PURPOSES : In this study, an eco-friendly mastic asphalt backfill material is developed to reduce production and construction temperatures by 40 ℃ compared with those recorded when using conventional hot-mix mastic asphalt backfill materials. METHODS : To reduce the production and construction temperatures, SIS polymer modifiers and gum rosin were selected, and gum rosin-modified SIS materials were applied to the mastic asphalt binder mix design. SIS is less viscous than SBS at high temperatures owing to its thermal characteristics, and incorporating gum rosin into SIS causes the latter to exhibit a loose and soft structure. To improve the performance of the mastic asphalt modified with SIS and gum rosin, three different filler mixes, i.e., 100% PMMA, 50% PMMA and 50% calcium carbonate, and 40% PMMA and 60% calcium carbonate were applied. RESULTS : The rosin-modified SIS reduces the viscosity of the developed mastic asphalt binders. In particular, incorporating 3.7% of gum rosin is beneficial to the mastic binder and does not degrade its low-temperature performance. Similarly, using 100% PMMA as a filler improves the performance but results in workability issues at high temperatures. CONCLUSIONS : Rosin-modified SIS and PMMA are promising alternatives for increasing the workability at high temperatures while maintaining the target performance of grade PG82-22 binders if the appropriate ratio of calcium carbonate is mixed with PMMA and an alternative filler comprising calcium carbonate is used.

PURPOSES : The objectives of this study are to develop the eco-friendly pavement material using polyurethane binder and evaluate mechanical properties of the developed binder and concrete. METHODS : The bending beam test was conducted to select the sample candidates of polyurethane binder based on the bending strength. The characteristics of viscosity, curing time, and temperature change of sample binder was examined on different temperature conditions. The mechanical properties of polyurethane binder was estimated using the dynamic modulus testing. The indirect tensile strength test was conducted on polyurethane binder concrete with different gradation and binder content for evaluating the mechanical properties of concretes. RESULTS : Based on the beading beam test, four different binder samples were prepared for estimate the mechanical properties. The viscosity of polyurethane binder tends to increase with increase of liquid temperature and the hardening phenomenon begins 10 to 15 minutes at room temperature after mixing the resin and hardener. It is observed that the dynamic modulus of binder increases as loading frequency increases and change of modulus is found to be the highest in the PU-2I binder type. The PU-2I binder concretes shows the largest value of indirect tensile strength and indirect tensile energy. CONCLUSIONS : The use of polyurethane binder as pavement materials is capable of increasing the pavement performance and reducing the detrimental environmental effect during the highway construction.

The In the experiment on flow using sand walls, when white clay + sand was mixed with glutinous rice, traditional paper and seaweed as adherents and preventive measures for cracks, the flow was higher than other sand wall mortars. This indicates that it is effective in improving flow. Moreover, in terms of strength, a mix of white clay+ sand, traditional paper and flour had a greater strength than a mix of white clay + sand, straws and flour. In the experiment to test for cracks and shrinking during drying, a composition of white clay + sand + traditional paper showed fewer cracks and less shrinking than the walls where straws were mixed in.

To date, chemical managements of plant bacterial diseases are complicated by limitations on use of antibiotics in agriculture, antibiotic resistance development, and limited efficacy of alternative control agents. In this study, thus, we performed screening of eco-friendly farming material (notice no. 2-4-064) containing tannic acid as new antibacterial-activity against 7 plant bacterial pathogens: Pectobacterium carotovorum subsp. carotovorum (Pcc), Ralstonia solanacearum (Rs), Acidovorax avenae subsp. citrulli (Aac), Xanthomonas cirti pv. citri (Xcc), Erwinia pyrifoliae (Ep), Clavibacter michiganensis subsp. michiganensis (Cmm), and Streptomycesscabies (Sc), Initial screening of antibacterial effects of eco-friendly farming material was performed using the paper disk diffusion method and co-cultivation in broth culture. Tannic acid based eco-friendly farming material showed inhibitory effect against Pcc, Rs, Aac, Xcc, Cmm, and Ss, whereas it did not show inhibition zone against Ep. However, when it tested by co-cultivation in broth culture, it showed strong inhibition effect against all pathogens that declined growth curve compared to bacterial pathogen only. Interestingly, when we observed morphological changes on those pathogens by SEM, cell morphologies of 7 pathogens were slightly changed that seem to be malfunction in their cell envelope.

Bacterial fruit blotch (BFB) is one of most important diseases in Cucurbitaceae due to infection of Acidovorax citrulli, causing huge economic losses damage worldwide. This seedborn disease spread rapidly at period of high temperature and humidity. The eco-friendly farming is getting popular. So far there was no effective agent to control BFB in eco-friendly farming. Therefore, effect of the material based on chinese nut-gall extract with antibacterial activity against BFB to was tested against A. citrulli. Different hosts showed various symptoms of BFB. Liquid formulation among exhibited most effective anti-bacterial activity on A. citrulli. Pot experiment in greenhouse showed the potential as an control agent of BFB in cucurbits. The treatment of material based on chinese nut-gall extract showed the positive effect on survival of the watermelon seedling and on the length of the cucumber seedling treated with A. citrulli. We cautiously conclude that the material based on chinese nut-gall extract used in this study may be good agents against major diseases of cucurbits in the future even though it is require to be tested with more study on field test.

In order to get effective and useful results after experiments, it is essential to classify and analyze data resulted from experiments. After these processes, obtained data enables us to have meaningful indications. During experiments, the main concern was to find the reducing ratio of formaldehyde concentrations compared to reference level of added material which affect the indoor air quality. Finally, the main objective of this study is to validate on optimal added amount of eco-friendly material for functional concrete.

지구 온난화, 오존층의 파괴, 기상이변 등 환경문제와 더불어 환경호르몬은 생체의 발육과 성장 및 각종 기능에 중대한 영향을 미치기 때문에 최근에 심각한 문제가 되고 있다. 환경호르몬은 플라스틱과 각종 산업폐기물로 인하여 발생되기 때문에 가정에서 버려지는 쓰레기를 줄이고 이러한 환경문제의 주범이 되는 소재의 대체 소재 개발이 절실히 필요하다고 볼 수 있다. 동일한 기능을 가진 상품이라면 환경오염 부하가 적은 상품, 예를 들면, 에너지효율이 높거나 폐기물 발생이 적은 소재를 선택하는 것이 최선의 방법이다. 일상생활에서 사용되는 석유기반 플라스틱이 분해되는데 필요한 기간은 최소 450년이 걸리며 원재료 가공부터 생산과 판매까지 환경오염을 일으키고 플라스틱의 원재료인 석유는 계속 고갈되고 있으므로 새로운 대체 원재료를 개발할 필요가 있다고 판단하며 본 연구에서는 대체소재 중 식물성 옥수수 소재 PLA보다 우수한 사탕수수 기반 레진으로 이루어진 Bio-PET에 대한 연구를 하고자 한다. 환경 보호 측면이나 기술적 편리성을 가진 Bio-PET는 불필요한 조정 없이 기존 PET의 완벽한 대체 원료가 되며 사탕수수라는 친환경 소재의 장점을 지니고 있고 바이오 에탄올로 만들어져 기존 PET와 같은 투명감과 기능성을 가지고 있기에 내열성, 내구성, 성형성면에서 기존 플라스틱보다 품질이 높기 때문에 차세대 친환경 소재로 사용이 적합하다. 향후에는 이 소재를 이용한 환경 조형물이나 인테리어 벽면 소재로도 응용할 필요가 있다고 판단되며 Bio-PET의 지속적인 연구를 통해 친환경 상품의 대표적 소재로의 역할을 찾고자 한다.