PURPOSES : Recently, corrosion and deterioration of highway facilities have been increasing owing to the excessive use of deicers. This study aimed to find an optimal snow removal method to develop countermeasures for the problem of excessive deicer use and improve the efficiency of snow removal. METHODS : Theoretical investigations and experiments related to deicing were conducted to determine the differences between deicing chemical types and states. Based on regional weather patterns, the entire country was categorized into four groups: warm and heavy snow, warm and light snow, cold and heavy snow, and cold and light snow, and matched with each regional office of the Korea Expressway Corporation. RESULTS : Optimal snow removal methods were proposed considering regional characteristics and deicing chemical types and states. CONCLUSIONS : Different deicer types were proposed according to the region type, such as using only salt and salt/calcium chloride in the warm and cold regions, respectively. Second, plowing was more effective at lower temperatures. Third, liquid deicer spraying could reduce the amount of deicer used. A liquid deicer is suitable for preliminary spraying because its quick-acting properties are superior to those of a solid deicer, although its lasting properties are inferior to those of the solid deicer.

The composition of the deicer sprayed on the highway is spreading over the highway by the scattering or snow removal activity, or car movement and consequently affecting the vegetation environment around the highway. These are the cause of the damage of fruit trees and crops, and also the cause of corrosion of highway structures. The goal of this study is to estimate the detected range of deicer components from a highway. The concentration of the deicer components in gauze and soil were investigated according to the crossing distance from the highway. The data collected were then used to estimate the concentration range of deicer components in a rage of distance up to 100 m from the highway where the deicer was spread. The sample time and weight of gauze were measured before and after installation, and the soil was collected at more than three points in parallel with the highway at the gauze installation point. The components in gauze and soil were investigated in addition to the deicer components (Ca2+, Na+, Cl-) as well as Mg2+ and K+. As Ca2+ and Cl- components of deicer were affected by agricultural use, Na+ component was selected as a tracer and further SAR (Sodium Adsorption Ratio) of soil was analyzed to examine the degree of influence on vegetation indirectly. The gauze concentration was evaluated by the concentration of the deicer ingredient at the background concentration of the blank gauze. The total amount of the deicer sprayed in the study road for 4 months (winter season) was about 93 ton/km. In the gauze test, the spread of the deicer was detected at a distance of 100 m in study area, but the concentration of the deicer in the gauze by distance decreased rapidly within 10 m from the highway. And concentration of the deicer components in gauze and soil came down after rainy season (August ~ Sep.). The results showed that the components of the deicer could be spread widely by the wind. The effective range of the deicer on vegetation based on SAR in soil was estimated to be less than 20 m from the highway. This study examines the concentration changes of the deicer components in gauze and soils and shows that deicer components sprayed on the highway are accumulated and moved over time by wind, snow removal, terrain, water system and land use around the highway.

Some of the deicer ingredients are the same as fertilizer ingredients from agricultural activities. The goal of this study is to distinguish the components of highway deicer from the components used for agriculture. Among the deicer ingredients, Ca and Cl are substances which can be supplied by fertilizer or livestock manure. However, fertilizer and livestock manure contain plenty of nitrogen, organic matter, phosphoric acid and magnesium, including deicer ingredients. The soil physico-chemical characteristics were analyzed according to the distance from the highway. The physico-chemical analysis items of the soil include electrical conductivity, total nitrogen (TN), available phosphate (Av.P), organic matter (OM), ammonia nitrogen (NH4-N), Cation Exchange Capacity (CEC). In the case of effective phosphoric acid, leaching into the subsoil is very low due to various binding mechanisms in the soil. However, it is considered that the compost (fertilizer) applied to the topsoil is mixed with the soil by the tillage or flattening operation. In addition to the organic matter content of the subsoil appear to 10% or more is that in some cases exhibit a similar level as the topsoil. The average soil organic matter content of about 2.6%. This results shows that an excess of organic compost in the study area flows into subsoil and was mixed with the subsoil. The high EC value at the points outside the snow removal effect range level is not considered to be affected by the deicer. The results of the survey showed that the values were differently detected by agricultural activities, and that they should be approached in a complex way in their interpretation.

