간행물
한국도로학회논문집 KCI 등재 International journal of highway engineering
- 발행기관 한국도로학회
- 자료유형 학술지
- 간기 격월간
- ISSN 1738-7159 (Print)2287-3678 (Online)
- 수록기간 1999 ~ 2024
- 주제분류 공학 > 토목공학 공학 분류의 다른 간행물
- 십진분류KDC 534DDC 625
권호리스트/논문검색
제21권 제4호 (2019년 8월) 11건
도로 포장 및 시설
1.
2019.08
구독 인증기관 무료, 개인회원 유료
PURPOSES: Spalling is one of the primary problems that lead to the damage of concrete pavements. The purpose of the study is to analyze the impact range of spalling that occurred in an area of concrete pavement by applying a variety of nondestructive and destructive testing methods.
METHODS: Spalling of the concrete pavement was categorized into four different sizes, 0 cm, 7.5 cm, 15 cm, and 30 cm. Nondestructive and destructive tests were performed at the point of spalling and 1 m away, respectively, and the obtained results were compared. The nondestructive tests included the electrical resistance test and the ultrasonic velocity test as well as strength tests by Schmidt hammer and concrete tester. The destructive tests included the direct compressive strength test and the chloride content test using field cored specimens. The test results helped in the analysis of the correlation between the current spalling damage condition and the expected damage acceleration.
RESULTS: Based on the present study, the repair area and depth of spalling for a partial depth repair was suggested. It was also shown that the size of the spalling is highly correlated with the chloride content and the electrical resistance of the concrete pavement.
CONCLUSIONS: The degree of spalling deterioration was found to be highly correlated with the chloride content and electrical resistance of the concrete pavement and based on the results, the extent of repair could be determined more quantitatively.
4,000원
2.
2019.08
구독 인증기관 무료, 개인회원 유료
PURPOSES : This paper is aimed at suggesting a novel approach for determining the pavement condition rating based on the tire-surface friction noise using a machine learning algorithm as a low-end pavement condition monitoring system.
METHODS : Vehicle on-board type noise measurement system according to the ISO11819-2, and the K-nearest neighbors with dynamic time warping algorithm were applied. The system and algorithm were empirically tested with a field study.
RESULTS : The developed AI- and noise-based pavement condition monitoring system demonstrated significantly positive results with a precision 90.8%, recall 84.8%, and f1-score 86.1%.
CONCLUSIONS: We herein confirmed that the acoustic property between the tire and road surface can be used for monitoring pavement conditions. It is believed this finding presented a new paradigm for monitoring pavement conditions based on visual information. However, extensive studies focused on the practical application of this method are required.
4,000원
3.
2019.08
구독 인증기관 무료, 개인회원 유료
PURPOSES: The objective of this study is to evaluate the structural capacity of asphalt pavement in subsurface cavity sections using falling weight deflectometer (FWD) backcalculation method.
METHODS: It is necessary to analyze the reduction of structural capacity in asphalt pavements due to the occurrence of subsurface cavities. The FWD testing was conducted on the cavity and intact asphalt pavement in the city of Seoul. The GAPAVE, backcalculation program for FWD deflections, was utilized to determine the layer moduli in asphalt pavements. The remaining life of asphalt pavements in cavity sections were predicted using the pavement performance model for fatigue cracking. The backcalculated layer moduli between cavity and intact sections were compared to determine the reduction of structural capacity due to subsurface cavity. The relationship between the reduction of layer modulus and cavity depth/length was analyzed to estimate the effect of cavity characteristics on the structural capacity degradation.
RESULTS: According to the FWD backcalculation results, the modulus of asphalt layer, subbase, and subgrade in cavity sections are generally lower than those in intact sections. In the case of asphalt layers, the backcalculated modulus in cavity section was reduced by 50% compared to intact section. A study for the prediction of remaining life of cavity section shows that the occurrence of subsurface cavity induces the decrease of the pavement life significantly. It is found that there is no close relationship between the backcalculated modulus and cavity length. However, the reduction of asphalt layer modulus is highly correlated with the cavity depth and was found to increase with the decrease of cavity depth.
CONCLUSIONS : This reduction of structural capacity due to the occurrence of cavities underneath asphalt pavements was determined using FWD backcalculation analysis. In the future, this approach will be utilized to establish the criteria of road collapse risk and predict the remaining life of cavity sections under numerous varied conditions.
4,000원
4.
2019.08
구독 인증기관 무료, 개인회원 유료
PURPOSES : The recent increase in the application of reclaimed asphalt pavement (RAP) calls for more research focusing the evaluation of pavement performance. For this matter, this study aims at evaluating pavement performance using the application rate of RAP.
METHODS: To obtain mixtures with RAP aggregate application rates of 10%, 25% and 30%, the gyratory compaction method was applied regarding the mix design process for determining the optimum asphalt content (OAC). Additionally, the in-direct tension (IDT) test, deformation strength test (DST), tensile strength ratio (TSR) test and dynamic modulus (DM) test were conducted to verify the effect of RAP application rate on pavement performance. Based on the above-mentioned results, performance evaluation was done to these RAP application of design or utilization to construction site. The performance evaluation analysis was performed using the Korean Pavement Research Program (KPRP) of second level for the pavement design.
