PURPOSES : This study evaluates the long-term performance of the asphalt overlay designed by the Seoul pavement design method which determines overlay thickness by considering existing pavement conditions, traffic volume, and bearing capacity of the pavement. METHODS : A total of 76 sections including 17 control sections and 59 design sections were constructed under various traffic conditions, overlay thicknesses and asphalt mixtures. The performance of the pavements has been monitored up to 60 months in terms of surface distresses, rutting, and longitudinal roughness. The service life of the pavements was estimated to be the period when the Seoul pavement condition index (SPI) becomes 6.0, i.e., a rehabilitation level. RESULTS : Overall, the service life of the pavements was 72 months in the control and 120 months for the design sections. For relatively thinner overlay sections than designed, the service life reduced significantly; 36 months for 15cm thick overlay and 120 months for 25cm thick overlay. The service life of the pavement in the bus-only lane was 78 months, which is 30 months shorter than that in mixed-traffic lanes. Out of the bus-only lanes, 56% of the pavement along bus stop was deteriorated early to be a poor condition while only 2% of the pavement in a driving lane was degraded to be poor. The overlay with Stone Mastic Asphalt (SMA) in the wearing surface had 38% longer life than that with conventional dense graded mixtures. CONCLUSIONS : Most of the overlays sections designed by the Seoul pavement design method were expected to survive 10 years, except for bus-only lanes. The control sections having 5 to 10 cm thick overlays showed significant lower performance than the design sections. Thus proper thickness and materials considering the characteristics of existing pavement and traffic volumes should be applied to secure the service life of overlays.

PURPOSES : In this study, the results of an intensive field survey of a composite pavement applied to an expressway in Korea are analyzed. The results are intended to be used as basic data for evaluating the composite pavement and for preparing quality control measures through a review and analysis of the change in the state of the tensile bonding strength of the composite pavement. METHODS : To evaluate, repeated field coring and indoor tensile bonding strength evaluations are conducted for five years, and the commonality evaluation of pavement using pavement condition investigation equipment is conducted annually. RESULTS : The results of this study show that the degree of reflective crack generation varies depending on the type of concrete pavement and type of asphalt mixture applied to the intermediate layer, and that the CRCP composite pavement exhibits better initial commonality than the JCP composite pavement. In addition, it is confirmed that the composite cross-section pavement section with MASTIC applied as an intermediate layer shows excellent adhesion performance between the lower concrete layers from the beginning of construction in all sections, as well as satisfied the quality control standards for good pavement and tensile adhesion even after approximately five years of public use. CONCLUSIONS : Based on a follow-up survey of the composite pavement testing sections, it is confirmed that the section constructed with the MASTIC intermediate layer and CRCP satisfies the quality control standards for good pavement conditions and tensile adhesion even after approximately five years of public use.

급냉법에 의한 역 열유도상전이(RTIPS) 공정을 사용하여 mesoporous polystyrene (PS), polyethersulfone (PES) 막 을 제조하였다. 급냉법에 의한 RTIPS 공정은 급냉 및 승온 시 도포 용액 내 용매 분자들의 결정 생성 및 성장을 통해 나노 규 모의 상전이를 야기시켜 mesoporous 기공들을 형성된다. 시차주사열량계(TA: DSC) 사용해 측정된 사용 용매 dimethylformamide (DMF)와 여러 고분자 함량의 고분자용액들에 대한 엔탈피 변화와 주사현미경(SEM)을 사용하여 측정한 고분자함량에 따른 제조된 막 구조, 그리고 비표면적 분석기(BET) 사용하여 측정한 고분자 함량에 따라 제조된 막의 기공크기분포 및 표준편 차 분석을 통해 RTIPS 공정 시 상전이 거동을 살펴보았다.

