Experimental Study on Interface Shear Strength of Concrete in Vertical Construction Joint

콘크리트 수직시공이음 접합면의 전단강도에 대한 실험적 연구

  • Kim, Ook-Jong (Division of Construction Business, Daelim Industrial Co.) ;
  • Kim, Young-Chan (Division of Architecture, Pukyong National Univesity)
  • Published : 2004.06.01

Abstract

In masive concrete placement, cracking problem due to hydration heat is frequently encountered. One of measure to solve this problem is to make a construction joint. However, it is cumbersome to make it by chipping the surface of joint. In this study, push-out test for 18 specimens was conducted to compare the interface shear strength of consturction joints whose surfaces were prepared with three methods; chipping, rib-lath, folded rib-lath. Compared to the specimens made with conventional surface chipping, those with rib-lathe showd excellent preformance increasing shear resistance capacity and the role of shear key conceived by folding rib-lath played important role in enhancing shear resistance.

수화열에 의한 균열은 대규모 콘크리트 타설시 흔하게 접하는 문제이며 이에 대한 해결은 시공이음을 만드는 것이다. 일반적인 방법으로 접합면을 할석으로 처리 하나 이 작업은 번거롭고 품질의 일관성을 유지하기 쉽지 않다. 본 연구에서는 접합면을 3가지 방법으로 처리하여 접합면의 전단강도를 비교하기 위한 18개의 시험체에 대한 push-out실험을 수행하였다. 할석으로 접합면을 만든 시험체에 비해 리브라스를 이용한 시험체가 전단저항에 월등한 성능을 보여 주었으며 그리고 리브라스를 절곡하여 만든 전단키가 전단저항을 향상시키는데 큰 역할을 하였다.

Keywords

References

  1. Bussell M, N, Cather R., 'Design and construction of joints in concrete structures', CIRIA report 146, London, 1995
  2. Zhu, Yu-ting, 'Bond betwsen new and old concrete', Analysis of concrete structures by fracture mechanics., Chapman and Hall, London, pp. 199~207. 1991
  3. Moriwaki, Takashi, Tsuji, Yukikazu, Hashimoto, Chikanori, Nakajima, Takahiro, 'Characteristics for strength of construction joint using polymer modified mortar as joint materials', Proceedings of the Japan Society of Civil Engineers, Vol. 31, No. 538, pp. 15-26, 1996, 5
  4. Moriwaki, Takashi, Tsuji, Yukikazu, Hashimoto, Chikanori, Kigure, Takeshi, "Perfonnance evaluationof construction joint existing in RC beam using polymer modified mortar as joint materials', Proceedings of the Japan Society of Civil Engineers, Vol. 31, No. 538, pp. 1-13, 1996, 5
  5. Ujike, Isao, Yoshida,Noriyoshi, Monshita, Shigekazu, 'Evaluation of mechanical properties of construction joint between new and old concrete under combined tensile and shear stresses', Journal-Society of Materials Science Japan, Vol. 47, No. 1, pp. 73-78, 1998
  6. Tsuji, Yukikazu, Sugiyama, Takafumi, Hashimoto, Chikanori, 'Effect of vertical construction joint on the structural behavior of reinforced concrete beam made of self compacting concrete.', Journal-Society of Materials Science Japan, Vol. 49, No. 10, pp. 1127-1132, 2000 Oct https://doi.org/10.2472/jsms.49.1127
  7. ACI, 'Building Code Requirements for Structural Concrete(ACI318-95) and Commentary(ACI 318R-95)', 1995