Ainalem Nega | Curtin University, Perth (original) (raw)

Papers by Ainalem Nega

International journal of pavement research and technology, Jun 17, 2024

ASCE Inspire 2023: Infrastructure Innovation and Adaptation for a Sustainable and Resilient World, 2023

Resilience and sustainability of civil infrastructure have become major problems for about four d... more Resilience and sustainability of civil infrastructure have become major problems for about four decades. The concept of resilience and sustainability rose to notice in the late 1980s and has become a central issue worldwide. Most researchers, engineer practitioners, as well as construction industry are focused either on resilience or sustainability operating only without a mutual consideration of the findings, which leads to severe ineffective and inefficient sustainability of civil infrastructure. Though big data and the sustainability of civil infrastructure analysis remain unsolved and lagging, several engineering sectors have applied artificial intelligence (AI) to solve problems and analyze big data using machine learning (ML). However, the civil infrastructure industry is lagging in integrating AI, remote sensing (RS), and 3D printing (3DP) in the development of sustainability of civil infrastructure, and no developed process on how to desegregate these new applications. The main purpose of this research is to review these new applications of artificial intelligence, remote sensing, and 3D printing techniques for the sustainability of civil infrastructure. Results indicated that artificial intelligence, remote sensing, and 3D printing technology can increase the reliability and sustainability of civil infrastructure and the level of automation and standardization of civil construction engineering and pavement maintenance engineering leading to effective and efficient improvement in worker safety, reliability, and sustainability of construction materials, climate adaptability, and maintenance and rehabilitation repair accuracy and flexibility.

Advanced Engineering Forum, 2016

The main objective this study is to evaluate the permanent deformation of buton rock asphalt (BRA... more The main objective this study is to evaluate the permanent deformation of buton rock asphalt (BRA) modified asphalt paving mixtures using dynamic creep test so that long term deformation behavior of asphalt mixtures can be characterized. The dynamic creep test was conducted on unmodified and BRA modified asphalt mixture using UTM25 machine. Asphalt cement of C170 from a regional supplier in Western Australia was used as the base asphalt binder for unmodified asphalt mixture; and BRA modified asphalt mixtures were made by substituting the base asphalt with 10, 20, and 30% (by weight of total asphalt binder) natural binder continuing granular BRA modified binder. The granular (pellets) BRA modified binder with a diameter of 7-10 mm was produced and extracted according the Australia Standard. Crushed granite was taken from a local quarry of the region; and dense graded for both unmodified and BRA modified asphalt mixture with the nominal size of 10 mm was used. The results of this anal...

International Conference on Transportation and Development 2022

We were studied tire and pavement interactions using finite element method. Several researchers&a... more We were studied tire and pavement interactions using finite element method. Several researchers' studies have focused on prediction to fully understand of tire-pavement contacts which has implication on flexible pavement damage predictions and life cycle assessments. The primary purpose of this study was to analyze and fully understand the interactions between deformable pavement and tires using the validated finite element model. A full tire-pavement interaction model was developed where flexible pavement was subdued to a monotonic and cyclic behavior of tire loading, 40 kN in measure dual-tires, and proper tire pressure, 700 kPa. A rolling resistance free body investigation was also executed using a finite element model to understand fully the interaction between tire and flexible pavement. A vehicle contact speed, 95 km/h, was applied where load was withdrawn for 1 s during cyclic time. Axisymmetric and tirepavement interactions were developed using a 3D finite element model. We revolved the axisymmetric analysis in Abaqus with respect to the tire axis on the vehicle so that the 3D tire model could be generated, then a contact load was placed to model. The total cyclic time was 10 s with a loading of 0.1 s and 0.9 s of resting. The contact area and deflection of thin and thick flexible pavements were also developed. Finally, results' analyses were compared to fully understand the modeling and its consequences on pavements.

