• Title/Summary/Keyword: 줄눈폭

Search Result 7, Processing Time 0.021 seconds

Evaluation of AASHTO Joint Opening Equation Based on the Analysis of Joint Movement of Concrete Pavement in Korea highway Test Road (시험도로 줄눈콘크리트포장 줄눈폭 변화분석을 통한 AASHTO 줄눈폭 예측식 타당성 연구)

  • Choi, Jeong Keun;Jeong, Jin Hoon;Lee, Seung Woo
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.26 no.5D
    • /
    • pp.805-812
    • /
    • 2006
  • To investigate the usefulness of AASHTO joint opening equation, joint movement of Korea Highway Test Road was monitored and analyzed. The monitored section included Lean, Rubble, BB3 subbase. Demac gauges were installed at each joint in the monitored section, and joint movements with temperature changes were monitored. The measured joint movements with temperature change were then analyzed based on ER (Effective Ratio). The effect of subbase, which was considered as 'C' value in AASHTO equation, was not shown in the observed joint movement. To study the effcet of sealing on joint opening two unsealed sections were included in the monitored section, and no effects of sealing on joint movement were observed.

Development of a Probabilistic Joint Opening Model using the LTPP Data (LTPP Data를 이용한 확률론적 줄눈폭 예측 모델 개발)

  • Lee, Seung Woo;Chon, Sung Jae;Jeong, Jin Hoon
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.26 no.4D
    • /
    • pp.593-600
    • /
    • 2006
  • Joint opening of jointed concrete pavement is caused by change in temperature and humidity of adjoined slab. The magnitude of joint opening influences on the load-transfer-efficiency and the behavior of sealant. If temperature or humidity decreases, joint opening increases. Generally maximum joint opening of a given joint is predicted by using AASHTO equation. While different magnitudes of joint opening at the individual joints have been observed in a given pavement section, AASHTO equation is limited to predict average joint opening in a given pavement section. Therefore the AASHTO equation may underestimate maximum joint for the half of joint in a given pavement section. Joints showing larger opening than the designed may experience early joint sealant failure, early faulting. Also unexpected spalling may be followed due to invasion of fine aggregate into the joints after sealant pop-off. In this study, the variation of the joint opening in a given pavement section was investigated based on the LTPP SMP data. Factors affecting on the variation are explored. Finally a probabilistic joint opening model is developed. This model can account for the reliability of the magnitude of joint opening so that the designer can select the ratio of underestimated joint opening.

Development of Mechanistic-empirical Joint Spacing Design Method for Concrete Pavements (역학적-경험적 콘크리트 포장 줄눈간격 설계방법 개발)

  • Park, Joo-Young;Hong, Dong-Seong;Lim, Jin-Sun;Jeong, Jin-Hoon
    • International Journal of Highway Engineering
    • /
    • v.13 no.4
    • /
    • pp.51-59
    • /
    • 2011
  • Tensile stress occurs and random crack develops in concrete pavement slab when it contracts by variation of temperature and humidity. The tensile stress decreases and the random crack is minimized by sawcutting the slab and inducing the crack with regular spacing. The random crack, joint damage, decrease of load transfer efficiency are caused by too wide joint spacing while too narrow joint spacing leads to increase of construction cost and decrease of comfort. A mechanistic-empirical joint spacing design method for the concrete pavement was developed in this study. Structurally and environmentally weakest sections were found among the sections showing good performance, and design strengths were determined by finite element analysis on the sections. The joint width for which the load transfer efficiency is suddenly lowered was determined as allowable joint with referring to existing research results. The maximum joint spacing for which the maximum tensile stress calculated by the finite element analysis did not exceed the design strength were found. And the maximum joint width expected by the maximum joint spacing were compared to the allowable joint width. The new method developed in this study was applied to two zones of Hamyang-Woolsan Expressway being designed. The same joint spacing as a test section constructed by 8.0m of joint spacing wider than usual was calculated by the design method. Very low cracking measured at 6 years after opening of the test section verified the design method developed in this study.

Effect of Joint Spacing on Early-Age Behavior of jointed Concrete Pavement (줄눈콘크리트 포장의 줄눈간격에 따른 초기거동 연구)

  • Yoon, Chang-Ho;Lee, Jae-Hoon;Kim, Hyung-Bae;Lee, Seung-Woo
    • International Journal of Highway Engineering
    • /
    • v.9 no.3
    • /
    • pp.101-110
    • /
    • 2007
  • Joint Spacing of Jointed Concrete Pavement has been uniformly designed and constructed as six-meter in Korea. However, engineering backgrounds to show the appropriateness of six-meter Joint Spacing has not been provided. In the on-going reseach of the development of Korea Pavement Reseach Program(KPRP), the optimum Joint Spacing is suggested as 6 to 8 meters according to the regional climatic conditions based on the mechanical-empirical analysis of short-term and long-term pavement distress. This study is a part of the investigation on the adequateness of Joint Spacing design specification suggested in KPRP. Joint Spacing was design and constructed as seven-meter Joint Spacing suggested as design specification in Korea Reseach Program(KPRP) and monitored the Load Transfer Efficiency(LTE), Random crack and compared with those of adjacent $6{\sim}7$ meter Joint Spacing concrete section.

  • PDF