Hyung Suk Lee | Applied Research Associates (original) (raw)
Uploads
Papers by Hyung Suk Lee
Current Situation The relationship between pavement friction and roadway safety may seem obvious:... more Current Situation The relationship between pavement friction and roadway safety may seem obvious: the more friction a roadway provides, the more control a driver will have, and the safer the roadway will be. However, crashes are complex events, and pavement friction is only one factor to consider along with driver distraction, tire wear, braking, visibility, and others. As engineers strive to make highways safer, balancing these factors requires a more precise understanding of the factors that contribute to safety. With friction, this is difficult because the desirable amount of friction itself depends on many factors, such as speed limits, type of traffic, type of road, etc. Most highway authorities use values for desirable friction that have been developed over time, but with changes in scientific methods of analysis as well as methods of design and construction, it is important to revisit issues like this one periodically to bring the latest techniques to bear and develop better ...
Segregation of asphalt mixtures, which denotes the non-uniform distribution of coarse and fine ag... more Segregation of asphalt mixtures, which denotes the non-uniform distribution of coarse and fine aggregate components, either causes short term premature failures or affects the long term pavement performance. Since segregation may result in a significantly altered aggregate structure of an asphalt mixture, it may increase the potential for rutting, among all other distresses. In this study, the effect of segregation or change in aggregate gradation that may negatively influence the rutting potential of asphalt mixtures was evaluated. The Dominant Aggregate Size Range (DASR) gradation model and the DASR porosity parameter, which have previously been identified to be well correlated with rutting performance, were used to identify the potential degradation of rutting performance due to segregation. A total of four roadway sections with different severity levels of segregation were selected and evaluated. The analysis results of mixture gradation, volumetric properties, and DASR porosity...
Journal of Engineering Mechanics, 2010
Economics, and environmental issues have spurred the introduction of the Warm Mix Asphalt (WMA) t... more Economics, and environmental issues have spurred the introduction of the Warm Mix Asphalt (WMA) technology in the pavement construction industry. The Florida Department of Transportation (FDOT) started using the WMA technology in 2006 based on reported benefits due to lower asphalt mixing and compaction temperatures. Limited field and laboratory studies have indicated that WMA may have similar performance as traditional Hot Mix Asphalt (HMA). However, some studies have also suggested that the use of WMA may increase long-term rutting and stripping potential and hence the long-term performance evaluation of the WMA mixtures is still warranted. With the primary objective of obtaining long-term field performance data of Florida’s WMA, the respective field performance of six representative WMA projects using five different technologies (one additive and four water foaming technologies) was monitored and documented in this paper. The performance of the WMA projects was then compared to t...
Current Situation The relationship between pavement friction and roadway safety may seem obvious:... more Current Situation The relationship between pavement friction and roadway safety may seem obvious: the more friction a roadway provides, the more control a driver will have, and the safer the roadway will be. However, crashes are complex events, and pavement friction is only one factor to consider along with driver distraction, tire wear, braking, visibility, and others. As engineers strive to make highways safer, balancing these factors requires a more precise understanding of the factors that contribute to safety. With friction, this is difficult because the desirable amount of friction itself depends on many factors, such as speed limits, type of traffic, type of road, etc. Most highway authorities use values for desirable friction that have been developed over time, but with changes in scientific methods of analysis as well as methods of design and construction, it is important to revisit issues like this one periodically to bring the latest techniques to bear and develop better ...
Segregation of asphalt mixtures, which denotes the non-uniform distribution of coarse and fine ag... more Segregation of asphalt mixtures, which denotes the non-uniform distribution of coarse and fine aggregate components, either causes short term premature failures or affects the long term pavement performance. Since segregation may result in a significantly altered aggregate structure of an asphalt mixture, it may increase the potential for rutting, among all other distresses. In this study, the effect of segregation or change in aggregate gradation that may negatively influence the rutting potential of asphalt mixtures was evaluated. The Dominant Aggregate Size Range (DASR) gradation model and the DASR porosity parameter, which have previously been identified to be well correlated with rutting performance, were used to identify the potential degradation of rutting performance due to segregation. A total of four roadway sections with different severity levels of segregation were selected and evaluated. The analysis results of mixture gradation, volumetric properties, and DASR porosity...
Journal of Engineering Mechanics, 2010
Economics, and environmental issues have spurred the introduction of the Warm Mix Asphalt (WMA) t... more Economics, and environmental issues have spurred the introduction of the Warm Mix Asphalt (WMA) technology in the pavement construction industry. The Florida Department of Transportation (FDOT) started using the WMA technology in 2006 based on reported benefits due to lower asphalt mixing and compaction temperatures. Limited field and laboratory studies have indicated that WMA may have similar performance as traditional Hot Mix Asphalt (HMA). However, some studies have also suggested that the use of WMA may increase long-term rutting and stripping potential and hence the long-term performance evaluation of the WMA mixtures is still warranted. With the primary objective of obtaining long-term field performance data of Florida’s WMA, the respective field performance of six representative WMA projects using five different technologies (one additive and four water foaming technologies) was monitored and documented in this paper. The performance of the WMA projects was then compared to t...