Airfield and Highway Pavements 2015, 2015

Full-depth asphalt concrete pavements are generally designed to control fatigue cracking and redu... more Full-depth asphalt concrete pavements are generally designed to control fatigue cracking and reduce potential rutting when subjected to repeated heavy traffic loads. A particular interesting question is whether a limit load exists below which excitation shakedown in the sense that the granular layer does not accumulate further deformation. Although pavement design guides give more weight to asphalt concrete layer failures, granular failure may not be ignored; especially for thin layers and/or heavy load. The behavior of granular layers used in base and, sub-base layers of flexible pavement is complicated due to its nonlinear elastoplastic response when subjected to dynamic traffic loading. The objective of this paper is to present a new simplified simulation model for the Shakedown behavior of granular layer in flexible pavement. This method is integrated with Mohr-Coulomb criterion, which is used and applied to simulate the response of unbound granular layers to dynamic loading in a numerical analysis. The results of analysis are then compared to simplify the results of modeling without considering shakedown effects and then, the conclusions are drawn.

Advanced Materials Research, 2013

The determination of appropriate pavement thickness using laboratory determined parameters is one... more The determination of appropriate pavement thickness using laboratory determined parameters is one of the key issues facing the road manager. Five different types of asphalt mixes were produced in laboratory to modify pavement performance mixture. The main objective of this study is to evaluate the characterization methods for fatigue performance of asphalt mixes to Western Australia road. In this study, laboratory test for indirect tensile modulus, dynamic creep, wheel tracking and aggregate gradation tests were taken to analyze each asphalt mixtures for a design traffic road. The results and analysis showed that AC20-75 asphalt mix blow is the most effective and efficient in pavement performance than the other asphalt mixes. AC14-75 was the second in rank to strengthen and durability of asphalt pavement. All asphalt mixes in this study can be used to strength and stable the overall stiffness of pavement, and modification rank can be described as AC20-75 Blow > AC14-75 Blow > ...

Advanced Materials Research, 2013

Modelling granular pavement materials has a significant role in the pavement design procedure. Mo... more Modelling granular pavement materials has a significant role in the pavement design procedure. Modelling can be through an experimental or numerical approach to predict the granular behaviour during cyclic loading. The current design process in Australia is based on linear elastic analysis of layers. The analysis is performed through a well-known program CIRCLY which is applied to model bound pavement material behaviour. The KENLAYER is one of the common pavement software models used for pavement design in the United States which performs non-linear analysis for granular materials. Alternatively, a general Finite Element program such as ABAQUS can be used to model the complicated behaviour of multilayer granular materials. This study is to compare results of numerical modelling with these three programs on two sample pavement models.

Advanced Materials Research, 2013

This study deals with the Austroads (2008) Guide to Pavement Technology Part 2: Pavement Structur... more This study deals with the Austroads (2008) Guide to Pavement Technology Part 2: Pavement Structural Design on which most road pavement designs in Australia are based. Flexible pavement designs and performance predictions for pavements containing one of more bound layers derived from the mechanistic Austroads pavement design methodology and the AASHTO-2004 approach are compared for Australian conditions, with consideration of subgrade and other material properties and local design preferences. The comparison has been made through two well-known programs namely CIRCLY (5.0) and KENLAYER. The study shows that each guide has its own advantages and disadvantages in predicting stress and strain in pavement layers under different conditions. The study recommends that modifications are necessary resulting in more realistic and longer lasting pavements in Australia.

International Journal of Engineering and Technology, 2015

While in the design of flexible pavement the significance of asphalt layers is understood, the ro... more While in the design of flexible pavement the significance of asphalt layers is understood, the role of granular layers supporting the asphalt layers should not be underestimated. The behavior of granular layers used in base, sub-base or subgrade layer of flexible pavement is complicated due to nonlinear elastoplastic response of materials subjected to dynamic load of traffic. Shakedown theory integrated with Mohr-Coulomb criterion is applied to simulate the response of granular layers to dynamic loading in a numerical analysis. The results of analysis is then compared to simple the results of modeling without considering shakedown effects and the conclusion is drawn.

Airfield and Highway Pavement 2013, 2013

The use of full depth asphalt pavement to construct and rehabilitate heavily loaded urban roads t... more The use of full depth asphalt pavement to construct and rehabilitate heavily loaded urban roads that has grown rapidly in Western Australia over the past 3 years. Five different types of asphalt mixes were produced in the laboratory according to the Australian Standard methods of sampling and testing asphalt to modify payment performance mixture. The main role of this research is to evaluate and assess the hotmix asphalt pavement performance characteristic for Western Australia road. In this study, laboratory test for tensile strength, resilient modulus, wheel tracking, asphalt binder content and Marshall Compaction test were taken and analyzed to each asphalt mixtures. Results showed that AC20-75 and AC14-75 Blow asphalt mixes were more efficient and effective in pavement performance as compared to the other mixes. In general, all the asphalt mixes that are used in this study can strength and stable the mixture stiffness of asphalt that is notable. The modification effect rank can be described as AC20-75 Blow > AC14-75 Blow > AC14-50 Blow > AC7-50 Blow > SMA7-50 Blow in this research.

