PURPOSES: The purpose of this research is to analyze the characteristics of panels that affect the evaluating results of riding quality and to evaluate the appropriateness of roughness management criteria based on ride comfort satisfaction. METHODS: In order to analyze the influence of panel characteristics of riding quality, 33 panels, consisting of civilians and experts, were selected. Also, considering the roughness distribution of the expressway, 35 sections with MRI ranging from 1.17 m/km to 4.65 m/km were selected. Each panel boarded a passenger car and evaluated the riding quality with grades from 0 to 10, and assessed whether it was satisfied or not. After removing outlier results using a box plot technique, 964 results were analyzed. An ANOVA was conducted to evaluate the effects of panel expertise, age, driving experience, vehicle ownership, and gender on the evaluation results. In addition, by using the receiver operating characteristics (ROC) curve, the MRI value, which can most accurately evaluate the satisfaction with riding quality, was derived. Then, the compatibility of MRI was evaluated using AUC as a criterion to assess whether the riding quality was satisfactory. RESULTS: Only the age of the panel participants were found to have an effect on the riding quality satisfaction. It was found that satisfaction with riding quality and MRI are strongly correlated. The satisfaction rate of roughness management criteria on new (MRI 1.6 m/km) and maintenance (MRI 3.0 m/km) expressways were 95% and 53%, respectively. As a result of evaluating the roughness management criteria by using the ROC curve, it was found that the accuracy of satisfaction was the highest at MRI 3.1-3.2 m/km. In addition, the AUC of the MRI was about 0.8, indicating that the MRI was an appropriate index for evaluating the riding quality satisfaction. CONCLUSIONS: Based on the results, the distribution of the panels’age should be considered when panel rating is conducted. From the results of the ROC curve, MRI of 3.0 m/km, which is a criterion of roughness management on maintenance expressways, is considered as appropriate.

PURPOSES : It is necessary to prevent premature failure of concrete pavements caused by durability problems. The purpose of this study was to find factors affecting the durability of concrete pavements, and suggest improvement methods for existing concrete mix design. METHODS: Factors influencing durability were derived from laboratory test data for common field failure conditions and main properties of concrete cores taken from the field. The improvement of concrete properties was investigated by evaluating the performance of existing and proposed mix proportion designs and curing methods. RESULTS: The compressive strength and the absorbing performance of the low Blaine cement and the high-strength mixture were better than those of the TypeⅠcement. Wet curing showed better compressive strength, elastic modulus, coefficient of thermal expansion, and absorption performance than air curing or compound curing. As a result of comparing concrete cores collected in the field, the sections with good durability showed good performance in terms of resistance to chloride ion penetration, absorption, and initial absorption rate. CONCLUSIONS: The absorption performance was considered as a possible foactor affecting durability of cement concrete pavements as a result of field core tests. In order to improve the durability of the pavement concrete, it is necessary to improve the existing mixtures and curing methods.