PURPOSES : The purpose of this study is to evaluate the performance characteristics of stone mastic asphalt (SMA) pavement by comparison with polymer modified asphalt (PMA) pavement and conventional asphalt pavement, to check the performance characteristics according to the pavement type, pavement materials, traffic volume, and environmental factors and to analyze the quality variation characteristics according to the pavement materials using data extracted from the database of the expressway long-term pavement performance. METHODS : Approximately 10% outlier data of pavement performance data were excluded in order to increase the reliability of the analysis results before evaluating the asphalt pavement performance. The performance model was developed through linear regression analysis by setting the performance period as the independent variable and the highway pavement condition index (HPCI) as the dependent variable. Descriptive statistic analysis of HPCI using the static package for social science (SPSS) tool and the analysis of variance was performed to identify the quality variation characteristics according to the pavement materials. The amount of de-icing agent and traffic level of service were classified as two levels in order to check the influence of traffic volume and environmental factors on the performance characteristics of the asphalt pavement. RESULTS : The tentative pavement performance lives were calculated at 19.3 years for new the SMA pavement (GPS-2), 14.3 years for the SMA overlay on the asphalt pavement (GPS-6), and 10.3 years for the SMA overlay on the concrete pavement (GPS-7). In case of the asphalt overlay, the tentative performance lives were calculated at 8.2 years for the PMA overlay on the asphalt pavement (GPS-6), 7.2 years for the PMA overlay on the concrete pavement (GPS-7), 7.2 years for the conventional asphalt overlay on the asphalt pavement (GPS-6), and 5.5 years for the conventional asphalt overlay on the concrete pavement (GPS-7). CONCLUSIONS : It was confirmed that the SMA pavement showed better performance and quality variation characteristics than the PMA and conventional asphalt pavement. The performance characteristics of the asphalt pavement (GPS-2) was better than the asphalt overlay pavement, and the asphalt overlay on the asphalt pavement (GPS-6) had better performance characteristics than the asphalt overlay on the concrete pavement (GPS-7). It was observed that the asphalt overlay on the asphalt pavement (GPS-6) was strongly influenced by the traffic volume and the asphalt overlay on concrete pavement (GPS-7) was strongly influenced by the traffic volume and de-icing agent.

PURPOSES: The purpose of this study is to analyze the service life of expressway pavement based on both traffic volumes and use of deicing chemicals. METHODS: A database was built using expressway rehabilitation history information from over the last decade. In order to estimate the service life of expressway pavement, various analysis methods were considered, and a decision was made to perform analysis using a method based on an accumulated rehabilitation ratio. The service life of expressway pavement was then analyzed by classifying the scale of traffic volume and extent of de-icing chemicals used. RESULTS: The service life of PMA and SMA ranged from 7.8 to 10.6 years and from 9.9 to 12.0 years, respectively. The service life of JCP ranged from 16.0 to 22.2 years, and the service life of CRCP was 33.5 years on average. Results of assessing service life according to traffic volumes and de-icing chemicals showed that the lower the traffic volumes were, the greater the service life of PMA and JCP, and the less that de-icing chemicals were applied, the greater the service life of JCP. CONCLUSIONS : The dependence of expressway pavement service life on traffic volumes and de-icing chemicals makes it possible to apply LCCA for regional maintenance plans and cost-effective selection of expressway pavement type.

PURPOSES: The purpose of this study is to evaluate physical properties, durability, fatigue resistance, and long-term performance of poly-urethane concrete (PU) which can be possible application of thin layer on long-span orthotropic steel bridge and to check structural stability of bridge structure. METHODS : Various tests of physical properties, such as flexural strength, tensile strength, bond strength and coefficient of thermal expansion tests were conducted for physical property evaluation using two types of poly urethane concrete which have different curing time. Freezing and thawing test, accelerated weathering test and chloride ion penetration test were performed to evaluate the effect of exposed to marine environment. Beam fatigue test and small scale accelerated pavement test were performed to assess the resistance of PU against fatigue damage and long-term performance. Structural analysis were conducted to figure out structural stability of bridge structure and thin bridge deck pavement system. RESULTS: The property tests results showed that similar results were observed overall however the flexural strength of PUa was higher than those of PUb. It was also found that PU materials showed durability at marine environment. Beam fatigue test results showed that the resistances of the PUa against fatigue damage were two times higher than those of the PUb. It was found form small scale accelerated pavement test to evaluate long-term performance that there is no distress observed after 800,000 load applications. Structural analysis to figure out structural stability of bridge structure and thin bridge deck pavement system indicated that bridge structures were needed to increase thickness of steel deck plate or to improve longitudinal rib shape. CONCLUSIONS: It has been known that the use of PU can be positively considered to thin layer on long-span orthotropic steel bridge in terms of properties considered marine environment, resistance of fatigue damage and long-term performance.

