고농도 염화칼슘 농도처리에 따른 토양개량제와 구절초의 염분저감 상승효과

윤용한,양지,박제민,주진희,Yoon, Yong-Han,Yang, Ji,Park, Je-Min,Ju, Jin-Hee 한국환경과학회 2021 한국환경과학회지 Vol.30 No.10

This study aimed to investigate the effects of soil amendment (heat-expanded clay and active carbon) and planting of Dendranthema zawadskii var. latilobum on the remediation of salt-affected soil and the plant growth under high calcium chloride (CaCl₂) concentration. The experimental group comprised treatments including Non treatment (Cont.), heat-expanded clay (H), active carbon (AC), planting (P), heat-expanded clay+planting (H+P), active carbon+planting (AC+P). A 200 mL solution of CaCl₂ at a concentration of 10 g·L^-1 was applied as irrigation once every 2 weeks. Compared to the Cont., the incorporation of the 'heat-expanded clay' amendment decreased electrical conductivity of the soil leachate and cation exchange capacity, whereas the growth of Dendranthema zawadskii var. latilobum was relatively increased. These results suggest that the combination of 'heat-expanded clay' amendment and planting will mitigate negative effect of de-icing salts and improve plant growth in salt-contaminated roadside soils.

도로 제설제 권장 살포량 산정식의 적정성 평가

김진국,양충헌 한국도로학회 2017 한국도로학회논문집 Vol.19 No.4

PURPOSES :This study evaluates the reasonableness of the recommended amount of deicing chemicals based on historical data for snow removal. The result can be used to aid decision-making for the reservation of cost-effective de-icing chemicals.METHODS :First, the recommended amount of de-icing chemical to use and historical usage data were evaluated to identify specific usage characteristics for each region. Road maintenance length and snow-removal working days were analyzed over the past five winter seasons. Next, differences in the recommended amount of chemical to use and actual use were compared using the Kolmogorov-Smirnov test. Last, the two types of data were analyzed using a chi-square test to verify if the two distributions of variation pattern are statistically significant. We found that there are significant differences between the data from each region during the past five winter seasons.RESULTS :The results showed that the equation for calculating the amount of de-icing chemical to use appears to be revised.CONCLUSIONS :The results imply that the equation for calculating the amount of de-icing chemical to apply as a national standard is very important when the public agency makes decisions related to snow-removal.

제설제에 노출된 서울시내 도로 시설물의 열화 환경 분석

윤인석 한국구조물진단유지관리공학회 2022 한국구조물진단유지관리공학회 논문집 Vol.26 No.1

제설제는 동절기 도로 위의 눈을 녹이기 위하여 사용되고 있으나, 서울과 같은 대도시에서 교통이 밀집한 도로 시설물의 열화를 촉진시키는 주요 요인 중의 하나이다. 도로 시설물의 합리적인 유지관리 전략을 수립하기 위하여 제설제에 노출된 도로 시설물의 환경분석이 필요하다. 본 연구는 서울시의 적설량 및 사용된 제설제량을 토대로 외래 염소농도를 계산하였다. 평균 표면 염소이온량을 구하고자 서울시의 5년간 기후환경 및 제설제 사용량을 이용하였으며, 주간선 및 보조간선율 17.5 ~ 30%, 제설제 노출 유효면적율 50 ~ 80% 수준에서 검토하였는데, 농축 속도는 0.073~ 0.077%/년, 최대 표면 염소이온량은 콘크리트 중량대비 2.2 ~ 2.31% 수준이었다. 본 연구결과는 염소이온 프로파일의 예측 또는 콘크리트 구체의 화학적 부식정도 등으로 종합적인 유지관리 대책을 수립하는데 활용될 수 있을 것으로 기대된다.

국도 상 도로시설물 대상 열화환경 조건 별 콘크리트 염화물 침투 특성 분석

민지영 ( Jiyoung Min ),이종석 ( Jong-suk Lee ),이탁곤 ( Tack-gon Lee ),차기혁 ( Ki-hyuk Cha ) 한국구조물진단유지관리공학회 2021 한국구조물진단유지관리공학회 논문집 Vol.25 No.5