시멘트 콘크리트 포장은 2010년도를 전후해서 내구성 문제에 기인한 것으로 판단되는 스폴링 및 스케일링 파손이 조기에 발생하였다. 이러한 파손은 이용객의 주행 쾌적성을 저하시키고 수명을 단축시켜 잦은 보수로 인해 예상보다 빠른 대규모의 개량사업을 계획할 수밖에 없게 만들었다. 이러한 파손을 방지하기 위해서 그동안 내구성 관리지표를 만들어 공기량 및 기포간격계수를 관리하고 콘크리트 포장의 품질관리를 기존 강도 및 평탄성에서 내구성으로 바꾸어 현재에 이르고 있다. 그러나 내구성 향상 노력이 내부 공극과 함께 설계, 시공 및 재료에 대한 다각적인 검토를 통한 파손 원인 도출이 필요하게 되었다. 내구성 파손의 결과는 스폴링 및 스케일링으로 나타나지만 그 원인이 내부 공극에 국한된 것인지 아니면 다른 요인과 병행해 이루어지는지 아니면 다른 요인이 더 큰 영향을 미치는지 알아야 더욱 효과적인 대책을 찾을 수 있기 때문이다. 본 연구는 현장 공용성에 근거해 콘크리트 포장의 내구성 파손원인을 찾아내기 위한 목적으로 시작되었다. 이를 위해서 현장의 내구성 파손을 정량화해야 하고 정량화한 콘크리트 포장의 파손상태를 기준으로 현장을 구분해야 하며 구분된 현장을 기준으로 건전한 구간과 파손된 구간을 나누고 서로 비교 하므로 의미 있는 내구성 파손원인을 도출할 수 있다. 그림 1과 같이 동일한 노선에서 파손율 변화는 구간에 따라 다른 수치를 나타내고 있으며 이것은 유사한 시공조건과 재령을 가지고 있어도 재료 및 품질 특징에 따라 다른 결과를 나타낼 수 있음을 보여주는 것이라고 판단되었다. 그림 2는 높은 파손율을 보이는 곳의 내구성 파손 특징을 보이는 것으로 파손구간 및 비교구간에서 코어를 채취하여 실내에서 구조성능, 내부조직, 배합상태 및 내구성능 시험을 실시하였다. 한정된 조사 구간에서 채취한 코어시험을 통해 얻은 잠정적인 결과는 내구성 파손을 유발하는 인자 가운데 하나로 수분 흡수 저항성으로 제안할 수 있다는 것으로 건전한 코어의 흡수 저항성은 인접 구간에서 채취한 파손부 코어에 비해서 우수한 수분흡수 저항성능을 나타내었다.

PURPOSES: This study investigates the effect on concrete pavement accordance with the curing methods in cool weather and supports the best method in the field. METHODS: Two field tests evaluated the curing methods of concrete pavement in cool weather. Firstly, five curing methods were tested, including normal curing compound, black curing compound, bubble sheet, curing mat, and curing mat covered with vinyl. Concrete maturity was compared from temperature data. Secondly, normal curing compound and curing mat with vinyl, which showed the best performance, were compared in terms of maturity and join condition index. RESULTS: From the field tests, it is an evident that curing mat with vinyl accelerated the concrete strength. Therefore, it is possible to conduct saw-cut works in cool weather, which minimizes damage on concrete at joint. CONCLUSIONS: For concrete pavement in cool weather, using curing mat with vinyl as the curing method could overcome the strength delay. Therefore, strength and durability problems on concrete at joint due to cool weather would be fewer in the future.

PURPOSES : This paper focuses on strength development according to the mix design with cement type and mineral admixture from laboratory and field tests in cool weather. METHODS : Two methods evaluated the mix design of concrete pavement in cool weather. Firstly, laboratory tests including slump, air contents, setting time, strength, maturity, and freezing-thawing test were conducted. Three alternatives were selected based on the tests. Secondly, a field test was conducted and the optimum mix design in cool weather was suggested . RESULTS : It is an evident from the laboratory test that a mix with type Ⅲ cement showed better performance than the one with type Ⅰ cement. There was a delay in strength development of a mix with mineral admixture compared to mix design without any mineral admixture. In the field test, type Ⅲ cement+flyash 20% mix design proved the best performance. CONCLUSIONS : For concrete pavement in cool weather, mix design using type Ⅲ cement could overcome the strength delay due to mineral admixture. Moreover, it is possible to make sure of durability of pavement. Therefore, strength and durability problems due to cool weather would decrease.