International Journal of Engineering and Technology, 2015

Airfield and Highway Pavements 2017

© ASCE. Pavement distress mechanisms become more prevalent in recent years such as surface ruttin... more © ASCE. Pavement distress mechanisms become more prevalent in recent years such as surface rutting and surface initiated wheel path cracking. The main objective of this study is to evaluate tire-pavement contact stress distribution of pavement response using finite element analysis. It also assesses some of the effects of tire related factors on tire contact pressures and its response on flexible pavement. Tire-pavement contact stress is simulated using 3-D finite element method in ABAQUS for five layers of flexible pavement at various loads. 40 kN wheel load to represent a set of dual tires were assumed to be uniformly distributed over the contact area between tire-pavement surface. Four different tire-inflation pressures (350, 490, 630, and 700 kPa) were used to investigate some of the effects of tire-pavement structure. The finite element (FE) model analyses were verified with experiment results. Results have shown that contact stresses vary significantly for the different types of tire-pavement contact that were investigated. The tire's finite element was validated using measured contact area and deflection

International Journal of Engineering and Technology, 2015

The complex moduli relationship related mixture moduli to temperature and time rate of loading ha... more The complex moduli relationship related mixture moduli to temperature and time rate of loading has been an integral part of several mechanistic-empirical (M-E) design procedures used throughout of the world. Seven asphalt concrete mixtures of different types of polymer modified binders (PMB) were produced in a laboratory to modify performance of asphalt mixture. The main role of this research is to evaluate the influence of these polymer modifiers on the pavement performance of asphalt mixture with the dynamic modulus, |E*| of hot-mix asphalt (HMA) mixture indicator in a laboratory test for Mainroad Western Australia and Fulton Hogan. In this study, the influence of temperature, loading frequency, and confining pressure on the dynamic characteristic of asphalt mixture were analysis, master curves of dynamic modulus of HMA mixtures were developed and data's were interpreted. Results showed that AC10 5.7% A35P (EVA) M7 B5, AC10 5.7% C450 M10 B5 and AC10 Multi 600/700 M5 B4 mixes method were the more efficient and effective in all categories of asphalt performance measures for strength and durability of HMA as compared to others polymer modifiers. A very good correlation (R 2 = 1) was found for each polymer modifier. This suggested that laboratory test using a various temperatures and loading frequencies can improve pavement mix design, lab and field control and assurance. A strong correlation between binder viscosity and temperature [R 2 = 1] for polymer modified asphalt mixture.

American Society of Civil Engineers, 2022

We were studied tire and pavement interactions using finite element method. Several researchers' ... more We were studied tire and pavement interactions using finite element method. Several researchers' studies have focused on prediction to fully understand of tire-pavement contacts which has implication on flexible pavement damage predictions and life cycle assessments. The primary purpose of this study was to analyze and fully understand the interactions between deformable pavement and tires using the validated finite element model. A full tire-pavement interaction model was developed where flexible pavement was subdued to a monotonic and cyclic behavior of tire loading, 40 kN in measure dual-tires, and proper tire pressure, 700 kPa. A rolling resistance free body investigation was also executed using a finite element model to understand fully the interaction between tire and flexible pavement. A vehicle contact speed, 95 km/h, was applied where load was withdrawn for 1 s during cyclic time. Axisymmetric and tirepavement interactions were developed using a 3D finite element model. We revolved the axisymmetric analysis in Abaqus with respect to the tire axis on the vehicle so that the 3D tire model could be generated, then a contact load was placed to model. The total cyclic time was 10 s with a loading of 0.1 s and 0.9 s of resting. The contact area and deflection of thin and thick flexible pavements were also developed. Finally, results' analyses were compared to fully understand the modeling and its consequences on pavements.

The attached document may provide the author's accepted version of a published work. See Cit... more The attached document may provide the author's accepted version of a published work. See Citation for details of the published work.

