PURPOSES: This study evaluated the effect of fog seal treatment utilizing an agricultural oil-based asphalt concrete sealant (ABCS) on the long-term performance of an asphalt pavement. METHODS: Fog seal treatment using ABCS was applied on 800 m of the pavement section in the test section with a total length of 2,400 m; the remaining pavement section was not considered for this treatment. A series of laboratory and field tests were conducted on both sections, including a Marshall stability test, penetration test, viscosity test, skid resistance test, and pavement surface macrotexture test. In addition, the pavement condition index (PCI) was determined 8 years after the ABCS application to evaluate the effect of the ABCS treatment on the pavement’s long-term performance. RESULTS : The ABCS-treated section exhibited a PCI of 75, whereas the non-treated section exhibited a value of 64. Furthermore, a MicroPAVERTM‚ pavement management system determined that the pavement deterioration rates (i.e., drops in PCI) were 3.6 and 5.1 per year for the ABCS-treated and non-treated sections, respectively. CONCLUSIONS : The results of the series of laboratory and field tests revealed that the ABCS treatment increased the pavement performance life by approximately 3.5 years.

PURPOSES: This study was conducted to investigate the causes of damage and to suggest proper repair methods for the sections in which a number of transverse cracks and faulting occurred in JCP (Jointed Concrete Pavement) slabs during the early-age performance period. METHODS: Field crack survey, FWD (Falling Weight Deflectometer) investigation, dowel bar installation condition survey, longitudinal profile survey, and in-situ core specimen inspection were conducted. . RESULTS : As a result of the analysis, it was found that there was no decline in the composite modulus of the subgrade reaction (k-value). The dowel bars were properly installed, but the LTE (Load Transfer Efficiency) of the joint and transverse cracks were analyzed to be very low. In addition, it was found that there are voids in the bottom of the slab at the joints and corners. Due to the excessive built-in curling in the early age of concrete pavement construction, upward curling displacement occurred at the joints and corners, resulting in voids at the bottom of the slab. As a result, it was found that transverse cracks occurred due to the defective joint LTE. CONCLUSIONS: Excessive built-in curling can cause early age cracks in the JCP slabs. In order to minimize the occurrence of reflection cracks after the application of the asphalt overlay in the future, concepts of alternative repair methods were proposed.

PURPOSES : The purpose of this study is to evaluate the performance of road stone block pavements using APT (Accelerated Pavement Testing), which can evaluate the short-term pavement performance of a pavement structure for a given traffic load. METHODS : The performance of stone block, concrete block, and asphalt (modified SMA) pavements were evaluated according to the cumulative equivalent load by using APT. The FWD (Falling Weight Deflectometer) test was used to analyze the deflection per unit load. In addition, the plastic settlement was analyzed by transverse profile measurement. RESULTS: The results of the APT of about 197,000 ESALs (Equivalent Single Axle Loads) show that there were no damages in the stone block, concrete block, and asphalt pavement, such as breakage of stone or concrete block, cracking of asphalt, deflection, and plastic settlement of the wheel-pass section. It was analyzed that the bearing capacity of each pavement section did not decrease sharply with increase in cumulative ESAL. The results of plastic settlement analysis show that in the case of asphalt pavement, the plastic settlement steadily progressed from the beginning of the APT, and a settlement of about 4.76 mm occurred. In the case of concrete block and stone block pavements, no significant change occurred after the initial stabilization step, and plastic settlement of about 1.01 mm and 0.17 mm occurred for the concrete block and stone block pavements, respectively. CONCLUSIONS : As a result of the analysis of the bearing capacity and plastic settlement after the APT, the performance of stone pavement was found to be similar to that of asphalt pavement and concrete block pavement. Therefore, it is concluded that stone pavements are applicable for the road pavement system.

