• 한국건축시공학회지
• /
• 제23권2호
• /
• pp.133-142
• /
• 2023

본 연구에서는 열화 콘크리트 구조물의 보수 시 현재 범용적으로 사용하고 있는 폴리머 시멘트 모르타르의 내화성능을 확보하기 위한 최적 배합을 도출하고자 폴리머 혼입량(2, 4, 6, 8%)에 따른 PP섬유의 길이(6, 12mm) 및 PP섬유 혼입량(0.05, 0.1Vol%)에 따른 섬유혼입 폴리머 시멘트 모르타르의 내화성능을 평가하였다. 실험결과 함수율 및 폴리머 혼입률이 높을수록 폭렬발생 가능성이 증가하며, PP섬유의 길이가 길고 혼입률이 증가할수록 폭렬저감에 효과적인 것으로 나타났다.

• 한국건축시공학회지
• /
• 제8권5호
• /
• pp.101-107
• /
• 2008

This study investigated fundamental characters of the concrete according to various fiber types and contents and their properties of spatting resistance and residual compressive strength after fire test corresponding to ISO and RABT heating corves. The results were summarized as following. The Flowability was gradually declined as the increase of fiber contents, and it was the most favorable with nylon(NY) fibers. The decrease of air contents due to increasing fiber contents was in order by polypropylene(PP), polyvinyl alcohol(PVA) and NY fibers. The compressive strengths were over 40 MPa at 7 days and 50 MPa at 28 days. It was in order by PVA, PP and NY fibers. For the spatting properties, all specimens were prevented at ISO heating curve. In the other hand, the partial spatting at the surface occurred on the plain without fibers, but it was prevented over 0.10 % of PVA and 0.05 % of PP and NY fibers at the RABT heating curve.

• 한국섬유공학회:학술대회논문집
• /
• 한국섬유공학회 2003년도 가을 학술발표회 논문집
• /
• pp.307-308
• /
• 2003

Improved wettability and dyeability of Polypropylene(PP) fabrics were obtained using glow discharge plasma by grafting nitrogen-containing active groups on the surface. Few studies of glow discharge plasma on PP fabrics exist. The objective of this study was to give a fabric a good affinity for water. (omitted)

• 한국구조물진단유지관리공학회 논문집
• /
• 제11권2호
• /
• pp.155-163
• /
• 2007

고강도 콘크리트(HSC)는 화재 시 폭렬현상과 함께 부재가 취성적인 거동을 하게 되는 단점을 지니고 있다. 폭렬현상은 화재 시 $100{^{\circ}C}$이상에서 부재내부의 수분 증발로 인하여 발생한 수증기가 수밀한 콘크리트에 갇혀 발생한다. 따라서 콘크리트 강도가 증가 할수록 수밀성이 높아져 폭렬의 정도가 심해진다. 콘크리트의 폭렬을 제어할 수 있는 방안으로는 폴리프로필렌 섬유(PP섬유)를 혼입하는 방법이 가장 효율적인 것으로 보고 되었다. 본 연구에서는 콘크리트 강도와 PP섬유 함유량을 변수로 하는 기둥 실험체에 대한 내화실험과 잔존강도실험을 수행하여 폭렬현상을 관찰하고 잔존강도를 측정하였다. 그 결과 콘크리트 강도가 60MPa에서 85MPa로 증가할 때 기둥 실험체의 잔존 축 강도는 10%증가하였다. 또한, PP섬유 함유량이 0%에서 0.2%까지 증가 할수록 잔존 축강도비는 68%에서 85%까지 증가하였으나, PP섬유 함유량이 0.2%이상에서는 잔존강도의 증가가 거의 나타나지 않았다.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 1999년도 봄 학술발표회 논문집(I)
• /
• pp.76-79
• /
• 1999

The purpose of this study is to investigate the spalling properties of high-performance concrete with the kinds of aggregates and polypropylene(below PP) fiber contents. According to the experimental results, concrete contained no PP fiber take place in the form of the surface spalling and the failure of specimens after fire test regardless of the kinds of aggregates. Concrete contained more than 0.05% of PP fiber with the kinds of aggregates does not take place the spalling. Concrete using basalt has better performance in spalling resistance that concrete using granite and limestone. It is found that residual compressive strength has 50~60% of their original strength. Although specimens after exposed at high temperature are cured at water for 28days, they do not recover their original strength.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2006년도 추계 학술발표회 논문집
• /
• pp.745-748
• /
• 2006