International Conference on Transportation and Development 2020

Airfield and Highway Pavements 2019, 2019

International journal of pavement research and technology, Jun 17, 2024

ASCE Inspire 2023: Infrastructure Innovation and Adaptation for a Sustainable and Resilient World, 2023

Resilience and sustainability of civil infrastructure have become major problems for about four d... more Resilience and sustainability of civil infrastructure have become major problems for about four decades. The concept of resilience and sustainability rose to notice in the late 1980s and has become a central issue worldwide. Most researchers, engineer practitioners, as well as construction industry are focused either on resilience or sustainability operating only without a mutual consideration of the findings, which leads to severe ineffective and inefficient sustainability of civil infrastructure. Though big data and the sustainability of civil infrastructure analysis remain unsolved and lagging, several engineering sectors have applied artificial intelligence (AI) to solve problems and analyze big data using machine learning (ML). However, the civil infrastructure industry is lagging in integrating AI, remote sensing (RS), and 3D printing (3DP) in the development of sustainability of civil infrastructure, and no developed process on how to desegregate these new applications. The main purpose of this research is to review these new applications of artificial intelligence, remote sensing, and 3D printing techniques for the sustainability of civil infrastructure. Results indicated that artificial intelligence, remote sensing, and 3D printing technology can increase the reliability and sustainability of civil infrastructure and the level of automation and standardization of civil construction engineering and pavement maintenance engineering leading to effective and efficient improvement in worker safety, reliability, and sustainability of construction materials, climate adaptability, and maintenance and rehabilitation repair accuracy and flexibility.

Advanced Engineering Forum, 2016

The main objective this study is to evaluate the permanent deformation of buton rock asphalt (BRA... more The main objective this study is to evaluate the permanent deformation of buton rock asphalt (BRA) modified asphalt paving mixtures using dynamic creep test so that long term deformation behavior of asphalt mixtures can be characterized. The dynamic creep test was conducted on unmodified and BRA modified asphalt mixture using UTM25 machine. Asphalt cement of C170 from a regional supplier in Western Australia was used as the base asphalt binder for unmodified asphalt mixture; and BRA modified asphalt mixtures were made by substituting the base asphalt with 10, 20, and 30% (by weight of total asphalt binder) natural binder continuing granular BRA modified binder. The granular (pellets) BRA modified binder with a diameter of 7-10 mm was produced and extracted according the Australia Standard. Crushed granite was taken from a local quarry of the region; and dense graded for both unmodified and BRA modified asphalt mixture with the nominal size of 10 mm was used. The results of this anal...

International Conference on Transportation and Development 2022

We were studied tire and pavement interactions using finite element method. Several researchers&a... more We were studied tire and pavement interactions using finite element method. Several researchers' studies have focused on prediction to fully understand of tire-pavement contacts which has implication on flexible pavement damage predictions and life cycle assessments. The primary purpose of this study was to analyze and fully understand the interactions between deformable pavement and tires using the validated finite element model. A full tire-pavement interaction model was developed where flexible pavement was subdued to a monotonic and cyclic behavior of tire loading, 40 kN in measure dual-tires, and proper tire pressure, 700 kPa. A rolling resistance free body investigation was also executed using a finite element model to understand fully the interaction between tire and flexible pavement. A vehicle contact speed, 95 km/h, was applied where load was withdrawn for 1 s during cyclic time. Axisymmetric and tirepavement interactions were developed using a 3D finite element model. We revolved the axisymmetric analysis in Abaqus with respect to the tire axis on the vehicle so that the 3D tire model could be generated, then a contact load was placed to model. The total cyclic time was 10 s with a loading of 0.1 s and 0.9 s of resting. The contact area and deflection of thin and thick flexible pavements were also developed. Finally, results' analyses were compared to fully understand the modeling and its consequences on pavements.

Airfield and Highway Pavements 2015, 2015

Full-depth asphalt concrete pavements are generally designed to control fatigue cracking and redu... more Full-depth asphalt concrete pavements are generally designed to control fatigue cracking and reduce potential rutting when subjected to repeated heavy traffic loads. A particular interesting question is whether a limit load exists below which excitation shakedown in the sense that the granular layer does not accumulate further deformation. Although pavement design guides give more weight to asphalt concrete layer failures, granular failure may not be ignored; especially for thin layers and/or heavy load. The behavior of granular layers used in base and, sub-base layers of flexible pavement is complicated due to its nonlinear elastoplastic response when subjected to dynamic traffic loading. The objective of this paper is to present a new simplified simulation model for the Shakedown behavior of granular layer in flexible pavement. This method is integrated with Mohr-Coulomb criterion, which is used and applied to simulate the response of unbound granular layers to dynamic loading in a numerical analysis. The results of analysis are then compared to simplify the results of modeling without considering shakedown effects and then, the conclusions are drawn.

