This paper presents experimental results for evaluating bond strength of FRP Hybrid Bars(HYB). In order to confirm the bond strength of HYB, direct bond strength tests were performed on 20 specimens. 20 specimens made of deformed steel bars were also tested for relative comparison. HYB and deformed steel bars were embedded in a concrete block with a size of 200 mm and different attachment lengths were applied depending on the diameter of the reinforcing bars. During the test, load and relative displacement(slip) were measured and the load-displacement behaviors of all specimens were analyzed from the measured results. The maximum bond strength of deformed steel bars were higher than that of HYB regardless of its diameter. However, after the maximum load, the deformed steel bars were more dominant than the HYB in the sudden load reduction tendency.

This study derived the unit of industrial water usage reflecting the latest industry trends. Available for establishing plans such as the master plan for water supply system and analyzed changes in the basic unit by a comparison with the current basic unit values. This study analyzed 4,038 samples with a sampling error of less than 1.5 % at the 95 % confidence level after removing outliers according to a log-normal distribution. As a result, the unit of industrial water usage per site area in the whole manufacturing industry was 7.11 m3/1,000m2/d. The ten industrial categories (C10, C13, C20, C21, C22, C25, C27, C30, C32, C33) showed a similar unit value compared to before, and the four industrials categories (C11, C17, C22, C31) showed a more unit value than before. With regard to the nine industrial categories (C14, C15, C16, C18, C19, C24, C26, C28, C29), the unit value decreased. Cases that companies examined before were the same as the companies examined in this study were analyzed. The result that the changes in the unit industrial water usage were reasonable was obtained. However, in some industrial categories (C17, C14, C24, C29), the unit value was changed by a small number of companies with large-scale water use or unit value of sampling had a large deviation. It was considered necessary to survey them periodically. The unit of industrial water usage derived by the survey in this study reflects the current industrial trends in 2016. Water use in manufacturing companies has continuously changed by the development of manufacturing technologies and simplification of manufacturing processes. In order to deal with this, it is considered necessary to survey the usage of industrial water periodically from a long-term perspective.

GFRP(Glass Fiber Reinforced Polymer Plastic) has a superior corrosion resistance, high specific strength/stiffness, etc. Therefore, such properties can be used to mitigate the problems associated with the use of conventional construction materials. In this study, the various rib and pitch distance of hybrid fiber GFRP bars were evaluated by experimental method. From the test result, thirty two types of FRP hybrid bars such as spiral type with the dimension of rib geometry were fabricated. To evaluate the bond properties of them, direct pull-out test was performed. All testing procedures including specimen preparation, set-up of test equipment and measuring devices were made in accordance with the recommendations of ASTM D 7913. From the test results, it was found that cross type hybrid GFRP reinforcing bars showed the highest bond strength than that of the others due to the higher relative rib area.

HYB(FRP Hybrid Bar) is composite structural material that combines reinforced bar and FRP. HYB has high elastic modulus and after-yield-hardening properties, despite its corrosion resistance and light weight. HYB under development has relatively stable corrosion durability. This study performs fundamental experiments for the long period UV exposed HYB, and carries out pull-out test for the freezing-thawing exposed specimens of ordinary reinforced bar, HYB, and UV exposed HYB. The effect of UV exposure and freezing-thawing did not affect the tensile property and strength of HYB. However, the bond strength reduction on the environment of accelerated corrosion should be considered in further study.

During the last two decades, fiber reinforced polymer (FRP) reinforcing bars for concrete structure have been extensively investigated and a number of FRP bars are commercially available. However, major shortcomings of the existing FRP bars are its high initial cost and low elastic modulus compared to conventional steel bars. Because of these reasons, Korea Institute of Civil Engineering and Building Technology (KICT) in Korea has developed the FRP Hybrid Bar which have the concept of material hybridization for concrete structures, especially for marine and waterfront concrete structures. This developed bar is new type material in construction field, verification of long term performance is very important for commercialization. In this paper, verification methodology on long term performance(corrosion, flexural behavior etc) of FRP Hybrid Bar is suggested.