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: This study supports the evidence that it is possible to rehabilitate a damaged pavement with a lane closure specifically based on the Gimcheon~Sunsan project. METHODS : The prediction results from the simulation programs were compared with field monitoring, which focused on traffic management planning, congestion (length, time, and passing speed), bypass, and user cost, among others. RESULTS : The research results showed that lane closure application and pavement repair of the aged pavement in Korea were possible, even though the prediction results were minimally different from the field monitoring. The road agency contributes to service life extension of the rehabilitated pavement using this method. CONCLUSIONS: A marginal effect caused by the lane closure was observed on travelling users or vehicles, and the user cost of pavement repair decreased. Therefore, introducing the repair method or rehabilitation in Korea is possible. Information dissemination through various media was properly done to execute the project well. Moreover, the construction area traffic utilized nearby alternative roads. Therefore, improving the repaired pavemen’s service life while ensuring that the pavement management agency can provide a road with comfortable user riding quality was possible.

제설용 소금에서 미세 입자가 많으면 융설의 즉효성은 있으나 눈이 압설인 경우에는 그 효과가 충분히 깊은 곳까지 미치지 못하고, 지속성이 미흡하다. 또한, 가볍기 때문에 차량 통행이나 바람에 의해서 비산 되기 쉽다. 반면에 굵은 입자가 많으면 눈을 녹이는데 필요한 시간이 많이 소요되고 입자의 일부가 노면 밖으로 튀어 재료의 손실이 발생한다. 따라서 본 연구에서는 제설용 소금의 입경에 따른 융빙성능, 합성입도별 지속성과 속효성을 만족할 수 있는 융빙성능과 재료 손실을 최소화 하기 위한 살포성 시험을 실시하여 최적의 입도 기준을 제시하였다. 입경별(10, 8, 5, 2.8, 1.2, 0.6, 0.3mm) 융빙성능 결과, -5℃에서는 입경이 클수록(5mm 이상, 특히 10mm) 지속성(120분)이 있었고, 시험시간 120분 대비 90분에서의 융빙율은 입경 2.8~0.3mm에서 평균 94%, 입경 10~5mm에서 평균 78% 로 나타났다. 시험 온도 -12℃, 시험시간 120분에서 융빙량은 10mm 입경에서 8g, 0.6mm 입경에서 30g 으로서, 저온에서는 굵은 입경 소금의 융빙성능이 크게 떨어지는 것 으로 나타났다. 4가지 합성입도에 따른 살포성 시험결과, 도로 폭 0~8m 까지의 소금 누적 잔류량은 84~90% 로서 현재 국내 대부분 도로관리기관에서 채택하고 있는 습염(고체 소금+염화칼슘 용액) 살포 시에는 소금 잔류량이 95% 이상으로 향상될 것으로 판단된다. 따라서 본 연구에서 제시한 제설용 소금의 최적 입도는 잔 입경, 중간 입경, 굵은 입경을 적절하게 조 합하여 속효성과 지속성을 확보할 수 있고, 살포 시 소금의 손실을 최소화 시킬 수 있을 것이다.

