• Proceedings of the Korean Society For Composite Materials Conference
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• 2003.10a
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• pp.42-45
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• 2003

Nondestructive damage sensing and mechanical properties for acid-treated carbon nanotube (CNT) and nanofiber (CNF)/epoxy composites were investigated using electro-micromechanical technique and acoustic emission (AE). Carbon black (CB) was used to compare to CNT and CNF. The results were compared to the untreated case. The fracture of carbon fiber was detected by nondestructive acoustic emission (AE) relating to electrical resistivity under double-matrix composites test. Sensing for fiber tension was performed by electro-pullout test under uniform cyclic strain. The sensitivity for fiber damage such as fiber fracture and fiber tension was the highest for CNT/epoxy composites. Reinforcing effect of CNT obtained from apparent modulus measurement was the highest in the same content. For surface treatment case, the damage sensitivity and reinforcing effect were higher than those of the untreated case. The results obtained from sensing fiber damage were correlated with the morphological observation of nano-scale structure using FE-SEM. The information on fiber damage and matrix deformation and reinforcing effect of carbon nanocomposites could be obtained from electrical resistivity measurement as a new concept of nondestructive evaluation.

• Journal of the Korean Geotechnical Society
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• v.19 no.4
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• pp.75-81
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• 2003

To investigate the reinforcing effect of subsurface layers of marine dredged clay(DMC) mixed with the micro-fiber(MF), a series of laboratory tests were performed on the DMC specimens with and without MF through uniaxial and triaxial compression tests. For the test programme, the elapsed time after dredging of marine clay, mixing rate and length of MF, and curing time of the composite were chosen as the important factors affecting the strength behaviour. The strength of the DMC mixed with MF and waste lime(WL) used for the admixture was found to be enhanced with the increasing content and length of MF, and with decreasing water content of DMC. MF and WL were applied as materials for trafficability improvement of the very soft reclaimed ground by DMC.

• Journal of the Korea Institute of Building Construction
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• v.8 no.5
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• pp.43-51
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• 2008

This study examines shear capacity performance and structural characteristics of reinforced concrete beam using carbon fiber sheet(CFS), g)ass fiber sheet(GFS), glass fiber steel plate(GSP) and carbon fiber bar CB) which are reinforcing materials for reinforced concrete beam in order to produce similar condition to repair and reinforce actual structure and aims to provide data available In designing and constructing reinforced concrete structures under the structural damage. This study obtains the following conclusions. After considering the shear experiment results. it was indicated that the CB reinforced test object was the best in the shear capacity improvement and ductility capacity as it was contained in the concrete and was all operated, Also, GFS reinforced test object indicated the reduced flexural capacity but good shear capacity. GSP reinforced test object had bigger reinforcing strength than other reinforcing test objects. On the other hand, it showed the lowest reinforcement effect as compared section thickness of reinforced material because it showed the bigger relativity a section thickness of reinforced material. If the adherence to the concrete is improved, it will seem to show bigger reinforcement effect.

• Journal of the Korean Geotechnical Society
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• v.19 no.6
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• pp.397-406
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• 2003

Several sensor systems are used to estimate the reinforcing effect of stabilizing pile in slopes, and to find a failure surface in slopes effectively. FBG(Fiber Brags Crating) sensor, V/W(Vibrating Wire) sensor and inclinometer have shown a great potentiality to serve real time health monitoring of the reinforcing structures. Field tests and test results have shown great solutions for sensor systems of Smart Structures. The purpose of this research is to seek for the relationships among the slope movement and the reinforcing effect of stabilizing pile, and the strain distribution of stabilizing pile in a active zone by analyzing the data from the in-situ measurement so that the possible failure surface should be well defined based on the relationships. The field test results have shown that the data by FBG sensor are well coincided with those of V/W sensor and inclinometer, and the reinforcing effect of the stabilizing pile is good enough.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.4
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• pp.863-874
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• 2015

The use of pile reinforcement is considered as one of the most promising techniques for improving load carrying capacity of piles in offshore area. In this study, to consider the horizontal and uplift bearing capacity of submerged breakwater bearing pile, exclusive analysis on load-transfer behaviour of pile was conducted. First of all, check the reinforcing effect from the three-dimensional finite element method, and estimate load transfer curve (ground reaction force). Based on these results, the reinforcing effect was quantified by estimating the coefficients of horizontal and uplift reinforcement of reinforced piles. Load transfer function with consideration of the reinforcing effect was proposed from estimated coefficients. A comparison of the analysis using the proposed load transfer function with three-dimensional finite element analysis has resulted that the proposed load transfer function is displaying good accuracy of predicting behavior of the load transfer between the pile and soil reinforcement. Interpretation of the submerged structure by applying a load transfer function considering the reinforcing effect, has shown that the reinforced pile's shear, bending moment and displacement are less than that of non-reinforced piles, while the subgrade reaction modulus arises greater. Thus, it is expected to be relatively cost effective in terms of design.

