Fereidoon Moghadas Nejad | AmirKabir University Of Technology (original) (raw)

Papers by Fereidoon Moghadas Nejad

Construction and Building Materials, 2022

Journal of Elastomers and Plastics, Mar 28, 2023

Despite being one of the potential candidates for a suitable elastomeric additive to modify aspha... more Despite being one of the potential candidates for a suitable elastomeric additive to modify asphalt binders, there is a lack of research on using chloroprene rubber (CR). This study evaluates the suitability of using CR to enhance asphalt binder properties, particularly rutting and fatigue performances. Two different grades of asphalt binder (60/70 and 85/100 penetration grade) were modified by 3.5% and 7% CR to meet this end. The conventional physical, high-temperature storage stability, rotational viscosity (RV), dynamic shear rheometer (DSR), multiple stress creep recovery (MSCR), and linear amplitude sweep (LAS) tests were used to examine various features of the CR-modified asphalt binder. Results indicate that CR decreases penetration, ductility, and temperature susceptibility and increases softening point and viscosity of the asphalt binder. Additionally, the CR-modified binder can present acceptable pumpability and workability within the construction temperature range. However, the CR-modified binder has phase separation potential, particularly at high modification contents. Based on the results of MSCR and LAS tests, CR can effectively increase the rutting resistance, elastic recovery, and fatigue life of the asphalt binder. Nevertheless, the CR-modified asphalt binder’s rutting and fatigue behaviors depend mainly on the grade of the base asphalt binder.

Three dimensioned finite element analysis were conducted on concrete block paving. In order to ve... more Three dimensioned finite element analysis were conducted on concrete block paving. In order to verify the calculated results, an experimental case study was analyzed. Good agreement was observed between the measured and the calculated results. Based on the finite element analysis results and available failure models, comprehensive design charts were developed for port and industrial pavement which can take into account; the sub grade and pavement layers properties as well as the tire pressure and the number of repetitive loads. In addition by using 3D finite element model mechanism of interlocking between pavers was discussed. Parametric study were conducted on 3D models and it was found that jointing width, shape, size and thickness of blocks have a significant influence on the behavior of block pavement.

International journal of pavement research and technology, Sep 26, 2019

Asphalt binder resistance to permanent deformation considerably influences total pavement resista... more Asphalt binder resistance to permanent deformation considerably influences total pavement resistance to rutting at the high service temperatures. To improve asphalt shear strength against rutting resistance, researchers have been used various modifiers and recently the use of waste materials as binder rheological enhancement agents is paid lots of attention. In this study, waste toner was adopted as an anti-rutting enhancement agent, and then neat asphalt binder was modified by waste toner at four dosages: 4, 8, 12 and 16% based on asphalt binder’s weight. The effectiveness of binder modification by waste toner to improve asphalt binder and mixture’s resistance to permanent deformation has been assessed by means of different met hods: the Superpave specification parameter, G*/sinδ , and the multiple stress creep and recovery (MSCR) test for asphalt binder and wheel track test for asphalt mixture to determine the rut depth for a certain number of loadings. Results showed that adding toner to neat asphalt binder can meaningfully enhance the anti-rutting performance of asphalt binder and subsequently asphalt mixture. Moreover, increasing the dosage of toner up to 12% in the modified asphalt binder amplifies the trend of rutting resistance improvement.