PURPOSES: Using recyclable materials in asphalt pavement industry is one of the essential tasks not only for saving construction budgets but also for mitigating environmental pollutions. Over the past decades, several efforts have been made by road maintenance agencies to incorporate various recyclable materials into virgin asphalt paving mixtures. As a result, reclaimed asphalt pavement (RAP), which consists of old pavement material was selected as one of most widely used recyclable materials. In this paper, the effects of using different amounts of single-recycled RAP (SRRAP) and double-recycled RAP (DRRAP) on the low-temperature characteristics of asphalt mixtures were investigated. METHODS: To evaluate the low-temperature characteristics of SRRAP and DRRAP mixtures, two experiments, the bending beam mixture creep test and semicircular bending fracture test were performed. The experimental parameters: creep stiffness, m-value, thermal stress, critical cracking temperature, fracture energy, and fracture toughness were computed then compared. RESULTS : RAP mixtures (SRRAP or DRRAP) showed lower mechanical performance compared with conventional asphalt mixtures. The differences became distinct with increased RAP addition. However, the performance differences between SRRAP and DRRAP mixtures were not significant in all cases, which indicate the possible application of re-recycling technology (DRRAP) in the asphalt pavement industry. CONCLUSIONS : The addition of RAP to virgin asphalt can mitigate low-temperature performance despite the improvement in fracture performance observed in some cases. Therefore, using RAP (SRRAP or DRRAP) mixtures on inter or sublayer construction, but not on the surface layer, is recommended. Moreover, the possibility of applying double-recycling technology in asphalt pavement industry can be introduced in this study because not significant performance differences were found between SRRAP and DRRAP mixtures especially at low temperature.

PURPOSES: The purpose of this study is to determine the effective maintenance method for a deteriorated jointed plain concrete pavement by evaluating the long-term performance of the repaired concrete overlay sections. METHODS: Long-term performance evaluation was conducted for the test section at the intersection between SeoPa and IlDong in National Road No. 37. Firstly, the distress conditions of the concrete pavement, which was constructed in December 2003, were evaluated by referring to the existing report. Secondly, the results of pretreatment, material properties, and initial performance evaluation were analyzed for the overlay test conducted in 2011. Finally, a field survey was carried out using visual inspection and nondestructive testing with a FWD in August 2018, and long-term performance evaluation was conducted for about seven years after maintenance. RESULTS: Visual inspection of the old concrete pavement showed severe damage such as joint spalling and asphalt patching. The cores taken from the old concrete had indirect tensile strength of 2.6-3.8 MPa. It is difficult to determine the freeze-thaw resistance because the average amount of air was only 1.6-2.2%, and spacing factor values were over 400㎛ regardless of location. During maintenance, overlay and partial depth repair were performed by applying three types of overlay materials which are typical in Korea. On the material side, high compressive strength (over 40 MPa) and chlorine ion penetration resistance (less than 1,000 coulomb) at 56 days were achieved. In August 2018, seven years after maintenance, visual inspection and nondestructive testing using FWD were conducted for long-term performance evaluation. Regardless of the maintenance materials, surface deficiencies such as spalling and map cracking occurred extensively near the joint. CONCLUSIONS: In conclusion, if the strength and durability index of aged concrete pavement is low, then it was determined that partial depth repair at the joint is not an effective maintenance alternative. In the case of overlay, the durability of the overlay material is considered the most important factor. In the absence of adequate reinforcement at the joint of the distressed concrete pavement, freeze-thaw damage caused by moisture penetration through the joint and failure of the old concrete are repeated, making it difficult to ensure long-term durability.

PURPOSES: Using recycled asphalt materials (called Reclaimed Asphalt Pavement: RAP) from existing asphalt pavement layers in newly constructed asphalt pavement is an essential option not only for lowering the construction budget but also for mitigating environmental pollution for society. For this reason, many pavement agencies in South Korea, the USA, and Canada have observed the effect of RAP on conventional asphalt pavement to evaluate and set proper material specifications and addable amounts. In this paper, effect of recyclable material on low-temperature performance of asphalt materials was investigated with two different mechanical tests. Among the recyclable material sources, RAP and Taconite Aggregate (TA), which is mainly produced in northern Minnesota (USA), were considered. METHODS : To evaluate the low-temperature mechanical performance of a RAP mixture, two different experimental tests (In-Direct Tensile (IDT) low temperature creep test and Semi-Circular Bending (SCB) test) were considered. The mechanical parameters creep-stiffness, relaxation modulus, fracture energy, and fracture toughness were computed then compared. RESULTS: More brittle characteristics were observed with RAP-added asphalt mixtures compared to the conventional asphalt mixtures, as expected. However, the differences of computed mechanical performances were not significantly distinct for RAP mixtures compared to conventional mixtures when the RAP proportion was around 20%, and with the addition of TA up to 20%. CONCLUSIONS : It can be concluded that up to 20% of RAP addition (along with TA up to 20%) in a virgin asphalt mixture does not provide significant performance reduction. This addable proportion can be viewed as a successful minimum level when considering the addition of RAP to hot-mix asphalt (HMA). Moreover, applying TA with RAP could offer a successful alternative for asphalt recycling and the materials industry.

