• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2012년도 춘계 학술논문 발표대회
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• pp.295-298
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• 2012

Repair and strengthening is necessary to extend the service life of existing buildings. Polymer-modified cement mortar (PCM) has been extensively used as a high performance material particularly for finishing and repairing works in concrete building because of itsexcellent adhesion, waterproofing, resistance to chemical attack, and workability. As PCM contains organic polymer, it is necessary to clarify its properties at high temperature under fire, on which sufficient data are not available. This paper evaluated the burn-up characteristics of polymer-modified cement mortar with cone calorimeter test, non-combustibility test and flammability test with experimental parameters such as the types of polymer, unit-polymer content, polymer-cement ratio and thickness of the specimen.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2005년도 봄학술 발표회 논문집(II)
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• pp.529-532
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• 2005

The effects of polymer-binder ratio and ceramic powder content on the drying shringage and strength of polymer-modified pastes using redispersible polymer powders and ceramic powder are examined. As a result, the drying shrinkage of the polymer-modified pastes using redispersible polymer powders tend to decrease with increasing polymer-binder ratio and ceramic powder content. Regardless of the type of polymer powder, the tensile strength and adhesion in tension of the polymer-modified pastes with ceramic powder tend to increase with increasing polymer-binder ratio and ceramic powder content.

• 한국도로학회논문집
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• 제17권6호
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• pp.47-54
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• 2015

PURPOSES : The objective of this study is to evaluate the early adhesive characteristic of asphalt emulsions, including polymer-modified emulsions, for chip seals using the surface energy concept, the bitumen bond strength (BBS) test, and the Vialit test. METHODS : Two general methods, the BBS test and Vialit test, were applied to investigate the bond strength and the aggregate loss, respectively. A new theory, the surface free energy (SFE) theory, was used to evaluate the adhesive characteristic between the emulsion and the aggregate. Based on the theory, the contact angles were measured, and then the surface energy components were calculated. Using those components, the work of adhesion (Wa) was calculated for each emulsion. To ensure reliable results, all the tests were performed under the same conditions, i.e., at $25^{\circ}C$ for 240 minutes of curing time. For the materials, three emulsions (CRS-2, CRS-2L, and CRS-2P) and one aggregate type (granite) were employed. RESULTS AND CONCLUSIONS : Under the same conditions, the modified emulsions showed better adhesive characteristics and curing behaviors than the unmodified emulsions. In addition, there was no significant difference between the various modified emulsions. One of the important findings is that the analysis by Wa presents more sensitive results than other methods. The results of the Wa showed that the CRS-2P emulsion has the best adhesive characteristics. Consequently, the use of modified emulsions for chip seals could prevent aggregate loss and allow open traffic earlier.

• 접착 및 계면
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• 제12권2호
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• pp.73-80
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• 2011

식물성 고분자인 대두단백질을 기반으로 하는 환경친화성 고분자 신소재에 관한 연구를 위해 가소제(1,3-propandiol, glycerol) 및 가교제(glutaraldehyde, epichlorohydrin, glyoxal, urea)에 의한 대두단백질 수지의 열적 특성을 TGA를 이용하여 분석하였고, 기계적 특성 분석과 SEM을 통하여 파단면을 관찰하였다. 그 결과, 가소제인 1,3-propandiol과 glycerol을 SPI (대두단백질)에 첨가함으로써 수지의 유연성이 증가하였고, 1,3-propandiol에 비하여 glycerol의 가소화 효과가 상대적으로 크게 나타났으며, 가교제인 glycerol, epichlorohydrin, glyoxal의 적용으로 첨가량이 증가할수록 대두단백질 수지의 강도와 열안정성이 증가하는 반면, urea의 경우, 대두단백과의 가교가 용이하지 않아 열안정성이 오히려 낮아지고, 강도가 감소함을 알 수 있었다.

• 접착 및 계면
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• 제3권4호
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• pp.19-26
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• 2002

고무입자로 강인화된 폴리카보네이트의 강인화 메커니즘을 연구하기 위하여 synchrotron X-선을 이용한 소각 X-선 산란법을 이용하여 실시간으로 변형 과정에서의 폴리카보네이트 내의 micro-void의 생성과 성장과정을 조사하였다. 시료는 직경 $0.3{\mu}m$의 가교화된 아크릴 고무입자로 강인화된 폴리카보네이트이며 wedge test 방식으로 시료에 변형을 가하면서 X-선을 조사하여 산란빔의 세기 변화를 살펴보았다. 변형이 증가함에 따라 산란빔의 세기가 증가하며 이는 폴리카보네이트 매트릭스 내의 micro-void의 생성에 의한 것으로 추정된다. 이러한 micro-void는 폴리카보네이트 매트릭스 내부에 생선된 것으로서 이는 고무입자와 매트릭스간의 계면분리 현상이나 고무입자 내부의 cavitation에 의한 void는 아닌 것으로 추정된다. 이 micro-void는 큰 void들과는 달리 특정한 변형 정도에 이르러 일정한 크기를 갖고 생성되기 시작하며 변형 정도가 증가하여도 그 크기는 증가하지 않고 단지 그 양만이 계속적으로 증가함을 알 수 있다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 1997년도 제12회 학술발표회 논문개요집
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• pp.169-169
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• 1997

