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
제22권 제1호 (2020년 2월) 12건
1.
2020.02
구독 인증기관 무료, 개인회원 유료
PURPOSES: Investigating road pavement conditions using an investigation vehicle is challenging especially if repeated driving is required on the by-lane, and the traffic in the investigation section is heavy. A technology used to investigate the road pavement conditions is studied herein using image data obtained by drone photography.
METHODS : Flight plans were made for the survey areas, and ground control point measurements were performed. The research section was filmed using drones. The acquired image data were modeled using Pix4Dmapper. The images taken by the drones were used to investigate the road pavement cracks. A digital surface model was extracted from the Pix4Dmapper modeling results using the Global Mapper program to investigate plastic deformation and flatness. As regards plastic deformation, the elevation of each point was extracted at intervals of 50 cm and 10 cm in the longitudinal and lateral directions, respectively, for 20 m× 10 m of the entire road. In terms of flatness, the elevation values for each point were extracted at intervals of 5 cm and 10 cm for the wheel path and 20 m for the entire roadway.
RESULTS: This study compared drone-captured images, which were consistent, and vehicle scan images and confirmed that the former can detect a large number of cracks on road surfaces. The results showing the difference in the elevation values of the road surface indicate that the section, wherein the plastic deformation occurs throughout the entire road surface, can be identified and evaluated. With regard to flatness, in future studies, the long-directional elevation value of the target segment extracted using Global Mapper is likely to be derived from the International roughness index, which is the international flatness index used in the ProVAL program developed and used by the Federal Highway Administration.
CONCLUSIONS : The road pavement status investigation conducted herein by utilizing drone-acquired images showed that repeated driving in a section is not required, and various analyses can be made in a single shot. If technologies, such as artificial intelligence, big data, and Internet of Things, which are the key components of the Fourth Industrial Revolution, are adapted, they can be used to investigate road pavement conditions and inspect completely constructed road lines and major road facilities.
4,000원
2.
2020.02
구독 인증기관 무료, 개인회원 유료
PURPOSES : In many European countries, the fine-size exposed aggregate concrete pavement (EACP) technique has been adopted for a quiet pavement. However, different noise reduction levels were reported based on the mixture design and texture conditions. This study aims to suggest a quality control condition for achieving low-noise texture and a mixture design procedure for exposed aggregate concrete overlay (EACO), which will provide the optimum mixture of the surface texture that can reduce the tire-pavement noise.
METHODS : The tire-pavement noise is highly influenced by the pavement surface texture. The surface texture of the EACP can be quantified by the mean texture depth (MTD) and the exposed aggregate number (EAN). The optimum condition for the low-noise texture of the EACP was investigated herein based on the analysis of the review of the texture conditions and noise measurement in many EACP sites.
RESULTS : The MTD and EAN criteria can be derived according to the investigated relationship between noise and texture condition. The optimum mixture design to satisfy these criteria can be achieved by controlling the maximum size of the coarse aggregate and the S/a.
CONCLUSIONS: This study aimed to suggest a quality control condition for achieving low-noise texture and an optimum mixture design for EACO. As a result, we found that the early traffic opening of EACO can be achieved by using high early-strength cement.
4,200원
3.
2020.02
구독 인증기관 무료, 개인회원 유료
PURPOSES: The noise problem in concrete pavements has an adverse effect to the road user or nearby residents and is generated by the contact between a tire and the pavement surface. Exposed aggregate concrete pavements have been adopted to solve the tire-pavement noise problem in the United States and Europe. However, the efficiency of the coagulation retarder and exposure equipment used for this kind of pavement has not yet been investigated. Therefore, this study aims to evaluate the ability of the coagulation retarder and exposure equipment in producing the optimum exposed aggregate texture to achieve low pavement noise. A method for the exposure time selection has also been introduced here.
