DOI QR코드

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Autogenous shrinkage of ultra high performance concrete considering early age coefficient of thermal expansion

  • Park, Jung-Jun (Structural Engineering Research Division, Korea Institute of Construction Technology) ;
  • Yoo, Doo-Yeol (School of Civil, Environmental and Architectural Engineering, Korea University) ;
  • Kim, Sung-Wook (Structural Engineering Research Division, Korea Institute of Construction Technology) ;
  • Yoon, Young-Soo (School of Civil, Environmental and Architectural Engineering, Korea University)
  • 투고 : 2013.03.07
  • 심사 : 2013.02.01
  • 발행 : 2014.03.25

초록

The recently developed Ultra High Performance Concrete (UHPC) displays outstanding compressive strength and ductility but is also subjected to very large autogenous shrinkage. In addition, the use of forms and reinforcement to confine this autogenous shrinkage increases the risk of shrinkage cracking. Accordingly, this study adopts a combination of shrinkage reducing admixture and expansive admixture as a solution to reduce the shrinkage of UHPC and estimates its appropriateness by evaluating the compressive and flexural strengths as well as the autogenous shrinkage according to the age. Moreover, the coefficient of thermal expansion known to experience sudden variations at early age is measured in order to evaluate exactly the autogenous shrinkage and the thermal expansion is compensated considering these measurements. The experimental results show that the compressive and flexural strengths decreased slightly at early age when mixing 7.5% of expansive admixture and 1% of shrinkage reducing admixture but that this decrease becomes insignificant after 7 days. The use of expansive admixture tended to premature the setting of UHPC and the start of sudden increase of autogenous shrinkage. Finally, the combined use of shrinkage reducing admixture and expansive admixture appeared to reduce effectively the autogenous shrinkage by about 47% at 15 days.

키워드

참고문헌

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피인용 문헌

  1. Multiscale Thermoelastic Analysis of the Thermal Expansion Coefficient and of Microscopic Thermal Stresses of Mature Concrete vol.12, pp.17, 2019, https://doi.org/10.3390/ma12172689
  2. Temperature development and cracking characteristics of high strength concrete slab at early age vol.74, pp.6, 2020, https://doi.org/10.12989/sem.2020.74.6.747