「시설물의 안전 및 유지관리 실시 세부지침(성능평가편)」의 내구성능 평가에서 열화환경 평가항목으로 제시된 제설제 및 비래염분에 의한 염해환경, 동해환경이 국내 국도 상 콘크리트 도로시설물의 염화물 침투특성에 미치는 영향을 살펴보았다. 강원 고성, 서울, 경기 고양, 부산에 위치한 교량 총 4개소, 강원권 방호울타리 4개소, 부산권 방호울타리 3개소 및 옹벽 1개소를 대상 시설물로 선정하였으며, 제설제에 의한 직접·간접적인 염해환경, 해안거리 및 교각 높이별 비래염분에 의한 염해환경에서 염화물 침투특성을 분석하였다. 분석 결과, (1) 제설제 살포일수(강설일수)에 따른 지역별 특성이 명확하게 구분되었고, (2) 바닥판 관통 누수 혹은 신축이음부를 통한 누수 등이 발생한 경우 침투 염화물량이 유의미한 수준까지 증가하였으며, (3) 부산 해안가에 위치한 교량의 경우 높이 20m까지 비래염분의 영향권에 해당함을 확인하였다. 이로부터, 동일한 시설물이라도 노출된 열화환경, 부재의 위치 및 높이, 열화진전상태에 따라 염화물 침투특성이 달라지기 때문에 시설물 점검 시 점검대상 부재 및 위치의 선정이 매우 중요함을 확인하였으며, 국내 지역별 및 부재별 열화환경에서의 염화물 침투특성에 관한 데이터 베이스를 구축한다면 콘크리트 시설물에 대한 선제적인 내구성능 관리가 가능할 것으로 기대된다. The deterioration environments caused by de-icing salt and airborne chlorides in the seashore, evaluated in the “Detailed guideline for safety and management practice of facilities (performance evaluation)”, were reviewed in terms of penetrated chlorides into concrete on various road facilities. Target concrete structures, in this study, were 4 concrete barriers in Gangwon area, 3 concrete barriers and 1 retaining wall in Busan area, and 4 bridges in Gangwon-do, Seoul, Gyeonggi-do, and Busan. The deterioration environments were classified into three categories: direct and indirect de-icing salt attack, and airborne salt attack depending on the distance to seashore and the height of pier, and the penetrated chlorides in to concrete were analyzed. The results showed that (1) the regional deterioration environments were clearly classified by de-icing salt sprayed days (snowfall days), (2) the penetrated chlorides increased significantly when leakage occurred through slabs or expansion joints, and (3) the airborne chlorides affected to a height of 20 m concrete in the seashore, Busan. From these, it could be confirmed that the chloride ion penetration properties depend on the exposed aging environment, member location and height, and deterioration status, even on the same structure, so the selection of target members and location is very important in the inspection and maintenance. If the database of penetrated chlorides properties in various deterioration environments is constructed, it is expected that the proactive durability management on concrete structures will be possible in the field.

Neuro-fuzzy model of concrete exposed to various regimes combined with De-icing salts

Ahmed Ghazy,Mohamed. T. Bassuoni 사단법인 한국계산역학회 2018 Computers and Concrete, An International Journal Vol.21 No.6

Adaptive neuro-fuzzy inference systems (ANFIS) can be efficient in modelling non-linear, complex and ambiguous behavior of cement-based materials undergoing combined damage factors of different forms (physical and chemical). The current work investigates the use of ANFIS to model the behavior (time of failure (TF)) of a wide range of concrete mixtures made with different types of cement (ordinary and portland limestone cement (PLC)) without or with supplementary cementitious materials (SCMs: fly ash and nanosilica) under various exposure regimes with the most widely used chloride-based de-icing salts (individual and combined). The results show that predictions of the ANFIS model were rational and accurate, with marginal errors not exceeding 3%. In addition, sensitivity analyses of physical penetrability (magnitude of intruding chloride) of concrete, amount of aluminate and interground limestone in cement and content of portlandite in the binder showed that the predictive trends of the model had good agreement with experimental results. Thus, this model may be reliably used to project the deterioration of customized concrete mixtures exposed to such aggressive conditions.

Kalman Filter 알고리즘을 활용한 제설제의 융빙 성능 평가에 관한 연구

공유석,김도완,가현길,이시원,문성호 한국도로학회 2020 한국도로학회논문집 Vol.22 No.1

PURPOSES: The intensiveness of highway management has increased owing to the growth in the number of vehicles and the rapid climate change. The disadvantages produced by these factors can affect management time and cost. Serious traffic accidents and traffic jam may be experienced when snow fall accumulates on highway surfaces and the friction between tires and pavements is lower than that in the general state, in a non-management condition. Such conditions need intensive management. In this regard, one of the spread methods used for the melting material is pre-wetted salt (PWS), which is the frequently used method in South Korea. In the PWS method, the solid material with CaCl2 is mixed with water in 30% concentration and then finally mixed with NaCl before application to pavements. The chloride-type melting material not only is cheaper, but also has a high melting property than the others. It can shorten the pavement or structure life by deterioration and corrosion. This melting material can affect the flora near the highways; hence, an eco-friendly de-icing agent must be utilized considering the environmental effect. METHODS : The Kalman filter algorithm (KFA) was utilized herein to develop optimization models using the performed test data. The KFA, which was developed from recursive filter algorithms, such as the low- and high-pass filters, applies a weighting filter to the Kalman filter. The algorithm has the property of utilizing the filter and updated estimations. In this regard, melting tests were performed for the real applicative utilization of de-icing agents. The KFA was also applied to reduce the error rates and optimize the relationships between the test data and the predictions. RESULTS: Comparing the measurements performed, the error was reduced by 1.69 g when the KFA was applied. Moreover, the error can be optimized to approximately 91.4% compared to the test errors. The prediction data had over 85% tendency in the test measurement, showing that the KFA application can reduce the error and increase the tendency. By comparison, the agent with CaCl2 showed the best ice melting performance within 10 min without surface temperature. However, the PWS with a 25% concentration indicated the best water melting performance from start to end of the test time, implying that this is a powerful agent in terms of performance. CONCLUSIONS : The melting test is an artificial test method; therefore, it can generate a huge error from the test. The error and the tendency can be controlled by tracking the measurement error and the white noise matrix using the KFA. A further research will be performed to track the measurement error and the white noise matrix. Other optimization methods will also be applied to reduce the experimental error.

