Inductive loop wire sensors embedded in the roadway surface are devices that indicate the presenc... more Inductive loop wire sensors embedded in the roadway surface are devices that indicate the presence or passage of vehicles and provide information that supports traffic management applications such as signal control. Malfunctioning in-roadway loop sensors can prevent traffic signals from sensing the presence of vehicles, a problem that can be particularly frustrating and dangerous for smaller vehicles, such as motorcycles and bicycles. To address sensor malfunction, the Federal Highway Administration (FHWA) in 2006 initiated a Small Business Innovation Research project, "Step-Frequency (SF) Ground Penetrating Radar (GPR) for Location and Evaluation of In-Roadway Sensors." This article describes this project, which was initiated to develop a nondestructive evaluation method employing GPR for detecting and assessing in-roadway inductive loop sensors. FHWA defined four objectives for the GPR detection of traffic sensor wires: (1) locate a loop wire sensor with a new SF GPR technique; (2) perform testing to determine whether the loop is functional; (3) scan the details of a sensor using GPR and classify the record based on the results of the previous step; and (4) perform detailed analysis of GPR data to assess the condition of a sensor, with the goal of detecting the causes of malfunction. Researchers developed and tested two complementary technologies: a passive probe sensor and a SF GPR-based method for data collection and analysis imaging. The passive probe successfully determines whether the loop is functioning and, if functioning, shows its location through a plot of its signal strength. The SF GPR method then images the loop wire in the pavement to evaluate potential cracks, defects, or deterioration in the wire or adjoining pavement. Although the loop wire imaging method developed and implemented in the FHWA study currently meets basic detection needs for many loop wire evaluation applications, improvements to the hardware and complementary software should lead to a commercially viable, high resolution product.
This research developed a more complete understanding of the mechanics of asphalt concrete perman... more This research developed a more complete understanding of the mechanics of asphalt concrete permanent deformation such that future methodologies for materials characterization and rutting performance prediction are guided by these principles. Currently, the Asphalt Mixture Performance Tester (AMPT) formerly known as the Simple Performance Tester (SPT) and corresponding Flow Number test are well poised to impact the state-of-the-practice. Salient aspects of the test and phenomena associated with rutting were reviewed. A mechanistic methodology was followed to determine relevant multiaxial stresses associated with rutting. In addition, a noncontact image-based strain measurement technique was developed to provide the radial and axial strain occurring during the test. Multiaxial strains measured under the application of two complementary stress states provided additional insight into the three dimensional mechanics of permanent strain growth in asphalt concrete. A single parameter like the Flow Number cannot provide this information. There are no guarantees that the Flow Number will be encountered in all mixtures and tests. The multiaxial characterization clearly shows that asphalt concrete mixtures can and do volumetrically compress or volumetrically dilate depending on stress state and density, sometimes before and after tertiary flow is achieved. Concepts of permanent strain path and permanent strain trajectory are utilized as a means to more clearly separate the contribution of binder apart from the contribution of aggregate on permanent deformations. Two distinctive sets of mixtures; one having measured rutting from an accelerated pavement test and the other having a broader variation in air void content and aggregate gradation were utilized to explore these concepts.