Advanced Materials Research, 2013

The determination of appropriate pavement thickness using laboratory determined parameters is one... more The determination of appropriate pavement thickness using laboratory determined parameters is one of the key issues facing the road manager. Five different types of asphalt mixes were produced in laboratory to modify pavement performance mixture. The main objective of this study is to evaluate the characterization methods for fatigue performance of asphalt mixes to Western Australia road. In this study, laboratory test for indirect tensile modulus, dynamic creep, wheel tracking and aggregate gradation tests were taken to analyze each asphalt mixtures for a design traffic road. The results and analysis showed that AC20-75 asphalt mix blow is the most effective and efficient in pavement performance than the other asphalt mixes. AC14-75 was the second in rank to strengthen and durability of asphalt pavement. All asphalt mixes in this study can be used to strength and stable the overall stiffness of pavement, and modification rank can be described as AC20-75 Blow > AC14-75 Blow > ...

Advanced Materials Research, 2013

Modelling granular pavement materials has a significant role in the pavement design procedure. Mo... more Modelling granular pavement materials has a significant role in the pavement design procedure. Modelling can be through an experimental or numerical approach to predict the granular behaviour during cyclic loading. The current design process in Australia is based on linear elastic analysis of layers. The analysis is performed through a well-known program CIRCLY which is applied to model bound pavement material behaviour. The KENLAYER is one of the common pavement software models used for pavement design in the United States which performs non-linear analysis for granular materials. Alternatively, a general Finite Element program such as ABAQUS can be used to model the complicated behaviour of multilayer granular materials. This study is to compare results of numerical modelling with these three programs on two sample pavement models.

Advanced Materials Research, 2013

This study deals with the Austroads (2008) Guide to Pavement Technology Part 2: Pavement Structur... more This study deals with the Austroads (2008) Guide to Pavement Technology Part 2: Pavement Structural Design on which most road pavement designs in Australia are based. Flexible pavement designs and performance predictions for pavements containing one of more bound layers derived from the mechanistic Austroads pavement design methodology and the AASHTO-2004 approach are compared for Australian conditions, with consideration of subgrade and other material properties and local design preferences. The comparison has been made through two well-known programs namely CIRCLY (5.0) and KENLAYER. The study shows that each guide has its own advantages and disadvantages in predicting stress and strain in pavement layers under different conditions. The study recommends that modifications are necessary resulting in more realistic and longer lasting pavements in Australia.

International Journal of Engineering and Technology, 2015

While in the design of flexible pavement the significance of asphalt layers is understood, the ro... more While in the design of flexible pavement the significance of asphalt layers is understood, the role of granular layers supporting the asphalt layers should not be underestimated. The behavior of granular layers used in base, sub-base or subgrade layer of flexible pavement is complicated due to nonlinear elastoplastic response of materials subjected to dynamic load of traffic. Shakedown theory integrated with Mohr-Coulomb criterion is applied to simulate the response of granular layers to dynamic loading in a numerical analysis. The results of analysis is then compared to simple the results of modeling without considering shakedown effects and the conclusion is drawn.

Airfield and Highway Pavement 2013, 2013

The use of full depth asphalt pavement to construct and rehabilitate heavily loaded urban roads t... more The use of full depth asphalt pavement to construct and rehabilitate heavily loaded urban roads that has grown rapidly in Western Australia over the past 3 years. Five different types of asphalt mixes were produced in the laboratory according to the Australian Standard methods of sampling and testing asphalt to modify payment performance mixture. The main role of this research is to evaluate and assess the hotmix asphalt pavement performance characteristic for Western Australia road. In this study, laboratory test for tensile strength, resilient modulus, wheel tracking, asphalt binder content and Marshall Compaction test were taken and analyzed to each asphalt mixtures. Results showed that AC20-75 and AC14-75 Blow asphalt mixes were more efficient and effective in pavement performance as compared to the other mixes. In general, all the asphalt mixes that are used in this study can strength and stable the mixture stiffness of asphalt that is notable. The modification effect rank can be described as AC20-75 Blow > AC14-75 Blow > AC14-50 Blow > AC7-50 Blow > SMA7-50 Blow in this research.