Structure and Infrastructure Engineering, Jun 5, 2023

Construction and Building Materials, May 1, 2023

International Journal of Civil Engineering, Feb 17, 2023

DergiPark (Istanbul University), Nov 30, 2021

Öz Examination of the criteria for maintaining distance between vehicles helps to better understa... more Öz Examination of the criteria for maintaining distance between vehicles helps to better understand the behavior of following behavior and traffic flow. In this study, time headway(TH) and time to collision(TTC) criteria have been studied using driving simulator. TH is divided into two types, including braking TH, TH at the moment of considerable brake, and following TH, TH during following. The results showed that by reaching TTC to a threshold, braking TH has increased to 1.5 sec. and after this value, braking TH has remained constant. Also the comparison between braking and following TH showed that, unlike following TH, braking TH has less variance and its values did not differ significantly between lanes. That is, the driver is trying to observe a fixed amount of braking TH, 1.1 seconds, all the time, and not get closer to the front vehicle accordingly. It can be said that among the criteria, braking TH is the most important factor and considering it can be helpful in the carfollowing models. Araçlar arasındaki mesafeyi korumak için kriterlerin incelenmesi yolun üzerindeki davranışları ve trafik akımını daha iyi anlamaya destek olur. Bu çalışmada zaman aralığı ve çarpışma süresi kriterleri sürüş simülatörü kullanarak incelenmiştir. Zaman aralığı, frenleme zaman aralığı ve takip zaman aralığı'na ayrılır. Sonuçlar çarpışma zamanının(TTC) bir eşiğe ulaşmasıyla ve frenleme zaman aralığının(TH) 1.5 sn.'ye yükseldiğini ve bu değerden sonra sabit kaldığını gösterdi. Ayrıca, frenleme zaman aralığı ve takip zaman aralığı arasında karşılaştırma, zaman aralığı'nı takip etmekten farklı olarak, frenleme zaman aralığı'nin daha az varyansa sahip olduğunu ve değerlerinin şeritler arasında önemli ölçüde farklılık göstermediğini gösterdi. Yani sürücü her zaman 1.1 sn. sabit bir frenleme zaman aralığısı gözlemlemeye çalışıyor ve buna göre ön araca yaklaşmıyor kriterler arasında zaman aralığı frenleme'nin en önemli faktör olduğu ve bunun dikkate alınması otomobil takip eden modellerde faydalı olabileceği söylenebilir.

Modeling and optimization in science and technologies, Dec 11, 2015

This chapter presents a hybrid meta-heuristic method which combines particle swarm optimization (... more This chapter presents a hybrid meta-heuristic method which combines particle swarm optimization (PSO) and genetic algorithm (GA) search procedures to predict the pavement condition index (PCI) based on Surveyed Inspection Units (SIUs). Both PSO and GA are used and a comparison is made among three approaches for evaluating the optimal arrangement of SIUs. A hybrid method was developed to build and optimize the models. The performances of these hybrid models were compared based on Sampling Error (SE), Total Network Inspection Error (TNIE), inspection time based on CPU time (seconds), total number of SIUs, and others. Based on the results of the computational experiments, one of the proposed heuristic procedures is used for solving problems in the arrangement of surveyed asphalt pavement inspection units. The study reveals that the hybrid model outperforms both the PSO and the GA based models.

Quarterly Journal of Applied Chemical Research, Jul 1, 2013

The fuel resistance property plays an important role in asphalts, but available standards for det... more The fuel resistance property plays an important role in asphalts, but available standards for determining this characteristic are presently lacking. In the present work, a number of polymer modified bitumen with styrene-butadiene-styrene (SBS) polymer (4, 5, 6% SBS) and SBS/ sulfur modified bitumen with various percentages of sulfur (1.65, 3, 3.5% based on polymer content) were prepared. Each sample was immersed in the fuel and after 24 hour its weight loss was measured to determine the effect of fuel on them. Results showed that, increase in SBS content caused improvement in physical and rheological properties of bitumen. After adding sulfur to SBS, conventional properties (softening point, penetration, ductility and temperature susceptibility) was improved. Rheological properties were determined

Journal of transportation engineering, Sep 1, 2021

AbstractThis paper examined the merits of using a polymer nanocomposite containing styrene-ethyle... more AbstractThis paper examined the merits of using a polymer nanocomposite containing styrene-ethylene/propylene-styrene (SEPS) and montmorillonite (MMT) clay to enhance bitumen thermomechanical prope...

International Journal of Pavement Engineering, Apr 6, 2022

Amirkabir Journal of Civil Engineering, Oct 23, 2021

Multimedia Tools and Applications, May 13, 2022

Journal of Materials in Civil Engineering, Feb 1, 2017

AbstractThis study is an attempt to identify the effective mix design and thermodynamic parameter... more AbstractThis study is an attempt to identify the effective mix design and thermodynamic parameters for the moisture damage of hot mix asphalt. In the present study, 24 different combinations of asphalt mixtures were made and evaluated using three types of aggregates with different mineralogical composition, two types of asphalt binders, and three types of additives. The components of surface-free energy of asphalt binders and aggregates are measured to provide thermodynamic parameters using the Wilhelmy Plate and Universal Sorption Device, respectively. To determine the performance of moisture sensitivity, environmental conditions simulation according to the modified Lottman test was used, and an indirect tensile strength test has been conducted on asphalt mixtures. The results of statistical analysis presented show that the free energy of cohesion, free energy of asphalt binder-aggregate adhesion, specific surface area of aggregates, and asphalt binder film thickness on the aggregate surface have a direc...