This study investigated the feasibility of using a monotonic direct tension test in the Asphalt M... more This study investigated the feasibility of using a monotonic direct tension test in the Asphalt Mixture Performance Tester (AMPT) with small-scale specimens to evaluate the crack properties of the asphalt materials. Ten loose asphalt mixtures collected from the Federal Highway Administration’s accelerated loading facility (ALF) test lanes combining various reclaimed asphalt pavement (RAP) and recycled asphalt shingles (RAS) percentages and warm mix asphalt technologies were tested at three loading rates and two ageing conditions. Various mechanical parameters and indexes were developed to analyse the experimental data. The laboratory monotonic testing results were compared with and statistically correlated with the ALF field cracking performance. The coefficients of variation from the experimental results indicated that the monotonic test has satisfactory repeatability. Test loading rates were found to have a significant impact on the behaviour of the test materials, and an actuator rate of 10 mm/min is considered to be ideal for all tested materials, including both short-term oven ageing and long-term oven ageing conditions. Ageing conditions were also found to dramatically influence the monotonic testing results. The experimental results illustrated that the components (percentage of RAP/RAS and binder performance grade) of the asphalt mixtures and the warm technologies have a clear effect on the monotonic testing, indicating that the test is capable of differentiating such asphalt mixtures. The parameters of the total fracture energy and the total energy divided by the inflection point slope from the laboratory monotonic test were found to have very strong correlation with the field performance. As a general conclusion, this study shows that the monotonic direct tension test in the AMPT is a very promising tool to evaluate the crack properties of the asphalt mixture due to the ease in the sample preparation, compatibility with the AMPT, strong correlation with field performance and feasibility for testing the field specimens.
Fatigue cracking is one of the major distresses in asphalt pavements. Accurate prediction of fati... more Fatigue cracking is one of the major distresses in asphalt pavements. Accurate prediction of fatigue life of asphalt pavements can be extremely important both during the design stage and for prediction of remaining service life of in-service pavements. Traditional fatigue life predictions based on bending beam tests can be costly and time-consuming. The uniaxial push–pull (tension–compression) tests run on cylindrical samples have been a novel alternative. However, the traditional sample size for the push–pull tests may prevent its use for thin in-service pavements. This paper presents the results of a study investigating the possibility of using smaller sample sizes for push–pull tests. The viscoelastic continuum damage (VECD) characteristics of regular and small-size samples are compared, and the difference is observed to be negligible. In addition, a practical fatigue life formulation is derived on the basis of VECD theory. Uniqueness of the derived fatigue life ( Nf) equation, differing from previously derived VECD-based Nf equations, stems from the fact that it does not force a certain form of equation to fit the damage characteristic curve. Finally, the differences in fatigue lives of different layers of the field sections at FHWA's accelerated loading facility are investigated.
This study investigated the feasibility of using a monotonic direct tension test in the Asphalt M... more This study investigated the feasibility of using a monotonic direct tension test in the Asphalt Mixture Performance Tester (AMPT) with small-scale specimens to evaluate the crack properties of the asphalt materials. Ten loose asphalt mixtures collected from the Federal Highway Administration’s accelerated loading facility (ALF) test lanes combining various reclaimed asphalt pavement (RAP) and recycled asphalt shingles (RAS) percentages and warm mix asphalt technologies were tested at three loading rates and two ageing conditions. Various mechanical parameters and indexes were developed to analyse the experimental data. The laboratory monotonic testing results were compared with and statistically correlated with the ALF field cracking performance. The coefficients of variation from the experimental results indicated that the monotonic test has satisfactory repeatability. Test loading rates were found to have a significant impact on the behaviour of the test materials, and an actuator rate of 10 mm/min is considered to be ideal for all tested materials, including both short-term oven ageing and long-term oven ageing conditions. Ageing conditions were also found to dramatically influence the monotonic testing results. The experimental results illustrated that the components (percentage of RAP/RAS and binder performance grade) of the asphalt mixtures and the warm technologies have a clear effect on the monotonic testing, indicating that the test is capable of differentiating such asphalt mixtures. The parameters of the total fracture energy and the total energy divided by the inflection point slope from the laboratory monotonic test were found to have very strong correlation with the field performance. As a general conclusion, this study shows that the monotonic direct tension test in the AMPT is a very promising tool to evaluate the crack properties of the asphalt mixture due to the ease in the sample preparation, compatibility with the AMPT, strong correlation with field performance and feasibility for testing the field specimens.
