Journal of the Korea Institute of Building Construction (한국건축시공학회지)

The Korean Institute of Building Construction (한국건축시공학회)
권호 표지
DOI QR코드

DOI QR Code

Evaluation of Shrinkage and Creep Behavior of Low-Heat Cement Concrete

저열 시멘트 콘크리트의 건조수축 및 크리프 거동 평가

  • Mun, Jae-Sung (Department of Architectural Engineering, Graduate School Kyonggi University) ;
  • Yang, Keun-Hyeok (Department of Plant.Architectural Engineering, Kyonggi University) ;
  • Kim, Si-Jun (Department of Plant.Architectural Engineering, Kyonggi University)
  • Received : 2016.05.12
  • Accepted : 2016.08.03
  • Published : 2016.08.20
Download PDF
⟨ Previous Next ⟩

Abstract

This study examined the long-term inelastic characteristics, including unrestrained shrinkage and creep, of low-heat cement concrete under different ambient curing temperatures. To achieve the designed compressive strength of 42MPa, water-to-binder ratios were selected to be 27.5, 30, and 32.5% for curing temperatures of 5, 20, and $40^{\circ}C$, respectively. Test results showed that the shrinkage strains of concrete mixtures tended to decrease with the decrease in curing temperature because of the delayed evaporation of internal capillary and gel waters. Meanwhile, creep strains were higher in concrete specimens under lower curing temperature due to the occurrence of the transition temperature creep. The design models of KCI provision gave better accuracy in comparison with test results than those of ACI 209, although a correction factor for low-heat cement needs to be established in the KCI provision.

개발된 저열 시멘트 콘크리트의 장기거동 특성인 비구속 건조수축과 크리프가 양생온도를 주요 변수로 측정하였다. 저열 콘크리트의 목표 압축강도인 42MPa를 고려하여 양생온도 5, 20, $40^{\circ}C$에서 물-결합재비는 각각 27.5, 30, 32.5%를 선택하였다. 콘크리트의 건조수축 변형률은 양생온도가 낮을수록 모세관 수 및 겔 공극수의 증발지연으로 인해 감소하는 경향을 보였다. 반면 크리프 변형률은 전이 온도 크리프의 발생으로 인하여 초기 양생온도가 낮은 실험체에서 높았다. 콘크리트 구조설계기준(KCI) 예측모델은 ACI 209 예측모델에 비해 실험결과와 잘 일치하였지만 개발된 저열 시멘트에 대한 보정계수의 제안이 필요하였다.

Keywords

References

  1. Gao PW, Lu X, Lin H, Li XY, Hou J. Effects of Fly Ash on the Properties of Environmentally Friendly Dam Concrete. Fuel. 2007 May;86(7):1208-1211 https://doi.org/10.1016/j.fuel.2006.09.032
  2. Tang SW, Cai XH, He Z, Shao HY, Li ZJ, Chen E. Hydration Process of Fly Ash Blended Cement Pastes by Impedance Measurement. Construction and Building Materials, 2016 June;113(15):939-950. https://doi.org/10.1016/j.conbuildmat.2016.03.141
  3. Langan BW, Weng K, Ward MA. Effect of Silica Fume and Fly Ash on Heat of Hydration of Portland Cement. Cement and Concrete Research. 2002 July;32(7):1045-1051. https://doi.org/10.1016/S0008-8846(02)00742-1
  4. Menendez G, Bonavetti VL, Irassar EF. Strength Development of Ternary Blended Cement with Limestone Filler and Blast-Furnace Slag. Cement and Concrete Composites. 2003 January;25(1):57-63.
  5. Aashay A, Gaurav S, Narayanan N. Ternary Blends Containing Slag and Interground/Blended Limestone: Hydration, Strength, and Pore Structure. Construction and Building Materials. 2016 January;102(15):113-124. https://doi.org/10.1016/j.conbuildmat.2015.10.179
  6. ACI Committee 207, Guide to Mass Concrete (ACI 207.1R-05). Michigan: American Concrete Institute; 2005. 30 p.
  7. Korea Concrete Institute. Mass Concrete Thermal Crack Control. Seoul: Kimoondang Publishing Company; 2010. 166 p.
  8. Kim SJ, Yang KH, Moon GD. Hydration Characteristics of Low-Heat Cement Substitute by Fly Ash and Limestone Powder. Materials. 2015 September; 8(9):5847-586.1 https://doi.org/10.3390/ma8095277
  9. Korea Concrete Institute. Concrete Structure Code. Seoul: Kimoondang Publishing Company; 2012. 342 p.
  10. ACI Committee 209, Prediction of Creep, Shrinkage, and Temperature Effects in Concrete Structures: Reapproved 2008(209R-92). Michigan: American Concrete Institute; 1992. 47 p.
  11. ASTM C 150/C150M-16. Standard Specification for Portland Cement. Pennsylvania: ASTM International; 2016. 10 p.
  12. KSA. Korea Industrial Standard. Seoul: Korean Standards Service Network; 2015. 1768 p.
  13. Korea Concrete Institute. New Concrete Engineering, Seoul: Kimoondang Publishing Company; 2001. 932 p.