RESULTS: From the DST results, the rutting resistance was improved as the application rates of RAP were increased. Additionally, all the IDT and toughness results satisfied the quality standards of the asphalt concrete pavement. However, the results did not conform with the tensile strength ratio standards with the application rates of RAP of 25% and 30%. This means that the standards, which should be considered when the addictive regeneration material is applied to the mixture when the RAP application rate is over 25%, were reflected.
CONCLUSIONS : The predicted performance decreased from the second level performance analysis with the increase in the RAP application rates. All the cases satisfied the design standards (fatigue cracking, rutting depth and international roughness index (IRI)). However, the results of them closed to these standards (up to 94% (Fatigue)).
4,000원
5.
2019.08
구독 인증기관 무료, 개인회원 유료
PURPOSES : This study is aimed at developing an asphalt pavement material with high elasticity and watertight through mix design and laboratory tests.
METHODS: High elastic (HE) asphalt modifier blended of thermoplastic elastomer, naphthene oil, mineral fiber and organic vulcanization accelerator was developed. Mix design was done to determine the aggregate gradation and optimum asphalt content for making high elastic and watertight asphalt mixture. Performance grade test of HE-modified asphalt binder as well as asphalt mixture tests, which include the tensile strength ratio test, Hamburg wheel tracking test, third-scale model mobile loading simulator(MMLS-3) test, four-point flexural fatigue test, and Texas reflection crack test were conducted to evaluate the characteristics of the HE-modified asphalt mixture.
RESULTS: 7.7% optimum binder content was determined through the mix design, which met the quality criteria of Marshall asphalt mixture. The binder test indicated that the grade of the HE-modified asphalt was PG76-28. The results of the mixture tests indicated a tensile strength ratio of 0.92 and a rut depth of 6.2 mm at 20,000 cycles of Hamburg Wheel-Tracking Test. The asphalt mixture test also showed that the rut depth of HE-modified mixture was 39% less than that of Guss asphalt mixture. The crack resistance of the HE-modified mixture was 1.65 times higher than that of the Guss asphalt mixture from the Texas reflection crack test results.
CONCLUSIONS: It can therefore be reasonable that HE-modified asphalt mixture is used as an intermediate layer in the asphalt overlay on concrete pavements. Additionally, the HE-modified asphalt mixture can be used for the asphalt pavement materials with high performance and watertight.
4,000원
6.
2019.08
구독 인증기관 무료, 개인회원 유료
PURPOSES : It is well known that low temperature cracking is one of the most serious distresses on asphalt pavement, especially for northern U.S. (including Alaska), Canada and the northern part of south Korea. The risk of thermal cracking can be numerically measured by estimating thermal stress of a given asphalt mixture. This thermal stress can be computed by low temperature creep testing. Currently, in-direct tensile (IDT) mixture creep test mentioned in AASHTO specification is used for measuring low temperature creep properties of a given asphalt mixture. However, IDT requires the use of expensive testing equipment for performing the sophisticated analysis process, however, very few laboratories utilize this equipment. In this paper, a new and simple performance test (SPT) method: bending beam rheometer (BBR) mixture creep testing equipment is introduced, and the estimated experimental results were compared with those of conventional IDT tests.
METHODS: Three different asphalt mixtures containing reclaimed asphalt pavement (RAP) and roofing shingles were prepared in the Korea Expressway Corporation (KEC) research laboratory. Using the BBR and IDT, the low temperature creep stiffness data were measured and subsequently computed. Using a simple power-law function, the creep stiffness data were converted into relaxation modulus, and subsequently compared. Finally, thermal stress results were computed from relaxation modulus master curve using Gaussian quadrature approach with condierations of 24 Gauss number.
RESULTS: In the case of the conventional asphalt mixture, similar trends were observed when the relaxation modulus and thermal stress results were compared. In the case of RAP and Shingle added mixtures, relatively different computation results were obtained. It can be estimated that different experimental surroundings and specimen sizes affected the results.
CONCLUSIONS: It can be said that the BBR mixture creep test can be a more viable approach for measuring low temperature properties of asphalt mixture compared to expensive and complex IDT testing methods. However, more extensive research and analysis are required to further verify the feasibility of the BBR mixture creep test.
4,000원
7.
2019.08
구독 인증기관 무료, 개인회원 유료
PURPOSES: The objective of this study is to evaluate and compare the stiffness characteristics and seasonal variation in surface deflections of block and asphalt pavements using the light weight deflectometer (LWD) and falling weight deflectometer (FWD).
METHODS: LWD and FWD testing was conducted on block and asphalt pavement sections in a low-impact development facility, to evaluate the structural capacity and seasonal variation in asphalt pavements. To analyze the seasonal variation in stiffness characteristics, this testing was performed in October 2016, January 2017, and March 2017 in the same drop locations.