To overcome shortcomings of fiber reinforced polymer (FRP), a hybridized FRP rebar was developed by the authors. This hybrid bar herein called “FRP Hybrid Bar” was fabricated by adopting advantages from two different materials, including glass fiber reinforced polymer (GFRP). Corrosion resistant characteristics of FRP Hybrid Bar were evaluated and the test results were explained in this paper. The use of the alternative reinforcement could allow concrete structures to extend life-span, to save maintenance and repair costs, etc. if the FRP Hybrid Bar was applied to RC structures located in a very corrosive environment, such as marina or harbor areas.

GFRP(Glass Fiber Reinforced Polymer Plastic) has a superior corrosion resistance, high specific strength/stiffness, etc. Therefore, such properties can be used to mitigate the problems associated with the use of conventional construction materials. In this study, the various rib and pitch distance of hybrid fiber GFRP bars were evaluated by experimental method. From the test result, thirty two types of FRP hybrid bars such as spiral and cross type with the dimension of rib geometry were fabricated. To evaluate the bond properties of them, direct pull-out test was performed. All testing procedures including specimen preparation, set-up of test equipment and measuring devices were made in accordance with the recommendations of ASTM D 7913. From the test results, it was found that cross type hybrid GFRP reinforcing bars showed the highest bond strength than that of the others due to the higher relative rib area.

Fiber-reinforced polymer (FRP) bars have advantages as a construction material, including corrosion resistance, lightweight and high tensile strength. However, FRP rebars have shortcomings, such as low elastic modulus comparing to the steel rebar. With these reasons, FRP bars have not been widely used to reinforced-concrete (RC) structures. To overcome these shortcomings, the steel-hybrid GFRP rebars were developed by the authors at Korea Institute of Civil Engineering and Building Technology (KICT). Mechanical properties of the developed steel-hybrid GFRP rebars were experimentally evaluated through this study. Both tensile and bonding tests were conducted and the mechanical performance was investigated as well as corrosion resistance. As a result of all tests, elastic modulus, tensile strength and boding strength of the steel-hybrid GFRP rebars were all improved in comparison with fully GFRP rebars.

FRP Hybrid Bar, composite structures composed of synthetic resins, deformed bar and glass fiber, was invented in order to solve corrosion of rebar in reinforced concrete structures. In order to bond deformed bar and glass fiber to FRP Hybrid Bar, synthetic resins is used. Curing time of the synthetic resins greatly affect productivity. If curing time of synthetic resins is short, cost of facilities is reduced and productivity is increased. Also, If this curing time is shorter or omitted, FRP Hybrid Bar can be commercialized. So, it can cause mass-production and substantial economic effect. Therefore, in this paper, optimum mix proportion is observed in order to increase economic efficiency of FRP Hybrid Bar and reduce curing time of synthetic resins. Total 9 variables are set, adjusting ratio of hardener ratio, and 3 resin moulds on each variables are fabricated. Optimum mix proportion is suggested based on data measured by temperature sensor.