PURPOSES: The permeable pavement type has been rapidly developed for solving problems regarding traffic noise in the area of housing complex and heavy rainwater drainage in order to account for the climate change. In this regards, the objective of this study is to figure out the characteristics of pavement types. METHODS: The laboratory test for deriving optimum asphalt content (OAC) was conducted using the mixtures of the permeable asphalt surface for the pavement surface from Marshall compaction method. Based on its results, the pavement construction at the test field was conducted. After that, the site performance tests for measuring the traffic noise, strength and permeability were carried out for the relative evaluation in 2 months after the traffic opening. The specific site tests are noble close proximity method (NCPX), Light falling deflectometer test (LFWD) and the compact permeability test. RESULTS : The ordered highest values of the traffic noise level can be found such as normal dense graded asphalt, drainage and porous structure types. In the results from LFWD, the strength values of the porous and drainage asphalt types had been lower, but the strength of normal asphalt structure had relatively stayed high. CONCLUSIONS: The porous structure has been shown to perform significantly better in permeability and noise reduction than others. In addition to this study, the evaluation of the properties and the determination of the optimum thickness for the subgrade course under the porous pavement will be conducted using ground investigation technique in the further research.

The world-wide need to reduce the energy used and the greenhouse gases emitted during cement manufacture has led to the pursuit of more eco-efficient materials, such as ground granulated blastfurnace slag(GGBS) and fly ash. Especially, GGBS is a by-product generated during the manufacture of pig ions. GGBS can be divided into water-cooled slag(WS) and air-cooled slag(AS). With comparison of WS, the AS is formed by allowing the molten slag to cool relatively slowly under ambient conditions. This study presents experimental findings on the mechanical and durability performance of cement concrete pavement with replacement of cement by WS and/or AS. In order to produce concrete specimens, total replacement of cement by GGBS(WS+AS) was fixed at 40% by mass. Concrete specimens were regularly monitored for the variation of mechanical properties such as flexural strength, compressive strength and initial surface absorption. In addition, in order to assess durability of concrete pavement with WS and/or AS, the chloride ion penetration resistance and scaling resistance tests were adopted, and the corresponding results were compared to those of plain concrete pavement. The test results indicated that the performance of concrete pavement was significantly dependent on the replacement level of WS by AS. Concrete specimens incorporating 20% replacement level of AS showed a poor mechanical performance, while 5% replacement of AS showed a beneficial effect both mechanical and durability performance. Especially, the 5% AS replacement led to the higher resistance of concrete pavement against frost-salt action. Based on the experimental results, the present study would be helpful to design high-performance cement concrete pavement.

To be better fit for highways, pavement systems are required to provide comfortable and safe driving and be structurally durable. Composite pavements can be an effective option as they are more durable by placing a high functional asphalt overlay on a rigid concrete base layer. In order to apply a composite pavement system to the field, it is necessary not only to develop technologies that prevent reflecting crack and deterioration of the base layer, but also to improve bonding performance of materials and ensure structural performance as a pavement system against traffic loading. In advanced countries like Japan, USA and Europe, high-functional composite pavement systems are being put into practice across new highway networks. In this study, we evaluated structural performance (rutting, reflecting crack, and deflection) by applying traffic loads of actual highways through an accelerated pavement tester (APT) of a composite pavement section made up of a quiet porous surface laid over a water-proofing layer, a continuously reinforced concrete base, and a lean concrete sub-base layer, which was developed with new pavement methods used for each layer prior to field application. The APT specimen was constructed with paving materials and equipment actually used on site in the same dimensions (W3.5m*L14m*H2m) as actual highway sections in Korea, and 3-axle double-wheel heavy load (45ton) cart type KALES(Korean Accelerated Loading and Environmental Simulator) traveling on the specimen in both directions was used to simulate traffic loading. After applying around 8,574,000 ESALs of traffic loads, no reflecting crack occurred on the asphalt surface of the composite pavement, without surface distress except for rutting. In order to examine what causes rutting of pavements, we surveyed thickness of pavements by layer and measured asphalt density.