METHODS: Sodium gluconate retarders were selected for use in this study. The retarder-water ratios of 1:1, 1:2, and 1:3 were investigated. The retarder was sprayed on a fresh concrete surface with rates of 200 g/m2, 300 g/m2, and 400 g/m2. The aggregates were then exposed to the surface using a steel brush and a water jet. The efficiencies for the low-noise texture, workability, and environmental impact produced by the two exposure devices were estimated. The EAN and the MTD were investigated according to the exposure time.
RESULTS : The aggregates were exposed after the retarder was sprayed on the fresh concrete surface; the exposure lasted for 18 h to 26 h each time. The retarder-water ratio of 1:2 and the spraying rate of 300 g/m2 produced an optimum surface texture for low noise. Additionally, the steel brush performed more effectively in exposing aggregate to the surface compared to the water jet. The selected exposure time window (ETW) was 28 h to 35 h.
CONCLUSIONS : The optimum retarder was the sodium gluconate retarder with a retarder-water ratio of 1:2 and a spraying rate of 300 g/m2. The steel brush showed a good performance in exposing the aggregates and showing the efficiency of the coagulation retarder in the given environment so as to produce the quality control condition. The ETW was influenced by the construction, mixture design, and construction environment; however, the selected ETW in this study was 26 h~35 h.
4,000원
4.
2020.02
구독 인증기관 무료, 개인회원 유료
PURPOSES: The intensiveness of highway management has increased owing to the growth in the number of vehicles and the rapid climate change. The disadvantages produced by these factors can affect management time and cost. Serious traffic accidents and traffic jam may be experienced when snow fall accumulates on highway surfaces and the friction between tires and pavements is lower than that in the general state, in a non-management condition. Such conditions need intensive management. In this regard, one of the spread methods used for the melting material is pre-wetted salt (PWS), which is the frequently used method in South Korea. In the PWS method, the solid material with CaCl2 is mixed with water in 30% concentration and then finally mixed with NaCl before application to pavements. The chloride-type melting material not only is cheaper, but also has a high melting property than the others. It can shorten the pavement or structure life by deterioration and corrosion. This melting material can affect the flora near the highways; hence, an eco-friendly de-icing agent must be utilized considering the environmental effect.
METHODS : The Kalman filter algorithm (KFA) was utilized herein to develop optimization models using the performed test data. The KFA, which was developed from recursive filter algorithms, such as the low- and high-pass filters, applies a weighting filter to the Kalman filter. The algorithm has the property of utilizing the filter and updated estimations. In this regard, melting tests were performed for the real applicative utilization of de-icing agents. The KFA was also applied to reduce the error rates and optimize the relationships between the test data and the predictions.
RESULTS: Comparing the measurements performed, the error was reduced by 1.69 g when the KFA was applied. Moreover, the error can be optimized to approximately 91.4% compared to the test errors. The prediction data had over 85% tendency in the test measurement, showing that the KFA application can reduce the error and increase the tendency. By comparison, the agent with CaCl2 showed the best ice melting performance within 10 min without surface temperature. However, the PWS with a 25% concentration indicated the best water melting performance from start to end of the test time, implying that this is a powerful agent in terms of performance.
CONCLUSIONS : The melting test is an artificial test method; therefore, it can generate a huge error from the test. The error and the tendency can be controlled by tracking the measurement error and the white noise matrix using the KFA. A further research will be performed to track the measurement error and the white noise matrix. Other optimization methods will also be applied to reduce the experimental error.
4,000원
5.