OBJECTIVES : This is a basic research for the domestic production of airport-airside deicers. This research selected basic materials for deicers appropriate for the pavement of domestic airports by evaluating the deicing performances of basic materials used in internationalstandard airport deicers and their impacts on pavements. METHODS: Laboratory investigation was conducted to evaluate the asphalt surface tensile strength, concrete scaling impact, ASR impact, and deicing performances of sodium formate (NaFm), potassium formate (KFm), sodium acetate (NaAc), and potassium acetate (KAc), which are the basic de-icing materials commonly used at international airports, approved by the FAA. In addition, the analyses were also performed on the airside deicer urea, which is currently used in domestic airports. RESULTS : Laboratory investigation confirmed that sodium formate, potassium formate, sodium acetate, and potassium acetate had superior surface tensile strength, concrete scaling impact, and deicing performance compared to airside urea, but they also had greater impacts on concrete ASR. Among these materials, sodium formate had the best asphalt surface tensile strength, concrete scaling impact, and deicing performance, while also having the greatest impact on ASR; hence, mitigation plans for ASR were needed, if it were to be used as airport-airside deicer. CONCLUSIONS : It is necessary to consider additional additives to prevent ASR of concrete pavements when developing airport-airside deicers using sodium formate, potassium formate, sodium acetate, and potassium acetate.

최근 들어 철근 부식, 콘크리트 포장표면의 박리파손, 환경 피해 등 염화물계 제설제의 사용에 따른 각종 피해가 보고되고 있으며, 이를 위해 대체 제설제의 개발을 위한 연구가 활발히 진행되고 있다. 하지만 개발된 제설제의 성능평가에 대한 연구는 대부분 실내실험을 위주로 한 기초적이고 제한적인 성능평가에 의존하고 있는 선정이다. 특히 제설제의 융빙성능은 제설제가 갖추어야 할 기본적인 성능으로, 합리적이고 체계적인 평가방법을 통한 융빙성능의 평가가 필수적이다. 본 연구에서는 기존 연구를 바탕으로 보다 구체적이고 현실적인 융빙성능 평가방법을 수립하였으며 그 절차에 따라 본 연구진에 의해 개발된 저염화물계 친환경 제설제인 EFD(Eco Friendly Deicer)의 융빙성능을 평가 및 검증하였다. 실내실험 결과, EFD는 국내 고속도로에서 사용 중인 습염식 제설제와 대등한 수준의 초기 융빙성능을 나타냈으며 2회의 현장살포 실험을 통해 EFD의 융빙성능을 검토한 결과, 전체적인 융빙성능이 습염식 제설제의 융빙 성능에 비해 큰 차이가 없음을 확인하였다.

본 연구에서는 제설제 피해에 따른 토양개량제 사용에 대한 가로변 하층식재로 이용될 수 있는 작살나무로 식물생육과 토양개량효과를 평가하고자 Control, T-W, T-SS, T-SC, T-TC를 실험구로 조성하여 식물생육과 토양화학성 변화를 분석하였다. 토양의 pH에서는 제설제 처리 후 수치가 다소 높아지는 경향이었으며 전기전도도의 경우 제설제 처리 후 증가한 후, 관수 및 토양개량제 처리 후 감소하여 초기값에 근접하는 경향이었다. 또한 치환성양이온 함량의 경우 칼슘이온(Ca2+)과 나트륨이온(Na+)에서 관수 및 토양개량제 처리한 실험구에서 유의한 수준으로 감소하여 그 효과를 검증할 수 있었으며 실험구별로는 T-SS, T-TC 실험구에서 양호한 수준이었다. 식물생육반응에서는 초기 활착시 개엽 상태가 얼마 지나지 않아 제설제를 처리하여 식물의 잎마름과 황엽현상이 빠르게 진행되었고, 잎의 낙화를 초래하였다. 하지만 토양개량제 처리 후 새순이 나타났으며, 지속적인 수세회복을 보였다. 엽록소 함량에서도 염화칼슘 처리 후 모든 실험구에서 감소하다가, 관수 및 토양개량제 처리 후 엽록소함량이 유의한 수준으로 상승하는 것을 확인할 수 있었다. 본 연구는 도시공원 및 가로수변 지피식물로 이용되면서 내염성이 강하다고 보고된 작살나무를 공시식물로 선정하여 제설제로 이용되고 있는 염화칼슘이 생육 및 토양이화학성에 미치는 영향을 알아보고자 한 것이다. 그러나 본 연구에서는 지피식물 중 작살나무 1종에 대해 실험구별 식재한 10주만의 결과를 제시하여 그 경향만을 확인한 것으로 향후 실제 제설제에 의해 피해를 받는 현장조사 및 측정을 통해 그 유의성을 추가적으로 검증해야 할 것이다. 본 연구의 결과는 최근 도로변 레인가든의 조성 등으로 인해 제설제의 가로변 집적이 우려되는 상황에 염화칼슘 저감 및 식물생육 활성화를 위한 기초자료 제공을 목적으로 한 것이므로 모든 식물과 대상지에 일반화 할 수는 없는 상태이므로 향후 다양한 식물과 토양처리기법 등에 대한 구체적 효과 검증이 뒷받침되어야 할 것이다.