시멘트 콘크리트 포장의 스케일링 저항성 평가방법에 관한 실험적 연구

이현기,오홍섭,심종성,심재원 한국구조물진단유지관리공학회 2015 한국구조물진단유지관리공학회 논문집 Vol.19 No.3

적설한랭지의 경우, 동절기의 동해 및 적설에 의한 교통통행의 원활을 기하기 위하여 제설제를 사용한다. 이와 같은 제설염의 사용은 동결융해 및 염화물에 의해 콘크리트의 급속한 스케일링 피해를 야기시킨다. 이에 대한 피해로 인하여 콘크리트 포장은 콘크리트의 피복두께감소에 따른 조기 열화 및 사용자의 안정성 등 여러 가지 문제를 발생시킨다. 이에 따라 국외적으로 이와 같은 현상에 대하여 평가를 하기위해 다양한 시험 및 평가 방법이 제시되고 있다. 하지만 국내에서는 아직 평가방법에 대한 규정은 없으며, 관련 연구 또한 미미한 수준이다. 따라서 본 논문에서는 각 기관 및 나라에서 제시되고 있는 평가방법을 조사하고, 각각의 규정에 따라 실험을 수행하여 결과를 도출하여비교⋅분석하였다. 나아가 이와 같은 실험방법과 실험결과의 고찰을 통하여 국내현장에 맞는 실험법을 제안하고자 한다. In cold-climate regions, deicing agents is used for smooth traffic on the road due to freezing and snowdrift in winter. The use of de-icing salts has resulted in the accelerated scaling damage of concrete with salt damage under freezing and thawing condition. Scaling is the deterioration of concrete where in the paste-mortar structure delaminates in flakes from the surface of the concrete. Due to such damage, concrete pavement causes various problems such as early deterioration according to the decrease in the thickness of cover concrete and user's stability issues. Accordingly, various tests and evaluation methods have been suggested in order to evaluate these phenomena in other countries. However, there have been no regulations for the evaluation method in South Korea, and related studies are also very rare. Therefore, in this study, the evaluation methods proposed by each institution and country were investigated and the experiments were performed according to each regulation, followed by the comparison and analysis of the results. Furthermore, this study aims to suggest the optimized experimental method adopted to domestic field through the discussion of such experimental methods and results.

시멘트 콘크리트 포장의 스케일링 저항성 평가방법에 관한 실험적 연구

이현기,오홍섭,심종성,심재원 한국구조물진단유지관리공학회 2015 한국구조물진단유지관리공학회 논문집 Vol.19 No.3

적설한랭지의 경우, 동절기의 동해 및 적설에 의한 교통통행의 원활을 기하기 위하여 제설제를 사용한다. 이와 같은 제설염의 사용은 동 결융해 및 염화물에 의해 콘크리트의 급속한 스케일링 피해를 야기시킨다. 이에 대한 피해로 인하여 콘크리트 포장은 콘크리트의 피복두께 감소에 따른 조기 열화 및 사용자의 안정성 등 여러 가지 문제를 발생시킨다. 이에 따라 국외적으로 이와 같은 현상에 대하여 평가를 하기 위해 다양한 시험 및 평가 방법이 제시되고 있다. 하지만 국내에서는 아직 평가방법에 대한 규정은 없으며, 관련 연구 또한 미미한 수준이 다. 따라서 본 논문에서는 각 기관 및 나라에서 제시되고 있는 평가방법을 조사하고, 각각의 규정에 따라 실험을 수행하여 결과를 도출하여 비교⋅분석하였다. 나아가 이와 같은 실험방법과 실험결과의 고찰을 통하여 국내현장에 맞는 실험법을 제안하고자 한다. In cold-climate regions, deicing agents is used for smooth traffic on the road due to freezing and snowdrift in winter. The use of de-icing salts has resulted in the accelerated scaling damage of concrete with salt damage under freezing and thawing condition. Scaling is the deterioration of concrete where in the paste-mortar structure delaminates in flakes from the surface of the concrete. Due to such damage, concrete pavement causes various problems such as early deterioration according to the decrease in the thickness of cover concrete and user's stability issues. Accordingly, various tests and evaluation methods have been suggested in order to evaluate these phenomena in other countries. However, there have been no regulations for the evaluation method in South Korea, and related studies are also very rare. Therefore, in this study, the evaluation methods proposed by each institution and country were investigated and the experiments were performed according to each regulation, followed by the comparison and analysis of the results. Furthermore, this study aims to suggest the optimized experimental method adopted to domestic field through the discussion of such experimental methods and results.