In this study, monitoring of food additives as an artificial sweetener on favorite foods of children,which are deal at retail store and stationery store around eliminatory school, was performed. We analyzed aspartame,potassium acesulfame, sodium saccharin, and cyclamate from candys, biscuits, chocolates and others. Total 604 items as targeted food were collected from the other country; 285 items of candys, 131 items of biscuits, 74 items of chocolates.,114 items of others. Targeted foods were classified by manufacture nation; 308 samples from domestic products,211 from China, 26 from Indonesia, and 59 items from other nations. Artificial sweeteners were detected from 75 cases of food stuff which were 38 native product, 25 China, 9 Indonesia, and 3 others. The percentage of detected artificial sweeteners was aspartame 7.8% (47 cases), potassium acesulfame 3.0% (18 cases), sodium saccharin 1.8%(11 cases), and cyclamate 2.6% (16 cases). The detected concentration were followed [average(minimum-maximum)mg/kg]; aspartame 817 (21-4,988), potassium acesulfame 192 (24-1,136), sodium saccharin 91 (5-326), and cyclamate 926 (8-4,680). Aspartame was detected mainly on Korea foods, and cyclamate and sodium saccharin were detected from Indonesia food, artificial sweeteners were detected Chinese food, broadly. As a result, 17 cases were violated against regulatory standard of cyclamate, and sodium saccharin. Considering average body weight (36.9 kg)and daily intake of biscuits (15.6 g) for elementary student, ratio of estimated daily intake and acceptable daily intake was 0.86% for aspartame, 0.54% for potassium acesulfame, 0.77% for sodium saccharin, and 3.56% for cyclamate.

탄소섬유는 경량이면서 높은 기계적 특성 때문에 우주항공, 선박, 자동차, 토목 및 건축과 같은 산업분야에서 그 어느 때 보다 더 광범위하게 적용되고 있다. 본 연구는 섬유혼입률 및 섬유길이 변화에 따른 탄소섬유 보강시멘트 복합재료( CFRC)의 역학적 특성과 휨 거동을 분석하였으며, 또한 자연 낙하시험에 의한 모르타르 시편에 대한 내충격성을 비교, 검토하였다. 더불어, 탄소섬유(CF)의 혼입률은 0.5%, 1.0%, 2.0% 및 3.0%로 변화를 주었으며, 각각의 섬유길이는 6 mm와 12 mm를 사용 하였다. 실험결과, 플로우 값은 탄소섬유의 뭉침현상으로 인해 유동성 측면에서 매우 불리하였으며, 단위용적질량은 다소 감소하였다. 특히, 압축강도는 탄소섬유 혼입량이 증가함에 따라 감소하는 것으로 나타내었다. 반면 휨 강도는 섬유 길이가 12 mm이고 2% 혼입한 것이 가장 높은 휨 강도를 보였다. 내충격성 시험결과, 보통 모르타르 시편은 완전파괴까지의 낙하횟수가 2∼3회 정도 걸리지만 반면 CFRC 시편은 섬유혼입량이 증가함에 따라 다소 차이가 있지만, 섬유길이가 12 mm이고 섬유혼입량 2% 인 경우 충격에 대한 저항성이 가장 높았다.

This paper is focused on flexural bahavior of cement composites reinforced with carbon fibers as a part of research for improving a seismic performance of structures using carbon fiber reinforced concrete(CRFC). Flexural behavior test was conducted on respective specimens reinforced with different fiber length(6mm, 12mm) and contents(0%, 0.5%, 1.0%, 2.0%, 3.0%). The result of the test showed that the flexural performance of carbon fiber reinforced cement composites are directly proportional to the fiber contents except for the specimen reinforced with 3% carbon fiber.

Light Emotion Friendly Concrete (LEFC) transmits light through plastic rods inserted in concrete to stimulate emotion and give new image to space. There is a characteristic that can give a diverse and sensuous feeling depending on the change of the diameter and the interval of the plastic. For the application in the field, it is necessary to analyze the mechanical characteristics according to the case. In this study, we investigate the change of the mechanical properties of the light transmitting concrete reinforced with PVA fiber according to the change of the diameter (5mm, 10mm) and spacing (10mm, 15mm, 20mm) of the plastic rod.

This study was conducted improve reduction of flexural performance cuased by using acrylic round bar. For the specimen, different fiber contents(0.2%, 0.4%)was used for recycled waste ALC and the bottom ash light weight aggregate respectively to confirm the flexural performance according to the fiber content. The result of the test showed that the specimen with 0.4% fiver content shown to have improvement of flexural performance.

This study was conducted to examine the workability of LEFC in relation to the types and the mix ratio of different foaming agents. The foam agents act as lightweight aggregates in the concrete matrix and provide an alternative to obtaining the adequate strength level for the foam concrete. The results of the test showed that the synthetic foam agents were able to act properly as replacements for the lightweight aggregates.

This study was conducted examine the workability of LEFC in relation to unit quantity of water and fiber addition. The LEFC should secure low weight and good flow by mixing light weight aggregate because the fresh concrete should cured so that gaps do not form between the acrlyic wedges and the concrete with the fresh. The slump tests revealed that fresh concrete with 180 units of water and 0.1% fiber content and fresh concrete with 190 units of water and 0.1%, 0.2% fiber content respectively had excellent workability.

This study was conducted examine the mechanical properties of LEFC in relation to the type of light weight aggregate and replacement ratio. For the specimen, different replacement ratio was used for recycled waste ALC and the bottom ash light weight aggregate respectively. The tests revealed that 60% of the waste ALC light weight aggregate is suitable for securing the optimal strength and light weight of the LEFC.

This study was conducted to examine the workability of LEFC in relation to the types and the mix ratio of different foaming agents. The foam agents act as lightweight aggregates in the concrete matrix and provide an alternative to obtaining the adequate strength level for the foam concrete. The results of the test showed that the synthetic foam agents were able to act properly as replacements for the lightweight aggregates.

This study was conducted examine the workability of LEFC in relation to unit quantity of water and fiber addition. The LEFC should secure low weight and good flow by mixing light weight aggregate because the fresh concrete should cured so that gaps do not form between the acrlyic wedges and the concrete with the fresh. The slump tests revealed that fresh concrete with 180 units of water and 0.1% fiber content and fresh concrete with 190 units of water and 0.1%, 0.2% fiber content respectively had excellent workability.

This study was conducted examine the mechanical properties of LEFC in relation to the type of light weight aggregate and replacement ratio. For the specimen, different replacement ratio was used for recycled waste ALC and the bottom ash light weight aggregate respectively. The tests revealed that 60% of the waste ALC light weight aggregate is suitable for securing the optimal strength and light weight of the LEFC.

According to the results of case studies on leakage in large scale aquarium structures, the causes have been identified as construction failure of sealant for joint of sealant design failure in acryilic panel and concrete substrate joints. However, as there currently are no standardized design or specifications for such principles, this study proposes a design formulation of a width and depth of sealant when applied to acrylic panels in large scale aquarium structures.

Unconditional usage of multi-layered waterproofing membrane system is common in large scale spatial structures in the contemporary setting. This study aims to evaluate the limitation of multi-layered waterproofing membrane system applied to the roofing system of large scale spatial structure and examine thoroughly whether such systems are suitable for steel plate concrete or not.