Pavement performance usually depends on the pavement’s material property, traffic and environmental conditions. Current pavement design programs such as the Mechanistic Empirical Pavement Design Guide use these factors in assessing the pavement life and performance in terms of different distresses like rutting and fatigue cracking. Theoretically, the cracking and rutting behaviour of pavements are based on accumulated strains experienced by the pavement which is brought by the weight and loading speed of vehicles. A steady state loading device was used in the field to evaluate pavement deflection’s behaviour in varying loading frequencies. It was observed that the pavement deflection increases as the loading frequency also increases until it approaches a certain frequency wherein the deflection decreases thereafter. In this study, a three-dimensional finite element pavement model was established using ABAQUS wherein the effect of the vehicle’s loading frequencies was analysed. The calculated static deflection and stress from the finite element (FE) model were found to have good correlation with the KENPAVE measured deflection and stress. The deflections of different pavement conditions were further studied and analysed by generating several pavement geometries and strength from the FE model using a frequency sweep response analysis. It was found that the geometric condition and the current modulus of the pavement can amplify the pavement deflection by a factor, β, depending on the loading frequency. The peak deflection was found to be occurring when the loading frequency approaches one of the pavement’s natural frequencies. Based on the finding from this study, the natural frequency is an important factor to be considered in designing pavements. Further study is recommended to understand more on how to minimize the effect of natural frequency to pavement life.

There are some places such as bridges in the heavily industrialized area where the pavement should have a strong resistance against heavy axle loading and waterproof function. In those places, many polymer-modified asphalt (PMA) pavements were applied to protect premature cracking, severe rutting and water intrusion without success. Therefore, a much tougher pavement material with waterproofing function was developed for those places. This study evaluated important properties of the special type asphalt mixture which is highly condensed to be almost void-free condition. A high-quality PMA binder with PG82-34 grade was used for preparing the mixture and the optimum binder content was determined to allow near 0% air void in the mix design. The deformation strength(SD) by Kim Test and rut depth by wheel tracking test were measured at 60℃ as high temperature properties. The flexural strength and fracture toughness was measured at -10℃ as low temperature property. The void-free AC showed the higher performance in all four properties than any other asphalt concretes which were prepared for comparison. Therefore, it was shown that the normal concern about limiting air voids within 3-5% was just an apprehension. The void-free AC can be applied for heavy duty pavement on the bridge where the water-proofing function and higher rutting and cracking resistance are required.

Tram had been widely used in South Korea until 1960s; however, introduction of automobiles made the tram disappear. KRRI (Korea Railroad Research Institute) has developed wireless tram in order to enhance transporting capacity in large city. Continuously supported and embedded track system supports load from a wireless tram. The track system is composed of concrete slab or precast concrete and groove rail. Surface of the track is usually constructed by asphalt concrete. The asphalt concrete layer is about 5 cm in depth and constructed between rails of which width is 1435 mm. Adhesion between concrete slab and asphalt concrete layer and constructability, which affects performance, were investigated through actual construction and testing at test-bed. Four different types of mixtures and structures were used. After construction, adhesion tests were performed including basic material tests. Guss-asphalt with SMA showed the best adhesion and constructability.