This study investigates the fundamental properties and examines spalling appearances and residual compressive strength of high strength concrete containing hybrid organic fibers subjected to fire. Test showed that overall, an increase of fiber content decreased the fluidity of concrete, but specimens containing polyvinyl alcoho(PVA)+polypropylene(PP) fiber and nylon(NY)+PP fiber had improved flow. In addition, the air content of all specimens was properly ranged in target value, regardless of fiber content. As for the spalling properties when completed the fire test, control concrete exhibited spalling occurrence due to sudden elevated temperature. However, specimens containing more than 0.1 vol% of PP fiber prevented the spalling, while specimens containing PP+CL and PVA+PP fiber can protected from fire in more than 0.15vol% of the fiber content. Importantly, a specimen containing only 0.05vol% of NY+PP showed the favorable spalling resistance performance.

• Fibers and Polymers
• /
• 제5권1호
• /
• pp.59-67
• /
• 2004

The development of high tenacity, high modulus monofilaments from Polypropylene/Clay nanocomposite has been investigated. Pure sodium montmorillonite nanoclay was modified using hexadecyl trimethyl ammonium bromide (HTAB) via an ion exchange reaction. Pure and modified clay were characterized through X-ray diffraction, FTIR and TGA. The modified clay was melt blended with polypropylene (PP) in presence of a swelling agent. Composite filaments from PP/Clay nanocomposite were prepared at different weight percentages of nanoclay and the spinning and drawing conditions were optimized. The filaments were characterized for their mechanical, morphological and thermal properties. The composite PP filaments with modified clay showed improved tensile strength, modulus and reduced elongation at break. The composite filaments with unmodified clay did not show any improvement in tensile strength but the modulus improved. The sharp and narrow X-ray diffraction peaks of PP/nanoclay composite filaments indicate increase in crystallinity in presence of modified clay at small loadings (0.5 %). The improved thermal stability was observed in filaments with modified as well as unmodified clays.

• 접착 및 계면
• /
• 제10권1호
• /
• pp.23-29
• /
• 2009

두 종류의 천연섬유, 즉 면섬유와 목분을 이용하여 제조한 폴리프로필렌 - 천연섬유 복합재료의 혼합가공시 유변학적 특성과 열적특성에 미치는 상용화제의 영향을 고찰하였다. 상용화제로는 무수말레인산이 그래프팅된 폴리프로필렌 공중합체를 사용하였다. 천연섬유의 종류에 관계없이 상용화제를 첨가할 때, 전반적으로 상용화제의 함량이 증가함에 따라 토오크 값이 상승함이 확인되었다. 또한, 시차 주사 열량계(DSC)와 X선 회절분석(XRD)을 통해 상용화제의 첨가시 복합재료의 결정화도가 약간 상승함이 확인되었다. 섬유의 종류에 따른 영향은 거의 관찰되지 않았으나, 혼합시 유변학적 물성, DSC 및 XRD 결과에 의하면, 면섬유의 경우가 목분보다는 PP-g-MAH와 더 나은 상호작용을 보이는 것으로 생각된다.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2004년도 춘계 학술발표회 제16권1호
• /
• pp.108-111
• /
• 2004

The polypropylene(PP) fiber is poised as a low cost alternative for reinforcement in structural applications in comparison with other high performance fibers, such as the polyvinyl-alcohol(PVA), polyethylene, carbon and aramid fiber. The mechanical properties of the composite are strongly determined by the interfacial behavior of fiber and cementitious matrix. The crack bridging mechanism contribute to composite toughness from activation of the fiber-matrix interface where energy is dissipated through debonding of the interface and fiber pullout. In this study, therefore, the pullout behavior of PP fibers is investigated. Experimental work includes the investigation of the interfacial properties, and the composite property. The quantification of interfacial properties, the frictional bond is achieved through single fiber pullout test. A study on the effect of inclination angle on fiber pullout behavior is also conducted.

• 폴리머
• /
• 제37권5호
• /
• pp.613-617
• /
• 2013

나노입자크기의 케냐프섬유를 폴리프로필렌에 첨가하였을 시, 복합소재의 물성변화를 관찰하였다. 천연크기의 케냐프섬유를 나노입자크기의 케냐프섬유로 대체하였을 시, 그 복합소재의 인장강도, 휨강도, 충격강도, 열변형온도가 증가한 반면에, 용융지수, 연신율(%), 충격강도 등이 감소하였다. 이는 나노입자크기의 케냐프섬유가 폴리프로필렌과 접촉하는 표면적의 증가와 섬유표면에 존재하는 휘발성 추출물질 등의 불순물의 감소에 따른 것으로 판단된다.