도로 포장 기술이 발달함에 따라 내구성 확보 등의 구조성능 중심에서 이용자의 승차감 및 소음 저감 등의 기능성 중심으로 변화하 고 있다. 최근 도로 소음에 대한 민원이 증가하고 있고 도로 소음으로 인한 피해를 보상하라는 판결 사례도 증가하고 있다. 이러한 문 제를 해결하기 위해 차량 소음 저감 효과가 우수한 저소음 포장을 적용하고 있다. 본 연구에서는 저소음 배수성 포장과 저소음 비배 수성 포장의 내구성 및 공용성을 평가하였으며, 기대수명 예측을 위해 국내에 있는 배수성 8종, 비배수성 3종의 제품을 이용하여 실내 성능 평가를 수행하였다. 국토교통부의 "아스팔트 콘크리트 포장 시공 지침(2021)"의 배수성 포장 품질기준 및 비배수성 혼합물에 대 한 품질기준에 따라 시험을 진행하였다. 아스팔트 혼합물의 생산, 저장, 운반 및 포설 시 아스팔트의 흘러내리는 양이 적합한지를 평 가하기 위해 드레인다운 시험을 진행하였고, 배수성 혼합물의 골재 비산 저항성을 평가하기 위해 칸타브로 손실률 시험을 진행하였다. 또한 포장의 수분 저항성을 평가하기 위해 인장강도비(TSR) 시험과 소성변형 저항성을 평가하기 위해 동적안정도 시험을 진행하였다. 이후, 배수성 포장의 투수 성능을 평가하기 위한 실내투수계수 시험을 진행하였고, 저소음 포장의 소음 저감 성능을 평가하기 위해 임 피던스 관을 이용한 흡음률 시험을 진행하였다. 시험 결과 모든 종류의 혼합물이 품질기준을 통과하여 충분한 기초 성능을 가지고 있 는 것으로 나타났고, 흡음률 시험의 경우 배수성 혼합물이 평균 0.779, 비배수성 혼합물이 평균 0.638의 흡음계수를 나타내었다. 배수 성 혼합물과 비배수성 혼합물의 평균 공극률은 각각 19.3%, 3.2%로 배수성 혼합물이 비배수성 혼합물에 비해 많은 공극률을 가지고 있어 소음 저감 성능이 비배수성에 비해 우수한 것으로 판단하였다.
한국 고속도로 포장은 1970년 경부고속도로 건설을 시작으로 많은 발전을 이루었으며, 최근 도로이용자에게 쾌적한 도로를 제공할 수 있는 배수성 아스팔트 포장에 대한 관심이 높아지고 있다. 본 연구에서는 한국 고속도로 배수성 아스팔트 구간에 대한 시공목적별, 신설과 유지보수 등을 구분하여 배수성 아스팔트 포장 적용현황을 분석하였다. 또한, 적용된 배수성 아스팔트 포장의 교통량을 조사 분석하였으며, 효율적인 교통량 그룹 선정 방법을 제시하였다. 고속도로에 적용된 배수성 아스팔트 포장의 전주기 평가를 위해 평가항 목을 제시하였다. 내구성평가 항목으로는 포장상태평가지수와 표면조도를 선정하였다. 기능성 평가 항목으로는 내부 공극 막힘여부를 확인할 수 있는 현장투수, 미끄럼저항지수, 포장노면과 타이어에서 발생하는 도로소음원 평가를 위한 도로소음을 선정하였다. 그리고 조사 항목들에 대한 배수성 아스팔트 포장의 전주기 평가를 통해 각각 조사 항목에 대한 정량적 분석평가를 수행하여 도로소음도 예 측식을 제안하였다.
Using porous asphalt in order to reduce traffic noise and increase road safety specially in rainy weather is become a time demand now a days. Traditional dense asphalt can not provide a well mannered drain systems, adequate road capacity and noise friendly environment, which can make harm to roadway, property and ultimately to the life. In contrast, porous asphalt provides a environment friendly, cost effective, high skid resistive and well drains pavement with great durability. Additionally, the ability of porous to decrease the number of crashes both in sunny and wet-weather are up to the mark. In this context, investigate the ability of porous asphalt allows for deeper insights into all the mentioned factors, which help to make a durable, time demandable, more safer pavements in the field of pavement engineering. By combining some lab tests, field tests and analyzing the data, this research offers more accurate and reliable results to lead a pavement situation adaptable.