2020.02
구독 인증기관 무료, 개인회원 유료
PURPOSES : This study investigates the abrasion characteristics of coarse aggregate using the Los Angeles (L.A.) abrasion test and the accelerated polishing machine (APM) test. The coarse aggregates are randomly exposed on the surface of asphalt concrete pavements and on exposed aggregate concrete pavements. The exposed aggregates play a very important role in providing skid resistance. Therefore, the adequate abrasion resistance of coarse aggregate must be ensured to maintain the skid resistance during service life. In Korea, the LA abrasion test is conducted according to the KS F 2508 standard for the evaluation of the abrasion resistance of coarse aggregate. However, the road surface abrasion is caused by the friction between the tire and the road surface structure; hence, whether the LA abrasion test, which evaluates the abrasion caused by the impact of coarse aggregates and steel balls, can evaluate the road surface abrasion is questionable. A comparison and an analysis between the APM and LA abrasion tests were conducted herein to evaluate the road abrasion. An analysis was also performed to analyze whether the abrasion characteristics appeared depending on the type of coarse aggregate.
METHODS: The results of the APM and LA abrasion tests for various aggregate types were obtained through a series of experiments and literature reviews. The correlation between the LA abrasion loss and the PV data was derived. In addition, the influence of the aggregate type on the abrasion resistance was investigated.
RESULTS : An abrasion resistance database was established, and the relationship between the rock types and the abrasion resistance was statistically determined. The results showed that the PV was increased to 0.54 along with a 1% increasing rate of the LA abrasion loss with a 0.67 coefficient of determination. The abrasion resistance was also influenced by the aggregate type, which was found to be statistically significant.
CONCLUSIONS: A good relationship between the PV and the LA abrasion loss was obtained, allowing the use of the LA abrasion test (KS F 2508) alone, to reasonably evaluate the abrasion resistance of the exposed aggregate texture. The aggregate types were also found to have an impact on the abrasion resistance.
4,000원
6.
2020.02
구독 인증기관 무료, 개인회원 유료
PURPOSES: Knowing the scope of deterioration of the concrete slab around spalling is important in determining the size of the partial-depth repair. The change in the material properties of the concrete slab, according to the severity of spalling and distance from spalling, is analyzed herein by performing non-destructive and destructive tests at the field and in the laboratory.
METHODS: The test slabs were determined by finding spallings with high or medium severity. The relative elastic modulus was measured near the spalling, far from spalling, and around the slab center using an impact echo equipment. The core specimens were obtained at the measurement positions. An absorption test was performed for the core specimens, while the impact echo and dynamic modulus tests were performed for the upper and lower parts of the core specimens under dry or saturated conditions. A compressive strength test was also performed for the upper and lower parts of the core specimens.
RESULTS : The absorption coefficient, relative elastic modulus, relative dynamic modulus, and relative compressive strength worsened as the measurement position became closer to the spalling distress and top of the slab. The worse material properties were measured for the spalling with a higher severity. The moisture condition of the specimens scarcely affected the material properties.
CONCLUSIONS : The impact echo test results obtained at the field showed a high correlation with the results of the absorption, impact echo, dynamic modulus, and compressive strength tests performed in the laboratory. Accordingly, a quicker and a more convenient nondestructive soundness evaluation of concrete pavements is expected to be realized using the field impact echo test method.
4,200원
7.
2020.02
구독 인증기관 무료, 개인회원 유료
PURPOSES: Nitrogen oxide (NOx) is a particulate matter precursor, which is a harmful gas contributing to air pollution and causes acid rain. The approaching methods for NOx removal from the air are the focus of numerous researchers worldwide. Titanium dioxide (TiO2) and activated carbon are particularly useful materials for NOx removal. The mechanism of NOx elimination by using TiO2 requires sunlight for a photocatalytic reaction, while activated carbon absorbs the NOx particle into the pore itself after contact with the atmosphere. The mixing method of these two materials with concrete, coating, and penetration methods on the surface is an alternative method for NOx removal. However, this mixing method is not as efficient as the coating and penetration methods because the TiO2 and the activated carbon inside the concrete cannot come in contact with sunlight and air, respectively. Hence, the coating and penetration methods may be effective solutions for directly exposing these materials to the environment. However, the coating method requires surface pretreatment, such as milling, prior to securing contact, and this may not satisfy economic considerations. Therefore, this study aims to apply TiO2 and activated carbon on the concrete surface by using the penetration method.
