Proceedings of the Geo-Shanghai 2014 International Conference, held in Shanghai, China, May 26-28... more Proceedings of the Geo-Shanghai 2014 International Conference, held in Shanghai, China, May 26-28, 2014. GSP 239 contains 42 technical papers which focus on paving material characterization and modeling, pavement evaluation, analysis, and construction, and pavement base and subgrade.
ABSTRACT Sustainable Construction Materials 2012 selects 37 papers that represent the latest deve... more ABSTRACT Sustainable Construction Materials 2012 selects 37 papers that represent the latest developments in construction materials that support sustainable development for infrastructures. Many of the selected papers were presented at the Second International Conference on Sustainable Construction Materials: Design, Performance and Application which occurred from October 18 – 22, 2012 in Wuhan, Hubei Province of China. The conference was hosted by the Wuhan University of Technology in collaboration with the Delft University of Technology in Netherland, Eindhoven University of Technology in Netherland, Southeast University in China, Arizona State University in USA, International Society for Concrete Pavements (ISCP), the American Society of Civil Engineers (ASCE), and the University of Tennessee, Knoxville in USA. The papers presented within the Sustainable Construction Materials 2012 Special Technical Publication are divided into two groups. The first group contains 20 papers which examine sustainable application of cementitious materials. Within this group a global perspective is provided on sustainable construction practices in a developing country. Additionally, more fundamental research is explored through the study of rheological behavior of fresh cement mortar and the examination of the effects of small recycled aggregate fractions in concrete production. The use of recycled materials such as waste tire rubber and rubber powder is also studied. The second group of papers contains 17 papers focused on bituminous material. A focus is placed on the use of waste material in asphalt cement such as reclaimed asphalt pavement (RAP), crumb rubber, and coal tar pitch. Studies were conducted to evaluate behavior of SBS and PE modified asphalt cement during the asphalt aging process. Pavement life, an important factor of sustainability, is presented with respect to fatigue life and a study of a new maintenance solution for porous asphalt cement pavements. Furthermore a study which examines different conditions in which volatile organic compound emission is influenced in asphalt cement is provided.
International Journal of Pavement Engineering, 2021
This study developed gradient decision tree boosting (GDTB) models to estimate dynamic moduli ( |... more This study developed gradient decision tree boosting (GDTB) models to estimate dynamic moduli ( | E ∗ | ) of hot mix asphalt (HMA) mixtures. The GDTB used as input the binder properties, mixture vo...
This collection contains 33 peer-reviewed papers presented at the 2015 International Symposium on... more This collection contains 33 peer-reviewed papers presented at the 2015 International Symposium on Frontiers of Road and Airport Engineering, held in Shanghai, China, October 26-28, 2015. These papers address innovations in asphalt materials and evaluation technologies applied to road and airport infrastructure. Topics include: performance characteristics of asphalt pavement; structural analysis and asphalt pavement design; and road traffic safety analysis. Pavement engineers, transportation researchers, and practitioners will find these papers valuable.
The Superpave mix design was developed in early 1990s during the Strategic Highway Research Progr... more The Superpave mix design was developed in early 1990s during the Strategic Highway Research Program (SHRP) (1987-1992) to replace the Hveem and Marshall mix design methods. It is one of the primary outcomes from the SHRP study. Superpave is a comprehensive asphalt mix design and analysis system, including a Performance Grade (PG) asphalt binder specification, a series of aggregate tests and specifications, a hot mix asphalt (HMA) design and analysis system, and computer software to integrate the system components. The Superpave mix design procedure involves careful material selection and volumetric proportioning as a first approach in producing a mix that will perform successfully. The four basic steps of Superpave asphalt mix design are materials selection, selection of the design aggregate structure, selection of the design asphalt binder content, and evaluation of the mixture for moisture sensitivity.
