low and high temperatures. In contrast, the outcomes of FTIR suggested that the ageing properties of asphalt were not improved significantly by WEO-MLT due to the presence of a carboxyl group in its composition. TGA indicated that the initial decomposition for rejuvenated asphalt was approximately close to virgin asphalt. The stripping resistance test divulged the comparable performance of the rejuvenated asphalt to that of virgin asphalt. Therefore, WEO-MLT can be potentially used in the rejuvenation of the aged asphalt, paving the way to sustainable and eco-friendly asphalt production.

Rejuvenation of Hot Mix Asphalt Incorporating High RAP Content: Issues to Consider

Journal IOP Conference Series: Earth and Environmental Science

DOI 10.1088/1755-1315/498/1/012009

The asphalt used to construct or rehabilitation roads often contains reclaimed asphalt pavement (RAP) in order to diminish not only the use of raw materials but also waste. However, when high level of RAP in hot mix asphalt (HMA) is used, the rejuvenating agents must be employed. A number of aspects must be taken into account to increase pavement service life as much as possible. Thus, the main issues related to the rejuvenation of asphalt mixtures with high levels of RAP are addressed in this paper. In particular, the focal points of this paper will focus on the use of reclaimed asphalt mixtures with maximum efficiency, special attention is paid to how the binder is structured and chemically composes, nature and dose selection of rejuvenator, as well as the diffusion, blending efficiency, homogeneity, time and temperature mixing. A review of the extant and related literature shows that RAP utilization holds promise for the sustainable pavements, provided that some issues were taken into consideration during the designing and application process.

Review on the potentials of natural rubber in bitumen modification

Journal IOP Conference Series: Earth and Environmental Science

DOI 10.1088/1755-1315/476/1/012067

In recent times both natural and synthetic rubber were blended with bitumen with the hope of producing a more durable hot mix asphalt. Although the application of natural rubber (NR) in bitumen modification have started long time ago prior to crumb rubber; only few literatures that completely characterised its performance are found today. This review aims to remind researchers and paving agencies on the benefits of NR rubberised asphalt. The study draw attention to NR production process and its unique properties, how NR was used to solve four major asphalt pavement failures namely rutting, fatigue, thermal cracking, and moisture susceptibility. It also presents barriers limiting the application of NR in bitumen modification with possible solution. Lastly, the concept of applying NR in warm mix asphalt was introduced.

A review on rejuvenating materials used with reclaimed hot mix asphalt

Journal Canadian Journal of Civil Engineering

publisher Canadian Science Publishing

DOI 10.1139/cjce-2019-0635

In recent years, flexible pavement construction technology has relied heavily on the use of reclaimed asphalt pavement (RAP). However, the brittle nature of RAP, which stems from the use of an aged asphalt, has introduced numerous complexities into the process, with important implications to pavement service life. The properties of the aged asphalt can be rejuvenated to improve the performance and the behavior of RAP mixtures. This paper presents a review of past works that have used rejuvenating materials with RAP, including their benefits and drawbacks, as well as the optimal approach to increase RAP content in asphaltic mixtures. The method of rejuvenating aged asphalt and the mechanism of rejuvenation are also reviewed. The findings of this review can be used to predict the current and future challenges in the regeneration of RAP mixtures using rejuvenating materials.

Restoration of Aged Bitumen Properties Using Maltenes

Journal IOP Conf. Series: Materials Science and Engineering

DOI 10.1088/1757-899X/713/1/012014

Reclaimed asphalt pavement (RAP), a material frequently used in asphalt mixtures, is associated with several environmental and economic advantages. Many existing road construction technologies are capitalising on the availability of recycled materials. This study has looked on the usage of maltene as a rejuvenator in aged bitumen. Bitumen with Pen 60-70 was chosen as the control binder. Maltene was added into the aged bitumen at various concentrations (5%, 10%, and 15%) by weight of total binder. The characteristics of rejuvenated bitumen were examined with penetration, softening point, penetration index (PI), viscosity, and storage stability. As the maltene concentration increased, aged bitumen characteristics improved, while the level of stiffness reduced. Mixing temperature and time were significantly linked to the efficiency of blending between aged-virgin binders. Lower mixing temperatures undermined the diffusion of the virgin bitumen into the aged binder, thereby impairing blending efficiency. The results indicate that 15% of maltene can rejuvenate the properties of aged bitumen.