應用本土化圍束混凝土模式於New RC柱構件撓曲行為之研究

SIMULATION OF THE FLEXURAL BEHAVIOR OF NEW RC COLUMNS WITH PROPOSED CONFINED CONCRETE STRESS-STRAIN MODEL

劉光晏(Kuang-Yen Liu) ； 吳振揚(Chen-Yang Wu) ； 李昱勳(Yu-Hsun Lee) ； 楊世豪(Shih-Hao Yang) ； 趙文成(Wen-Chen Jau)

《中國土木水利工程學刊》 30卷3期 (2018/09) Pp. 231-241

https://doi.org/10.6652/JoCICHE.201809_30(3).0007

摘要

本研究完成8組大型New RC柱同心軸壓實驗，探討核心圍束混凝土之軸向壓縮行為。混凝土設計強度為70MPa，縱向鋼筋設計強度為690MPa，橫向鋼筋設計強度為420MPa（N系列）及790MPa（H系列），橫向鋼筋間距為4倍與6倍間距，以比較不同圍束效應對核心混凝土之影響。根據實驗成果，本研究建議本土化New RC受橫向鋼筋圍束之應力與應變關係，並應用於New RC柱構件之撓曲強度與變形能力分析。分析結果顯示，針對撓曲破壞控制之New RC柱構件，採用本研究提出之混凝土組成律，經由斷面分析軟體（如：XTRACT）進行彎矩曲率分析並考量塑性鉸長度之貢獻，可有效掌握撓曲強度與變形發展過程，與實驗成果間有良好一致性。

關鍵字

高強度鋼筋混凝土 ； 方柱 ； 圍束 ； 應力應變關係 ； 撓曲行為

並列摘要

In this study, the experimental program of 8 square New RC columns under concentric loading was carried out. The nominal compressive strength of the concrete is 70 MPa. The yielding strength for longitudinal reinforcement is 690 MPa. For transverse reinforcement, the cross-sectional area should be provided by ACI 318-14, and the yielding strength is between 420 MPa and 790 MPa to compare the differences in the confinement effect of the core concrete on the strength of different transverse reinforcements. From experimental result, it is expected to propose a local-based stress-strain model for confined high strength concrete. Furthermore, this study presents the seismic evaluation of columns based on the proposed stress and strain model for confined concrete used in New RC column. The load and displacement relationship of New RC columns with flexural failure mode can be analyzed by conducting the moment-curvature analysis with XTRACT first, and followed by the integration process of moment-area method, as well as the contribution of plastic hinge length, to obtain the element behavior from elastic to inelastic state.

並列關鍵字

New RC ； square column ； confinement ； stress-strain model ； flexural behavior