摘要(英) |
The purpose of the experimental study is to investigate seismic behavior of the new RC beams with high-strength (SD675MPa) screw bars, curtailed according to the design of ACI318-11[1] and NZS3101-2006[2]. Three cantilever beams subjected to cyclic loading were adopted for the pilot test. #8 SD685 screw bars (3-#8 set at upper bars and 3-#8 set at bottom bars) and #4 SD785/420 deformed bars were used in the test specimens. Furthermore, the #4 bars as transverse hoops were designed according to the seismic specification of ACI318-11. One beam without beam bar cut-off as a control specimen and the other two with 1-#8 beam bar curtailment at upper bars (ACI cut-off design) and at bottom bars (NZS cut-off design) were adopted for the test specimens. To realize the effect of transverse hoop strength on beam seismic performance, one beam designed using high strength #4 hoops whereas the other using normal strength #4 SD420 hoops.
Test results showed the cut-off design specified in ACI318-11 did not apply to the curtailment of high-strength screw-type #8 reinforcement. This is because the cut-off point of the #8 reinforcement is not lengthy enough. However, the cut-off design provided from NZS3101-2006 could be feasible for the curtailment of the high strength steel. Further study on the curtailed design of such high strength steel reinforcement is required. It was also repealed the curtailed beams with different hoop strengths, #4 SD785 and #4 SD420, had similar seismic behavior. |
參考文獻 |
[1] ACI Committee 318, Building Code Requirement for Structural Concrete, ACI318-11 & Commentary, American Concrete Institute, 2011.
[2] Standards Association of New Zealand, NZS 3101: New Zealand Concrete Structures Standard, Part 1- the Design of Concrete Structures, Part 2- Commentary on the Design of Concrete Structures, New Zealand, 2006.
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