The Federal Highway Administration’s Office of Infrastructure Research and Development has initia... more The Federal Highway Administration’s Office of Infrastructure Research and Development has initiated a full-scale accelerated pavement testing experiment to evaluate the fatigue cracking performance of sustainable asphalt materials and mix designs. Recycled asphalt pavement (RAP) contents providing up to 40% asphalt binder replaced (ABR) by 44% by RAP by weight have been incorporated in hot mix asphalt (HMA) production as well as reduced-temperature warm mix asphalt (WMA) that was produced with water foaming and chemical additive. Recycled asphalt shingles (RAS) have been incorporated to provide 20% ABR in HMA. The objective of the experiment is to establish realistic boundaries for high-RAP & RAS mixtures employing WMA technologies based on percent binder replacement and binder grade changes when combined together. This paper will document the construction, the as-built engineering properties of the 10 different test sections characterized in the laboratory, and the full scale fatigue cracking performance.
Key findings of the various researchers involved in the Strategic Highway Research Program (SHRP)... more Key findings of the various researchers involved in the Strategic Highway Research Program (SHRP) asphalt program are described. Emphasized are those fundamental chemical and physical properties of the binder that relate to its susceptibility to various distresses. Consideration and evaluation of the polar and nonpolar molecules assists in understanding the performance of a given asphalt. The polars largely dictate the ability of an asphalt to resist permanent deformation. Low temperature cracking and fatigue cracking are largely influenced by the nonpolar fraction. The impact of aging and asphalt compatibility on these distress modes is also discussed.
Some states require lime to be added to aggregates in hot mix asphalt to improve moisture resista... more Some states require lime to be added to aggregates in hot mix asphalt to improve moisture resistance and extend the longevity of pavements. Until now, however, there was no test to detect whether lime had actually been added to the hot mix asphalt. This article describes the development of a new test that uses Fourier-Transform Infrared spectroscopy to determine whether or not lime has been added to the hot mix asphalt. The test can detect even minute traces of lime in asphalt in as little as 30 seconds. Two chemical analysis methods for measuring the lime levels accurately have also been developed. The American Association of State Highway and Transportation Officials currently is weighing the lime tests for adoption as industry standards, with a decision expected sometime in 2007.
Raman spectroscopy is a versatile tool for the study of cementitious materials due to its sensiti... more Raman spectroscopy is a versatile tool for the study of cementitious materials due to its sensitivity to both amorphous as well as crystalline phases. However, this is not a well-established technique in cement chemistry due to fluorescence of these materials posing significant difficulties in the analysis. An alternative method to combat fluorescence, which has not yet been fully utilized in the Raman analysis of cementitious materials, is surface enhanced Raman spectroscopy (SERS). This technique involves the enhancement of the Raman signal by many orders of magnitude following the adsorption of analyte molecules on metal nanostructures. This paper discusses potential benefits of developing a technique based on SERS for concrete materials and also presents some preliminary results correlating Raman spectra with the aggregation of silver nanoparticles on samples.
Journal of Materials in Civil Engineering, Jul 1, 2018
AbstractThis study explored the effect of amorphous nanoaluminosilicate, with controlled silicon ... more AbstractThis study explored the effect of amorphous nanoaluminosilicate, with controlled silicon to aluminum ratio, on the hydration of portland cement. The effect of these nanomaterials on the ear...
... To be more exact, the equilibrium distribution of species changes with temperature according ... more ... To be more exact, the equilibrium distribution of species changes with temperature according to the usual thermodynamic relations, but there is an ... R. and Schweighardt, FK Science 1975,188,49 9 Pimentel, GC and McClellan, AL The Hydrogen Bond', WH Freeman and Co ...