RESULTS : It was found from that the average center deflections in the asphalt and block pavements were 218 ㎛ and 2974 ㎛, respectively. The center deflections measured using FWD testing in block pavement are 15 times those measured in asphalt pavement. It was also observed that LWD deflections in block pavements were decreased by approximately 65-90% as the air temperature dropped from 20 to 4℃. The degree of reduction in block pavement was significantly higher when compared with asphalt pavement, which showed a 25- 50% reduction in deflection.
CONCLUSIONS: When using block pavements for roadways, the structural capacity of the pavement system should be considered during the design and construction stages. In block pavements, the use of low-quality material and insufficient compaction in the base and subgrade layers can induce a reduction in structural capacity, which would lead to the need for frequent repair work. A reinforcement underneath the block layer would be an appropriate measure for improving the structural support and extending the service life.
4,000원
도로교통체계
8.
2019.08
구독 인증기관 무료, 개인회원 유료
PURPOSES : The purpose of this study is to find out how to perform a visual-based conjoint analysis of signs, specifically for those in subway systems.
METHODS: To identify the current problems with signs, we conducted installation case studies on subway signs and developed visualized materials for survey. The visualized survey cards were used to record the subjects’preferences in the conjoint analysis.
RESULTS: Based on the current problems of sign, we developed the profile cards and used the visualized survey cards to conduct the survey for conjoint analysis. From the conjoint analysis using the visualized survey cards, it was found that the values of Pearson’s R and Kendall’s tau are close to 1. This suggests that our model is a very fitted model for conjoint analysis.
CONCLUSIONS: We concluded that a conjoint analysis of subway signs could be reliably performed by using visualized survey cards.
4,300원
9.
2019.08
구독 인증기관 무료, 개인회원 유료
PURPOSES: We studied the signal operation method with a focus on swift evacuation of people from disaster-affected urban areas.
METHODS: We selected Yeouido, which is at a high risk of being affected by natural disasters, as the urban area in our study. The analysis time for the Yeouido network was divided into four stages of six hours each, based on the traffic characteristics. The disaster scenarios were divided into small-scale and large-scale, and the analysis time and the disaster scale were set as the variables.
RESULTS: From the analysis, it was found that the evacuation efficiencies were similar in the cases of entry control and increasing the green light duration for the main direction. However, the most effective approach is to apply entry control in case of disasters occurring at dawn and in the evening, with relatively low traffic volume. The most effective method is to increase the green light duration for the main direction of the main line in the time zone.
CONCLUSIONS: As the scale of the disaster and the traffic volume increase, there is a limit on the extent to which the evacuation time could be reduced through signal operation. Therefore, signal control is most effective when the traffic volume is low and the disaster scale is small.
4,500원
10.
2019.08
구독 인증기관 무료, 개인회원 유료
PURPOSES: The purpose of this study is to identify the key factors that influence a driver’s trust in road-freezing risk information
METHODS : A survey was designed and conducted in the metropolitan area to analyze drivers’perception towards road-freezing risk information. A binary logistic regression model was developed based on the survey responses. The statistically significant model coefficients were determined and their odds ratios were calculated. Finally, they were considered as the key factors influencing drivers’trust in roadfreezing risk information.
RESULTS : The developed binary logistic regression model was validated through statistical tests. The final results indicated that previous experiences of accidents on slippery roads, as well as route choice patterns are statistically significant, having 95% confidence levels.
CONCLUSIONS : Previous experiences of accidents on slippery roads and road choice patterns are the factors that most significantly influence drivers’trust in road-freezing risk information. The findings of this study will be used as fundamental data in establishing tailored road-freezing risk mitigation procedures and services.
4,000원
11.
2019.08
구독 인증기관 무료, 개인회원 유료
PURPOSES: This study presents the results of the collection rate of various road debris dummies using Automated Road Debris Remover System(ROBOS), which is a newly developed automatic road-debris removal system. In addition, for traffic flow safety, appropriate safe deceleration distances for ROBOS are estimated using VISSIM.
METHODS: A total of 12 kinds of road debris dummies were selected based on the opinions of public agencies, and randomly placed on the road. Repeated tests were performed. The road debris dummies were placed on the center of the lane, the shoulders, and the median. During the test, the ROBOS running speed was maintained at 15 km/h for an approximately 10-km-long roadway, and the collection and loading process was performed five times under the same condition. For the simulations, the road debris was assumed to be placed on Lane 1 under different traffic conditions and grades. Multiple simulations were conducted, and the average values were used to obtain appropriate safe deceleration distances for ROBOS.
RESULTS: The dummies were considerably large and heavy, and the collection rate was very high for the very light dummy. The simulation results indicate that during debris collection using ROBOS, when the traffic volume is relatively low, the degree of change in traffic flow is high, and when the traffic flow rate is high, the risk of an accident is also considerable.
CONCLUSIONS : We demonstrated that the debris collection efficiency of ROBOS is very high when the brush-conveyor and vacuum are used simultaneously. Further, when the exact location of road debris on specific lanes and for specific traffic volumes is known, a safe deceleration distance is recommended.
4,000원