기하급수적인 인구증가와 한정된 경작지로 인한 미래 식량수요에 대한 우려가 커지고 있다. 2005년 현재 전세계 65억인구를 위해 헥타당 4명정도분의 식량공급으로 이를 극복하였지만 2030년 세계인구가 80억이상이 되면 헥타 당 5명이상을 위한 식량을 공급하여야 한다. 이를 위해서는 지속가능한 방식으로 전세계 농업생산성을 향상시켜 날로 급증하는 식량 안보를 강화해 나가는 것이 필요하다. 이를 위한 하나의 방법으로 1996년이래 생명공학작물 을 통한 농업생산성을 향상시키는 시도가 지속되고 있다. 지난 5년간 종자시장의 CAGR은 약 8.7%로 2013년 현재 394억달러의 시장가치를 지니며 이중 생명공학작물종자는 CAGR 17%, 시장가치 201억달러로서 일반종자의 CAGR 2.8, 시장가치 193억달러에 비해 급속한 신장을 이루었다. 2013년 현재 전세계 27개국, 1800만 농민들이 1억 7520만 헥타에서 GM작물을 재배하고 있다. 1) 옥수수 ; 미국 전체 옥수수 재배면적 3억4천4백만 헥타의 96%이상이 생명공학 옥수수이며 이중 67% 가 삼중 후대교배종 이상의 품종이다. 브라질의 경우, 2009년이래, 생명공학 옥수수 재배면적은 급격히 증가하여 2012 년에는 전체면적의 85%에 도달하였으며, 이 중 68%이상이 이중후대교배종이었다. 새로운 생명공학 옥수수개 발은 Refuge 경감대책을 위해 작용기작이 다른 해충저항성 및 새로운 제초제 저항성, 가뭄 저항성 /Water-optimaization, 생산성 향상, 질소 이용 효율 증진 등이 주요 타겟이다. 2) 대두 ; 2011년 현재 콩 종자시장 규모는 2011년 현재 약 55억$ 정도이며 이 중 생명공학 대두 종자는 21.8% (12억 달러)를 차지하고 있다. 2012년 현재는 전체 미국 대두재배면적의 98% (3157만 헥터)를 생명공학 대두가 차지 하고 있다. 1%정도가 LibertyLink® 이고, 나머지는 모두 Roundup Ready® 저항성 대두이다. 새로운 생명공학 대 두는 새로운 제초제저항성, 새로운 해충저항성, 선충 저항성, 수확량 향상, 영양성분 강화 (High oleic acid, Omega 3, High oil, High stearate 등)등이 주요 타겟이다. 전 세계 채소종자시장의 가치도 계속 성장하고 있는 중이다. 상업채소종자시장의 규모는 46억 $(2011)에서 매년 7 ~ 8%의 연평균복합성장률(CAGR)을 반영하여 2025년에는 약 130억 $ 정도로 증가할 것으로 추정되고 있다. 인 도, 중국과 같은 많은 개발도상국에서 자가채종 종자에서 상업종자, 특히 교배종 종자로의 전환이 급증하고 있다. 인도에서는 급격한 도시화로 인해 도시근교의 주요 채소재배면적은 감소하고 있으며 중국내 채소재배는 고품질 의 종자가 필요한 고품질의 농산물 수출이 증가하는 따라 영향을 받아 증가하고 있다. 서구 국가의 경우, 새롭고, 구별되고, 건강에 좋으며, 색다른 채소에 대한 수요가 증가하고 있어 이에 따라 종자 가격과 산물 가격이 상승되는 것이 받아들여지고 있다. 신선한 가공채소 트렌드는 어린 상추 잎과 시금치 잎 재배면적을 증가시키고 있다. Spring mix lettuce 파종 비율은 일반적인 상추 파종비율에 비해 20배 이상 증가하였다. 전체적으로 교배종 종자의 가격은 매년 5~8%정도 증가하고 있으며, 고정종(OP) 종자의 경우 매년 2~6%정도 가격이 상승하고 있다