Federal Highway Administration2021PDFMagazineHuie, MaryHarman, ThomasNelson, Eileen S.Pauly, Ralp... more Federal Highway Administration2021PDFMagazineHuie, MaryHarman, ThomasNelson, Eileen S.Pauly, RalphSkrocki, ChadPark, HyungjunClaussen, KirkGrooms, LindseyPiskai, Katie B.Leslie, EdAzari, HodaShurbutt, JimMeininger, RichardDylla, Heather L.Youtcheff, JackUnited States. Federal Highway Administration. Office of Research, Development, and TechnologyUnited States. Federal Highway Administration. Office of Research, Development, and TechnologyUnited StatesPolicy, legislation and regulationTechnological innovationsResearchTechnologyPublic information programsFHWA-HRT-21-004Public Roads is the quarterly magazine of the Federal Highway Administration (FHWA). Reading Public Roads is the easiest way to keep up-to-date on developments in federal highway policies, programs, and research and technology. More specifically, the magazine "covers" advances and innovations in highway/traffic research and technology, critical national transportation issues, important activities and achievements of FHWA and others in the highway community, specific FHWA program areas, and subjects of interest to highway industry professionals. Each issue contains standard departments that include information on topics of general interest, notices of recent publications in research and development and in technology applications, Internet-related information applicable to transportation professionals, programs and courses offered by the National Highway Institute, and a calendar of major conferences and special events. Public Roads also emphasizes the continuing commitment of FHWA to be a world leader in promoting highway research and technology transfer. For almost its entire 80 years, Public Roads was exclusively an in-house research journal for engineers, scientists, and economists. However, in the summer of 1993, Public Roads broadened its scope to represent the entire FHWA and to be relevant to a wider audience. The expanded audience includes all FHWA employees; international, national, state, and local transportation officials; members of highway-related professional societies and associations; researchers at technical libraries and technology transfer centers; professors and students of engineering and traffic management; members of appropriate congressional committees; and others interested in highway research and technology and in FHWA policies and programs.115
An innovative, simple, and easy-to-use test method for quality assurance testing of asphalt binde... more An innovative, simple, and easy-to-use test method for quality assurance testing of asphalt binders at the mix plant was developed. This new method, the Binder Quality Control Test (QCT), uses an air jet to produce indentation and a laser deflectometer to measure the resulting deflection. The QCT is conducted under constant stress and temperature similar to the traditional Penetration test (ASTM D5) except instead of the penetration needle, an air jet is used with a loading time of 20 s and a recovery time of 60 s under no load. Unlike the Penetration test, the QCT measures both the loading and recovery characteristics of a binder. The complete creep-recovery curve is measured stored. The measurement of recovery properties allows for successful discrimination of both unmodified and polymer modified binders. Several performance-graded and penetration-graded asphalt binders were tested with and without modifiers, which included polymers as well as Recycled Engine Oil Bottoms (REOB). At this time the QCT has the potential to be implemented as a control test, an informational test that would trigger more complex acceptance testing. Possible applications of the QCT method include an alternative to traditional Penetration testing, quick and easy determination of asphalt tank contamination issues, assistance in value engineering projects, and with formuation of polymer modified binders. This paper describes the development and implications of using the QCT developed in this research.
Recent work in our laboratories has been concerned with obtaining a better understanding of the p... more Recent work in our laboratories has been concerned with obtaining a better understanding of the phenomena associated with coal liquefaction (1). initial study of three bituminous coals discussed the changes that occur in oxygen containing functional groups (2). It was ...
Sixth International Conference on Maintenance and Rehabilitation of Pavements and Technological Control (MAIREPAV6)International Society for Maintenance and Rehabilitation of Transportation InfrastructureTransportation Research Board, 2009
This paper explores the essential work of fracture (EWF) testing method for mixtures as a means t... more This paper explores the essential work of fracture (EWF) testing method for mixtures as a means to further validate its application for asphalt binders. The method is an energy-based testing approach that has been used extensively for the failure characterization of ductile materials. It allows for a direct determination of the essential work required for failure (we), as well as an approximate critical crack tip opening displacement (CTOD), thus providing a measure of strain tolerance in the presence of flaws. Previous studies have shown that the CTOD of the binders correlated well with fatigue performance in various trial pavements and accelerated loading facility (ALF) lanes at the Turner-Fairbank Highway Research Center (TFHRC). This paper documents and discusses the test results for mixture samples as used in the TFHRC ALF lanes. The determination of mixture and CTOD parameters allows for a direct comparison with binder and CTOD parameters as well as in service performance.
