• Journal of the Korea Concrete Institute
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• v.16 no.1 s.79
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• pp.125-129
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• 2004

Hydrating concrete pavement is typically subjected to temperature-induced stresses that drive cracking mechanisms at early concrete ages. Undesired cracking plays a key role in the long-term performance of concrete pavement systems. The loss of support beneath the concrete pavement due to curling caused by temperature changes in the pavement may induce several significant distresses such as punch out pumping, and erosion. The effect of temperature on these distress mechanisms is both significant and intricate. Because thermal conductivity dominates temperature flow in hydrating concrete over time, this material property is back-calculated by transforming governing equation of heat transfer and test data measured in laboratory. Theoretically, the back- calculated thermal conductivity simulates the heat movements in concrete very accurately. Therefore, the back- calculated thermal conductivity can be used to calibrate concrete temperature predicted by models.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.04a
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• pp.469-474
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• 1999

The object of study is analysis to joint crack behavior of cracked joint concrete pavement. In the new constructing concrete pavement, joint crack behavior was compared general joint depth D/4 with joint depth D/3 and D/5 that it's environmental effects changed temperature and humidity. After joint saw cutting joint section was predicted crack at joint depth D/5 test section from the result for monitoring development of crack. In the setting of data logger system of the joint section, it's data compared see with the naked eye. In the research, development of crack at the joint section should effect to joint saw timing latter than joint depth. This performance could be the minimum of deterioration to the early curing. In this research, At new constructing of joint concrete pavement of highway, the monitoring system be setting after finished paving and joint sawing. The system and see with the naked eye could be analysis to pavement behaviors from collecting data at the test section. This system could be monitoring shot term and long term. In this report, joint section of crack behavior analysis used to collected data during a month after paving and joint sawing.

• International Journal of Highway Engineering
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• v.14 no.5
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• pp.57-65
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• 2012

PURPOSES: It is important to consider the long-term performance of concrete pavement, because concrete pavement is more exposed to the various environmental conditions than any other concrete structures. One of the several methods to evaluate the long-term performance of concrete during winter is KS F 2456. Relative dynamic modulus of elasticity shows the resistance to freezing and thawing. METHODS: To measure relative dynamic modulus of elasticity, ultra sonic is generally used. But in this study, to measure the relative dynamic modulus of elasticity, both ultra sonic and shear wave were used and then compared each other. RESULTS: The results from the measurement by ultrasonic wave and shear wave were divided into three types. Type 1 : Specimens are good and relative dynamic modulus of elasticity did not decrease until 300 cycle. Type 2 : The relative dynamic modulus of elasticity decreased from the late cycle.(about 150 cycle later) Type 3 : The relative dynamic modulus of elasticity consistently decreased from the beginning. As a result of ANOVA, there is no difference according to measuring method, in type 2 and 3. But there is a difference according to measuring method, in type 1's relative dynamic modulus of elasticity. CONCLUSIONS: It is proved that shear wave can be used to understand the damage tendency of relative freezing and thawing and to measure the relative dynamic modulus of elasticity.

• International Journal of Highway Engineering
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• v.19 no.2
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• pp.113-126
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• 2017