The paper presents various investigations conducted for evaluation of the performance of polymer combined Vacuum Tower Bottom (VTB) modified asphalt mixes by comparison with different modified mixes in the laboratory scale. In order to verify the possibility of polymer combined VTB as a modifier in the asphalt binder, one base unmodified binder and two different types of modified asphalt binders well known for their good performance in the field were compared in the laboratory scale by rheological performance tests. Frequency Sweep Test (FST) and Multi Stressed Creep and Recovery (MSCR) test with DSR (Dynamic Shear Rheometer) were performed and confirmed its good performance. Secondly, various performance tests were adopted for various modified asphalt mixtures with same aggregate gradation and asphalt binder content. As to evaluate the overall performance, crack resistance and durability of dense graded mixtures, Dynamic modulus tests, Semi Circular Bending (SCB) tests and Cantabro tests were conducted for different types of mixes, respectively. Variance tests and analysis concluded several results. In the case of binder, the polymer combined VTB modifier is the primary affecting factor in performance upgrade when comparing with other binder types including base binder. The modified effects on mixtures were clearly shown in all performance tests although performance ranking out of various test types were different. Dynamic modulus are higher at low temperature and high reduced frequency while smaller modification effects in high temperature and lower reduced frequency. According to SCB test results, fracture resistance could be better than other mix types while durability of them are relatively lower. It can be concluded that polymer base VTB modifier can be act as a good modifier with increasing stiffness and fracture energy from test results. However, there are a couple of concerns remained in terms of performance verification of modifier. Therefore it is required to conduct performance simulation with MEPDG and field verification test and monitoring performance.

PURPOSES: Case studies of an asphalt-overlay project with a performance-based contract method were conducted on a national highway in Korea to evaluate the effect of the method on asphalt pavement maintenance. This study evaluated the procedure of the performance-based contract method. METHODS: In this study, an asphalt-pavement maintenance project for a national highway was assessed with a performance-based contract to investigate the advantage of the new contract procedures. This is the first trial applying the performance-based contract to a pavementrehabilitation project in Korea. In the four case studies, the warranty period of the performance-based contract was designed for seven years. The research team monitored the construction site to compare the normal contract method with the performance-based contract method. The case studies’project sites were investigated after the end of the construction. RESULTS : Based on the limited case studies, the performance-based contract method could extend the service life of the asphalt pavement and reduce the pavement-maintenance budget because the quality control was well managed by the contractors. However, a few construction laws would be necessary to apply the performance-based contract method in the future. CONCLUSIONS : Using the performance-based contract, the construction company made great efforts to guarantee the warranty period and to apply the optimal maintenance method, based on the pavement distress condition. The contractor and the agency would need to understand the new performance-based contract system for it to be activated. Therefore, a proper education program for the performancebased contract system would be needed to educate the stakeholders regarding the procedures and their effects on the pavement management and maintenance.

PURPOSES : In this study, the pavement condition of non-mill-and-overlay and mill-and-overlay on deteriorated concrete pavement was compared. In addition, the suitable time to perform the initial overlay was investigated.METHODS : The condition of the pavement sections that were not additionally overlaid on non-mill-and-overlay or mill-and-overlay on deteriorated concrete pavements was investigated according to overlay pavement age. The condition of non-mill-and-overlay and mill-andoverlay sections of expressway route 25, which has more information on overlay history than other routes, was compared according to the number of times of overlay. The relation between the concrete pavement condition just before the overlay and the number of times of overlay was investigated for the non-mill-and-overlay and mill-and-overlay sections for which the first overlay was performed in the same year.RESULTS: The pavement condition of the non-mill-and-overlay sections was better than that of the mill-and-overlay sections, showing higher Highway Pavement Condition Index(HPCI) regardless of overlay pavement age. The number of reflection crackings of the non-mill-and-overlay sections was smaller than that of the mill-and-overlay sections. As a result of observing the cores obtained from the overlay sections, the proportion of the deteriorated non-mill-and-overlay sections was smaller than that of the mill-and-overlay sections. The SD measured just before the overlay on the concrete pavement for which additional overlay was not performed was smaller than that for which additional overlay was performed regardless of the milling of the concrete slab surface. The HPCI of the concrete pavement for which overlay was performed just once was higher than that for which overlay was performed more than one time.CONCLUSIONS : Accordingly, it was concluded that the condition of the non-mill-and-overlay sections was better than that of the milland-overlay sections. In addition, the better the condition of concrete pavement just before the initial overlay, the longer the duration of the overlay effect.

