| 研究生: |
黃勝暉 Huang, Sheng-Hui |
|---|---|
| 論文名稱: |
普通混凝土梁承受彎矩、剪力與扭矩之行為與規範印證 Behavior and Validation of Code Provisions of Reinforced Concrete Beam under Combined Bending, Shear, and Torsion |
| 指導教授: |
方一匡
Fang, I-Kuang |
| 學位類別: |
碩士 Master |
| 系所名稱: |
工學院 - 土木工程學系 Department of Civil Engineering |
| 論文出版年: | 2011 |
| 畢業學年度: | 99 |
| 語文別: | 中文 |
| 論文頁數: | 134 |
| 中文關鍵詞: | 扭矩 、組合載重 、軟化 、AASHTO-LRFD 、ACI318 |
| 外文關鍵詞: | torsion, combined loading, soften, AASHTO-LRFD, ACI318 |
| 相關次數: | 點閱:94 下載:6 |
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本文旨在探討相同鋼筋量及斷面性質之普通混凝土梁在彎矩(M)、剪力(V)與扭矩(T)組合載重作用之承力行為與AASHTO-LRFD (2007)及ACI318-08規範之印證。
本研究試體為10根斷面尺寸為250×350mm之鋼筋混凝土矩形梁,梁長分別為1500mm及2100mm,主要考慮變數為扭矩及彎矩組合載重比例T/M=0、1/10與1/8及空心斷面與實心斷面試體。
主要研究結果如下:(1)試體之破壞模式符合Elfgren所建議強度互制關係之第一類破壞模式,強度互制式之理論破壞載重較為保守。 (2)T/M比值增加時,造成試體頂面產生斜裂縫,軟化效應使混凝土抗壓強度降低。(3)於相同鋼筋量與斷面大小條件下,試體之撓曲韌性主要受T/M比值及核心混凝土之影響 (4)隨著T/M比例從0增加至1/8,實心斷面試體與空心斷面試體之撓曲強度分別會折減約8~13%及10~12%。(5)依據ACI318-08及AASHTO-LRFD (2007)所需設計鋼筋量是實際鋼筋量分別為1.25與1.32倍,結果顯示規範設計所需鋼筋量較為保守。
This thesis presents the behavior of reinforced concrete beams, having same section and amount of reinforcement, subjected to combined bending (M), shear (V), and torsion (T). The requirements of longitudinal reinforcement according to AASHTO-LRFD (2007) and ACI318-08 Codes are also studied.
The beam specimens, 250×350 mm cross section, having test lengths of 1500mm and 2100mm were tested. The main parameters included ratio of torsion to bending T/M= 0, 1/10, and 1/8, and solid and hollow sections.
Results indicated that conservative estimate of failure load and failure mode one were found by comparison with Elfgren’s interaction equation. The softening effect of concrete at top surface of beam caused the decrease of concrete compressive strength. Under the condition of same section size and amount of reinforcement, the flexural ductility was mainly affected by T/M ratio and concrete core.
As T/M values increased from 0 to 1/8, the flexural strength of solid and hollow specimens decreased about 8-13% and 10-12%, respectively. The amount of longitudinal reinforcement required by ACI318-08 and AASHTO-LRFD (2007) Codes was 1.25 and 1.32, respectively, times that actually provided in beams.
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