PURPOSES : This study proposes standards for rural access road pavement section and thickness design considering existing access road construction conditions; the study also proposes a complementary policy that can be used for design convenience. METHODS : Various literature review and case studies had been performed in terms of rural access road section and thickness design, both domestically and internationally, and this was followed by domestic rural access road field surveys. KPRP and KENLAYER were used to analyze the commonalities and predict the remaining life. Data on real cost is used to select an appropriate construction method through economic analysis. RESULTS : The economic efficiency of concrete pavement ($15{\times}15$) was the highest in terms of economic efficiency of performance life and traffic volume. In the case of asphalt pavement, it is considered that the most economical method is to implement micro-surfacing method four times as a preventive maintenance method (once every 10 years and 4.5 years for asphalt concrete pavement and MS construction method, respectively). Repairable asphalt pavement is advantageous for areas where heavy vehicles are expected to pass. In the case of other general areas, it is considered economical to place concrete ($15{\times}15$) pavement. However, as analytical results on its performance life are unavailable, it is to be considered for study in the future. CONCLUSIONS : This study proposed interim design guidelines based on various domestic and international design guidelines and case studies. However, in order to develop the final design criteria applicable to the field, it is necessary to (a) estimate the bearing capacity of the lower level of the pavement at various sites, (b) estimate the daily traffic volume, (c) implement advanced low-cost pavement technologies, and (d) propose maintenance standards and techniques for long-term performance.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.4D
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• pp.345-356
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• 2012

Road pavement requires repetitive maintenance works to maintain satisfactory service level to the public. However, the repetitive maintenance works upon deteriorated pavement structure make negative effects to deterioration speed. It often leads to inefficient use of limited budget. For that reason, the pavements require reconstruction work to recover their original performance. Recently, construction demands in the Korean national highway have already been reached to maximum level, and the aged pavements start to demand much more reconstruction works. However, in the real world, road agencies have often been confused when they determine maintenance design for such aged road sections due to budget constraint. It is because there is no reliable long-term maintenance strategy that supports their decision making. To support their decision making, this paper aimed to suggest the best maintenance strategy considering changing process of pavement performance by repetitive maintenance works. As an analysis method, probability distribution and hazard function to estimate the life expectancy were adopted, and then the results were used for long-term life cycle cost analysis with deterministic or Monte-Carlo method under various scenarios. As an empirical study, the Korean national highway data that has long-maintenance history data since 1986 has been applied. Last, this paper considered quality assurance of maintenance work to improve maintenance quality. These could be important information as a part of long-term maintenance strategy of pavement.

• International Journal of Highway Engineering
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• v.18 no.4
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• pp.9-18
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• 2016

PURPOSES : This study aimed to evaluate the performance of pavement management works and to develop a function for estimating the level of service (LOS) and cost of service (COS) for the systematic and quantitative management of pavement performance in the public sector. METHODS : The International Roughness Index (IRI) was used as the performance index for pavement management. Long-term pavement performance data for a period of 7 years (2007-2014) collected by the National Highway Pavement Management System and historical maintenance budget data published by the South Korean government were used to develop the LOS-COS function. Based on the function, a model for estimating the appropriate budget as well as the network conditions was suggested. RESULTS : There was high degree of correlation between pavement performance and the investment level (R = - 0.74). The developed LOS-COS function suggested that the unit cost to improve the network IRI to 1 m/km was 32.6 billion KRW. Further, the maintenance costs normalized with respect to the LOS levels were LOS-A = 88.2 billion KRW, LOS-B = 55.6 billion KRW, and LOS-C = 23.0 billion KRW. CONCLUSIONS : This study proposes a simple way of developing a LOS-COS function. It also shows how to develop a network budget demand and condition estimation model using the LOS-COS function. In addition, it is the first attempt to evaluate the road maintenance budget in South Korea. It is expected that these results will help in the negotiations between the road managers and budget makers.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.12
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• pp.532-541
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• 2016

The objective of this paper is to support accurate pavement condition assessment and decision of proper maintenance method and time by conducting visual inspection and calculating the remaining life of pavement from falling weight deflectometer(FWD) data. Each was implemented in the same long-term performance pavement(LTPP) sections. Visual inspection was executed to measure pavement condition indices such as crack, rutting and international roughness index(IRI) and the Seoul Pavement Index(SPI) was calculated based on these results. The dynamic modulus was back-calculated from the FWD data. The remaining pavement lives were determined from equivalent single axle loading(ESAL) and FWD data. Correlation of maintenance priority by each result value was examined. Consequently, the correlation between remaining life to Crack and Rutting was higher than the other factors or indicesbecause IRI is not related to FWD value and SPI value consists with IRI value and other indices. The R-square value of correlation of FWD with Crack and Rutting was 0.65, which indicated an insufficient correlation. Consequently, when decision of maintenance of method, time, etc. is determined, FWD data have to be considered with Crack and Rutting because of those relations.