새만금 호의 수질 개선을 위하여 국가에서 해수 유통을 증가시킴에 따라 해수 유통 빈도 증가로 인한 새만금 호 내 염분과 저 층수 교환 변화를 알아보기 위하여, EFDC(Environmental Fluid Dynamics Code) 모델을 이용하였다. 갑문 개폐 횟수를 하루 1회에서 2회로 증 가했을 때, 새만금 호 내부 수위는 최대 약 0.7 m 상승하였다. 염분은 서측 방조제 근방에서 2.12 psu 증가하였으며, 담수 유입 부근에서는 1.18 psu 감소하였다. 입자추적을 이용하여 저층수 교환 정도 분석한 결과, 수심 5m 이하 입자 잔류율은 Case 2(1일 2회 개방)에서 Case 1(1 일 1회 개방)에 비해 2.52% 감소한 것으로 나타났다. 이는 수문 개폐 횟수를 증가시켰을 때, 저층수 교환이 더 활발해 질 수 있다는 것을 알 수 있다. 따라서 해수 유통 증가에 따른 염분 및 저층수 교환 증가로 새만금 호의 수질 개선이 될 수 있다고 판단된다.
본 연구는 기후변화에 따른 콩의 한해 및 습해에서의 안정생산 재배법 확립을 위한 물관리 방법별 생육특성 및 수량을 알아보기 위하여, 2021년과 2022년 2년에 걸쳐 무처리, 무굴착 땅속배수, 지중점적 관개 및 무굴착 땅속배수 + 지중점적 관개(관·배수 통합) 4처리로 수행하였다. 연차간 토양수분함량 및 토양수분장력은 관·배수 통합 처리구에서 토양 수분 장력 변이가 낮고, 안정적 토양수분 유지가 가능했으며, 2021년 생육특성 조사에서는 관·배수 통합 처리구 초장이 57.1㎝로 가장 길게 나타나, 가장 짧은 무관개 43.1㎝ 대비 32.5% 더 길게 조사되었으며, 2022년 초장 또한 같은 경향으로 관·배수 통합 > 지중점적관개 > 무굴착 땅속배수 > 무관개 순서로 길었다. 수량구성요소에서도 생육특성과 같은 경향을 보였으며, 이에 수량도 수량구성요소가 가장 높았던 관·배수 통합 처리구에서 연차간 각각 409, 346 kg/10a로 가장 많았다. 그러나, 관개량 및 물 이용효율 평가에서는 관·배수 통합 처리구가 지중점적관개 처리구 대비 일평균 관개량 203.1 ton/10a 더 많을 뿐만 아니라, 물 이용효율에서도 45.6% 더 낮게 나왔기 때문에 추후, 기후변화 환경에서의 효율적인 물관리와 한정된 농업용수 사용을 최대화로 할 수 있는 관개량에 따른 더 세부적인 연구가 추가된다면, 현재 지구온난화 등의 영향으로 범지구적 물 부족 현상이 나타나는 환경에서 보다 더 물 효율성을 극대화 시키고, 안정적인 콩 물관리 재배기술 개발의 기초자료가 될 수 있을 것으로 사료된다.
PURPOSES : Fine dust significantly affects the atmospheric environment, and various measures have been implement to reduce it. The aim of this study is to reduce fine dust on roads by implementing porous pavements and a clean road system using the low-impact development technique.
METHODS : We conducted quality tests (draindown, cantabro loss rate, tensile strength ratio, dynamic stability, and indoor permeability coefficient tests) and performance evaluation (dynamic modulus and Hamburg wheel-tracking tests) on the porous asphalt mixture. Subsequently, we constructed a porous pavement road in a test bed and conducted a permeability test. In the test bed, we installed a nozzle, a water tank, and a fluid pump to water the roadside. After the clean road system was completely installed, we measured the concentration of fine dust before and after water was sprayed. Additionally, we conducted a total suspended solids (TSS) test to confirm the reduction in re-suspended dust.
RESULTS : All results from the quality test of the porous asphalt mixture satisfy the standards stipulated by the Ministry of Land, Infrastructure and Transport. Results from the dynamic modulus test show a low plastic deformation resistance but a high fatigue crack resistance. The results from the Hamburg wheel-tracking test satisfy the U.S. Department of Transportation standards. After the porous pavement was constructed, a permeability test was conducted, and the result satisfies the standard value. Using a particle counter, we measured the concentration of fine dust before and after water spraying, and results show 12.08% and 10.23% for PM10 and PM2.5 particles, respectively. The results from the TSS test show that after the initial water spray, almost all re-suspended dust are removed from a road. In unfavorable road conditions, almost all re-suspended dust are removed after a second water spray.
