DOI QR코드

DOI QR Code

폴리믹스 혼입 고강도 콘크리트의 펌프압송 성상에 관한 실험적 연구

An Experimental Study on Pumpability Characteristics of High Strength Concrete Mixed Polymix

  • Lee, Joo-Ho (LOTTE Engineering & Construction Company, Research & Development Institute) ;
  • Moon, Hyung-Jae (LOTTE Engineering & Construction Company, Lotte World Tower Construction Site in Jamsil) ;
  • Kim, Jeong-Jin (LOTTE Engineering & Construction Company, Research & Development Institute)
  • 투고 : 2012.02.09
  • 심사 : 2012.08.09
  • 발행 : 2012.10.31

초록

기존 내화성능 확보기술인 섬유혼입 콘크리트의 경우 내화성능을 높이기 위해 섬유량이 과다하게 투입되면 초고압 펌핑시 엉킴현상이 발생하여 압송효율이 급격히 저하되는 문제점이 있다. 이에 이 연구에서는 기존 섬유 이외에 추가로 유동성 개선효과 및 내화성능을 확보할 수 있는 폭렬방지재를 개발하여 이를 활용한 60~80 MPa 고강도 콘크리트의 펌프압송성능 개선을 이 연구의 목표로 설정하였다. 이 연구에서 사용된 폭렬방지재는 pp섬유, 나일론 섬유 및 폴리머 분말을 혼입한 폴리믹스로서 이를 활용한 결과는 다음과 같다. 섬유혼입 유무에 따른 굳지않은 특성 중 슬럼프 플로우는 섬유투입시 압송 후 기존 대비 약 70% 물성이 개선되었고, 공기량은 섬유혼입에 관계없이 압송 후 다소 증가하였다. 압축강도는 재령 28일에서 설계기준강도를 상회하였고, 휨 강도는 압축강도 발현율 대비 12~15%로 기존 경향과 유사하게 나타났다. 탄성계수는 섬유혼입시 감소하였지만, 기준값 이상으로 문제는 없을 것으로 사료된다.

The aims of this research is to develop a fire resistant admixture to enhance high-pressured pumping of high-strength concrete (HSC) with a compressive strength of 60~80 MPa. Generally, the efficiency of HSC high-pressured pumping is dramatically reduced due to entanglement of short fibers added to prevent fire spalling. Therefore, the fire resistant admixture that can facilitate pumping of fire resistant HSC is urgently needed presently. The fire resistant HSC mix is comprised of Polypropylene fiber, Nylon fiber and Polymer powder. The test results showed that the slump-flow was improved by approximately 70% of the HSC without fire resistant admixture. However, the air void content was increased slightly due to the addition. The standard design compressive strength at 28-days was satisfied, while its flexural strength was similar to the concrete without the admixture. Since the flexural strength was 12~15% of its compressive strength, the general trend of flexural to compressive strength ratio in normal concrete was maintained. Even though its elastic modulus was decreased by adding the admixture, the study results showed that the concrete can be used for construction since all of the test results exceeded the code requirements.

키워드

참고문헌

  1. High-Rise Buildings Construction Manual, Daewoo E&C, Korea, 2007, pp. 8-15.
  2. Jee, S. W. and Seo, C. H., "Development of Concrete Pumping Technology in High-Rise Buildings," Review of Architecture and Building Science, Vol. 50, No. 4, 2006, pp. 66- 71.
  3. The Fire Performance of High-Strength Concrete Columns, Beams Management Standards, Notice 2008-334 from Ministry of Land, Transport and Maritime Affairs, Korea, 2008.
  4. ACI Committee 304, "Placing Concrete by Pumping Methods," ACI Materials Journal, Vol. 92, No. 4, 1995.
  5. Morimoto, S., "Change of Flowability of Self-Compacting Concrete due to Pumping(ポンプ壓送による自己充塡コン クリ一トの流動性變化)," Koghi University of Technology, Master dissertation, Japan, 2003, pp. 19-28.
  6. Jiro Sakue, J., "Change in Flowability of Self-Compacting Concrete due to External Force(外力による自己充塡コン クリ一トの流動性變化のメカニズム)," Koghi University of Technology, Master dissertation, Japan, 2006, pp. 15-22.
  7. Kim, S. H., Jee, S. W., and Seo, C. H., "Experimental Study on the Characteristics of Internal Pressure on Pipeline in High Pressure Pumping for High-rise Building," Journal of the Architectural Institute of Korea, Structure and Construction, Vol. 23, No. 12, 2007, pp. 149-156.
  8. Yasumichi, K., "An Experimental Study on the Pumpability of High Strength Concrete(高强度コンクリ−トのポ ンプ壓送性に關する實驗的硏究)," Proceedings of the Korea Concrete Institute, Vol. 28, No. 1, 2006, pp. 1217-1222.
  9. Ko, J. W., Kim, J. J., Lee, S. H., Moon, H. J., and Park, S. J., "An Experimental Study on the Physical Property Change of High Strength Concrete for High-rise Building Before and After Concrete Pumping Transfer," Journal of the Architectural Institute of Korea, Structure & Construction, Vol. 26, N. 9, 2010, pp. 71-78.
  10. Kwon, H. W., "An Experimental Study on the Pumpability Considering an Effective Ratio of Concrete Delivery Cylinder in Stationary Concrete Pump," Proceedings of the Korea Concrete Institute, Vol. 21, No. 1, 2009, pp. 149-150.

피인용 문헌

  1. Fire Resistance Performance of High Strength Concrete with Fiber Types vol.14, pp.3, 2014, https://doi.org/10.5345/JKIBC.2014.14.3.223
  2. An Experimental Study on the Concrete Pumping Technology of High Performance Concrete for the High-Rise Building Construction vol.15, pp.4, 2015, https://doi.org/10.5345/JKIBC.2015.15.4.375
  3. A Study on Economically-Efficient Binder Combination of 80MPa Ultra High Strength Concrete vol.3, pp.1, 2015, https://doi.org/10.14190/JRCR.2015.3.1.064