• International Journal of Highway Engineering
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• v.2 no.2
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• pp.139-148
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• 2000

Currently existing Accelerated Pavement Testing (APT) systems developed in several countries have been employed mainly to test the performance of asphalt pavement. Meanwhile, the length of concrete pavement is similar to that of asphalt pavement in expressways of Korea. and is expected to increase due to its durability and compatibility to our weather condition. To meet the society's demand of having our own APT system which can examine the long-term performance of concrete pavement, a contract study to develop Korea Accelerated Loading and Environment Simulator (KALES) for concrete pavement has been performed for 3 years from 1997 through 1999. Through the project, a detailed design was Peformed for the KALES system in which the entire structure of KALES, loading mechanism, wandering mechanism, suspension system, driving system were proposed. Also in advance to design a full-scale KALES system, a sample scale model was manufactured and tested for operating motion and force distribution. It is evident that the proposed prototype KALES system will provide higher degree of traffic simulation and durable operation, based on the satisfactory fatigue analysis.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.42 no.4
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• pp.537-548
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• 2022

It is important to design the pavement thickness considering heavy-duty traffic loads, which can cause excessive stress and strain in the pavement. Port-rear roads and industrial roads have many problems due to early stress in pavement because these have a higher ratio of heavy loads than general roads such as national roads and expressways. Internationally, composite pavement has been widely applied in pavement designs in heavy-duty areas. Composite pavement is established as an economic pavement type that can increase the design life by nearly double compared to that of existing pavement while also decreasing maintenance and user costs. This study suggests a thickness design method for composite pavement using roller-compacted concrete as a base material to ensure long-term serviceability in heavy-duty areas such as port-rear roads and industrial roads. A three-dimensional finite element analysis was conducted to investigate the mechanical behavior and the long-term pavement performance ultimately to suggest a thickness design method that considers changes in the material properties of the roller-compacted concrete (RCC) base layer. In addition, this study presents a user-friendly catalog design method for RCC-base composite pavement considering the concept of linear damage accumulation for each container trailer depending on the season.

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.4
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• pp.633-641
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• 2021

The study performed long-term performacne evaluation on the hot mix asphalt using the steel slag aggregates and Reclaimed Asphalt Pavement (RAP). The laboratory comparative evaluation was conducted between conventional Hot Mix Asphalt (HMA) which is entitled WC-2 and HMA containing steel slag and RAP which is entitled ES WC-2(R). Dynamic stability test, dynamic modulus test, and fatigue crack test were conducted during the comparative evaluation process. The dynamic stability test result showed that ES WC-2(R) was 140% higher than WC-2. It is noted that ES WC-2(R) showed no inflection point whereas WC-2 showed inflection point during the dynamic stability test which implies ES WC-2(R) has the higher moisture susceptability than WC-2. The dynamic modulus of ES WC-2(R) were 342.3%, 486.7%, and 350.0% higher than WC-2 at medium temperature of 21℃, low temperature of -10℃, and high temperature of 38℃ respectively. The test result showed that rutting resistance of ES WC-2(R) is higher than WC-2 at all temperature spectrum. The fatigue resistance of ES WC-2(R) were 31.7%, 325.3%, 899.9% higher at low stress level, medium stress level, and high stress level, respectively. The test result showed that ES WC-2(R) is higher than WC-2 at all stress levels. Based on the laboratory comparative evaluation, The in-situ scale Accelerated Pavement Test (APT) was conducted comparing WC-2 and WC-2(R). APT found that the rutting resistance of WC-2(R) was 45% higher than WC-2.