본 연구에서 10℃ 이하의 저온환경에서 콘크리트 강도 발현이 늦어지는 현상을 개선하기 위해 조강 시 멘트와 플라이애쉬, 고로슬래그 혼합시멘트로 강도 발현을 개선하기 위한 응결 특성에 대한 비교 실험을 수행하였다. 응결 특성 분석 실험은 표 1과 같이 6종 배합과 4~10℃ 온도 조건에서 실시하였다. 2성분계 혼합 시멘트의 응결 시간에 대한 분석 결과는 그림 1과 같다. 초결의 경우 전체적으로 살펴보 면 3종 시멘트를 사용한 경우의 응결 시간이 1종 시멘트를 사용한 배합보다 더 빨리 나타났다. 4℃ 온도 조건에서는 3종 시멘트를 사용한 경우, 광물성 혼화재들이 들어가지 않은 배합이 가장 빠른 초결이 나타 났으며, 다음으로 플라이애쉬, 그리고 슬래그 순으로 나타났다. 하지만 다른 온도조건(10℃, 15℃, 20℃) 에서는 슬래그와 플라이애쉬의 초결은 큰 차이가 없었다. 1종의 경우에서는 슬래그를 사용한 경우와 혼화 재를 사용하지 않은 배합이 유사하게 나타났으며, 플라이애쉬를 사용한 경우가 가장 늦었다. 이러한 경향 은 전 온도조건에서 유사하였다. 다음으로 종결에 대한 분석 결과, 시멘트 종류에 대한 경향은 초결과 유 사하였다. 1종 시멘트를 사용한 배합에서는 4℃에서 일반시멘트를 사용한 경우가 가장 빨랐으며, 다음으 로 슬래그, 그리고 플라이애쉬 순으로 나타났다. 전체적으로 보면 고속도로 콘크리트 포장 시공 시 사용 하는 1종-F2S0-6%의 배합보다 3종시멘트에 플라이애쉬나 슬래그를 사용한 배합의 초결 및 종결 모두 다 앞당겨지는 것을 확인하였다. 본 연구에서는 10℃ 이하의 저온환경에서 콘크리트 강도 발현을 개선하기 위해 혼합 시멘트에 대한 응 결 특성을 분석하였다. 저온 환경에서 플라이애쉬 또는 고로슬래그를 혼합하여 사용하는 경우 1종 시멘트 와 비교하여 3종 시멘트를 사용하였을 때 초결 및 종결이 조기에 달성되는 것을 확인하였다. 향후 3종 혼 합 시멘트 사용에 대한 특성 분석 연구를 추가적으로 수행할 예정이다.

PURPOSES: The behavior of a concrete pavement in a tunnel was investigated, based on temperature data obtained from the field and FEM analysis. METHODS: The concrete pavement in a tunnel was evaluated via two methods. First, temperature data was collected in air and inside the concrete pavement both outside and inside the tunnel. Second, FEM analysis was used to evaluate the stress condition associated with the slab thickness, joint spacing, dowel, and rock foundation, based on temperature data from the field. RESULTS : Temperature monitoring revealed that the temperature change in the tunnel was lower and more stable than that outside the tunnel. Furthermore, the temperature difference between the top and bottom of the slab was lower inside the tunnel than outside. FEM analysis showed that, in many cases, the stress in the concrete pavement in the tunnel was lower than that outside the tunnel. CONCLUSIONS : Temperature monitoring and the behavior of the concrete pavement in the tunnel revealed that, from an environmental point of view, the condition in the tunnel is advantageous to that outside the tunnel. The behavior in the tunnel was significantly less extreme, and therefore the concrete pavement in the tunnel could be designed more economically, than that outside the tunnel.

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.

터널은 토공부와 비교하면 어둡고 갇힌 공간이기 때문에 콘크리트 포장 시공시 품질관리가 어려워 교 통 개방 후 승차감이 불량하거나 심각한 소음 문제가 발생한다. 일반적으로 토공부의 노후 콘크리트 포장 에서는 주행 쾌적성 문제를 해결하기 위해 다이아몬드 그라인딩 공법(DG)을 적용하여왔다. 하지만 돌출 된 fin이 깨지거나 마모가 되면 그 기능이 다하여 재시공이 필요한 문제가 있다. 이러한 문제점을 해결하 기 위해 개발된 공법이 NGCS (Next Generation Concrete Surface)이다. 본 연구에서는 토공부 콘크리 트 포장에 적용된 NGCS 공법을 터널 내 포장에 적용하여 도로 이용자의 주행 쾌적성을 향상을 위한 노력 을 진행하였다. 일반 종방향 타이닝, DG 및 NGCS을 건설중인 터널에 적용한 후 공용성을 평가하였다. 공용성 평가결과, 평탄성에서는 NGCS 공법과 DG 우수하였으며, 종방향 타이닝이 가장 낮았다. 미끄럼 마찰 저항에서는 DG가 가장 높았고, 다음으로 NGCS 및 종방향 타이닝 순으로 평가되었다. 실내외 소음 평가 결과, NGCS 구간의 소음도가 가장 낮았으며, 다음으로 DG, 종방향 타이닝 순이었다. 전체적인 평 가 결과, 고기능성 표면처리 공법인 NGCS를 터널 내 콘크리트 포장에 적용한다면 주행 안전성을 높이고 소음을 감소시켜 쾌적한 주행환경을 구현할 수 있을 것이다.

