自充填混凝土梁撓曲行為分析之研究

Abstract

本研究係探討自充填混凝土與普通混凝土梁受靜態載重作用下之撓曲行為，利用Xtract程式模擬梁斷面之彎矩-曲率，進而推求梁撓曲行為之載重及變位關係，並與試驗值作一比較。共分析32支梁構件，其中27支為自充填混凝土梁、另5支為普通混凝土梁，探討之變數為混凝土強度、拉力筋量、壓力筋量、箍筋間距、剪跨比等，以期了解採用Xtract程式模擬自充填混凝土梁撓曲行為之可行性。分析結果歸納如下: 1.比較梁試體之撓曲行為之試驗值及Xtract程式之分析值，發現兩者的破壞過程相似，顯示所分析梁斷面之彎矩-曲率，可利用共軛梁法推求梁撓曲行為之載重-位移。 2.Xtract程式分析之梁斷面的極限彎矩，因考慮圍束混凝土的影響，其分析值較ACI規範計算值更接近實際破壞情形。 3.在箍筋強度≦420MPA的條件下，由Xtract程式分析推求之位移及載重值較試驗值低，顯示採用Xtract程式分析方法計算梁構件的位移及載重值是偏向保守與安全的。 4.根據分析結果可以推論現行以Xtract程式用於計算OPC梁撓曲強度的方法應可適用於SCC梁撓曲強度之計算。

The purpose of this study is to investigate the flexural behavior of self-consolidation concrete（SCC）beams under static load. The cross section of beam of moment-curvature relationship can be simulated by using the Xtract program, furthermore, the load-displacement relationship of the flexural behavior of the beam can be obtained, and then compared with the experimental values. A total of 32 beams were analyzed in this study: five were normal concrete beams and the rest were SCC beams. The amount of compression reinforcement, spacing of transverse reinforcement and the strength of transverse reinforcement were taken into consideration. The conclusions can be made from the results: 1.After comparing the flexural behavior of the experimental values and the values obtained by Xtract, it could be found that the failure behavior were similar. It showed that the load-displacement relationship of the beams could be obtained by using conjugated beam method. 2.Because of the consideration of the confined concrete, the ultimate moment of the beam calculated by Xtract program are closer to the real failure condition than from ACI code . 3.Under the condition that the strength of transverse reinforcements bellowed 420 MPa, the displacements and loads obtained by Xtract program are less than the experimental results. It implies that the displacements and loads obtained by Xtract program are conservative and on the safe side. 4.According to the results of analysis, the method of calculating the flexural strength OPC beams by using Xtract program also can be used in SCC beams.