• Title/Summary/Keyword: LTPP

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A Study for Joint Freezing in Concrete Pavement (콘크리트포장의 줄눈의 잠김에 대한 연구)

  • Lee, Seung-Woo
    • International Journal of Highway Engineering
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    • v.3 no.1 s.7
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    • pp.165-176
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    • 2001
  • Joints in jointed concrete Pavement are designed to control against randomly occurred cracks within slabs, which may be caused by temperature or moisture variation. The advantage of these artificial cracks (joints) over naturally occurred cracks are easy access of protections, such as installation of joint seal and load transfer mechanism. The potential benefits of joint seals are to prevent infiltration of surface water through the joint into underlying soil and intrusion of incompressible materials (debris, fine size aggregate) in to the joint, which may prevent weakening of underlying soils and spallings due to excessive compressive stress, respectively. For the adequate design of joint seal, horizontal variation of joint widths (horizontal joint movements) are essential inputs. Based on long-term in-situ joint movement data of sixteen jointed concrete pavement sections in Long Term Performance Pavement Seasonal Monitoring Program (LTPP SMP), it was indicated that considerable Portion of joints showed no horizontal movements with change in temperature. This Phenomenon is called 'Joint Freezing'. Possible cause for joint freezing is that designed penetrated cracks do not occur at a joint. In this study, a model for the prediction of the ratio of freezing joints in a particular pavement sections is proposed. In addition, possible effects of joint freezing against pavement performance are addressed.

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Cost Analysis of Asphalt Pavements Reinforced with Glass Fiber and Polymer Modified Using Falling Weight Deflectometer (Falling Weight Deflectometer를 이용한 섬유보강 아스팔트 및 폴리머 개질 아스팔트 포장의 비용 효과 분석)

  • Kim, Boo-Il;Lee, Moon-Sup;Jeon, Sung-Il;Kim, Sang-Kyu
    • International Journal of Highway Engineering
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    • v.11 no.4
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    • pp.153-160
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    • 2009
  • Falling Weight Deflectometer (FWD) tests were performed to evaluate the structural capacity of glass fiber reinforced (GFR), polymer modified (PM), and unmodified asphalt pavement in Korea-LTPP (Long Term Pavement Performance) section. FWD tests showed that the tensile strains of GFR and PM asphalt pavements at the bottom of asphalt layer were 29% and 21% less than that of unmodified asphalt pavement. The structural capacity was then used as a performance criterion for calculating the cost effect of GFR and PM asphalt pavements. From the results, 5cm of asphalt layer thickness was reduced by applying GFR asphalt, and 3cm by applying PM asphalt. However, construction cost of PM and GFR asphalt pavement were increased due to the higher GFR and PM asphalt price. Life cycle cost analysis showed that the initial construction cost of GFR and PM asphalt pavement were higher but the management and user cost were less than those of unmodified asphalt pavement.

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Condition Evaluation of the Pavement Foundations Using Multi-load Level FWD Deflections (다단계 하중 FWD를 사용한 도로기초 상태평가 연구)

  • Park, Hee-Mun;Kim, Richard Y.;Park, Seong-Wan
    • Journal of the Korean Geotechnical Society
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    • v.19 no.6
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    • pp.261-271
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    • 2003
  • A condition evaluation procedure for the pavement foundations using multi-load level Falling Weight Deflectometer(FWD) deflections is presented in this paper. A dynamic finite element program incorporating a stress-dependent material model, was used to generate the synthetic deflection database. Based on this synthetic database, the relationships between surface deflections and critical responses, such as stresses and strains in base and subgrade layers, have been established. FWD deflection data, Dynamic Cone Penetrometer(UP) data, and repeated load resilient modulus testing results used in developing this procedure were collected from the Long Term Pavement Performance (LTPP) and North Carolina Department of Transportation (NCDOT) database. Research effort focused on investigation of the effect of the FWD load level on the condition evaluation procedures. The results indicate that the proposed procedure can estimate the pavement foundation conditions. It is also found that structurally adjusted Base Damage Index (BDI) and Base Curvature Index (BCI) are good indicators for the prediction of stiffness characteristics of aggregate base and subgrade respectively. A FWD test with a load of 66.7 kN or less does not improve the accuracy of this procedure. Results from the study for the nonlinear behavior of a pavement foundations indicate that the deflection ratio obtained from multi-load level deflections can predict the type and quality of the pavement foundation materials.