콘크리트 포장의 파손 중의 하나인 스폴링은 도로를 주행하는 운전자의 승차감을 저해하는 요인 중의 하나로 다양한 원인들에 의해서 발생한다. 본 연구에서는 스폴링 발생 가능성의 많은 원인 중의 하나로 균열부의 닫힘현상과 Zero Stress Temperature의 상관성을 3가지의 콘크리트 포장에서의 계측 결과를 바탕으로 검토하였다. 콘크리트 시공시 대기 및 콘크리트 온도에 의해 결정되는 ZST는 기존 문헌에서처 럼 콘크리트 포장의 횡방향 균열부 거동과 상관성이 있는 것으로 나타났다. 특히 철근이 삽입된 연속철근 콘크리트 포장에서는 시공 초기 및 장기 공용 후에도 철근이 균열부의 과도한 벌어짐을 구속하는 효과가 있어 ZST 이하에서는 온도에서는 균열 닫힘현상이 나타나지 않았으나, 그 이상에서는 발생하였다. 이로 인해 횡방향 균열부에 압축응력이 크게 발생하여 스폴링 발생 가능성이 있었다. 반면, 줄눈이 설치되어 있는 Whitetopping의 경우는 ZST에 상관없이 균열 닫힘현상은 발생하지 않았다. 따라서, 콘크리트 포장 의 초기 온도관리를 한다면 공용성 향상 및 수명 연장 효과를 기대할 수 있을 것이다.

PURPOSES: This study aims to evaluate the runoff reduction with permeable pavements using the SWMM analysis. METHODS: In this study, simulations were carried out using two different models, simple and complex, to evaluate the runoff reduction when an impermeable pavement is replaced with a permeable pavement. In the simple model, the target area for the analysis was grouped into four areas by the land use characteristics, using the statistical database. In the complex model, simulation was performed based on the data on the sewer and road network configuration of Yongsan-Gu Bogwang-Dong in Seoul, using the ArcGIS software. A scenario was created to investigate the hydro-performance of the permeable pavement based on the return period, runoff coefficient, and the area of permeable pavement that could be laid within one hour after rainfall. RESULTS : The simple modeling analysis results showed that, when an impervious pavement is replaced with a permeable pavement, the peak discharge reduced from 16.7 m3/s to 10.4 m3/s. This represents a reduction of approximately 37.6%. The peak discharge from the whole basin showed a reduction of approximately 11.0%, and the quantity decreased from 52.9 m3/s to 47.2 m3/s. The total flowoff reduced from 43,261 m3 to 38,551 m3, i.e., by approximately 10.9%. In the complex model, performed using the ArcGIS interpretation with fewer permeable pavements applicable, the return period and the runoff coefficient increased, and the total flowoff and peak discharge also increased. When the return period was set to 20 years, and a runoff coefficient of 0.05 was applied to all the roads, the total outflow reduced by 5195.7 m3, and the ratio reduced to 11.7%. When the return period was increased from 20 years to 30 and 100 years, the total outflow reduction decreased from 11.7% to 8.0% and 5.1%, respectively. When a runoff coefficient of 0.5 was applied to all the roads under the return period of 20 years, the total outflow reduction was 10.8%; when the return period was increased to 30 and 100 years, the total outflow reduction decreased to 6.5% and 2.9%, respectively. However, unlike in the simple model, for all the cases in the complex model, the peak discharge reductions were less than 1%. CONCLUSIONS : Being one of the techniques for water circulation and runoff reduction, a high reduction for the small return period rainfall event of penetration was obtained by applying permeable pavements instead of impermeable pavement. With the SWMM analysis results, it was proved that changing to permeable pavement is one of the ways to effectively provide water circulation to various green infrastructure projects, and for stormwater management in urban watersheds.

