本論文旨在探討自充填混凝土梁承受彎矩、剪力及扭矩組合載重下之承力行為並驗證AASHTO-LRFD (2007)規範與ACI318-08規範中關於縱向鋼筋量規定之適用性。
本研究共利用10根相同斷面尺寸250×350 mm，長度為1.5與2.1米之鋼筋混凝土梁，主要變數為扭矩與彎矩之比值(T/M=0、1/10、1/8)及實心與空心斷面等。
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)梁承受扭矩時頂面混凝土會產生軟化效應，使梁之極限彎矩強度與韌性遞減。(3)試體之撓曲強度隨T/M比值增加而減少，T/M比值增加1/8時實心與空心試體折減約13%與24%。(4)試體之韌性隨T/M比值增加而減少，T/M比值增加1/8實心與空心試體皆折減約70%。(5)試體破壞時承受的剪力越小，韌性比值就越大，2.1m梁之韌性比值約為1.5m梁之1.2倍。(6)實心試體之韌性優於空心試體，實心試體之韌性比值約為空心試體之1.45倍。(7)在相同組合載重與梁長，且試體均達破壞載重下，自充填混凝土之韌性比值約為普通混凝土之1.2倍。(8)依ACI318-08規範與AASHTO-LRFD規範設計斷面所需之縱向鋼筋量約為實際值之1.37倍與1.29倍，即規範之設計規定較為保守。

This thesis presents the behavior of self-compacting concrete beams subjected to combined bending, shear, and torsion. The requirements of longitudinal reinforcement according to AASHTO-LRFD and ACI318-08 codes are also studied. The results of previous studies were used for the study of failure modes, flexural strength and ductility, and variations of principal strains.
The beam specimens, 250×350 mm cross section, having test lengths of 1.5m and 2.1m, respectively, were tested. The main parameters included ratio of torsion to bending (T/M=0, 1/10, 1/8) and solid and hollow sections.
Results indicated that failure mode one and conservative estimate of failure load were found by comparison with Elfgren’s interaction equation. The softening effect of concrete at top surface of beam caused the decrease of flexural strength and ductility. The flexural strength decreased around 13%~24% as T/M value increased from 0 to 1/8. More decrease of flexural ductility was found in hollow section than solid section. The decrease of flexural ductility was approximately 70% for sections with T/M=1/8.
The flexural ductility for beams having length of 2.1m was about 1.2 times that of beams having length of 1.5m. Under the same conditions, the flexural ductility of self-compacting concrete beams is 1.3 times that of normal concrete beams. The amount of longitudinal reinforcement required by ACI318-08 and AASHTO-LRFD codes was 1.37 and 1.29 times that actually provided in beams, respectively.

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