A Study for Roughness of Joungbu Expressway (중부고속도로 평탄성 특성에 관한 연구)

  • Kim, Sung-Ho;Suh, Young-Chan;Cho, Yoon-Ho;Park, Kyung-Boo
    • International Journal of Highway Engineering
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    • v.3 no.2 s.8
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    • pp.131-140
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    • 2001
  • Concrete pavement of Jungbu Expressway composed of CRCP(Continuously Reinforced Concrete Pavement) and JCP(Jointed Concrete Pavement). The CRCP was firstly constructed and applied to new expressway in Korea. It is a good source of the study to analyze the performance of CRCP and JCP because it experiences same amount of traffic and environmental loading. Up to the present, condition survey has conducted several times during 13 years but roughness measurement has not been carefully conducted. Through comparisons among several types of pavement(CRCP, JCP, Asphalt) by roughness, CRCP is superior to JCP. In addition, connected sections in the highway such as bridges and tunnels that have higher IRI values, about 5mm/m, than normal sections should be considered appropriated maintenance such as diamond grinding. The relationship between IRI and distresses carried out by Korea Highway Cooperation in 1999 skewed that the number of crack is related to IRI value in JCP, while other distresses of JCP and CRCP are not shown clearly. The comparison study with IRI values between Jungbu Expressway and GPS-3(JCP) and GPS-5(CRCP) of LTPP data also showed that roughness of Jungbu Expressway is not inferior to that of the state. Some of section showed larger values of IRI are linked with under-9round structures for passages and drainages. The overall performance considering only roughness, the CRCP is also superior to JCP in sections with under-ground tunnels.

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Internal Property and Stochastic Deterioration Modeling of Total Pavement Condition Index for Transportation Asset Management (도로자산관리를 위한 포장종합평가지수의 속성과 변화과정의 모델링)

  • HAN, Daeseok;DO, Myungsik;KIM, Booil
    • International Journal of Highway Engineering
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    • v.19 no.5
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    • pp.1-11
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    • 2017
  • PURPOSES : This study is aimed at development of a stochastic pavement deterioration forecasting model using National Highway Pavement Condition Index (NHPCI) to support infrastructure asset management. Using this model, the deterioration process regarding life expectancy, deterioration speed change, and reliability were estimated. METHODS : Eight years of Long-Term Pavement Performance (LTPP) data fused with traffic loads (Equivalent Single Axle Loads; ESAL) and structural capacity (Structural Number of Pavement; SNP) were used for the deterioration modeling. As an ideal stochastic model for asset management, Bayesian Markov multi-state exponential hazard model was introduced. RESULTS:The interval of NHPCI was empirically distributed from 8 to 2, and the estimation functions of individual condition indices (crack, rutting, and IRI) in conjunction with the NHPCI index were suggested. The derived deterioration curve shows that life expectancies for the preventive maintenance level was 8.34 years. The general life expectancy was 12.77 years and located in the statistical interval of 11.10-15.58 years at a 95.5% reliability level. CONCLUSIONS : This study originates and contributes to suggesting a simple way to develop a pavement deterioration model using the total condition index that considers road user satisfaction. A definition for level of service system and the corresponding life expectancies are useful for building long-term maintenance plan, especially in Life Cycle Cost Analysis (LCCA) work.