Inductive loop wire sensors embedded in the roadway surface are devices that indicate the presenc... more Inductive loop wire sensors embedded in the roadway surface are devices that indicate the presence or passage of vehicles and provide information that supports traffic management applications such as signal control. Malfunctioning in-roadway loop sensors can prevent traffic signals from sensing the presence of vehicles, a problem that can be particularly frustrating and dangerous for smaller vehicles, such as motorcycles and bicycles. To address sensor malfunction, the Federal Highway Administration (FHWA) in 2006 initiated a Small Business Innovation Research project, "Step-Frequency (SF) Ground Penetrating Radar (GPR) for Location and Evaluation of In-Roadway Sensors." This article describes this project, which was initiated to develop a nondestructive evaluation method employing GPR for detecting and assessing in-roadway inductive loop sensors. FHWA defined four objectives for the GPR detection of traffic sensor wires: (1) locate a loop wire sensor with a new SF GPR technique; (2) perform testing to determine whether the loop is functional; (3) scan the details of a sensor using GPR and classify the record based on the results of the previous step; and (4) perform detailed analysis of GPR data to assess the condition of a sensor, with the goal of detecting the causes of malfunction. Researchers developed and tested two complementary technologies: a passive probe sensor and a SF GPR-based method for data collection and analysis imaging. The passive probe successfully determines whether the loop is functioning and, if functioning, shows its location through a plot of its signal strength. The SF GPR method then images the loop wire in the pavement to evaluate potential cracks, defects, or deterioration in the wire or adjoining pavement. Although the loop wire imaging method developed and implemented in the FHWA study currently meets basic detection needs for many loop wire evaluation applications, improvements to the hardware and complementary software should lead to a commercially viable, high resolution product.
This research developed a more complete understanding of the mechanics of asphalt concrete perman... more This research developed a more complete understanding of the mechanics of asphalt concrete permanent deformation such that future methodologies for materials characterization and rutting performance prediction are guided by these principles. Currently, the Asphalt Mixture Performance Tester (AMPT) formerly known as the Simple Performance Tester (SPT) and corresponding Flow Number test are well poised to impact the state-of-the-practice. Salient aspects of the test and phenomena associated with rutting were reviewed. A mechanistic methodology was followed to determine relevant multiaxial stresses associated with rutting. In addition, a noncontact image-based strain measurement technique was developed to provide the radial and axial strain occurring during the test. Multiaxial strains measured under the application of two complementary stress states provided additional insight into the three dimensional mechanics of permanent strain growth in asphalt concrete. A single parameter like the Flow Number cannot provide this information. There are no guarantees that the Flow Number will be encountered in all mixtures and tests. The multiaxial characterization clearly shows that asphalt concrete mixtures can and do volumetrically compress or volumetrically dilate depending on stress state and density, sometimes before and after tertiary flow is achieved. Concepts of permanent strain path and permanent strain trajectory are utilized as a means to more clearly separate the contribution of binder apart from the contribution of aggregate on permanent deformations. Two distinctive sets of mixtures; one having measured rutting from an accelerated pavement test and the other having a broader variation in air void content and aggregate gradation were utilized to explore these concepts.
This study investigated the feasibility of using a monotonic direct tension test in the Asphalt M... more This study investigated the feasibility of using a monotonic direct tension test in the Asphalt Mixture Performance Tester (AMPT) with small-scale specimens to evaluate the crack properties of the asphalt materials. Ten loose asphalt mixtures collected from the Federal Highway Administration’s accelerated loading facility (ALF) test lanes combining various reclaimed asphalt pavement (RAP) and recycled asphalt shingles (RAS) percentages and warm mix asphalt technologies were tested at three loading rates and two ageing conditions. Various mechanical parameters and indexes were developed to analyse the experimental data. The laboratory monotonic testing results were compared with and statistically correlated with the ALF field cracking performance. The coefficients of variation from the experimental results indicated that the monotonic test has satisfactory repeatability. Test loading rates were found to have a significant impact on the behaviour of the test materials, and an actuator rate of 10 mm/min is considered to be ideal for all tested materials, including both short-term oven ageing and long-term oven ageing conditions. Ageing conditions were also found to dramatically influence the monotonic testing results. The experimental results illustrated that the components (percentage of RAP/RAS and binder performance grade) of the asphalt mixtures and the warm technologies have a clear effect on the monotonic testing, indicating that the test is capable of differentiating such asphalt mixtures. The parameters of the total fracture energy and the total energy divided by the inflection point slope from the laboratory monotonic test were found to have very strong correlation with the field performance. As a general conclusion, this study shows that the monotonic direct tension test in the AMPT is a very promising tool to evaluate the crack properties of the asphalt mixture due to the ease in the sample preparation, compatibility with the AMPT, strong correlation with field performance and feasibility for testing the field specimens.