CONCLUSIONS : The results of all of quality tests performed on a porous asphalt mixture satisfy the standards. By applying the results to a test bed, the problem of securing water is solved. Using the clean road system, 12.08% and 10.23% of PM10 and PM2.5 particles are removed, respectively. The system removes PM10 particles (larger particles) more effectively compared with PM2.5 particles. IN the future, we plan to revise the maintenance plan such that the porous pavement can exhibit long-term performance. Because pipe freezing may occur in the winter, we plan to analyze the periodic maintenance plan of the porous pavement and develop a solution to mitigate the issue of freezing pipes in the winter.
본 연구는 2018, 2019, 2020년 논에서의 배수 깊이에 따른 식용(일미찰), 사료용 옥수수(광평옥) 그리고 장류콩(대원콩) 및 나물콩(해품콩)에 대한 생육 특성과 수량 구성요소를 비교 검토하고자 수행하였다. 논의 배수로 폭은 80cm로 고정하고 깊이를 20cm과 40cm로 각각 달리하였다. 연차간에 있어서 일미찰은 간장, 착수고, 이삭무게 이삭착립장 및 이삭 수량이 고도의 유의성이 나타났으며, 광평옥도 일미찰과 유사한 반응을 보였다. 배수로 깊이에서는 40cm가 20cm보다 수량이 고도로 유의하게 높았다. 한편, 연차간 해품콩은 간장, 분지, 꼬투리 수, 미 성숙 종자률, 100립 중 및 종실 수량에 고도의 유의한 차이를 보였다. 반면, 대원콩은 간장, 100립중, 수량간에 고도로 유의하였다. 배수로 깊이 간에는 해품콩과 대원콩의 수량은 통계적 유의한 차이는 나지 않았지만 20cm보다 40cm에서 수량이 약간 높았다. 본 연구 결과 옥수수의 수량은 배수로 깊이에서 따라 통계적인 고도 유한 차이를 보였으나 콩은 통계적인 차이는 나타나지 않았으나 40cm이 20cm보다는 높았다. 한편 콩은 미성숙 종자률은 배수로 깊이에 효과적으로 차이를 보였다. 따라서 논에서 옥수수 또는 콩을 재배시 가장자리에 20cm 배수로 보다는 40cm 배수로 설치를 권장한다.
Total of 325 estuaries in Korea were surveyed to analyze the effect of presence of sluice gate on the estuary environment and fish community from 2016 to 2018. Fish community in closed and open estuaries showed differences generally, and the relative abundance (RA) of primary freshwater species in the closed and migratory species in the open estuaries were high. The result of classifying species by habitat characteristics in closed and open estuaries showed similar tendencies at the estuaries of south sea and west sea. The relative abundances of primary freshwater species in the closed estuaries at the estuaries of south sea and west sea were the highest, but estuarine and migratory species were high in both closed and open estuaries at the estuaries of east sea. Primary freshwater species showed higher abundances in the closed estuaries with reduced salinity due to blocking of seawater since they are not resistant to salt. However, primary freshwater species in open estuaries at east sea was higher than that of the closed estuaries, which is considered to be the result of reflecting the characteristics (tide, sand bar, etc.) of the east sea. Korea Estuary Fish Assessment Index (KEFAI) was showed to be higher at open estuaries than closed in all sea areas (T-test, P<0.001), the highest KEFAI was observed in closed estuaries at south sea, and open estuaries in east sea. Fish community of closed and open estuaries in each sea areas showed statistically significant differences (PERMANOVA, East, Pseudo-F=3.0198, P=0.002; South, Pseudo-F=22.00, P=0.001; West, Pseudo-F=14.067, P=0.001). Fish assemblage similarity by sea areas showed a significant differences on fish community in closed and open estuaries at east sea, south sea, and west sea (SIMPER, Group dissimilarity, 85.85%, 88.36%, and 88.05%). This study provided information on the characteristics and distribution of fish community according to the types of estuaries. The results of this study can be used as a reference for establishing appropriate management plans according to the sea areas and type in the management and restoration of estuaries for future.
A heat pump system using wasted heat from thermal effluent to supply the heating energy can reduce energy consumption and emissions of greenhouse gases by greenhouse facilities nearby. The Jeju National University consortium constructed a heat pump system using the thermal effluent from the Jeju thermal power plant of KOMIPO to provide with cool or hot water to greenhouse facilities located 2.5km from the power station. In this paper, the system configuration of the heat pump system was summarized, and the results of operations for demonstration of a heating performance carried out during the winter season in 2018 were investigated. Therefore, if the heating control by supplying thermal effluent to the facility greenhouse, it can contribute to reducing the energy cost and improving quality.
PURPOSES : This study aims to develop drainage minor-structure materials using asphalt mixtures, and to apply construction methods.