The interlocking of aggregate is critical during compaction. Nevertheless, few mix design specifi... more The interlocking of aggregate is critical during compaction. Nevertheless, few mix design specifications include any specific requirements for locking points, mainly because it is difficult to determine when interlocking happens during compaction precisely. This study's objectives were to validate the locking point concept by applying performance tests and evaluating aggregate interlocking influence on the rutting resistance and the fatigue cracking. Two types of asphalt mixture composed of limestone aggregates and PG 64–22 binder and designed at different Ndesign were used in this study. Two types of performance tests, the Flow Number and the IDEAL CT, were used to determine and confirm the locking point's definitions. Results showed that the locking point (LP)2-2-3 and LP3 definitions during Superpave gyratory compaction were the most reasonable to define the locking point based on the vertical axial strain from the Flow Number and the Cracking Tolerance Index (CTindex) from the IDEAL CT test..
Abstract The use of recycled plastic and rubber for asphalt modification is gaining increasing at... more Abstract The use of recycled plastic and rubber for asphalt modification is gaining increasing attention for the development of sustainable pavements. However, phase separation among the rubber, plastic, and asphalt remains a major challenge for a large-scale field application. In this study, several approaches were tested to improve the compatibility of the modified binder blends including the increase of recycled rubber content, the addition of compatibilizer, and the use of pre-commingled recycled rubber-plastic blends. The rheological properties and microstructure of the modified asphalt were evaluated by using dynamic shear rheometer tests and optical microscopy, respectively. Furthermore, the compatibility of the binder blends was characterized using the cigar tube test. Compared with adding plastic and rubber independently or with additional compatibilizer, the asphalt modified with the pre-combined recycled rubber-plastic blends showed a significant improvement of the compatibility, resulting in enhanced physical properties, which present a promising pathway to large-scale commercial applications of plastic and rubber modified asphalt.
Abstract In this study, waste glass powder (d50 = 15.4 μm) obtained by crushing soda lime glass b... more Abstract In this study, waste glass powder (d50 = 15.4 μm) obtained by crushing soda lime glass bottles was investigated as a raw material for geopolymer cement. The waste glass (WG) powder and class C fly ash (FC) were mixed at varying ratios (100:0, 75:25, 50:50, 25:75, 0:100) and activated by sodium hydroxide solutions of different concentrations (0 M, 2.5 M, 5 M, 7.5 M, 10 M). The geopolymer pastes were cured at ambient temperature and the compressive strengths at increasing curing ages were tested. The mechanical properties were analyzed with respect to the kinetics and Si/Al ratio of the reaction system. The experimental results suggested that the WG mostly acted as an inert filler at early ages due to the slow reaction rate. However, the strength performance improved significantly after the curing age of 14 days, which was attributed to the reaction between WG and FC. The geopolymer made by mixing WG and FC at a ratio of 1:3 (Si/Al = 3.038) and 5 Mol NaOH solution achieved a compressive strength of 34.5 MPa. The microstructure and minerology of the geopolymers analyzed by the SEM-EDX and XRD suggested the coexistence of sodium aluminate silicate hydrate (N-A-S-H) gel and calcium aluminate silicate hydrate (C-A-S-H) gel in geopolymer matrix. The results of leaching tests indicated the potential environmental impact caused by the leaching of excessive alkali, which should be carefully managed during the mix design. The sustainability analysis including the embodied energy and carbon footprint confirmed the environmental friendliness of WG geopolymer. This study exhibited the feasibility of producing WG geopolymer concrete at ambient temperature and the potential synergy between the waste glass recycling and geopolymer industry.
Transportation Research Record: Journal of the Transportation Research Board, 2020
As the concept of sustainable pavement gains prominence, a growing number of industrial wastes an... more As the concept of sustainable pavement gains prominence, a growing number of industrial wastes and recycled materials have been utilized in the pavement industry to preserve natural resources. This study investigates the potential use of waste glass powder-based geopolymer cement as a stabilizing agent in recycled waste glass aggregate (GA) bases. Two recycled materials, waste glass powder (GP) and class F fly ash (FF), were used as the raw materials in the preparation of geopolymer. Virgin aggregate (VA) was replaced by GA at varying replacement ratios as the pavement base materials, and the mechanical behaviors before and after geopolymer stabilization were evaluated. Without stabilization, the incorporation of over 10% GA caused significant detrimental effects on the California bearing ratios (CBR) of base materials, which should be carefully managed in pavement construction. However, all geopolymer stabilized samples showed decent strength properties, indicating the effectivenes...