Geosynthetics International, Oct 1, 2020

Disclaimer The AM is yet to be copyedited and formatted in journal house style but can still be r... more Disclaimer The AM is yet to be copyedited and formatted in journal house style but can still be read and referenced by quoting its unique reference number, the digital object identifier (DOI). Once the AM has been typeset, an "uncorrected proof" PDF will replace the "accepted manuscript" PDF. These formatted articles may still be corrected by the authors. During the Production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal relate to these versions also. Version of record The final edited article will be published in PDF and HTML and will contain all author corrections and is considered the version of record. Authors wishing to reference an article published Ahead of Print should quote its DOI. When an issue becomes available, queuing Ahead of Print articles will move to that issue"s Table of Contents. When the article is published in a journal issue, the full reference should be cited in addition to the DOI.

Road Materials and Pavement Design, Jun 1, 2018

This paper examines the effect of waste toner on fatigue resistance of asphalt binder. Fatigue re... more This paper examines the effect of waste toner on fatigue resistance of asphalt binder. Fatigue resistance of toner-modified asphalt binders was studied implementing the linear amplitude sweep test, which has been approved by AASHTO as a provisional standard and is currently being considered as a specification test for evaluating fatigue resistance of original and modified asphalt binders. The linear amplitude sweep is a cyclic torsion test conducted with a dynamic shear rheometer (DSR) which uses increasing loading amplitudes to accelerate the damage process. In order to characterise a waste toner as an additive for modifying an original asphalt binder, the XRD test has been done. DSR test results were used to determine fatigue resistance parameters and dissipated energy ratio to investigate fatigue behaviour of toner-modified asphalt binders. This paper argues that the improved fatigue resistance properties of toner-modified asphalt binders are reflected in the enhancement of the number of loading cycles, shortening crack length and degrading dissipated energy which remains in the specimens.

Theoretical and Applied Fracture Mechanics, Jun 1, 2023

Construction and Building Materials, 2022

Journal of Elastomers and Plastics, Mar 28, 2023

Despite being one of the potential candidates for a suitable elastomeric additive to modify aspha... more Despite being one of the potential candidates for a suitable elastomeric additive to modify asphalt binders, there is a lack of research on using chloroprene rubber (CR). This study evaluates the suitability of using CR to enhance asphalt binder properties, particularly rutting and fatigue performances. Two different grades of asphalt binder (60/70 and 85/100 penetration grade) were modified by 3.5% and 7% CR to meet this end. The conventional physical, high-temperature storage stability, rotational viscosity (RV), dynamic shear rheometer (DSR), multiple stress creep recovery (MSCR), and linear amplitude sweep (LAS) tests were used to examine various features of the CR-modified asphalt binder. Results indicate that CR decreases penetration, ductility, and temperature susceptibility and increases softening point and viscosity of the asphalt binder. Additionally, the CR-modified binder can present acceptable pumpability and workability within the construction temperature range. However, the CR-modified binder has phase separation potential, particularly at high modification contents. Based on the results of MSCR and LAS tests, CR can effectively increase the rutting resistance, elastic recovery, and fatigue life of the asphalt binder. Nevertheless, the CR-modified asphalt binder’s rutting and fatigue behaviors depend mainly on the grade of the base asphalt binder.

Three dimensioned finite element analysis were conducted on concrete block paving. In order to ve... more Three dimensioned finite element analysis were conducted on concrete block paving. In order to verify the calculated results, an experimental case study was analyzed. Good agreement was observed between the measured and the calculated results. Based on the finite element analysis results and available failure models, comprehensive design charts were developed for port and industrial pavement which can take into account; the sub grade and pavement layers properties as well as the tire pressure and the number of repetitive loads. In addition by using 3D finite element model mechanism of interlocking between pavers was discussed. Parametric study were conducted on 3D models and it was found that jointing width, shape, size and thickness of blocks have a significant influence on the behavior of block pavement.

