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Evaluation of Bond-Slip Behavior of High Strength Lightweight Concrete with Compressive Strength 120 MPa and Unit Weight 20 kN/m3

압축강도 120 MPa, 단위중량 20 kN/m3 고강도 경량 콘크리트 부착-슬립 거동 평가

  • Dong-Gil Gu (Dept. of Civil & Environmental Engineering, Gachon University) ;
  • Jun-Hwan Oh (Dept. of Civil & Environmental Engineering, Gachon University) ;
  • Sung-Won Yoo (Dept. of Civil & Environmental Engineering, Gachon University)
  • 구동길 (가천대학교 토목환경공학과) ;
  • 오준환 (가천대학교 토목환경공학과) ;
  • 유성원 (가천대학교 토목환경공학과)
  • Received : 2023.01.09
  • Accepted : 2023.01.27
  • Published : 2023.03.30

Abstract

The demand for lightweight and high-strength materials is increasing. However, studies on the bond of concrete and reinforcing bars for high-strength lightweight concrete with a compressive strength of 120 MPa and a unit weight of 20 kN/m3 to structural members are lacking. Therefore, in this paper, 108 specimens of high-strength lightweight concrete with a compressive strength of 120 MPa and a unit weight of about 20 kN/m3 were fabricated, a direct pull-out test was performed, and the bond characteristics were evaluated by comparing the test results with design code. Compared to the decrease in unit weight, the solid bubble shows relatively little reduction in compressive strength and modulus of elasticity. It was f ound to have larger slip and parameter values than concrete with low compressive strength and unit weight.

최근 구조물의 장대화로 인하여 고강도 재료의 경량화 요구가 빈번해지고 있는 실정이다. 하지만 현재까지는 압축강도 120 MPa, 단위중량 20 kN/m3 정도의 고강도 경량 콘크리트를 구조부재에 적용하기 위한 콘크리트와 철근의 부착 특성에 관한 연구가 부족한 실정이다. 따라서 본 논문에서는 압축강도 120 MPa, 단위중량 20 kN/m3 정도의 고강도 경량 콘크리트 108개의 시편을 제작하여 직접 인발 부착실험을 수행하였고, 실험결과와 현행 설계기준과 비교하여 부착특성을 평가하였다. 솔리드버블은 단위중량 감소에 비해서 압축강도 및 탄성계수 감소효과는 상대적으로 적게 나타나, 초경량화를 위해서는 반드시 적용되어야 할 재료로 판단되며, ACI-408R의 부착강도 산정식과 실험결과는 비교적 유사한 것으로 판단되며, 더 낮은 압축강도, 단위중량의 콘크리트보다 더 큰 슬립 및 매개변수 값을 가지는 것으로 나타났다.

Keywords

Acknowledgement

본 연구는 국토교통부/국토교통과학기술진흥원의 지원(과제번호 RS-2020-KA156177)으로 수행되었음.

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