보 단부에 철판을 매립한 PC 콘크리트 보의 실험연구

An Experimental Study on PC Concrete Beams with Steel Plate Embedded at the End of Beams

본 연구에서는 PC보의 접합부 성능을 개선하기 위하여 보 단부에 steel plate를 매립한 SPE Beam(Steel Plate Embedded Beam)의 휨성능 평가 실험을 수행하였다. PC보의 공장제작 단계에서부터 시공하중과 완공시 마감하중이 가해지는 단계별 설계 프로세스를 검토하여 12m 스팬의 실물크기 보를 제작하였다. 보 단부의 매립 철판에는 부착력확보를 위하여 stud bolt를 설치하였으며 철판의 매립깊이가 각각 250mm와 450mm인 두 시험체를 제작하여 실험을 수행하였다. 강연선의 프리스트레싱 효과로 인하여 하중을 제거하였을 때 처짐 복원률이 평균 87.0%로 나타났으며, 항복 후에도 강성이 점점 증가하여 완전소성에 도달할 당시 하중이 항복하중보다 약 1.8배 높은 tri-linear 거동을나타내었다. 단부에 매립된 철판의 최소 깊이인 250mm 시험체의 실험종료 후에도 접합부는 양호한 상태를 나타내어접합 철판의 최소 매립깊이를 250mm로 제안하였다.

In this study, an experiment was conducted to evaluate the flexural performance of steel plate embedded beams, in which the steel plate was embedded at the end of the PC beam. From the factory manufacturing stage of the PC beam, the design process of each step in which the construction and finishing loads were applied at completion was reviewed to produce a 12 m span beam. A stud bolt was installed on the embedded steel plate at the end of the beam to ensure adhesion, and the experiment was performed using two specimens with embedded depths of 250 and 450 mm. When the load was removed owing to the pre-stressing effect of the strand, the displacement recovery rate averaged 87.0%, and the stiffness gradually increased even after yielding, exhibiting trilinear behavior that was approximately 1.8 times higher than that of the yield load when the load reached perfect plasticity. Even after the 250-mm test, which was the minimum depth of the steel plate embedment in the beam end, the joint remained in excellent condition, indicating that the bonded steel plate had a minimum depth of 250 mm.