도시 열환경 개선을 위해 국내외 도로포장 분야에서 다양한 연구가 진행 중에 있으며, 태양의 근적외선 반사를 통해 노면의 온도를 저감하는 반사형 차열성 포장 공법도 그 일환으로 연구와 실용화가 진행되어 왔다. 특히 일본의 도쿄도에서는 2002년 9월에 ‘살수를 필요로 하지 않는 포장노면의 온도상승을 억제하는 신기술’을 주제로 공모를 실시하여, 국토교통성 관동지방정비국 내에 ‘환경포장 동경 프로젝트’ 일환으로 차열성 포장과 보수성 포장에 대한 소규모 공개 시험시공을 추진하였다. 국내에서는 2005년 12월부터 수행된 ‘장수명 친환경 도로포장 재료 및 설계시공 기술개발’의 세부 연구과제로 ‘도심지 열섬완화를 위한 포장시스템개발’에서 주차장 부지를 배수성 포장으로 개량한 후 차열성과 투수성 포장에 대한 시험시공 및 추적조사를 실시하였다. 이러한 연구를 토대로 서울시에서는 2009년, 2010년 공용 중인 도로에 차열성 포장 시험시공을 실시하였으나 내구성이 미흡하여 6개월만에 조기파손이 발생하였다. 본 연구는 반사형 도료를 이용한 차열성 포장의 현장공용성 향상을 위해 개선된 차열성 도료를 개발하였다. 이에 대하여 내마모성 실내시험, 포장가속시험을 통한 공용성 평가시험, 주차장 진입구간 시험시공을 통한 내마모성 및 노면온도 저감 효과를 분석하였다. 차열성 포장의 현장공용성 및 노면온도 저감 효과를 평가하기 위해 기존 아스팔트 포장(장기공용으로 골재노출), 국외 우수 반사도료 개량형(A), 미끄럼방지 도료 개량형(B)을 대상으로 시험을 실시하였다. 시험 결과 도료 A, B 모두 내마모 시험(SPS-KTS 1102-1890:2005)에 따른 품질기준(50만회, 1%이하)을 충족하였다. 포장가속시험의 경우 그림 1]의 (b)에서와 같이 시공한지 15일밖에 되지 않는 아스팔트 포장에 도포한 결과 유분이 도료를 용해시켜 충분히 경화되지 않고 분리현상이 발생하였다. 반면 장기 공용한 아스팔트 포장의 경우 약 1년간 추적 조사한 결과 도료의 부착상태가 양호하였다. 따라서 차열성 포장은 신설보다는 유분이 어느 정도 없어진 3∼6개월 후에 적용하는 것이 바람직한 것으로 판단되었다. 온도저감 효과는 기존 아스팔트 포장과 비교하여 약 2.5∼3.5℃로 다소 적게 나타났는데, 이는 장기간 공용으로 아스팔트 바인더가 떨어져나가 표면색이 회색에 가까웠기 때문으로 판단되었다. 따라서 차열성 포장은 아스팔트 바인더가 안정적으로 유지되고 있는 신설포장일수록 상대적으로 온도저감 효과가 크게 나타나며, 노면온도를 상승시키는 근적외선을 반사함에 따라 낮 시간 포장체의 복사열 축적이 저감되어 일몰 후 도심 열섬현상을 완화하는 효과도 기대할 수 있다.

PURPOSES : This study focuses on the evaluation of interface performance with varying surface texture and tack coat application in an asphalt overlay. METHODS : The evaluation is carried out in two phases: tracking test and interface bond strength test. Using an image processing tool, tracking test is conducted to evaluate the susceptibility of the tack coat material to produce excessive tracking during application. Using the pull-off test method, the bond strength test is performed to determine the ability of the interface layer to resist failure. RESULTS: Results show that the underseal application yields less tracking compared to other applications. However, the bond strength is barely within the minimum acceptable value. On the other hand, RSC-4 produces higher bond strength for all surface types, but the drying time is long, which produces excessive tracking. CONCLUSIONS: While underseal application may be suitable for a trackless condition, the bond strength is less appealing compared to the rest of the tack applications available. RSC-4 demonstrated a high and consistent bond strength performance, but more time is required for drying to avoid excessive tracking. Tack coat application and surface type combination produce varying results. Therefore, these should be considered when selecting suitable future tack coat application options.