Transportation Research Record: Journal of the Transportation Research Board, 2019
In this study, an analytic method was developed for detecting potential oil contaminants in aspha... more In this study, an analytic method was developed for detecting potential oil contaminants in asphalt mixtures using gel permeation chromatography (GPC) and Fourier-transform infrared spectroscopy (FTIR). This study was initiated when the authors were contacted by a major contractor whose field crew reported spots of loose asphalt pavement and suspected the pavement surface was being contaminated with spills of petroleum-based oils or other soluble chemicals. Oil contamination would change the content and performance grade of the asphalt binder in the mixture, thus compromising the properties and performance of the asphalt pavement. The proposed method involved extracting asphalt binders from potentially contaminated asphalt mixtures using the solvent tetrahydrofuran (THF), testing the extracted binders using GPC and FTIR, and comparing their results with those of the pure asphalt binder and oil contaminants. This study first verified the proposed method by testing artificially contam...
AbstractLocking point is an important concept in selecting a proper aggregate gradation in the as... more AbstractLocking point is an important concept in selecting a proper aggregate gradation in the asphalt mixture design. The locking point can be defined as the moment during asphalt mixture compacti...
Journal of Transportation Engineering, Part B: Pavements, 2019
AbstractThis study developed a gradient boosted model (GBM) to enhance the fatigue cracking predi... more AbstractThis study developed a gradient boosted model (GBM) to enhance the fatigue cracking predictive performance of transfer functions in the mechanistic-empirical pavement design guide (MEPDG). ...
Proceedings of the Geo-Shanghai 2014 International Conference, held in Shanghai, China, May 26-28... more Proceedings of the Geo-Shanghai 2014 International Conference, held in Shanghai, China, May 26-28, 2014. GSP 239 contains 42 technical papers which focus on paving material characterization and modeling, pavement evaluation, analysis, and construction, and pavement base and subgrade.
ABSTRACT Sustainable Construction Materials 2012 selects 37 papers that represent the latest deve... more ABSTRACT Sustainable Construction Materials 2012 selects 37 papers that represent the latest developments in construction materials that support sustainable development for infrastructures. Many of the selected papers were presented at the Second International Conference on Sustainable Construction Materials: Design, Performance and Application which occurred from October 18 – 22, 2012 in Wuhan, Hubei Province of China. The conference was hosted by the Wuhan University of Technology in collaboration with the Delft University of Technology in Netherland, Eindhoven University of Technology in Netherland, Southeast University in China, Arizona State University in USA, International Society for Concrete Pavements (ISCP), the American Society of Civil Engineers (ASCE), and the University of Tennessee, Knoxville in USA. The papers presented within the Sustainable Construction Materials 2012 Special Technical Publication are divided into two groups. The first group contains 20 papers which examine sustainable application of cementitious materials. Within this group a global perspective is provided on sustainable construction practices in a developing country. Additionally, more fundamental research is explored through the study of rheological behavior of fresh cement mortar and the examination of the effects of small recycled aggregate fractions in concrete production. The use of recycled materials such as waste tire rubber and rubber powder is also studied. The second group of papers contains 17 papers focused on bituminous material. A focus is placed on the use of waste material in asphalt cement such as reclaimed asphalt pavement (RAP), crumb rubber, and coal tar pitch. Studies were conducted to evaluate behavior of SBS and PE modified asphalt cement during the asphalt aging process. Pavement life, an important factor of sustainability, is presented with respect to fatigue life and a study of a new maintenance solution for porous asphalt cement pavements. Furthermore a study which examines different conditions in which volatile organic compound emission is influenced in asphalt cement is provided.