목 적 : 확산강조영상은 골격근 손상이 있을 때 조기에 근육의 신호강도 변화를 알 수 있고 양성과 악성 척추 압박골절의 감별 진단에 유용하다고 보고 되고 있지만 질환에 따른 현성확산계수(Apparent Diffusion Coefficient:ADC)의 연구는 많이 보고 되고 있지 않다. 이에 단순 압박 골절과 전이성 척추암이 b value에 따라서 어떠한 변화가 있는지를 알아보고자 본원에서 시행하고 있는 b value 0 400,1400(s/mm²)를 이용하여 각각의 Signal Intensity의 표준화된 값과 물 분자의 확산 정도를 수치화 하는 ADC, 그리고 신호대 잡음비(Signal to Noise:SNR)를 비교하였다. 대상 및 방법 : 2013년 3월부터 2013년 12월까지 MR판독에서 단순복합골절과 전이성 척추암을 의심하는 환자 중 전자의무기록상 확정된 환자로 두 질환 별로 11명씩 총 22명을 대상으로 하였고 평균연령은 각 질환 별로71.2, 56.6세다. 검사장비는 1.5 Tesla Achieva MRI시스템과 Syn-Spine Coil를 사용하였다. Sequence는 DWI SE-EPI Sagittal(Diffusion Weighted Imaging Spin Echo-Echo Planar Imaging Sagittal)영상으로 TR(ms) 1988, TE(ms) 68, FOV(mm) 300, Mat. 128×128, Thk.(mm) 4, Gap(mm) 0.4, Slice 13, b-factor(s/mm²) 0,400,1400의 Parameter를 이용하였다. 데이터 분석은 확산강조영상 b value 0(s/mm²) 영상에서 SI(Signal Intensity)가 높은 질환 부위에 ROI(Region of Interest)를 잡았고 정상부위는 질환부위 바로 위에서 측정하였다. MRIcro Program을 사용하여 b-value 0, 400, 1400(s/mm²)의 영상으로 각각의 SI를 구하였고 b-value의 각 영상을 가지고 Metlab Software를 이용하여 ADC map을 구하여 이 영상을 가지고 MRIcro Program을 사용해 동일한 위치에 ROI를 적용하여 ADC를 구하였다. 데이터 분석은 첫째 두 질환 별로 b value 0 기준으로 400, 1400(s/mm²)의 SI를 표준화하여 비교 분석하였고(SI400/SI0, SI400/SI0) 둘째 두 질환의 정상부위와 질환부위의 ADC와 SNR를 비교 분석하였다. 통계의 유의성은 MS Excel 의 T-Test를 이용하였다. 결 과 : 단순압박골절의 표준화 값(SI400/SI0, SI400/SI0)은 0.47±0.04, 0.23±0.03이고 전이성 척추암의 표준화 값 (SI400/SI0, SI400/SI0)은 0.57±0.07, 0.32±0.08로 나왔고 두 질환 별 표준화 값은 통계적으로 유의하게 나왔다 (p<0.05). 단순압박골절 질환부위의 b value 400(s/mm²)과1400(s/mm²)에 대한 ADC(mm²/s)는 1.70±0.16, 0.93±0.28이고 전이성 척추암은 1.24±0.21, 0.80±0.15로 측정되었다. 두 질환에서 b value 400(s/mm²)에 대한 ADC(mm²/s)는 통계적으로 유의하게 나왔으나(p<0.05) b value 1400(s/mm²)에 대한 ADC(mm²/s)는 유의하지 않았다(p>0.05). 단순압박골절과 전이성 척추암 질환부위의 b value(0/400/1400(s/mm²) 에 따른 SNR 보면 65.61±2.61/36.32±2.92/20.22±2.16, 48.40±2.72/39.27±7.51/23.02±6.25로 측정되었다. 결 론 : 위 연구는 본원에서 검사하고 있는 b value 0,400,1400(s/mm²)을 이용하여 연구를 하였으며 b value 400(s/mm²)에서 두 질환에서의 표준화 된 값과 현성확산계수의 확연한 차이가 있었다. 결론적으로 일반적인 척추 자기공명영상 검사와 병행하여 확산강조영상의 현성확산계수를 가지고 다양한 척추 질환에 적용시킨다면 보다 정확한 진단에 도움이 될 거라 사료된다. 본 연구의 제한점으로 다양한 b value를 적용하지 못했고 성별, 나이, 각 질환의 병기 및 시기, 전이암의 최초 발병 부위를 정립하지 않았으며 측정 부위를 조영제를 사용한 영상이 아닌 단순히 b value 0(s/mm²)에서 고신호 강도가 나오는 곳의 데이터로 결론을 도출한 점은 앞으로 보완해야 할 것이다.

