Shear capacity of a Textile Reinforced Concrete (TRC) was investigated by an experimental study. Control beam (unstrengthened) and eight beams strengthened with TRC were fabricated to confirm the reinforcing performance in this study. Test variables considered the number, width, spacing of TRC, and reinforcing method accordance with type of attachment. As a results, it was validated that the shear capacity of beams strengthened with TRC in comparison with unstrengthened beam increased from 11.4% to 54.3% according to the amount of TRC. Experimental results indicated an increase in both load carrying and deformation capacities, and also ductility when using multiple layers of textile.

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.

Concrete structure is a construction material with durability and cost-benefit, however the corrosion in embedded steel causes a critical problem in structural safety. This paper presents an evaluation of chloride resistance and pull-off performance with various corrosion level. For the work, OPC(Ordinary Portland Cement) concrete and GGBFS(Ground Granulated Blast Furnace Slag) concrete are prepared with normal steel. Artificially notch induced FRP Hybrid Bar is also prepared and embedded in OPC concrete and accelerated corrosion test is performed. Through the test, FRP Hybrid Bar with notch is evaluated to have insignificant effect on pull-off capacity when corroded steel shows only 21% level of pull-off capacity. Furthermore GGBFS concrete with normal steel shows over 70% level of pull-off capacity due to reduced corrosion currency.

Recently, buildings tend to be large size, complex shape and functional. As the size of buildings is becoming massive, the need for structural health monitoring(SHM) technique is ever-increasing. Various SHM techniques have been studied for buildings which have different dynamic characteristics and are influenced by various external loads. Generally, the visual inspection and non-destructive test for an accessible point of structures are performed by experts. But nowadays, the system is required which is online measurement and detect risk elements automatically without blind spots on structures. In this study, in order to consider the response of non-linear structures, proposed a signal feature extraction and the adaptive threshold setting algorithm utilized to determine the abnormal behavior by using statistical methods such as control chart, root mean square deviation, generalized extremely distribution. And the performance of that was validated by using the acceleration response of structures during earthquakes measuring system of forced vibration tests and actual operation.

Along with the increased display devices, the supply for LCD waste glass has rapidly increased. However, there is a problem for recycling. In this study, the possibility of using LCD waste glass as a substitutive material of fine aggregate is determined and compared from the test of the compressive strength and split tensile strength. Finally, it is possible to confirm the results of the failure aspect and analysis of this test.

In order to estimate the influence of chloride de-icing materials which mainly cause the corrosion of steel structures, the salt spray test was conducted and the corrosion level of steel was investigated. The concentration of the chloride de-icing materials and the number of the spray were selected as variables, and the influence of chloride de-icing materials was estimated according to weight reduction of steel specimens.

This paper introduces the recent development of GFRP-steel hybridized rebar and deals with an evaluation of its mechanical performance by authors. The objective of this study is to investigate tensile and bonding performance of the GFRP-steel hybridized rebar. The effect of hybridization on tensile properties was evaluated by comparing the results of tensile test with those of non-hybrid GFRP bars. The surface of the bar was designed and experimentally evaluated to obtain the sufficient bond strength in this study. To ensure the long-term durability of GFRP-steel hybridized rebar to corrosion resistance, the individual and combined effects of environmental conditions are currently under investigation.

Recently, systematic management strategy and planning infrastructure is improved the efficiency of infrastructure maintenance are prepared. In this study, a overall rating software tool is developed for SOC facilities to enable rapid analysis results of complex process.

This study was conducted for the development of degradation model for the coated steel member in the atmospheric environment. Field inspection data was assessed against the existing evaluation factors which were proposed by the related research process. A correlation between evaluated degradation score and service life of coated steel member was plotted on the graph, and degradation of the coated steel member could be evaluated by quantitative analysis method.