• 한국구조물진단유지관리공학회 논문집
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• 제17권5호
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• pp.94-104
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• 2013

본 연구에서는 고유동성의 VA/VeoVA 개질 시멘트 모르타르의 기초적 성능을 측정한 후 콘크리트의 보수용 재료에 매우 중요한 요구성능인 부착강도에 대한 피착체의 표면에 존재하는 표면수량의 영향을 검토하는 연구가 수행하였다. 시험체의 배합은 VA/VeoVA는 결합재인 시멘트에 대하여 고형분비 (폴리머시멘트비; P/C)에 의하여 10, 20, 30, 50, 75%, 잔골재는 시멘트의 중량에 대하여 각각 1:1, 1:3의 비율을 적용하였다. 고유동성 VA/VeoVA 개질 시멘트 모르타르의 기초적인 성능을 토대로 부착강도, 잔갈림성, 재료분리 저항성이 좋은 시험체를 선택하였다. 시험체는 C:F=1:1인 경우 P/C=20%, 30%의 시험체 2개가 선택되었으며, C:F=1:3인 경우 P/C=50%의 시험체 1개, 총 3개가 선택되었으며 이 3개의 배합에 대하여 피착체의 표면수량에 따른 고유동성 VA/VeoVA 개질 시멘트 모르타르의 특성을 파악하였다. 본 연구를 통해 콘크리트 피착체에 살포된 표면수는 부분적으로 고유동성 VA/VeoVA 개질 시멘트 모르타르의 부착강도를 증진하고, 유동성을 개선하는 효과가 있다는 결론을 얻었다.

• 접착 및 계면
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• 제11권4호
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• pp.137-143
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• 2010

Glass beads (GBs) were modified via plasma polymerization coatings in order to enhance the adsorption of polycyclic aromatic hydrocarbons (PAHs) in cigarette smoke and activated carbons (ACs) were also utilized for comparative purposes. First, GBs and ACs were subjected to surface modification via plasma polymerization coating of acrylic acid, acrylonitrile, 1,3-diaminopropane, thiophene or dimethylphosphite with a RF plasma (13.56 MHz) generator. Next, their adsorption behavior was evaluated with a home-made 4-port smoking machine by collecting the total particulate matters (TPMs) on a Cambridge filter pad, followed by the separation of PAHs via solid phase extraction and analysis with GC/MS. Finally, the plasma polymerization coatings were analyzed by FT-IR/ATR to elucidate the adsorption mechanism, while the topology of the modified GBs and ACs were studied by FE-SEM.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2001년도 봄 학술발표회 논문집
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• pp.1017-1022
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• 2001

The bend resistance of coated reinforcing bar is greatly influenced by adhesion strength of bar and coating materials and transformation of coating materials to the bar. Expecially, tearing state or a limited microscopic cracks are predicted on the inside and outside of bending angle because of adhesion strength and elongation is very different with types of polymer materials using bar coating, and these parts are accelerated corrosion as penetration of bar corrosion effects factor. In this study, cement modified polymer are prepared four types and differ from polymer cement ratio of 50% and 100%, coating thickness of 250$\mu$m and 450$\mu$m, coating number, curing age of 3, 7, 14 and 280days, and then tested bend resistance as bending angle $90^{\circ}$, $135^{\circ}$ and $180^{\circ}$ for observe the microscopic demage effect according as bar bend. From the test results, when is used cement modified polymer as coating materials of bar, St/BA is showed excellent bend resistance than a polyacrylic emulsion and SBR because of softness. But it is to need attention because as coating parts are pressed down and tearing, also experimental study is proceeded to corrosion potential on the inside and outside of coated reinforcing bar.

• KSTLE International Journal
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• 제10권1_2호
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• pp.1-5
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• 2009

This paper reports an investigation on nanotribological properties of silicon nanochannels coated by a diamond-like carbon (DLC) film. The nanochannels were fabricated on Si (100) wafers by using photolithography and reactive ion etching (RIE) techniques. The channeled surfaces (Si channels) were then further modified by coating thin DLC film. Water contact angle of the modified and unmodified Si surfaces was examined by an anglemeter using the sessile-drop method. Nanotribological properties, namely friction and adhesion forces, of the Si channels coated with DLC (DLC-coated Si channels) were investigated in comparison with those of the flat Si, DLC-coated flat Si (flat DLC), and Si channels, using an atomic force microscope (AFM). Results showed that the DLC-coated Si channels greatly increased hydrophobicity of silicon surfaces. The DLC coating and Si channels themselves individually reduced adhesion and friction forces of the flat Si. Further, the DLC-coated Si channels exhibited the lowest values of these forces, owing to the combined effect of reduced contact area through the channeling and low surface energy of the DLC. This combined modification could prove a promising method for tribological applications at small scales.