International journal of pavement research and technology, Sep 26, 2019

Asphalt binder resistance to permanent deformation considerably influences total pavement resista... more Asphalt binder resistance to permanent deformation considerably influences total pavement resistance to rutting at the high service temperatures. To improve asphalt shear strength against rutting resistance, researchers have been used various modifiers and recently the use of waste materials as binder rheological enhancement agents is paid lots of attention. In this study, waste toner was adopted as an anti-rutting enhancement agent, and then neat asphalt binder was modified by waste toner at four dosages: 4, 8, 12 and 16% based on asphalt binder’s weight. The effectiveness of binder modification by waste toner to improve asphalt binder and mixture’s resistance to permanent deformation has been assessed by means of different met hods: the Superpave specification parameter, G*/sinδ , and the multiple stress creep and recovery (MSCR) test for asphalt binder and wheel track test for asphalt mixture to determine the rut depth for a certain number of loadings. Results showed that adding toner to neat asphalt binder can meaningfully enhance the anti-rutting performance of asphalt binder and subsequently asphalt mixture. Moreover, increasing the dosage of toner up to 12% in the modified asphalt binder amplifies the trend of rutting resistance improvement.

Structure and Infrastructure Engineering, Jun 5, 2023

Construction and Building Materials, May 1, 2023

International Journal of Civil Engineering, Feb 17, 2023

DergiPark (Istanbul University), Nov 30, 2021

Öz Examination of the criteria for maintaining distance between vehicles helps to better understa... more Öz Examination of the criteria for maintaining distance between vehicles helps to better understand the behavior of following behavior and traffic flow. In this study, time headway(TH) and time to collision(TTC) criteria have been studied using driving simulator. TH is divided into two types, including braking TH, TH at the moment of considerable brake, and following TH, TH during following. The results showed that by reaching TTC to a threshold, braking TH has increased to 1.5 sec. and after this value, braking TH has remained constant. Also the comparison between braking and following TH showed that, unlike following TH, braking TH has less variance and its values did not differ significantly between lanes. That is, the driver is trying to observe a fixed amount of braking TH, 1.1 seconds, all the time, and not get closer to the front vehicle accordingly. It can be said that among the criteria, braking TH is the most important factor and considering it can be helpful in the carfollowing models. Araçlar arasındaki mesafeyi korumak için kriterlerin incelenmesi yolun üzerindeki davranışları ve trafik akımını daha iyi anlamaya destek olur. Bu çalışmada zaman aralığı ve çarpışma süresi kriterleri sürüş simülatörü kullanarak incelenmiştir. Zaman aralığı, frenleme zaman aralığı ve takip zaman aralığı'na ayrılır. Sonuçlar çarpışma zamanının(TTC) bir eşiğe ulaşmasıyla ve frenleme zaman aralığının(TH) 1.5 sn.'ye yükseldiğini ve bu değerden sonra sabit kaldığını gösterdi. Ayrıca, frenleme zaman aralığı ve takip zaman aralığı arasında karşılaştırma, zaman aralığı'nı takip etmekten farklı olarak, frenleme zaman aralığı'nin daha az varyansa sahip olduğunu ve değerlerinin şeritler arasında önemli ölçüde farklılık göstermediğini gösterdi. Yani sürücü her zaman 1.1 sn. sabit bir frenleme zaman aralığısı gözlemlemeye çalışıyor ve buna göre ön araca yaklaşmıyor kriterler arasında zaman aralığı frenleme'nin en önemli faktör olduğu ve bunun dikkate alınması otomobil takip eden modellerde faydalı olabileceği söylenebilir.

Modeling and optimization in science and technologies, Dec 11, 2015

This chapter presents a hybrid meta-heuristic method which combines particle swarm optimization (... more This chapter presents a hybrid meta-heuristic method which combines particle swarm optimization (PSO) and genetic algorithm (GA) search procedures to predict the pavement condition index (PCI) based on Surveyed Inspection Units (SIUs). Both PSO and GA are used and a comparison is made among three approaches for evaluating the optimal arrangement of SIUs. A hybrid method was developed to build and optimize the models. The performances of these hybrid models were compared based on Sampling Error (SE), Total Network Inspection Error (TNIE), inspection time based on CPU time (seconds), total number of SIUs, and others. Based on the results of the computational experiments, one of the proposed heuristic procedures is used for solving problems in the arrangement of surveyed asphalt pavement inspection units. The study reveals that the hybrid model outperforms both the PSO and the GA based models.