Fatigue cracking is one of the major distresses in asphalt pavements. Accurate prediction of fati... more Fatigue cracking is one of the major distresses in asphalt pavements. Accurate prediction of fatigue life of asphalt pavements can be extremely important both during the design stage and for prediction of remaining service life of in-service pavements. Traditional fatigue life predictions based on bending beam tests can be costly and time-consuming. The uniaxial push–pull (tension–compression) tests run on cylindrical samples have been a novel alternative. However, the traditional sample size for the push–pull tests may prevent its use for thin in-service pavements. This paper presents the results of a study investigating the possibility of using smaller sample sizes for push–pull tests. The viscoelastic continuum damage (VECD) characteristics of regular and small-size samples are compared, and the difference is observed to be negligible. In addition, a practical fatigue life formulation is derived on the basis of VECD theory. Uniqueness of the derived fatigue life ( Nf) equation, differing from previously derived VECD-based Nf equations, stems from the fact that it does not force a certain form of equation to fit the damage characteristic curve. Finally, the differences in fatigue lives of different layers of the field sections at FHWA's accelerated loading facility are investigated.
This study investigated the feasibility of using a monotonic direct tension test in the Asphalt M... more This study investigated the feasibility of using a monotonic direct tension test in the Asphalt Mixture Performance Tester (AMPT) with small-scale specimens to evaluate the crack properties of the asphalt materials. Ten loose asphalt mixtures collected from the Federal Highway Administration’s accelerated loading facility (ALF) test lanes combining various reclaimed asphalt pavement (RAP) and recycled asphalt shingles (RAS) percentages and warm mix asphalt technologies were tested at three loading rates and two ageing conditions. Various mechanical parameters and indexes were developed to analyse the experimental data. The laboratory monotonic testing results were compared with and statistically correlated with the ALF field cracking performance. The coefficients of variation from the experimental results indicated that the monotonic test has satisfactory repeatability. Test loading rates were found to have a significant impact on the behaviour of the test materials, and an actuator rate of 10 mm/min is considered to be ideal for all tested materials, including both short-term oven ageing and long-term oven ageing conditions. Ageing conditions were also found to dramatically influence the monotonic testing results. The experimental results illustrated that the components (percentage of RAP/RAS and binder performance grade) of the asphalt mixtures and the warm technologies have a clear effect on the monotonic testing, indicating that the test is capable of differentiating such asphalt mixtures. The parameters of the total fracture energy and the total energy divided by the inflection point slope from the laboratory monotonic test were found to have very strong correlation with the field performance. As a general conclusion, this study shows that the monotonic direct tension test in the AMPT is a very promising tool to evaluate the crack properties of the asphalt mixture due to the ease in the sample preparation, compatibility with the AMPT, strong correlation with field performance and feasibility for testing the field specimens.
