외적 포스트텐셔닝 보강에서 데비에이터의 위치에 따른 전단보강효과 (Shear Strengthening Effect by Deviator Location in Externally Post-tensioning Reinforcement)

서지정보

· 발행기관 : 대한건축학회
· 수록지 정보 : 대한건축학회논문집 구조계 / 34권 / 6호 / 3 ~ 10페이지
· 저자명 : 이수헌, 신경재, 이희두

초록

본 논문은 기손상된 철근콘크리트(RC) 보의 외적 포스트텐셔닝 강봉 보강에서 데비에이터의 위치에 따른 전단보강 효과를 나타낸다. 3개의 RC 보와 8개의 외적 포스트텐셔닝 강봉 보강된 보를 대상으로 데비에어터의 수, 위치, 하중 패턴에 따라 실험을 수행하였다. 보강은 하중전달 능력의 증가와 기존의 처짐 회복, 사인장균열의 과도한 성장을 방지하였다. 보 중앙의 한개 보다 두개의 데비에이터는 효과적으로 부하능력을 증가시켰다. 사인장균열이 발생하는 영역에 데비에이터가 위치할 경우, 포스트텐셔닝에 의한 보강효과는 더 증대되었다.

영어초록

This paper described the shear strengthening effect by deviator location in pre-damaged reinforced concrete (RC) beams strengthened with externally post-tensioning steel rods. Three reinforced concrete beams as control beam and eight post-tensioned beams using external steel rods were tested to fail in shear. The externally post-tensioning material was a steel rod of 22mm diameter, and it had a 655MPa yield strength and an 805MPa tensile strength. Specimens depend on multiple variables, such as the number of deviators, location of deviator, and load pattern. The pre-damaged loads up to about 2/3 of ultimate shear capacities were applied to specimens using displacement control and the diagonal shear crack just occurred at these loading levels. And then, the post-tensioning up to when a strain of steel rod reaches about 2000 was continuously applied to beam. A displacement control was changed to a load control during post-tensioning. The post-tensioning resulted in increase of load-carrying capacity and restoration of existing deflection. Also, it prevented the existing diagonal cracks from excessively growing. Two deviators effectively improved the load capacity when compared with in case of test which one deviator at mid-span installed. When deviators were located near region which the diagonal crack occurred on, the strengthening impact by post-tensioning was greater.

참고자료

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