METHODS : Surface penetrants, namely silane siloxane and silicate, were used in this study. Photocatalyst TiO2 and adsorbent activated carbons were selected. TiO2 was formed by the crystal structures of anatase and rutile, while the activated carbons were plant- and coal-type materials. Each penetrant was mixed with each particulate matter reductant. The mixtures were sprayed on the concrete surface using concentration ratios of 8:2 and 9:1. A scanning electron microscopy with energy dispersive X-ray equipment was employed to measure the penetration depth of each specimen. The optimum concentration ratio was selected based on the penetration depth.
RESULTS: TiO2 and activated carbon were penetrated within 1 mm from the concrete surface. This TiO2 distribution was acceptable because TiO2 and activated carbon locate to where they can directly come in contact with sunlight and air pollutant, respectively. Infiltration to the concrete surface was easily achieved because the concrete voids were bigger than the nanosized TiO2 and microsized activated carbon. The amount of penetration for each particulate matter reductant was measured from the concrete surface to a certain depth.
CONCLUSIONS : The mass ratio on the surface can be predicted from the mass ratio of the particulate matter reductant measurement distributed through the penetration depth. The optimum mass ratio was also presented. Moreover, the mixtures of TiO2 with silane siloxane and activated carbon with silicate were recommended with an 8:2 concentration ratio.
4,900원
8.
2020.02
구독 인증기관 무료, 개인회원 유료
PURPOSES: This study aims to evaluate the resistance to chemical attack of combined organic and inorganic hybrid mortars as the repair materials (i.e., HRM mortar) used for concrete road facilities through a comparison with mortars made from cement repair materials (i.e., IRM mortar).
METHODS: Inorganic materials used as a binder and two mineral fillers were adopted to produce HRM mortars. The ratio of the main resin versus the hardener was fixed at 2:1. For comparison, IRM mortars made of cement repair materials were also manufactured. The mortars were exposed to chemical solutions, such as NaCl, MgSO4, Na2SO4, and H2SO4, with the same concentration of 5% after 7 days of curing. The compressive strength, compressive strength loss, mass ratio, and relative bulk density of the mortar samples exposed to the chemical solutions were measured at predetermined periods. In addition, a scanning electron microscope observation was performed to evaluate the microstructures and the products formed by the chemical reaction of the mortar samples.
RESULTS : As a result, the resistance to chemical attack of the HRM mortars was found to be much better than that of the IRM mortars, regardless of the types of attacking sources. This finding implies that HRM is a highly promising and versatile material because of its excellent resistance to chemical attack.
CONCLUSIONS: The application of the combined organic and inorganic hybrid mortars is a possible option for repair of concrete road facilities exposed to aggressive environments.
4,000원
9.
2020.02
구독 인증기관 무료, 개인회원 유료
PURPOSES: In this study, a method of maximizing visibility by effectively installing rear reflectors on freight cars was analyzed to reduce traffic accidents caused by poor visibility of trucks at night.
METHODS: Comparisons were made when a (1) rear reflector, (2) rear reflector and line contour, and (3) rear reflector and full contour were installed in a truck using virtual driving simulation. The safety level of each installation method was quantitatively analyzed by selecting the cognitive distance, safe distance maintenance, and deceleration in the case of using stone embankment as an effective safety measure.
RESULTS : When the rear reflector and full contour was installed, the cognitive range was the longest, and the safety distance could be maintained for a relatively long time. In addition, it was possible to stop or avoid a collision when a sudden event occurred.
CONCLUSIONS: The severity of rear-end crash with freight cars is very high at night, mostly because drivers are unaware of the freight car ahead. Accidents can be prevented if drivers can recognize cargo trucks. Based on the results of this study, the installation of a truck's rear reflector and full contour system will enhance night visibility, and the number of traffic accidents will also decrease.
4,000원
10.
