|
Title |
Proposal of Development Length of Grade 700 MPa Deformed Bars in Tension
|
|
Authors |
권동욱(Dong-Uk Kwon) ; 이재훈(Jae-Hoon Lee) |
|
DOI |
https://doi.org/10.4334/JKCI.2022.34.5.465 |
|
Keywords |
콘크리트구조 설계기준; 항복강도 700 MPa; 직선 정착; 정착길이; 수정계수 KCI code; grade 700 MPa; straight anchorage; development length; modification factor |
|
Abstract |
In this study, based on 412 anchorage test results using beam specimens with lap spliced bars in tension, the development length calculated by KCI code (2021) and the tested value were compared. Even where transverse reinforcement was placed to satisfy the provision for deformed bars with specified yield strengths exceeding 550 MPa, 47 % of the calculated development lengths of Grade 600 MPa deformed bars were shorter than the tested value. The results for Grade 700 MPa deformed bars were found to be unsafe. The trend for reinforcing bars with yield strengths not less than 500 MPa without the effect of steel strength appears to be similar to that for yield strengths less than 500 MPa. A modification factor for increasing the development length of deformed bars with specified yield strengths exceeding 500 MPa is proposed, and the safety of straight anchorage of Grade 700 MPa deformed bars was verified.
|