In this study, finite element analysis was performed to analyze the load carrying capacity of corroded plate girder. Consequently, web buckling load indicated drastic reduction in corrosion thickness less than 1 millimeters. Therefore, if the plate girder is seriously corroded to time of drastic reduction of web buckling load, it will need appropriate maintenance and reinforcement to guarantee of safety.

The Goal of research is that budget maintenance of Bridge Shoes in Highway were estimated in network-level bridges. We determined the life cycle of Bridge Shoes with HBMS(Highway Bridge Management System) data by the survival analysis probability model. We developed the method that predicted cost of maintenance in all bridge shoes of the highway bridge in Korea.

In this study, applicability of the steel grid composite deck to temporary or building structure is reviewed. structural performance such as flexural strength, and serviceability is compared with those of the existing deck structures. the result shows that the steel grid composite deck is applicable to horizontal supporting member of temporary of building structure.

In order to apply the mechanical deck joint to the prefabricated steel gird composite decks, shear resistance of the joint composed of concrete shear key and high-tension bolt was evaluated by the push-out test experimentally and analytically. In this study, shear resistance of the joint installed in the deck is evaluated by design equation. In comparison with resistances estimated by design equation and test results, the deck joint is structurally safe enough, and in the case of pointed loading efficient width of the prefabricated steel grid composite deck is about 1m long.

The purpose of this paper is to find an limitation to detect the defect of damaged asphalt pavement structures for improved infrared thermography. We use heat source of a natural light to detect the defect efficiently. The heat source was applied to the asphalt specimens containing maximum depth of 3cm internal timber. It was found that the depth of 3cm internal timber could be detected by this method. In addition, we used the improved image processing to make the damage zone displayed clear in the image obtained from the thermographic operation.

RC(Reinforced Concrete) 부재는 인장영역에서 보강재가 하중을 지지해야 하므로, 철근부식은 내구성 뿐 아니라 안전성에서도 매 우 중요하다. 본 연구에서는 최근 개발된 FRP Hybrid Bar와 일반 철근을 매립한 RC 보부재를 제작하였으며, ICM(Impressed Current Method) 를 적용하여 철근부식을 촉진시켰다. 기존의 이론식인 Faraday 법칙을 이용하여 부식량을 평가하였으며, 일반설계강도를 가진 콘크리트 보부 재에 대하여 휨시험을 수행하였다. 일반 철근에서는 부식량이 4.9∼7.8% 수준으로 평가되었으며 이에 따른 휨 저항능력은 -25.4∼-50.8% 수준 으로 감소하였다. FRP Hybrid Bar를 매립한 RC 보에서는 부식과 휨 저항 감소가 평가되지 않았는데, 이는 에폭시 도료로 코팅된 철근의 우수 한 내부식성에 기인한다. 촉진 부식실험에서는 FRP Hybrid Bar의 우수한 내부식성 및 부착성능을 확인하였는데, 실용화를 위해서는 장기적인 침지를 통한 내구성 평가가 필요하다고 판단된다.

In this study, the antioxidative activity and functional food activities of water and ethanol extracts from Pinus densiflora root were examined. It was more effective to use ethanol than water when extracting phenolic compounds. The extracted phenolic compounds from Pinus densiflora root for biological activities were examined. The phenolic compounds extracted with water and 80% EtOH were 1.86±0.04 mg/g and 6.85±0.16 mg/g, respectively. DPPH free radical scavenging activity of water and EtOH were each 86% and 85% at 100 μg/mL phenolics, respectively. ABTS radical decolorization activity was 48% in water and 68% in EtOH at 200 μg/mL. Antioxidant Protection Factor (PF) were 1.74 PF in water and 1.96 PF in EtOH at 50 μg/mL. TBARs of water and EtOH were 93% and 98%, respectively at 100 μg/mL. The inhibition activity on xanthine oxidase was 83.7% in water extracts and 79.6% in ethanol extracts. Inhibition on xanthine oxidase of water and ethanol extracts showed a higher inhibition effect than allopurinol. The inhibition activity on α-glucosidase was 14.8% in water extracts and 91.6% in ethanol extracts. The result suggests that P. densiflora root extracts may be useful as as functional food material.

