CALCULATION OF THE FLEXURAL CAPACITY OF R.C BEAMS STRENGTHENED WITH PRESTRESSED CFRP UNDER SUSTAINING LOAD AND ANALYSIS OF THE INFLUENTIAL FACTORS
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摘要: 粘贴预应力碳纤维布加固混凝土构件是一种行之有效的加固方式,通过对持载下预应力碳纤维布加固钢筋混凝土梁受弯破坏理论分析和总结,推导出承载力计算公式,并通过理论计算分析了持载及预应力水平对承载力的影响。分析结果表明:当受压区混凝土压碎时,梁的极限承载力随着持载的增大而逐渐降低,随着预应力水平增大而逐渐增大且具有极值;当碳纤维布拉断时,梁的承载力随着持载的增大而逐渐增大,而随着预应力水平的增大逐渐降低。持载对极限承载力的影响较小,可以忽略;最后基于加固后构件的延性探讨了预应力CFRP有效张拉应变的控制值。Abstract: The concrete members strengthened with prestressed CFRP is an effective method. Through the theoretical analysis and summary of flexural failure of reinforce concrete beams strengthened with prestressed CFRP under sustaining load,the simplified calculation formulas of load carrying capacity are presented?and the influence of the sustaining loads and pre-stressed levels on ultimate load-carrying capacity are analyzed. The theoretical analysis results indicated that when the concrete in the compression zone is crushed,ultimate load-carrying capacity is decreasing with sustaining loads increasing,whereas ultimate load-carrying capacity is increasing with prestressed levels increasing and has extreme value. When CFRP sheet is ruptured,the change of ultimate?load-carrying capacity was completely contrary to that of the crushe concrete in compression zone. The effect of sustaining loads on ultimate load-carrying capacity isn't obvious and can be ignored. Finally control value on tensile strain of the CFRP is also given based on the ductility failure of the strengthened members.
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Key words:
- prestressed CFRP sheet /
- strengthen /
- reinforce concrete beams /
- flexural capacity /
- sustaining load
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