METHODS : The AP-5, 120-150A, and 150-200A binders were adopted to select the optimal asphalt binder for the domestic application of asphalt concrete in curb construction. The mixture design of asphalt mixtures has applied the standard for evaluating asphalt curb mixtures in Korea. Test construction utilized asphalt curb equipment to evaluate asphalt mixtures, according to the type of asphalt binder.
RESULTS : The results of the asphalt mixture design indicated that the optimum asphalt content was determined at 2–3% air void for each type of asphalt binder, and the quality of the asphalt mixture applied with asphalt curb binder was excellent. In addition, the quality difference was significant, depending on the temperature of the asphalt mixture at each phase of the asphalt curb construction.
CONCLUSIONS : Asphalt curb construction using asphalt materials has a large impact on the quality, depending on the temperature of the asphalt mixture, therefore management at the appropriate temperature is important when applying it to the site. Further research is also required on the production, transportation, and dedicated equipment of asphalt mixtures.
This study investigated the odor dilution rate at 15 locations around three schools in Seoul using an onsite olfactometer. In addition, odor intensity, odor quality, and hedonic tone by direct sensory method were measured along with measurement of the field odor dilution rate, and instrument analysis using odor sensor array and TD-GC was also measured. Onsite olfactometer measurements show that only one of the three schools measured odors exceeding the strict emission acceptance standard of 10 at three points. The average odor intensity at each point measured by the direct sensory method of five persons was in the range of 2.7 to 0.3. The difference in the number of odor dilution rates around schools in Seoul could be related to the level of income by region. The odor environment around each school was judged to be well managed in areas with higher income levels, indicating a lower odor dilution rate. The correlation coeffcient between the odor intensity measured by the direct sensory method and the onsite olfactometer was 0.79, indicating high correlation. The correlation coefficient of sensor array and TD-GC toward the odor intensity was -0.28 and 0.02, respectively. This suggests that a method based on a person's sense of smell should be introduced when measuring low-level odor dilution rates in non-industrial areas, such as school zones.
Environmental fundamental facilities have different odor emission characteristics depending on the type of treatment facilities. To overcome the limitations of the olfactometry method, research needs to be conducted on how to calculate the dilution factor from the individual odor concentrations. The aim of this study was to determine the air dilution factor estimated from manually measured concentration data of individual odor substances (22 specified odor species) in three environmental treatment facilities. In order to calculate the optimum algorism for each environmental fundamental facility, three types of facilities were selected, the concentration of odor substances in the exhaust gas was measured, and the contribution of the overall dilution factor was evaluated. To estimate the dilution factor, four to six algorism were induced and evaluated by correlation analysis between substance concentration and complex odor data. Dilution factors from O municipal water treatment (MWT) and Y livestock wastewater treatment (LWT) facilities showed high level of dilution factors, because concentration levels of hydrogen sulfide and methylmercaptan, which had low odor threshold concentrations, were high. In S food waste treatment (FWT) facility, the aldehyde group strongly influenced dilution the factor (dominant substance: acetaldehyde, i-valeraldhyde and methylmercaptan). In the evaluation of four to six algorism to estimate the dilution factor, the vector algorism (described in the text) was optimum for O MWT and Y LWT, while the algorism using the sum of the top-three dominant substances showed the best outcome for S FWT. In further studies, estimation of the dilution factor from simultaneously monitored data by odor sensors will be developed and integrated with the results in this study.
PURPOSES : This study aims to reduce the urban heat island phenomenon via utilization of porous asphalt pavements.
METHODS : One of the many known functions of porous asphalt is that it reduces the urban heat island phenomenon. Indoor experiments
were conducted to compare the surface temperature of sprinkled dense-graded and porous asphalt and outdoor experiments were conducted
to verify the difference between the two asphalt pavements under external conditions.
RESULTS : The results of the indoor experiment demonstrated that the temperatures of the two pavements were similar and that the porous
asphalt pavement exhibited low temperature when sprinkled; the temperature of the porous asphalt was approximately 2 °C lower than that
of the dense-graded asphalt pavement. The results of the outdoor experiment showed that the peak temperatures of the two pavements were
approximately the same as usual. However, it was confirmed that the surface temperature of the porous asphalt pavement at night after sunset
was lower than that of the dense-graded asphalt pavement and that the peak temperature dropped for approximately 1~2 days after the rainfall..
CONCLUSIONS : Porous asphalt pavement has a lower surface temperature than normal dense-graded asphalt pavement, under the
presence of moisture in the pavement. In addition, it was confirmed that the lower surface temperature of the porous asphalt pavement is due
to the low heat emission of the pavement at night. Accordingly, it is believed that the application of the porous asphalt pavement will not only
have known effects but also significant impacts on the reduction of urban heat island phenomena.