• Korean Journal of Acupuncture
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• v.22 no.4
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• pp.43-56
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• 2005

Objectives : The acupuncture has been used as treatment of disease in the oriental medicine. In this study, it was investigated at had an effects of Heart JEONGGYEOK(心正格) of SAAM five evolutive phase acupuncture techniques(舍岩五行鑛法) for appling deficiency in the heart induced by experimental focal ischemia. Materials and methods : The focal ischemia was induced by middle cerebral artery occlusion for 2hours. The groups divided into 6 groups, normal(intactness group), control(no therapy group after ischemia-induced), AT1(reinforcing acupoint of Heart JEONGGYEOK : acupuncture therapy group at LR1, HT9 after ischemia-induced), AT2(reinforcing acupoint of Kidney JEONGGYEOK : acupuncture therapy group at LU8, KI7 after ischemia-induced) AT3(combination of reinforcing acupoint of Heart JEONGGYEOK and Kidney JEONGGYEOK : acupuncture therapy group at LR1, HT9, LU8, KI7 after ischemia-induced) AT4(reinforcing and reducing acupoint of Heart JEONGGYEOK : acupuncture therapy group at LR1, HT9, HT3, KI10 after ischemia-induced), AT4(reinforcing and reducing acupoint of Heart JEONGGYEOK : acupuncture therapy group at LRI, HT9, HT3, KI10 after ischemia-induced). Acupuncture therapy was carried out during 3 weeks after focal ischemia-induced. Eight-arm radial maze was used for the behavioral task and neuropretective effect of acupuncture therapy was observed by Cresyl violet, AchE, ChAT-stain. Results : The error rate in the eight-arm radial maze task was significantly decreased in AT3 group on 3days, in AT1 and AT4 groups on 4days, in AT3 and AT4 groups on 5days compared to the control group. The rate of correct choice was significantly increased AT4 group compared to the control group. The density of neurons in the hippocampal CA1 were significantly increased in all experiment groups, AT1, AT2, AT3 and AT4 groups compared to the control group. The density of AchE in the hippocampal CA1 was significantly increased in AT4 group compared to the control group. The density of ChAT in the hippocampal CA1 were significantly increased in AT1 and AT3 group compared to the control group. Conclusions : These results suggest that reinforcing and reducing acupoint of Heart JEONGGYEOK could be used as a medication for controlling the stroke by deficiency in the heart.

• The Korean Journal of Ceramics
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• v.2 no.3
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• pp.142-146
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• 1996

The molten carbonate fuel cell matrices, which are usually made of high surface, fine particle size ${\gamma}-LiAlO_2$ are reinforced with coarse particles of the same material and alumina fibers. An the effects of reinforcing materials on pore characteristics, sintering properties and mechanical properties of the matrices are examined.Among the matrices examined, the highest mechanical reinforcement has been achieved in the one containing 10 wt.% coarse particles and 20 wt.% alumina fibers.

• Corrosion Science and Technology
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• v.4 no.3
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• pp.81-88
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• 2005

The effects of rebar corrosion on the structural behaviour of reinforced concrete structures were discussed based on recent experimental investigation. The load carrying capacity of the deteriorated beams was quantitatively estimated by evaluating the degree of rebar corrosion in terms of the average cross-sectional loss of longitudinal reinforcing bars and bond deterioration between corroded reinforcing bars and concrete.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.05a
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• pp.834-837
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• 2004

In this study, the electric accelerated reinforcing bar corrosion test was carried out to estimate the coefficient of electrolytic corrosion based on the concept of Faraday's law according to rebar corrosion rate and concrete compressive strength which had an effect on the actual corrosion mass loss. The results of this paper allow the prediction of corrosion amount in the electric accelerated reinforcing bar corrosion test method.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.04a
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• pp.651-656
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• 2000

The strain compatibility analysis shows that the influential parameters of loading type, reinforcing ratio, and span-depth ratio affect on the tendon stress in unbonded prestresses concrete member significantly. However, existing test results did not comply exactly with the analytical results. In consequence, the present study was planned to examine the parameters in order to complete Moon/Lim's design equation. The test variables with 12 specimens were loading type, reinforcing ratio, and span-depth ratio. As results, the effect of influential parameters were examined throughly and Moon/Lim's design equation was proven to be accurate.