International Journal of Pavement Engineering, 2021
This study developed gradient decision tree boosting (GDTB) models to estimate dynamic moduli ( |... more This study developed gradient decision tree boosting (GDTB) models to estimate dynamic moduli ( | E ∗ | ) of hot mix asphalt (HMA) mixtures. The GDTB used as input the binder properties, mixture vo...
This collection contains 33 peer-reviewed papers presented at the 2015 International Symposium on... more This collection contains 33 peer-reviewed papers presented at the 2015 International Symposium on Frontiers of Road and Airport Engineering, held in Shanghai, China, October 26-28, 2015. These papers address innovations in asphalt materials and evaluation technologies applied to road and airport infrastructure. Topics include: performance characteristics of asphalt pavement; structural analysis and asphalt pavement design; and road traffic safety analysis. Pavement engineers, transportation researchers, and practitioners will find these papers valuable.
The Superpave mix design was developed in early 1990s during the Strategic Highway Research Progr... more The Superpave mix design was developed in early 1990s during the Strategic Highway Research Program (SHRP) (1987-1992) to replace the Hveem and Marshall mix design methods. It is one of the primary outcomes from the SHRP study. Superpave is a comprehensive asphalt mix design and analysis system, including a Performance Grade (PG) asphalt binder specification, a series of aggregate tests and specifications, a hot mix asphalt (HMA) design and analysis system, and computer software to integrate the system components. The Superpave mix design procedure involves careful material selection and volumetric proportioning as a first approach in producing a mix that will perform successfully. The four basic steps of Superpave asphalt mix design are materials selection, selection of the design aggregate structure, selection of the design asphalt binder content, and evaluation of the mixture for moisture sensitivity.
The interlocking of aggregate is critical during compaction. Nevertheless, few mix design specifi... more The interlocking of aggregate is critical during compaction. Nevertheless, few mix design specifications include any specific requirements for locking points, mainly because it is difficult to determine when interlocking happens during compaction precisely. This study's objectives were to validate the locking point concept by applying performance tests and evaluating aggregate interlocking influence on the rutting resistance and the fatigue cracking. Two types of asphalt mixture composed of limestone aggregates and PG 64–22 binder and designed at different Ndesign were used in this study. Two types of performance tests, the Flow Number and the IDEAL CT, were used to determine and confirm the locking point's definitions. Results showed that the locking point (LP)2-2-3 and LP3 definitions during Superpave gyratory compaction were the most reasonable to define the locking point based on the vertical axial strain from the Flow Number and the Cracking Tolerance Index (CTindex) from the IDEAL CT test..
Abstract The use of recycled plastic and rubber for asphalt modification is gaining increasing at... more Abstract The use of recycled plastic and rubber for asphalt modification is gaining increasing attention for the development of sustainable pavements. However, phase separation among the rubber, plastic, and asphalt remains a major challenge for a large-scale field application. In this study, several approaches were tested to improve the compatibility of the modified binder blends including the increase of recycled rubber content, the addition of compatibilizer, and the use of pre-commingled recycled rubber-plastic blends. The rheological properties and microstructure of the modified asphalt were evaluated by using dynamic shear rheometer tests and optical microscopy, respectively. Furthermore, the compatibility of the binder blends was characterized using the cigar tube test. Compared with adding plastic and rubber independently or with additional compatibilizer, the asphalt modified with the pre-combined recycled rubber-plastic blends showed a significant improvement of the compatibility, resulting in enhanced physical properties, which present a promising pathway to large-scale commercial applications of plastic and rubber modified asphalt.