The Federal Highway Administration’s Office of Infrastructure Research and Development has initia... more The Federal Highway Administration’s Office of Infrastructure Research and Development has initiated a full-scale accelerated pavement testing experiment to evaluate the fatigue cracking performance of sustainable asphalt materials and mix designs. Recycled asphalt pavement (RAP) contents providing up to 40% asphalt binder replaced (ABR) by 44% by RAP by weight have been incorporated in hot mix asphalt (HMA) production as well as reduced-temperature warm mix asphalt (WMA) that was produced with water foaming and chemical additive. Recycled asphalt shingles (RAS) have been incorporated to provide 20% ABR in HMA. The objective of the experiment is to establish realistic boundaries for high-RAP & RAS mixtures employing WMA technologies based on percent binder replacement and binder grade changes when combined together. This paper will document the construction, the as-built engineering properties of the 10 different test sections characterized in the laboratory, and the full scale fatigue cracking performance.
Key findings of the various researchers involved in the Strategic Highway Research Program (SHRP)... more Key findings of the various researchers involved in the Strategic Highway Research Program (SHRP) asphalt program are described. Emphasized are those fundamental chemical and physical properties of the binder that relate to its susceptibility to various distresses. Consideration and evaluation of the polar and nonpolar molecules assists in understanding the performance of a given asphalt. The polars largely dictate the ability of an asphalt to resist permanent deformation. Low temperature cracking and fatigue cracking are largely influenced by the nonpolar fraction. The impact of aging and asphalt compatibility on these distress modes is also discussed.
Some states require lime to be added to aggregates in hot mix asphalt to improve moisture resista... more Some states require lime to be added to aggregates in hot mix asphalt to improve moisture resistance and extend the longevity of pavements. Until now, however, there was no test to detect whether lime had actually been added to the hot mix asphalt. This article describes the development of a new test that uses Fourier-Transform Infrared spectroscopy to determine whether or not lime has been added to the hot mix asphalt. The test can detect even minute traces of lime in asphalt in as little as 30 seconds. Two chemical analysis methods for measuring the lime levels accurately have also been developed. The American Association of State Highway and Transportation Officials currently is weighing the lime tests for adoption as industry standards, with a decision expected sometime in 2007.
Raman spectroscopy is a versatile tool for the study of cementitious materials due to its sensiti... more Raman spectroscopy is a versatile tool for the study of cementitious materials due to its sensitivity to both amorphous as well as crystalline phases. However, this is not a well-established technique in cement chemistry due to fluorescence of these materials posing significant difficulties in the analysis. An alternative method to combat fluorescence, which has not yet been fully utilized in the Raman analysis of cementitious materials, is surface enhanced Raman spectroscopy (SERS). This technique involves the enhancement of the Raman signal by many orders of magnitude following the adsorption of analyte molecules on metal nanostructures. This paper discusses potential benefits of developing a technique based on SERS for concrete materials and also presents some preliminary results correlating Raman spectra with the aggregation of silver nanoparticles on samples.
Journal of Materials in Civil Engineering, Jul 1, 2018
AbstractThis study explored the effect of amorphous nanoaluminosilicate, with controlled silicon ... more AbstractThis study explored the effect of amorphous nanoaluminosilicate, with controlled silicon to aluminum ratio, on the hydration of portland cement. The effect of these nanomaterials on the ear...
... To be more exact, the equilibrium distribution of species changes with temperature according ... more ... To be more exact, the equilibrium distribution of species changes with temperature according to the usual thermodynamic relations, but there is an ... R. and Schweighardt, FK Science 1975,188,49 9 Pimentel, GC and McClellan, AL The Hydrogen Bond', WH Freeman and Co ...