PURPOSES: This study analyzes the available working time at work-zone on the Expressway in accordance to the new capacity manual. METHODS: Sensitivity analysis on variables were conducted to calculate the adjusted capacity at work-zone based on previous researches. RESULTS : The main factors which affect available working time at the work-zone were its capacity, number of lanes, terrain and lane width. Other factors have minimal effect on the available working time. Based on the analysis, a calendar of lane closures was suggested. CONCLUSIONS : A series of studies concluded that the capacity at work-zone in the new capacity manual reduced to 76-82% of the existing manual. As such, the available working time decreased. Furthermore, the factors affecting the available working time needs to be considered when making a plan to rehabilitate the distressed pavement.

PURPOSES: This study is to suggest tunnel length to spray curing compound, based on the field tests. METHODS : At first field test, length from the entrance of tunnel to wet wall was checked by visual survey. The second and third test, various sensors were installed in concrete or in tunnel, such as RH sensor, temperature sensor, portable weather station and etc.. And also, test for bleeding and retaining water of concrete were conducted to evaluate environmental effect on concrete pavement. RESULTS: The result of the field experiment for tunnel length to spray curing compound indicates that length changes depending on tunnel length, season, and location. Environmental condition of a short tunnel was not much different between location near entrance and at center of tunnel. However, in case of a medium and long tunnel, effect of outside environmental condition decreased, when location moved into tunnel center of it. CONCLUSIONS: From the testing results, it can be proposed that optimum tunnel length to spray curing compound is 60m for a medium and long tunnel, and whole length for a short tunnel.

PURPOSES: This study aims to develop a strength test method for irregularly shaped concrete block paver. METHODS : Ten (10) different types of concrete block pavers including porous and dense blocks were tested for strength capacities. Destructive and non-destructive methods were used to develop a strength test method for irregularly shaped concrete block paver. The flexural strength evaluation was conducted in accordance to KS F 4419, while compressive strength was conducted with a 45.7mm-diameter core specimen. The impact echo test method was used to evaluate the elastic modulus. Finally, regression analysis was used to investigate the relationship between flexural strength, compressive strength and elastic modulus based on their corresponding test results. RESULTS : The flexural strength of the tested block pavers ranged from 4MPa to 10MPa. At 95% confidence level, the coefficients of determination between compressive-flexural strength relationship and compressive strength-elastic modulus relationship were 0.94 and 0.84, respectively. These coefficients signified high correlation. CONCLUSIONS : Using the test method proposed in this study, it will be easier to evaluate the strength of irregularly shaped concrete block pavers through impact echo test and compressive test, instead of the flexural test. Relative to the flexural strength requirement of 5MPa, the minimum values of compressive strength and elastic modulus, as proposed, are 13.0MPa and 25.0GPa, respectively.

PURPOSES: This study aims to evaluate the performance of interlocking block pavement system for low speed highway. METHODS: Through on-site monitoring, environmental impact assessment of interlocking block pavement such as heat island reduction, traffic safety, noise pollution were evaluated as compared with asphalt pavement. Also the pavement condition and roughness were evaluated according to performance period. RESULTS: Surface temperature of interlocking block pavement was about 7 degree lower than asphalt pavement in midsummer. Compared to asphalt pavement, vehicle speed reduction effect of interlocking block pavement was about 2kph. For low speed driving, the noise pollution was measured at a similar level for both asphalt and interlocking block pavement. After 42month service period, the breakage of block was only 0.24% for the whole surveyed area. IRI of interlock block pavement was estimated within the range of 5~8m/km. CONCLUSIONS : Depending on the performance monitoring results such as heat island reduction, providing traffic safety and keeping a good pavement condition for a long service period, it assures that interlocking block pavement was applicable for low speed road.