Flexural and Shear Behavior of Prestressed Reinforced Continuous Beams and Analysis

预应力钢筋连续梁的弯曲和剪切行为及分析

• 批准号: 10650454
• 负责人: KOBAYASHI Kazuo
• 金额: $ 1.79万
• 依托单位: Osaka Institute of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10650454/
• 关键词: Prestress; Crack width; Flexural strength; Moment redistribution; Shear strength; Nonlinear analysis; 極限解析法

Flexural and shear behavior of two-span continuous prestressed reinforced concrete (PRC) beams with mean prestress of about 3N/mmィイD12ィエD1 and mechanical prestressing degree of about 0.5 was studied in comparison with that of comparable reinforced concrete (RC) beams, and then those test results were compared with calculations obtained from a nonlinear analysis and design equations.Conclusions obtained from this study are summarized as follows.1) Width of flexural crack was considerably smaller in PRC beam than RC beam, and was somewhat larger in unbonded beam than bonded one. Those could be estimated relatively well using steel stress by nonlinear analysis and crack width equation by the JSCE Code.2) Ultimate flexural strength of PRC beam was higher by about 8% on the average than that of comparable RC beam, and then that of unbonded beam was lower by maximum 10% than that of bonded one. Those could be estimated well by applying the limit analysis.3) Ridity of PRC beam after flexural cracking was higher than that of RC beam, and use of high strength concrete of f'ィイD2cィエD2=80N/mmィイD12ィエD1 was very effective for improving member rigidity.4) Moment redistribution initiated after flexural cracking, but no significant difference could be recognized in load-moment relations at loading point or intermediate support between PRC and RC beams and between two types beams of f'ィイD2cィエD2=40 and 80N/mmィイD12ィエD1. Flexural behavior up to the ultimate state after cracking of PRC beams could be estimated well by a nonlinear analysis applied in this study.5) Ultimate shear strength of PRC beam without web reinforcement was larger by about 55% on the average than that of comparable RC beam.6) Measured ultimate shear strength was fairly in excess of calculation obtained by setting all of safety factors in design equation of the JSCE Code to be 1.0.7) Stirrup strains in PRC beam could be estimated well by the modified compression field theory.

研究了平均预应力约为3N/mmィイD12ィエd1、机械预应力度约为0.5的两跨预应力钢筋混凝土连续梁的抗弯和抗剪性能，并将试验结果与基于非线性分析和设计方程的计算结果进行了比较。结论1)预应力混凝土梁的受弯裂缝宽度明显小于钢筋混凝土梁，而无粘结梁的裂缝宽度略大于有粘结梁。2)PRC梁的极限抗弯强度平均比可比钢筋混凝土梁高8%左右，而无粘结梁的极限抗弯强度比有粘结梁低10%左右。3)钢筋混凝土梁受弯开裂后的刚度高于钢筋混凝土梁，采用f‘ィイD2CィエD2=80n/mmィイD12ィエD1高强混凝土对提高构件刚度是非常有效的。4)弯裂后开始的弯矩重分配，但在加载点或中间支承处的荷载-弯矩关系在预应力混凝土梁和钢筋混凝土梁之间以及f’ィイD2CィエD2=40和80n/mmィイD12ィエD1两种梁之间没有显著差异。5)无腹筋混凝土梁的极限抗剪强度比钢筋混凝土梁的极限抗剪强度平均提高约55%。6)实测的极限抗剪强度远远超过JSCE规范设计公式中所有安全系数为1.0时的计算值。0.7)修正的压力场理论可以较好地估计PRC梁中的箍筋应变。

项目成果

小野由博、小林和夫 他: "PRC連続はり部材の基本的耐荷特性に関する研究"コンクリート工学年次論文報告集. 21巻・3号. 967-972 (1999)

小野义博、小林一夫等：“PRC连续梁构件基本承载性能研究”混凝土工程年报第21卷第3期967-972（1999）

Yoshihiro ONO, Kazuo KOBAYASHI et al.: "Study on Fundamental Load Carrying Properties of Prestressed Reinforced Concrete Continuous Beams"Proc. Of the JCI. Vol.21,No.3. 967-972 (1999)

小野义博、小林一雄等：“预应力钢筋混凝土连续梁基本承载性能研究”Proc.