The dynamic modulus (|E * |) of asphalt mixtures is one of the most important inputs in Mechanist... more The dynamic modulus (|E * |) of asphalt mixtures is one of the most important inputs in Mechanistic-Empirical (ME) pavement analysis and design. Several models have been developed to predict the dynamic modulus based on mixture volumetrics and material properties. This study aimed to calibrate and validate two commonly used models (i.e., Hirsch model and Alkhateeb model) for predicting the dynamic modulus of asphalt mixtures in Qatar. Based on the study outcomes, the Hirsch model was found to have a high prediction performance of asphalt mixture moduli before calibration with a coefficient of determination (R 2) of 87.2 % between predicted and measured values. This R 2 value improved slightly after calibration to 89.2 %, Alkhateeb model, on the other hand, had a coefficient of determination of 70.8 % before calibration, which also improved to 89.2 % after calibration. The moduli predicted by the Hirsch model before and after calibration were employed in this study to perform a mechanistic-empirical analysis of the performance of various typical pavement sections in Qatar. According to the findings, the percentage change in the predicted fatigue damage due to the use of the calibrated Hirsch model reached more than 50 % with an average value of 17.33 %, while the percent change in rutting reached 14 % with an average value of 3.65 %. These results highlight the importance of using locally calibrated models for the dynamic modulus in order to improve performance predictions.
Advances in Materials and Pavement Performance Prediction, 2018
This paper was made possible by the NPRP grant (NPRP 7-110-2-056) from the Qatar National Researc... more This paper was made possible by the NPRP grant (NPRP 7-110-2-056) from the Qatar National Research Fund (a member of Qatar Foundation). The statements made herein are solely the responsibility of the authors.
Engineering, Construction and Architectural Management, 2020
PurposePavement is one of the main elements of the roads network. It is extremely essential to st... more PurposePavement is one of the main elements of the roads network. It is extremely essential to study and understand the factors affecting its performance and highlight the most important ones for decision-makers and pavement experts to consider during the design, construction and maintenance stages. The purpose of this paper was to identify the factors affecting pavement performance and rank them according to their importance using Analytic Hierarchy Process (AHP) for decision-makers and pavement experts to consider during the design, construction and maintenance stages.Design/methodology/approachA survey was developed considering 29 factors found in the literature that affect pavement performance. The survey was sent to pavement professionals in Qatar to rate their perception of factors affecting pavement performance to enhance roads' sustainability. 205 responses were collected and analyzed using AHP.FindingsThe findings indicate that the factor “unconsidered heavy vehicles vo...
There is pressing and growing demand from the public to design and construct roads with a low noi... more There is pressing and growing demand from the public to design and construct roads with a low noise level. This paper investigated the acoustic performance of asphalt pavements in the State of Qatar to assist transport authorities in designing and constructing quieter pavements. In this study, a field-testing setup was assembled to measure the tire-pavement noise of dense-graded asphalt (DGA) pavements at the source using the on-board sound intensity (OBSI) method. The repeatability and reproducibility of test results demonstrated that the assembled OBSI test setup could measure the sound intensity with excellent repeatability and reproducibility. The measured noise level of existing pavements varied from 101.8 dBA to 106.2 dBA depending on the age of pavement sections. Measured noise levels of pavements in Qatar were higher than typical DGA pavements in Europe and the US. Test results also demonstrated that the acoustic performance of pavements in Qatar deteriorates faster compared...
Nanotechnology has contributed significantly to different subfields of the construction industry,... more Nanotechnology has contributed significantly to different subfields of the construction industry, including asphalt pavement engineering. The improved properties and new functionalities of the nanomaterials have provided different desired properties of asphalt. In this study, the effectiveness of multi-walled carbon nanotubes (MWCNT) in resisting the oxidation of polymer-modified asphalt was measured. A total of three different percentages (0.5%, 1%, and 1.5%) of MWCNT were used to modify the Styrene-Butadiene (SB) and styrene–butadiene–styrene (SBS) modified asphalt (4% and 5%). The laboratory oxidized asphalt samples were evaluated by an atomic force microscopy machine. The oxidation of the polymer-MWCNT modified asphalt is measured by simulating the existing functional group of the asphalt and as a function of the adhesive force. It is observed that the use of MWCNT in SB and SBS can increase the resistance to oxidation.
The acoustical performance of asphalt pavements changes with time due to combined effects of envi... more The acoustical performance of asphalt pavements changes with time due to combined effects of environmental conditions and various distresses induced by repeated and heavy traffic. This study examined the changes in the acoustical performance of dense graded asphalt (DGA) pavements over time in the State of Qatar. Tire-pavement noise was measured using on board sound intensity (OBSI) method. The OBSI noise measurements were conducted on DGA pavements with different age and the results were analyzed to evaluate the effect of aging on tire-pavement noise. The results demonstrated that the tire-pavement noise increased with pavement age. The frequency analysis of three road segments showed that at early stage of pavement service life, the noise level is more affected at higher frequency due to the densification and increased air pumping mechanism. At later stage of pavement service life, the noise level is more affected at lower frequency due to the change in pavement surface conditions...
