PURPOSES : Owing to industrial development, the occurrence of continuous environmental damage such as abnormal weather is accelerating because of a rapid increase in carbon emissions. Therefore, various efforts are expended worldwide to realize a low-carbon ecofriendly society. In the construction industry, various efforts have been realized to reduce environmental pollution such as greenhouse gas emissions, for example by introducing eco-friendly materials and reducing industrial waste. In this study, an asphalt pavement technology that can reduce production and construction temperatures by more than 60 °C is developed to reduce the amount of carbon generated in the asphalt industry. METHODS : The performance of a half-warm asphalt binder developed using thermoplastic elastomers and low-temperature additives was assessed. In addition, the change in the quality of a mixture due to the use of the half-warm asphalt binder was evaluated. RESULTS : As the amount of thermoplastic elastomer used increases, the performance grade of the asphalt binder increases as well. When 3% or more of the elastomer is incorporated, the target performance grade of the asphalt binder is satisfied. In addition, by incorporating the thermoplastic elastomer and a low-temperature additive, the overall moisture and rutting resistance increased even at relatively low production and compaction temperatures. CONCLUSIONS : Additional measures to stabilize quality and improve economic feasibility will present a new paradigm for investigations into eco-friendly asphalt concrete pavements.

PURPOSES : In this study, to improve the quality and construction performance of backfill materials for road excavation and restoration, the basic properties of rapid-hardening materials and stone sludge are analyzed to propose an optimal mix design. METHODS : To utilize rapid-hardening materials and stone sludge as controlled low-strength materials for pipeline construction in downtown areas, specimens were prepared for each compounding condition of fast-hardening materials. Flow, slump, and compressive strength tests were performed at various setting times. Subsequently, the physical and mechanical characteristics of the rapid-hardening backfill material for each mixing factor were analyzed. RESULTS : When ultrafast hardening cement and stone sludge are used, a setting time exceeding 30 min is required for a water–binder (W/B) ratio of 200% or higher. Considering the economic feasibility of ultrafast hardening cement, a W/B of 300% is considered the most suitable when high-performance superplasticizer and retarders are mixed. A flow test was performed on the rapid-hardening backfill material and the results show that if the mixing time exceeds 10 min, then the fluidity decreases rapidly, which necessitates a higher amount of superplasticizer. When ultrafast hardening cement is used, the initial strength (based on 4 h) is 0.7 MPa or higher for all formulations at a W/B ratio of 300%, and the compressive strength decreases slightly as the amount of superplasticizer is increased by 0.1%. CONCLUSIONS : Based on the fluidity and strength of the backfill material, which is composed of a rapid-hardening material and stone sludge, the most optimal performance is achieved when ultrafast-hardening cement with a W/B ratio of 300% is used in addition to a highperformance fluidizing agent 0.3% (wt./B) and retarder 0.2% (wt./B).

돌발성 해충인 매미나방의 방제체계 수립을 위해 시판 유기농업자재 21종에 대한 살충 활성을 실내 검정하였다. 90% 이상의 살충 활성을 보인 유기농업자재 11종을 선발하였으며, 유효성분들을 분석하였다. PLS 제도의 대응하여 본 연구 결과는 돌발성 매미나방의 친환경 방제 및 향후 유기농업자재의 개발에도 활용이 가능할 것으로 생각된다.

Lithium-ion batteries (LIBs) are powerful energy storage devices with several advantages, including high energy density, large voltage window, high cycling stability, and eco-friendliness. However, demand for ultrafast charge/discharge performance is increasing, and many improvements are needed in the electrode which contains the carbon-based active material. Among LIB electrode components, the conductive additive plays an important role, connecting the active materials and enhancing charge transfer within the electrode. This impacts electrical and ionic conductivity, electrical resistance, and the density of the electrode. Therefore, to increase ultrafast cycling performance by enhancing the electrical conductivity and density of the electrode, we complexed Ketjen black and graphene and applied conductive agents. This electrode, with the composite conductive additives, exhibited high electrical conductivity (12.11 S/cm), excellent high-rate performance (28.6 mAh/g at current density of 3,000 mA/g), and great long-term cycling stability at high current density (88.7 % after 500 cycles at current density of 3,000 mA/g). This excellent high-rate performance with cycling stability is attributed to the increased electrical conductivity, due to the increased amount of graphene, which has high intrinsic electrical conductivity, and the high density of the electrode.