Quarterly Journal of Applied Chemical Research, Jul 1, 2013

The fuel resistance property plays an important role in asphalts, but available standards for det... more The fuel resistance property plays an important role in asphalts, but available standards for determining this characteristic are presently lacking. In the present work, a number of polymer modified bitumen with styrene-butadiene-styrene (SBS) polymer (4, 5, 6% SBS) and SBS/ sulfur modified bitumen with various percentages of sulfur (1.65, 3, 3.5% based on polymer content) were prepared. Each sample was immersed in the fuel and after 24 hour its weight loss was measured to determine the effect of fuel on them. Results showed that, increase in SBS content caused improvement in physical and rheological properties of bitumen. After adding sulfur to SBS, conventional properties (softening point, penetration, ductility and temperature susceptibility) was improved. Rheological properties were determined

Journal of transportation engineering, Sep 1, 2021

AbstractThis paper examined the merits of using a polymer nanocomposite containing styrene-ethyle... more AbstractThis paper examined the merits of using a polymer nanocomposite containing styrene-ethylene/propylene-styrene (SEPS) and montmorillonite (MMT) clay to enhance bitumen thermomechanical prope...

International Journal of Pavement Engineering, Apr 6, 2022

Amirkabir Journal of Civil Engineering, Oct 23, 2021

Multimedia Tools and Applications, May 13, 2022

Journal of Materials in Civil Engineering, Feb 1, 2017

AbstractThis study is an attempt to identify the effective mix design and thermodynamic parameter... more AbstractThis study is an attempt to identify the effective mix design and thermodynamic parameters for the moisture damage of hot mix asphalt. In the present study, 24 different combinations of asphalt mixtures were made and evaluated using three types of aggregates with different mineralogical composition, two types of asphalt binders, and three types of additives. The components of surface-free energy of asphalt binders and aggregates are measured to provide thermodynamic parameters using the Wilhelmy Plate and Universal Sorption Device, respectively. To determine the performance of moisture sensitivity, environmental conditions simulation according to the modified Lottman test was used, and an indirect tensile strength test has been conducted on asphalt mixtures. The results of statistical analysis presented show that the free energy of cohesion, free energy of asphalt binder-aggregate adhesion, specific surface area of aggregates, and asphalt binder film thickness on the aggregate surface have a direc...

Geosynthetics International, Oct 1, 2020

Disclaimer The AM is yet to be copyedited and formatted in journal house style but can still be r... more Disclaimer The AM is yet to be copyedited and formatted in journal house style but can still be read and referenced by quoting its unique reference number, the digital object identifier (DOI). Once the AM has been typeset, an "uncorrected proof" PDF will replace the "accepted manuscript" PDF. These formatted articles may still be corrected by the authors. During the Production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal relate to these versions also. Version of record The final edited article will be published in PDF and HTML and will contain all author corrections and is considered the version of record. Authors wishing to reference an article published Ahead of Print should quote its DOI. When an issue becomes available, queuing Ahead of Print articles will move to that issue"s Table of Contents. When the article is published in a journal issue, the full reference should be cited in addition to the DOI.

Road Materials and Pavement Design, Jun 1, 2018

This paper examines the effect of waste toner on fatigue resistance of asphalt binder. Fatigue re... more This paper examines the effect of waste toner on fatigue resistance of asphalt binder. Fatigue resistance of toner-modified asphalt binders was studied implementing the linear amplitude sweep test, which has been approved by AASHTO as a provisional standard and is currently being considered as a specification test for evaluating fatigue resistance of original and modified asphalt binders. The linear amplitude sweep is a cyclic torsion test conducted with a dynamic shear rheometer (DSR) which uses increasing loading amplitudes to accelerate the damage process. In order to characterise a waste toner as an additive for modifying an original asphalt binder, the XRD test has been done. DSR test results were used to determine fatigue resistance parameters and dissipated energy ratio to investigate fatigue behaviour of toner-modified asphalt binders. This paper argues that the improved fatigue resistance properties of toner-modified asphalt binders are reflected in the enhancement of the number of loading cycles, shortening crack length and degrading dissipated energy which remains in the specimens.

Theoretical and Applied Fracture Mechanics, Jun 1, 2023