Journal of Transportation Engineering, Part B: Pavements, 2019
AbstractThis study presents a comprehensive laboratory evaluation and statistical analysis of the... more AbstractThis study presents a comprehensive laboratory evaluation and statistical analysis of the effect of aging on the viscoelastic properties of asphalt mixtures. Asphalt mixtures were subjected...
The modification by polymers and nanomaterials can significantly improve different properties of ... more The modification by polymers and nanomaterials can significantly improve different properties of asphalt. However, during the service life, the oxidation affects the constituents of modified asphalt and subsequently results in deviation from the desired properties. One of the important properties affected due to oxidation is the adhesive properties of modified asphalt. In this study, the adhesive properties of asphalt modified with the polymers (styrene-butadiene-styrene and styrene-butadiene) and carbon nanotubes were investigated. Asphalt samples were aged in the laboratory by simulating the field conditions, and then adhesive properties were evaluated by different tips of atomic force microscopy (AFM) following the existing functional group in asphalt. Finally, a predictive modelling and machine learning technique called the classification and regression tree (CART) was used to predict the adhesive properties of modified asphalt subjected to oxidation. The parameters that affect ...
International Journal of Pavement Engineering, 2017
Abstract The rheological properties of asphalt binders change with aging. Aging is accelerated at... more Abstract The rheological properties of asphalt binders change with aging. Aging is accelerated at elevated temperatures due to binder oxidation, leading to fatigue cracking and eventually pavement failure under heavy and repeated traffic loading. This study examined the effect of various antioxidant additives and copolymers with antioxidant agents on retarding the aging of asphalt binders. The performance of antioxidants was evaluated at the binder and mastic levels. Two unmodified binders were tested and fine asphalt mixtures made with these binders and three different aggregates were prepared and evaluated. Fatigue characteristics of asphalt binders and fine portion of asphalt mixtures (FAM) were determined before and after aging and an aging index was defined to evaluate the effect of antioxidants and copolymers on aging. The results showed that certain antioxidants and copolymers such as Redicote AP, Solprene and Calprene may retard the aging and improve the rheological properties of the asphalt binders. In addition, the results of FAM testing confirmed the favourable effect of certain antioxidants on improving the resistance to fatigue. In addition, the type of aggregate was found to influence the rate of aging of asphalt mixtures.
The dynamic modulus (|E * |) of asphalt mixtures is one of the most important inputs in Mechanist... more The dynamic modulus (|E * |) of asphalt mixtures is one of the most important inputs in Mechanistic-Empirical (ME) pavement analysis and design. Several models have been developed to predict the dynamic modulus based on mixture volumetrics and material properties. This study aimed to calibrate and validate two commonly used models (i.e., Hirsch model and Alkhateeb model) for predicting the dynamic modulus of asphalt mixtures in Qatar. Based on the study outcomes, the Hirsch model was found to have a high prediction performance of asphalt mixture moduli before calibration with a coefficient of determination (R 2) of 87.2 % between predicted and measured values. This R 2 value improved slightly after calibration to 89.2 %, Alkhateeb model, on the other hand, had a coefficient of determination of 70.8 % before calibration, which also improved to 89.2 % after calibration. The moduli predicted by the Hirsch model before and after calibration were employed in this study to perform a mechanistic-empirical analysis of the performance of various typical pavement sections in Qatar. According to the findings, the percentage change in the predicted fatigue damage due to the use of the calibrated Hirsch model reached more than 50 % with an average value of 17.33 %, while the percent change in rutting reached 14 % with an average value of 3.65 %. These results highlight the importance of using locally calibrated models for the dynamic modulus in order to improve performance predictions.
Advances in Materials and Pavement Performance Prediction, 2018
This paper was made possible by the NPRP grant (NPRP 7-110-2-056) from the Qatar National Researc... more This paper was made possible by the NPRP grant (NPRP 7-110-2-056) from the Qatar National Research Fund (a member of Qatar Foundation). The statements made herein are solely the responsibility of the authors.
Engineering, Construction and Architectural Management, 2020
PurposePavement is one of the main elements of the roads network. It is extremely essential to st... more PurposePavement is one of the main elements of the roads network. It is extremely essential to study and understand the factors affecting its performance and highlight the most important ones for decision-makers and pavement experts to consider during the design, construction and maintenance stages. The purpose of this paper was to identify the factors affecting pavement performance and rank them according to their importance using Analytic Hierarchy Process (AHP) for decision-makers and pavement experts to consider during the design, construction and maintenance stages.Design/methodology/approachA survey was developed considering 29 factors found in the literature that affect pavement performance. The survey was sent to pavement professionals in Qatar to rate their perception of factors affecting pavement performance to enhance roads' sustainability. 205 responses were collected and analyzed using AHP.FindingsThe findings indicate that the factor “unconsidered heavy vehicles vo...