Selection of Long-Term Pavement Performance Sections for Development of Distress Prediction Model in National Asphalt Pavement (국도 아스팔트 포장 파손예측모델 개발을 위한 장기 관측 구간 선정에 관한 연구)

  • Kwon, Soo-Ahn;Yoo, Pyeong-Joon;Kim, Ki-Hyun;Cho, Yoon-Ho
    • International Journal of Highway Engineering
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    • v.4 no.1 s.11
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    • pp.123-134
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    • 2002
  • Special pavement test sections were selected to develop a distress prediction model on asphalt pavement of National Highway. Experimental design was conducted for the selection of LTPP sections on in-service pavement(new and overlaid pavement) using several variables affecting pavement performance. Preliminary sections that satisfied the design template were chosen from the national highway database, and final selection was fixed through field inspection. The number of monitoring section is 95 including 47 overlaid pavement. A pavement distress data such as crack and rutting were collected for two years. An interim pavement performance analysis was peformed to show feasibility of performance monitoring program. Data related pavement such as traffic, weather, material characteristic and crack etc. should be collected for next project years and distress prediction model will be developed through the statistical analysis.

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Feasibility Study of AASHTO86 Design Method for Bonded Concrete Overlay (AASHTO86 접착식 콘크리트 덧씌우기 설계법의 타당성 연구)

  • Park, Jong Won;Kim, Young Kyu;Han, Seung Hwan;Lee, Seung Woo
    • International Journal of Highway Engineering
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    • v.15 no.2
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    • pp.47-55
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    • 2013
  • PURPOSES : This study aimed to evaluate the feasibility of AASHTO86 design method for Bonded Concrete Overlay. METHODS : The Feasibility of AASHTO86 design method for Bonded Concrete Overlay is investigated based on the following study : i) Sensitivity analysis of designed service life of Bonded Concrete Overlay by major design input for AASHTO86 guide. ii) Comparison of actual Bonded Concrete Overlay life and predicted Bonded Concrete Overlay life by AASHTO86. iii) Finding the stress component influence the potential distress of Bonded Concrete Overlay based on 3-d FEM analysis. iv) Exploring the limitation of AASHTO86 in the aspect of design input. RESULTS : Sensitivity analysis showed that the condition of existing pavement significantly on the Bonded Concrete Overlay life. Also the overlay thickness affect the Bonded Concrete Overlay life. The comparison of actual Bonded Concrete Overlay life and predicted Bonded Concrete Overlay life showed relatively good agreement when the early distress sections are excluded in comparison. Bonding stress occurred at the interface may be larger than the bond strength used in the specification of Bonded Concrete Overlay construction. CONCLUSIONS : Bonded Concrete Overlay life predicted by the AASHTO86 may not be reliable. Number of points to improve the reliability in the design of Bonded Concrete Overlay are suggested in this study.

Performance and Economic Analysis for Rut-resistance Pavement Considering Life Cycle Cost (LCC를 고려한 내유동포장의 공용성 및 경제성 분석에 관한 연구)

  • Do, Myungsik;Han, Daeseok;Yoo, Inkyoon;Lee, Soohyung
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.26 no.5D
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    • pp.783-796
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    • 2006
  • Rut-resistance pavement is adopted to prevent pavement from plastic deformation since 1998. The objective of this paper is to investigate performance and economic efficiency between rut-resistance pavement and conventional hot-mix asphalt(HMA) on national highway. The pavement deterioration models incorporated in HDM-4 have been calibrated and adapted to local road conditions based on observed pavement rut-depth data. Based on calibration result of HDM-4, the economic evaluation including road agency cost and user cost is performed for 34 road pavement sections. Furthermore, we presented optimal timing for maintenance and performance levels subject to different budget. We found that rut-resistance pavement is performing better than conventional hot-mix asphalt in most road sections. Furthermore, we confirmed that the application of HDM-4 is useful for pavement project planning and evaluation. More investigation is needed to enlarge the scope of the pavement data and to explore more deeply socio-environmental cost and delay cost.