• Nuclear Engineering and Technology
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• 제41권8호
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• pp.1127-1134
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• 2009

Concrete has three major properties after a penetration-reinforcing agent is applied on its surface. First, the durability is improved by the sol-gel process of synthesized material from the polycondensation of TEOS (tetra-ethoxyorthosilicate) and acrylate monomer. Second, the capability to absorb impact energy is reinforced through the formation of a soft and flexible layer of organic monomers by Tea (Tetra Ethyl Amin). Third, the capability to prevent deterioration is enhanced by adding isobutyl-orthosilicate and alcohol. The performance and application of an agent developed through the synthesis of organic and inorganic material in an effort to prevent concrete from deterioration and improve the durability of concrete structures were verified in diverse experiments. The results of these experiments showed that the application of the proposed penetration-reinforcing agent has the effect of increasing the compressive strength by filling up the internal pores of concrete with physically and chemically stable compounds after penetrating the concrete. It also improves the durability against the deterioration factors such as salt water damage, carbonation, freezing and thawing, and compound deterioration. Therefore, it is confirmed that the penetration-reinforcing agent is a useful substance for the management and repair of concrete structures.

• Current Research on Agriculture and Life Sciences
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• 제31권4호
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• pp.250-255
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• 2013

As a renewable nanomaterial, cellulose nanocrystal (CNC) isolated from wood grants excellent mechanical properties in developing high performance nanocomposites. This study was undertaken to compare the reinforcing efficiency of two different CNCs, i.e., cellulose nanowhiskers (CNWs) and cellulose nanofibrils (CNFs) from hardwood bleached kraft pulp (HW-BKP) as reinforcing agent in polyvinyl alcohol (PVA)-based nanocomposite. The CNWs were isolated by sulfuric acid hydrolysis while the CNFs were isolated by 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO)-mediated oxidation. Based on measurements using transmission electron microscopy, the individual CNWs were about $6.96{\pm}0.87nm$ wide and $178{\pm}55nm$ long, while CNFs were $7.07{\pm}0.99nm$ wide. The incorporation of CNWs and CNFs into the PVA matrix at 5% and 1% levels, respectively, resulted in the maximum tensile strength, indicating different efficiencies of these CNCs in the nanocomposites. Therefore, these results suggest a relationship between the reinforcing potential of CNCs and their physical characteristics, such as their morphology, dimensions, and aspect ratio.

• 한국재료학회지
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• 제27권9호
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• pp.477-483
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• 2017

This present study deals with the microstructure and tensile properties of 600 MPa-grade high strength and seismic resistant reinforcing steels. The high strength reinforcing steel (SD 600) was fabricated by Tempcore processing, while the seismic resistant reinforcing steel (SD 600S) was air-cooled after hot-rolling treatment. The microstructure analysis results showed that the SD 600 steel specimen consisted of a tempered martensite and ferrite-pearlite structure after Tempcore processing, while the SD 600S steel specimen had a fully ferrite-pearlite structure. The room-temperature tensile test results indicate that, because of the enhanced solid solution and precipitation strengthening caused by relatively higher contents of C, Mn, Si and V in the SD 600S steel specimen, this specimen, with fully ferrite-pearlite structure, had yield and tensile strengths higher than those of the SD 600 specimen. On the other hand, the hardness of the SD 600 and SD 600S steel specimens changed in different ways according to location, dependent on the microstructure, ferrite grain size, and volume fraction.

• 한국건축시공학회지
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• 제2권3호
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• pp.131-138
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• 2002

The objective of the study is to examine the characteristic correlations between reinforcing carbon fiber and interfacial adhesion agent since the interfacial adhesion strength between reinforcing carbon fiber and matrices is believed to be an essential element influencing the physical properties in carbon fiber reinforced cement composite using slurry method. The integrity of interfacial adhesion between reinforcing fiber and cement not only affects the quality of fiber reinforced cement composite but also influences to a large degree the physical properties of the cement composite when producing carbon fiber reinforced cement composite using slurry method. Having analyzed the physical properties 1.e., water content, tensile strength, flexural strength and flexural toughness of carbon fiber reinforced cement composite specimens, C-PAM(cation polyacrylamide) was determined to be an optimum interfacial adhesion agent. The study has also demonstrated that interfacial adhesion strength varies largely on the content and type of the reinforcing fiber. Judging from magnified view of the tensile shear cross-section using VMS(video microscope system), interfacial adhesion strength between reinforcing fiber and matrices is affected by the type of interfacial adhesion agent. According to the result of the experiments, C-PAM was determined to be an ideal interfacial adhesion agent when using carbon fiber in producing carbon fiber reinforced cement composite with the optimum content of carbon fiber being established.