Federal Highway Administration2021PDFMagazineHuie, MaryHarman, ThomasNelson, Eileen S.Pauly, Ralp... more Federal Highway Administration2021PDFMagazineHuie, MaryHarman, ThomasNelson, Eileen S.Pauly, RalphSkrocki, ChadPark, HyungjunClaussen, KirkGrooms, LindseyPiskai, Katie B.Leslie, EdAzari, HodaShurbutt, JimMeininger, RichardDylla, Heather L.Youtcheff, JackUnited States. Federal Highway Administration. Office of Research, Development, and TechnologyUnited States. Federal Highway Administration. Office of Research, Development, and TechnologyUnited StatesPolicy, legislation and regulationTechnological innovationsResearchTechnologyPublic information programsFHWA-HRT-21-004Public Roads is the quarterly magazine of the Federal Highway Administration (FHWA). Reading Public Roads is the easiest way to keep up-to-date on developments in federal highway policies, programs, and research and technology. More specifically, the magazine "covers" advances and innovations in highway/traffic research and technology, critical national transportation issues, important activities and achievements of FHWA and others in the highway community, specific FHWA program areas, and subjects of interest to highway industry professionals. Each issue contains standard departments that include information on topics of general interest, notices of recent publications in research and development and in technology applications, Internet-related information applicable to transportation professionals, programs and courses offered by the National Highway Institute, and a calendar of major conferences and special events. Public Roads also emphasizes the continuing commitment of FHWA to be a world leader in promoting highway research and technology transfer. For almost its entire 80 years, Public Roads was exclusively an in-house research journal for engineers, scientists, and economists. However, in the summer of 1993, Public Roads broadened its scope to represent the entire FHWA and to be relevant to a wider audience. The expanded audience includes all FHWA employees; international, national, state, and local transportation officials; members of highway-related professional societies and associations; researchers at technical libraries and technology transfer centers; professors and students of engineering and traffic management; members of appropriate congressional committees; and others interested in highway research and technology and in FHWA policies and programs.115
An innovative, simple, and easy-to-use test method for quality assurance testing of asphalt binde... more An innovative, simple, and easy-to-use test method for quality assurance testing of asphalt binders at the mix plant was developed. This new method, the Binder Quality Control Test (QCT), uses an air jet to produce indentation and a laser deflectometer to measure the resulting deflection. The QCT is conducted under constant stress and temperature similar to the traditional Penetration test (ASTM D5) except instead of the penetration needle, an air jet is used with a loading time of 20 s and a recovery time of 60 s under no load. Unlike the Penetration test, the QCT measures both the loading and recovery characteristics of a binder. The complete creep-recovery curve is measured stored. The measurement of recovery properties allows for successful discrimination of both unmodified and polymer modified binders. Several performance-graded and penetration-graded asphalt binders were tested with and without modifiers, which included polymers as well as Recycled Engine Oil Bottoms (REOB). At this time the QCT has the potential to be implemented as a control test, an informational test that would trigger more complex acceptance testing. Possible applications of the QCT method include an alternative to traditional Penetration testing, quick and easy determination of asphalt tank contamination issues, assistance in value engineering projects, and with formuation of polymer modified binders. This paper describes the development and implications of using the QCT developed in this research.
Recent work in our laboratories has been concerned with obtaining a better understanding of the p... more Recent work in our laboratories has been concerned with obtaining a better understanding of the phenomena associated with coal liquefaction (1). initial study of three bituminous coals discussed the changes that occur in oxygen containing functional groups (2). It was ...
Sixth International Conference on Maintenance and Rehabilitation of Pavements and Technological Control (MAIREPAV6)International Society for Maintenance and Rehabilitation of Transportation InfrastructureTransportation Research Board, 2009
This paper explores the essential work of fracture (EWF) testing method for mixtures as a means t... more This paper explores the essential work of fracture (EWF) testing method for mixtures as a means to further validate its application for asphalt binders. The method is an energy-based testing approach that has been used extensively for the failure characterization of ductile materials. It allows for a direct determination of the essential work required for failure (we), as well as an approximate critical crack tip opening displacement (CTOD), thus providing a measure of strain tolerance in the presence of flaws. Previous studies have shown that the CTOD of the binders correlated well with fatigue performance in various trial pavements and accelerated loading facility (ALF) lanes at the Turner-Fairbank Highway Research Center (TFHRC). This paper documents and discusses the test results for mixture samples as used in the TFHRC ALF lanes. The determination of mixture and CTOD parameters allows for a direct comparison with binder and CTOD parameters as well as in service performance.
Uploads
Papers by Jack Youtcheff