PURPOSES : Nowadays, cavity phenomena occur increasingly in pavement layers of downtown areas. This leads to an increment in the number of potholes, sinkholes, and other failure on the road. A loss of earth and sand from the pavement plays a key role in the occurrence of cavities, and, hence, a structural-performance evaluation of the pavement is essential. METHODS: The structural performance was evaluated via finite-element analysis using KPRP and KICTPAVE. KPRP was developed in order to formulate a Korean pavement design guide, which is based on a mechanical-empirical pavement design guide (M-EPDG). RESULTS: Installation of the anti-freezing layer yielded a fatigue crack, permanent deformation, and international roughness index (IRI) of 13%, 0.7 cm, and 3.0 m/km, respectively, as determined from the performance analysis conducted via KPRP. These values satisfy the design standards (fatigue crack: 20%, permanent deformation: 1.3 cm, IRI: 3.5 m/km). The results of FEM, using KICTPAVE, are shown in Figures 8~12 and Tables 3~5. CONCLUSIONS: The results of the performance analysis (conducted via KPRP) satisfy the design standards, even if the thickness of the anti-freezing layer is not considered. The corresponding values (i.e., 13%, 0.7 cm, and 3.0 m/km) are obtained for all conditions under which this layer is applied. Furthermore, the stress and strain on the interlayer between the sub-grade and the anti-freezing layer decrease gradually with increasing thickness of the anti-freezing layer. In contrast, the strain on the interlayer between the sub-base and the anti-freezing layer increases gradually with this increase in thickness.

PURPOSES : The field application and performance of continuously reinforced concrete pavement (CRCP), constructed by using the mechanical tube-feeding method, are evaluated in this study. METHODS: The location of the rebar was evaluated by using the MIRA system. The early-age CRCP performance was evaluated via visual survey, in which the crack spacing and crack width were examined. RESULTS: The location of longitudinal reinforcing bars was evaluated via MIRA testing and the results showed that the longitudinal rebars all lie within a given tolerance limit (±2.5 cm) of the target elevation. In addition, owing to the low temperature when the concrete was pured, the crack spacing in the Dae-Gu direction is slightly wider than that of the Gwang-Ju direction. Almost all of the crack spacings lay within the range of 1.0 m~3.0 m. A crack width of <0.3 mm was measured at the pavement surface. However, as revealed by the field survey, the crack spacing was not correlated with the crack width. CONCLUSIONS : In CRCP constructed by using the mechanical tube-feeding method, almost all of the longitudinal reinforcing bars lay within the tolerance limit (2.5 cm) of the target elevation. The concrete-placing temperature affects the crack spacing, owing to variations in the zero-stress temperature. Crack survey results show that there is no correlation between the crack spacing and crack width in CRCP.

PURPOSES: This paper investigates behavior and performance of concrete pavement in tunnel based on temperature data from field. METHODS : In this study, there are 4 contents to evaluate concrete pavement in tunnel, First, Comparison for distress was conducted at outside, transition, and inside part of tunnel. Secondly, temperature data was collected in air and inside concrete pavement in outside and inside tunnel. Thirdly, FEM analysis was performed to evaluate stress condition, based on temperature data from field. Finally, performance prediction was done with KPRP program. RESULTS: From the distress evaluation, failure of inside tunnel was much less than it of outside tunnel, Temperature change in tunnel was less than out side, and also it was more stable. According to result of FEM analysis, both curling stress status of inside tunnel was lower than it of outside tunnel. Based on KPRP program analysis, performance of inside tunnel was longer than outside. CONCLUSIONS : Through all study about behavior and performance of concrete pavement in tunnel, condition in tunnel has more advantages from environmental and distress point of view. Therefore, performance of inside tunnel was better than outside.