Characteristics of Early Strength and Velocity Development in High Strength Concrete Containing Fly Ash

플라이애시를 함유한 고강도 콘크리트의 조기 강도와 속도 발현 특성

  • 이회근 (성균관대학교 토목공학과) ;
  • 윤태섭 (성균관대학교 토목공학과) ;
  • 이광명 (성균관대학교 토목공학과)
  • Published : 2001.05.01

Abstract

The use of fly ash in cement and concrete industries has many benefits including engineering, economic, and ecological aspects. However, it has a disadvantage of low strength development, especially at early ages. In this study, in order to overcome this problem, the early strength accelerating agent($NA_{2}$ $SO_{4}$) was selected and applied to the production of high strength concrete(HSC) containing fly ash. It was found that the compressive strength of fly ash concrete incorporating TEX>$NA_{2}$ $SO_{4}$ has greater than that of concrete containing fly ash only until 7 days after casting. From the microstructural point of view, ettringite increased and pores decreased in fly ash concrete incorporating TEX>$NA_{2}$ $SO_{4}$ , leading to the development of early age strength. It was also found that the velocity vs. strength relationship of HSC is considerably different from that of low-strength concrete(LSC). Therefore, in order to predict early age strength of HSC, a estimation equation different from that for LSC is needed.

Keywords