Abstract In this study, waste glass powder (d50 = 15.4 μm) obtained by crushing soda lime glass b... more Abstract In this study, waste glass powder (d50 = 15.4 μm) obtained by crushing soda lime glass bottles was investigated as a raw material for geopolymer cement. The waste glass (WG) powder and class C fly ash (FC) were mixed at varying ratios (100:0, 75:25, 50:50, 25:75, 0:100) and activated by sodium hydroxide solutions of different concentrations (0 M, 2.5 M, 5 M, 7.5 M, 10 M). The geopolymer pastes were cured at ambient temperature and the compressive strengths at increasing curing ages were tested. The mechanical properties were analyzed with respect to the kinetics and Si/Al ratio of the reaction system. The experimental results suggested that the WG mostly acted as an inert filler at early ages due to the slow reaction rate. However, the strength performance improved significantly after the curing age of 14 days, which was attributed to the reaction between WG and FC. The geopolymer made by mixing WG and FC at a ratio of 1:3 (Si/Al = 3.038) and 5 Mol NaOH solution achieved a compressive strength of 34.5 MPa. The microstructure and minerology of the geopolymers analyzed by the SEM-EDX and XRD suggested the coexistence of sodium aluminate silicate hydrate (N-A-S-H) gel and calcium aluminate silicate hydrate (C-A-S-H) gel in geopolymer matrix. The results of leaching tests indicated the potential environmental impact caused by the leaching of excessive alkali, which should be carefully managed during the mix design. The sustainability analysis including the embodied energy and carbon footprint confirmed the environmental friendliness of WG geopolymer. This study exhibited the feasibility of producing WG geopolymer concrete at ambient temperature and the potential synergy between the waste glass recycling and geopolymer industry.
Transportation Research Record: Journal of the Transportation Research Board, 2020
As the concept of sustainable pavement gains prominence, a growing number of industrial wastes an... more As the concept of sustainable pavement gains prominence, a growing number of industrial wastes and recycled materials have been utilized in the pavement industry to preserve natural resources. This study investigates the potential use of waste glass powder-based geopolymer cement as a stabilizing agent in recycled waste glass aggregate (GA) bases. Two recycled materials, waste glass powder (GP) and class F fly ash (FF), were used as the raw materials in the preparation of geopolymer. Virgin aggregate (VA) was replaced by GA at varying replacement ratios as the pavement base materials, and the mechanical behaviors before and after geopolymer stabilization were evaluated. Without stabilization, the incorporation of over 10% GA caused significant detrimental effects on the California bearing ratios (CBR) of base materials, which should be carefully managed in pavement construction. However, all geopolymer stabilized samples showed decent strength properties, indicating the effectivenes...
Transportation Research Record: Journal of the Transportation Research Board, 2019
In this study, an analytic method was developed for detecting potential oil contaminants in aspha... more In this study, an analytic method was developed for detecting potential oil contaminants in asphalt mixtures using gel permeation chromatography (GPC) and Fourier-transform infrared spectroscopy (FTIR). This study was initiated when the authors were contacted by a major contractor whose field crew reported spots of loose asphalt pavement and suspected the pavement surface was being contaminated with spills of petroleum-based oils or other soluble chemicals. Oil contamination would change the content and performance grade of the asphalt binder in the mixture, thus compromising the properties and performance of the asphalt pavement. The proposed method involved extracting asphalt binders from potentially contaminated asphalt mixtures using the solvent tetrahydrofuran (THF), testing the extracted binders using GPC and FTIR, and comparing their results with those of the pure asphalt binder and oil contaminants. This study first verified the proposed method by testing artificially contam...
AbstractLocking point is an important concept in selecting a proper aggregate gradation in the as... more AbstractLocking point is an important concept in selecting a proper aggregate gradation in the asphalt mixture design. The locking point can be defined as the moment during asphalt mixture compacti...
Journal of Transportation Engineering, Part B: Pavements, 2019
AbstractThis study developed a gradient boosted model (GBM) to enhance the fatigue cracking predi... more AbstractThis study developed a gradient boosted model (GBM) to enhance the fatigue cracking predictive performance of transfer functions in the mechanistic-empirical pavement design guide (MEPDG). ...
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Papers by Baoshan Huang