In this study, the anti-inflammatory effect of hyaluronidase (HAase) inhibition was determined from 92 species of oriental herbal medicine extracted with water and ethanol solvents because of their non-toxicity in the human body. The water extracts of Evodia officinalis (86.8%), Thuja orientalis (80.8%), Carthami semen (66.5%), Melia azedarach (74.7%), Siegesbeckia pubescens (61.3%), Saururus chinensis (49.15%) showed a relatively greater anti-inflammatory activity. The ethanol extracts of Ailanthus altissima and Saururus chinensis demonstrated the highest anti-inflammatory effect at above 90%. Saururus chinensis was selected for its high anti-inflammatory effect in both water and ethanol extract. Ethanol was more effective than water and optimal extraction conditions for phenolic compounds was determined to be extraction with 50% ethanol for 12 hours. The extracts from Saururus chinensis in optimal condition showed 70~80% anti-inflammatory effect when 100~250 μg/mL phenolic concentration was treated. Concentration of above 500 μg/mL decreased the inhibitory effect. The anti-inflammatory effect and extraction yield were increased by ultra-fine grind technology, indicating that this method can be used to increase the extraction yield of phenolic compounds from medicinal plants.

본 연구에서는 비용예측모델과 성능예측모델을 이용하여 네트워크 레벨에서 향후 교량과 터널 유지관리 비용과 성능을 예측할 수 있는 방법론은 개발하였다. 현재 국내의 시설물 유지관리 관련 연구는 대부분 단일 시설물에 집중되어 있어 도로망차원의 네트워크 레벨 분석 에는 적용하기 어렵다. 따라서 시설물군 단위로 유지관리 계획을 수립해야하는 실무주체에게 유의한 정보를 제공하지 못하고 있는 실정이다. 본 연구의 예측모델은 시설물의 성능에 현재 시특법에 의해 평가하고 있는 상태외 사용성과 기능성을 포함하였으며, 기본 분석과 확장 분석을 통해 각 시설물의 조치 시기와 연간 예산을 추정할 수 있다. 또한 사례 분석을 통해 기술적 타당성을 검증하였다. 본 연구의 방법론이 활성화된 다면 다수의 시설물의 비용대비 미래 성능을 파악할 수 있으며, 효과적인 중장기 예산 수립을 할 수 있을 것으로 판단된다.

This paper presents an analysis technique considering double-layer concrete and time-dependent diffusion behavior, and the results are compared with those from the previous test results through reverse analysis. Through consideration of time effect, the relative error decreases, which shows more reasonable results. Utilizing the diffusion coefficients from Life365, relative errors increases and it needs deeper penetration depth(e) and lower diffusion coefficient ratio(D1/D2) due to higher diffusion coefficient.

Tensile performance of the recently developed “FRP Hybrid Bar” at Korea Institute of Civil Engineering and Building Technology (KICT) is experimentally evaluated by the authors. FRP Hybrid Bar is introduced to overcome the low elastic modulus of the existing GFRP bars to be used as a structural member in reinforced concrete structures. The concept of material hybridization is adapted to increase elastic modulus of GFRP bars by using steel. This hybridized GFRP bar can be used in concrete structures as a flexural member with a sufficient level of elastic modulus. In order to verify the effect of material hybridization on tensile properties, tensile tests are conducted. The results for both FRP Hybrid Bar and the existing GFRP bars are compared. The results indicate that the elastic modulus of FRP Hybrid Bar can be enhanced by up to approximately 250 percent by the material hybridization with a reasonable tensile strength. To ensure the long-term durability of FRP Hybrid Bar to corrosion resistance, the individual and combined effects of environmental conditions on the bar itself as well as on the interface between rebar and concrete are currently under investigation.