2020.02
구독 인증기관 무료, 개인회원 유료
PURPOSES : The purpose of this study is to analyze the improvement effect of the distributed arrangement of a vehicle base, which is a policy on maximizing the cost efficiency and timely/spatial effectiveness of special transportation system (STS) operation for improving the mobility of the elderly and disabled.
METHODS: (1) The characteristics of the current distributed arrangement of an STS vehicle base in an urban area was analyzed. (2) The quantitative improvement effect was derived by analyzing the actual measurement of operation during STS distributed arrangement test operation in Namyangju city.
RESULTS : (1) Cities with large area and populations, which have a distributed living zone in an urban area, have a higher distributed arrangement ratio than urbanized smaller cities. (2) Based on the effectiveness analysis of the STS distributed arrangement test operation, the total travel time and distance decreased.
CONCLUSIONS : (1) For the STS distributed arrangement, parking spots, driver standby, and restrooms must be prepared. Facilitating STS as a public institution consignment makes it easier to secure a vehicle base and management by utilizing public facilities. (2) Implementing the STS distributed arrangement of vehicle base allows for efficient response to demand through effective management of vehicles, which eventually decreases travel time and distance. This decrease not only reduces management costs but also increases supply expansion without an increase in the number of vehicles.
4,000원
11.
2020.02
구독 인증기관 무료, 개인회원 유료
PURPOSES : This study aims to investigate the effect of the propagation time of variable message sign (VMS) information and drivers’ detour rate on the VMS performance under non-recurrent traffic states.
METHODS: A microscopic simulation model (i.e., VISSIM and VISSIM COM User Interface) was developed at a location where VMS messages were most frequently displaced in 2018 from the Busan Regional Construction and Management Administration. The non-recurrent traffic states realized in this study were one- and two-lane close cases with scenarios involving multiple propagation times from 0 min to 20 min in 2 min increments and detour rates from 0% to 50%, in 10% increments. The measures of effectiveness are the average delay per vehicle, total travel time, and reduction rate of the total travel time based on the average value of 30 multiple simulation runs for individual scenarios.
RESULTS:For the one- and two-lane close cases, the reduction rate of the total travel time increased as the propagation time shortened and the detour rate became bigger. The optimal (i.e., 0 min propagation time and 50% detour rate) and worst (i.e., 20 min propagation time and 10% detour rate) scenarios produced 41.1% (8.9 h) and 6.4% (1.4 h) and 26.4% (86.5 h) and 1.4% (4.7 h) of the total travel time for the one- and twolane close cases, respectively.
CONCLUSIONS : The study results implied that the late propagation time and the low detour rate might not significantly influence the VMS system. Therefore, it is important to improve the information process time for the shorter propagation time and the reliability of the VMS information for a higher detour rate, which will result in a better VMS system performance.
4,000원
12.
2020.02
구독 인증기관 무료, 개인회원 유료
PURPOSES: This paper presents the development and evaluation of the smart hardware-in-the-loop systems (SMART-HILS) that evaluate traffic signal operations of a new real-time traffic signal control system called SMART SIGNAL at the traffic management center (TMC) level.
METHODS: The layouts of the hardware and software components of the SMART-HILS were introduced in this study and its performance was tested using real-time traffic signal operation algorithms embedded in the SMART SIGNAL control server by utilizing the VISSIM simulation model. In this study, the SMART-HILS management software was developed using .NET programming language. Fewer random seed numbers were used for the test scenarios by conducting statistical tests to address the shortcomings of a longer time due to the adoption of the simulation time as the real-time by the TMC server.
RESULTS : It was determined that SMART-HILS can communicate with TMC and VISSIM for both upload and download directions within acceptable time constraints and evaluate new design algorithms for traffic signal timing.
CONCLUSIONS : In practice, traffic engineers can utilize SMART-HILS for testing the traffic signal operation alternatives before their selection and implementation. This application could increase the productivity of traffic signal operation.
4,000원