• 한국지반공학회지:지반
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• 제10권2호
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• pp.57-68
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• 1994

뿌리말뚝을 이용하여 기초 지반을 보강할 때 효과적인 배치 방법을 알기 위하여, 사질토 지반에서 R.H. Bassets와 N.C. Last가 제안한 보강패턴에 대하여, 말뚝 길이, 기초 길이 방향의 말뚝 간격과 말뚝 열의 수를 변화시키며 물리 모형 실험을 실시하였다. 모형 실험 결과에 의하면, 뿌리말뚝 길이와 기초 폭의 비($L_p/B_f$)가 5이상일 때 지지력은 거의 증가하지 않는다. 그리고 기초 길이 방향의 말뚝 간격이 작을수록 지반 보강 효과는 크지만, 기초 길이,방향의 말뚝 간격이 말뚝 직경의 약 6배일 때 말뚝 1개당 보강효과가 가장 좋았다. R.H. Bassett와 N.C.Last가 제안한 보강패턴에서 둘째열 말뚝의 보강 효과가 가장 우수하였으며, 가장 바깥 열의 말뚝은 보강 효과가 거의 없었다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.691-706
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• 2008

ATP(Automatic Train Protection) system in railway signaling system is the important one grasping the position and velocity of a train. The wayside transmitter of ATP system is installed between rails. In concrete slab track, the signal current using wayside transmitter of ATP system is influenced by reinforcing bars. The magnetic coupling between reinforcing bars and wayside transmitter of ATP system as a filter makes an input current distorted. So, it makes an alternating current signal with a desirable size not transmit to on-board system of a train. Way to decrease the distortion of an input current signal frequency is to avoid maximum induction current frequency. And the induction phenomenon between reinforcing bars insulated and wayside transmitter of ATP system does not occur. In this paper, we represent the model about wayside transmitter of ATP system and reinforcing bars on the concrete slab tracks, and calculated the parameters demanded for the model. Also, we demonstrated it through the Maxwell program. Furthermore, we calculated impedance on wayside transmitter used in KVB system and ERTMS/ETCS system which are a kind of ATP system, frequency response of induction current, using the Matlab, and demonstrated the validity of it, using the PSpice program.

• 한국안전학회지
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• 제25권6호
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• pp.128-136
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• 2010

In according with concrete structural design standard, it is common designing flexure reinforcement concrete to induce tension failure. So reinforcing ratio is limited to inducing tension failure. And maximum reinforcing ratio is regulated to protecting concrete compression strength caused by over reinforced building. Minimum reinforcing ratio is also limited in designing standard to protecting brittle failure as extremely using less reinforcing bar. But in minimum reinforcing ratio it is extremely conservative or it is sometimes impossible to induce stable tension-failure because they are depending on yield failure and experienced method and concrete designing standard strength. Therefore the purpose of the present paper is to evaluate the flexural behavior of minimum steel ratio of reinforced concrete of beams and to propose the guide-line of equation of minimum steel ratio by performing static flexural test of 16 beams according to size effect, number of steel, yielding stress of steel, and concrete compressive strength which are presumed effective variables. From experimental results, the equation of minimum steel ratio was newly proposed considered size effect.

• 지역사회간호학회지
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• 제20권2호
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• pp.123-133
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• 2009

Purpose: This study aimed to classify nursing interventions by developing a list of interventions for family nursing care. Methods: A new intervention list was confirmed after the researchers' discussion and professional consult. All possible interventions were re-organized. Results: Five grand categories were identified, which include health education, providing direct nursing care, utilization and referral of community resources, reinforcing family resources, and stress management. The category of health education consists of anticipatory guidance, training and education, providing information, and consult and motivation. The category of providing direct nursing care consists of identifying problem, providing technical nursing, providing family tailored nursing care, family contract, monitoring or evaluation, and collaboration with experts. The utilization and referral of community services includes utilization of health care facilities, utilization of social welfare facilities, use of neighbors, friends, and relatives, connecting to professionals or supporting groups, and utilization of other sources. Reinforcing family resources includes reinforcing economic resources, reinforcing physical resources, and reinforcing human resources. Stress management includes reorganization of perception, resolving conflicts, division of role, preparing communication strategies, time management, creating familiarity, supporting spirituality, and developing sense of humor. Conclusion: This study provides useful resources to promote nursing activities by identifying possible family nursing interventions.

• Geomechanics and Engineering
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• 제25권2호
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• pp.123-134
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• 2021

In this paper, the carbon fiber reinforced plastic (CFRP) grids embedded in polymer cement mortar (PCM) shotcrete (CFRP-PCM method) was conducted to repair the degraded tunnel linings with a cavity. Subsequently, the reinforcing effect of the CFRP-PCM method under different degrees of lining deterioration was quantitatively evaluated. Finally, the limit state design method of the M-N interaction curve was conducted to determine whether the structure reinforced by the CFRP-PCM method is in a safe state. The main results indicated that when the cavity is at the shoulder, the lining damage rate is more serious. In addition, the remarkably reinforcing effect on the degraded tunnel linings could be achieved by applying a higher grade of CFRP grids, whereas the optimization effect is no longer obvious when the grade of CFRP grids is too high (CR8); Furthermore, it is found that the M-N numerical values of the ten reinforcing designs of the CFRP-PCM method are distributed outside the corresponding M-N theoretical interaction curves, and these designs should be avoided in the corresponding reinforcing engineering.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2002년도 가을 학술발표회 논문집
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• pp.781-786
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• 2002

We develop the performance improving agent of penetration reinforcing applied on concrete by which main components use compounds of metal alkoxide and silicate(Ti). Also, we investigate on the type and amount of organic solvent which need the hydrolysis and water condensation reaction of Ti. The penetration reinforcing agent developed this study can penetrate deeper than 50mm without relation to concrete strength. Also the performance improving agent composed of the combination of Ti and organic solvent A, improve performance in keeping out or removement of deterioration material. waterproof and strength.