International Journal of Engineering and Technology, 2015

Airfield and Highway Pavements 2017

© ASCE. Pavement distress mechanisms become more prevalent in recent years such as surface ruttin... more © ASCE. Pavement distress mechanisms become more prevalent in recent years such as surface rutting and surface initiated wheel path cracking. The main objective of this study is to evaluate tire-pavement contact stress distribution of pavement response using finite element analysis. It also assesses some of the effects of tire related factors on tire contact pressures and its response on flexible pavement. Tire-pavement contact stress is simulated using 3-D finite element method in ABAQUS for five layers of flexible pavement at various loads. 40 kN wheel load to represent a set of dual tires were assumed to be uniformly distributed over the contact area between tire-pavement surface. Four different tire-inflation pressures (350, 490, 630, and 700 kPa) were used to investigate some of the effects of tire-pavement structure. The finite element (FE) model analyses were verified with experiment results. Results have shown that contact stresses vary significantly for the different types of tire-pavement contact that were investigated. The tire's finite element was validated using measured contact area and deflection

International Journal of Engineering and Technology, 2015

The complex moduli relationship related mixture moduli to temperature and time rate of loading ha... more The complex moduli relationship related mixture moduli to temperature and time rate of loading has been an integral part of several mechanistic-empirical (M-E) design procedures used throughout of the world. Seven asphalt concrete mixtures of different types of polymer modified binders (PMB) were produced in a laboratory to modify performance of asphalt mixture. The main role of this research is to evaluate the influence of these polymer modifiers on the pavement performance of asphalt mixture with the dynamic modulus, |E*| of hot-mix asphalt (HMA) mixture indicator in a laboratory test for Mainroad Western Australia and Fulton Hogan. In this study, the influence of temperature, loading frequency, and confining pressure on the dynamic characteristic of asphalt mixture were analysis, master curves of dynamic modulus of HMA mixtures were developed and data's were interpreted. Results showed that AC10 5.7% A35P (EVA) M7 B5, AC10 5.7% C450 M10 B5 and AC10 Multi 600/700 M5 B4 mixes method were the more efficient and effective in all categories of asphalt performance measures for strength and durability of HMA as compared to others polymer modifiers. A very good correlation (R 2 = 1) was found for each polymer modifier. This suggested that laboratory test using a various temperatures and loading frequencies can improve pavement mix design, lab and field control and assurance. A strong correlation between binder viscosity and temperature [R 2 = 1] for polymer modified asphalt mixture.

American Society of Civil Engineers, 2022

We were studied tire and pavement interactions using finite element method. Several researchers' ... more We were studied tire and pavement interactions using finite element method. Several researchers' studies have focused on prediction to fully understand of tire-pavement contacts which has implication on flexible pavement damage predictions and life cycle assessments. The primary purpose of this study was to analyze and fully understand the interactions between deformable pavement and tires using the validated finite element model. A full tire-pavement interaction model was developed where flexible pavement was subdued to a monotonic and cyclic behavior of tire loading, 40 kN in measure dual-tires, and proper tire pressure, 700 kPa. A rolling resistance free body investigation was also executed using a finite element model to understand fully the interaction between tire and flexible pavement. A vehicle contact speed, 95 km/h, was applied where load was withdrawn for 1 s during cyclic time. Axisymmetric and tirepavement interactions were developed using a 3D finite element model. We revolved the axisymmetric analysis in Abaqus with respect to the tire axis on the vehicle so that the 3D tire model could be generated, then a contact load was placed to model. The total cyclic time was 10 s with a loading of 0.1 s and 0.9 s of resting. The contact area and deflection of thin and thick flexible pavements were also developed. Finally, results' analyses were compared to fully understand the modeling and its consequences on pavements.

The attached document may provide the author's accepted version of a published work. See Cit... more The attached document may provide the author's accepted version of a published work. See Citation for details of the published work.

International Conference on Transportation and Development 2020

Airfield and Highway Pavements 2019, 2019