There is pressing and growing demand from the public to design and construct roads with a low noi... more There is pressing and growing demand from the public to design and construct roads with a low noise level. This paper investigated the acoustic performance of asphalt pavements in the State of Qatar to assist transport authorities in designing and constructing quieter pavements. In this study, a field-testing setup was assembled to measure the tire-pavement noise of dense-graded asphalt (DGA) pavements at the source using the on-board sound intensity (OBSI) method. The repeatability and reproducibility of test results demonstrated that the assembled OBSI test setup could measure the sound intensity with excellent repeatability and reproducibility. The measured noise level of existing pavements varied from 101.8 dBA to 106.2 dBA depending on the age of pavement sections. Measured noise levels of pavements in Qatar were higher than typical DGA pavements in Europe and the US. Test results also demonstrated that the acoustic performance of pavements in Qatar deteriorates faster compared...
Nanotechnology has contributed significantly to different subfields of the construction industry,... more Nanotechnology has contributed significantly to different subfields of the construction industry, including asphalt pavement engineering. The improved properties and new functionalities of the nanomaterials have provided different desired properties of asphalt. In this study, the effectiveness of multi-walled carbon nanotubes (MWCNT) in resisting the oxidation of polymer-modified asphalt was measured. A total of three different percentages (0.5%, 1%, and 1.5%) of MWCNT were used to modify the Styrene-Butadiene (SB) and styrene–butadiene–styrene (SBS) modified asphalt (4% and 5%). The laboratory oxidized asphalt samples were evaluated by an atomic force microscopy machine. The oxidation of the polymer-MWCNT modified asphalt is measured by simulating the existing functional group of the asphalt and as a function of the adhesive force. It is observed that the use of MWCNT in SB and SBS can increase the resistance to oxidation.
The acoustical performance of asphalt pavements changes with time due to combined effects of envi... more The acoustical performance of asphalt pavements changes with time due to combined effects of environmental conditions and various distresses induced by repeated and heavy traffic. This study examined the changes in the acoustical performance of dense graded asphalt (DGA) pavements over time in the State of Qatar. Tire-pavement noise was measured using on board sound intensity (OBSI) method. The OBSI noise measurements were conducted on DGA pavements with different age and the results were analyzed to evaluate the effect of aging on tire-pavement noise. The results demonstrated that the tire-pavement noise increased with pavement age. The frequency analysis of three road segments showed that at early stage of pavement service life, the noise level is more affected at higher frequency due to the densification and increased air pumping mechanism. At later stage of pavement service life, the noise level is more affected at lower frequency due to the change in pavement surface conditions...
Journal of Transportation Engineering, Part B: Pavements, 2019
AbstractThis study presents a comprehensive laboratory evaluation and statistical analysis of the... more AbstractThis study presents a comprehensive laboratory evaluation and statistical analysis of the effect of aging on the viscoelastic properties of asphalt mixtures. Asphalt mixtures were subjected...
The modification by polymers and nanomaterials can significantly improve different properties of ... more The modification by polymers and nanomaterials can significantly improve different properties of asphalt. However, during the service life, the oxidation affects the constituents of modified asphalt and subsequently results in deviation from the desired properties. One of the important properties affected due to oxidation is the adhesive properties of modified asphalt. In this study, the adhesive properties of asphalt modified with the polymers (styrene-butadiene-styrene and styrene-butadiene) and carbon nanotubes were investigated. Asphalt samples were aged in the laboratory by simulating the field conditions, and then adhesive properties were evaluated by different tips of atomic force microscopy (AFM) following the existing functional group in asphalt. Finally, a predictive modelling and machine learning technique called the classification and regression tree (CART) was used to predict the adhesive properties of modified asphalt subjected to oxidation. The parameters that affect ...
International Journal of Pavement Engineering, 2017
Abstract The rheological properties of asphalt binders change with aging. Aging is accelerated at... more Abstract The rheological properties of asphalt binders change with aging. Aging is accelerated at elevated temperatures due to binder oxidation, leading to fatigue cracking and eventually pavement failure under heavy and repeated traffic loading. This study examined the effect of various antioxidant additives and copolymers with antioxidant agents on retarding the aging of asphalt binders. The performance of antioxidants was evaluated at the binder and mastic levels. Two unmodified binders were tested and fine asphalt mixtures made with these binders and three different aggregates were prepared and evaluated. Fatigue characteristics of asphalt binders and fine portion of asphalt mixtures (FAM) were determined before and after aging and an aging index was defined to evaluate the effect of antioxidants and copolymers on aging. The results showed that certain antioxidants and copolymers such as Redicote AP, Solprene and Calprene may retard the aging and improve the rheological properties of the asphalt binders. In addition, the results of FAM testing confirmed the favourable effect of certain antioxidants on improving the resistance to fatigue. In addition, the type of aggregate was found to influence the rate of aging of asphalt mixtures.
Uploads
Papers by Okan Sirin