This study presented a model of enterprise that operates an integrated system, and studied about an integrated element of ISO 9001:2000 and ISO 14001:2004 standard. In addition to this, it grasped what the obstacle elements are in use of an integrated system, and analyzed the effect in use of an integrated system through the survey on 58 enterprises that operate an integrated system, From the result of this study, we have known that the obstacle elements in operation of an integrated system are in lack of understanding of process, in lack of execution ability of system, in unfamiliarity of system and lack of willingness of the executives.

Cercospora kikuchii에 의해서 발병된 대두종자의 부패균에 대한 획득저항성기작을 구명코자 본 연구를 실시하였다. 1. 대두의 건전종자, 자연열개종자, 인위적 상처종자 및 자반병 감염종자재의 전단백질 함량에는 차이가 없었으나 peroxidase활성도는 감염종자에서 월등히 높았다. 2. 대두의 건전종자와 자반병 감염종자의 종피 및 자엽내의 단백질함량에는 큰 차이가 없었으며 peroxidase활성도는 자엽에서는 차이 가 없었으나 종피에서 건전한 종피보다 자반병에 감염된 종자가 2.5배 정도 높은 활성도를 보였다. 3. Polyphenol oxidase는 대두의 건전종자의 자반병 감염종자 모두 활성도가 너무 낮아 측정할 수 없었다. 4. 전기영동에 의한 peroxidase isozyme pattern은 건전종자와 감염종자간에 차이가 없었다. 5. 자반병에 대한 저항성기작은 자반병균에 의하여 대주종피 자체내에서 생화학적 방어기작이 더욱 활성화 하였으며 peroxidase활성도의 증가는 병원균에 대한 반응으로 사료된다.

Structural behavior of blast-resistant door composed with steel plate and inner con’c core was analyzed according to composite and non-composite condition. The results showed that maximum and permanent deflection decrease in the case of composite condition. And as the impact on blast-resistant door increases and radical deformation occurs, there is not much difference in the deflection of the door.

In this study the design sensitivity of blast-resistant door composed with steel plate and inner RC core was analyzed according to increased steel ratio of plate and rebar. The results showed that compressive failure of inner concrete decreased rapidly in the case of specific steel ratio, and that the overall structural performance such as deflection did not changed substantially.

Blast-resistant doors are installed to protect human life, precious equipments and materials in the plant and other similar industrial facilities, national important SOC, evacuation facilities and military shelter. In this study structural behavior according to the boundary condition is analyzed. For the simulation the FE program LS-DYNA is used. Anaylsis results will be used to design blast-resistant door in detail.

Blast-resistant doors are installed to protect human life, precious equipments and materials in the plant and other similar industrial facilities, national important SOC, evacuation facilities and military shelter. In this study structural type and design consideration for blast-resistant doors are reviewed to design a bullet- and blastproof structures including doors.

Since power plants are primarily using seawater as cooling water, they have been severely damaged quite often by various marine organisms inflow in power plants. So, various screen system - bar screen, travelling screen, drum screen and debris filter - have been used as a facility preventing harmful substances into the water intake of power plants. However, it is not enough to prevent too small organisms such as krill shrimp and large mucilages such as jellyfish. Therefore, it is necessary to study the screen system that can prevent harmful substances more efficiently. In the present study, the principal and shape of a air bubble barrier system was proposed as a screen system for preventing harmful substances. Then, analytical studies were carried out to evaluate environmental loading acting on the barrier structure.

This study was conducted to develop a bended steel-hybrid GFRP (Glass Fiber Reinforced Polymer) bar. The steel-hybrid GFRP bar was to develop for replacing steel rebar for RC structures which were built in the corrosive environment. To be used for RC structures, a bended type of steel-hybrid GFRP bar is required. This study explains the results of current status of the project.

Based on the study of the Rule of Mixture for FRP (Fiber Reinforced Polymer), it was found that the tensile strength of FRP rebars (reinforcing bars) with circular cross-sections could be estimated with proper reduction coefficients. In this study, a reduction coefficient for FRP rebars with a diameter of 16 mm was proposed.