李松辉, 赵国藩, 王松根. CFRP加固混凝土梁各受力阶段的剥离机理[J]. 工程力学, 2005, 22(1): 153-158.
引用本文: 李松辉, 赵国藩, 王松根. CFRP加固混凝土梁各受力阶段的剥离机理[J]. 工程力学, 2005, 22(1): 153-158.
LI Song-hui, ZHAO Guo-fan, WANG Song-gen. MECHANISM OF COVER DELAMINATION OR FRP DEBONDING OF CFRP STRENGTHENED RC BEAMS AT DIFFERENT STAGE[J]. Engineering Mechanics, 2005, 22(1): 153-158.
Citation: LI Song-hui, ZHAO Guo-fan, WANG Song-gen. MECHANISM OF COVER DELAMINATION OR FRP DEBONDING OF CFRP STRENGTHENED RC BEAMS AT DIFFERENT STAGE[J]. Engineering Mechanics, 2005, 22(1): 153-158.

CFRP加固混凝土梁各受力阶段的剥离机理

MECHANISM OF COVER DELAMINATION OR FRP DEBONDING OF CFRP STRENGTHENED RC BEAMS AT DIFFERENT STAGE

  • 摘要: 粘贴碳纤维片加固混凝土梁的试验数据和破坏模式表明,在锚固措施可靠的情况下,界面粘贴失效或基面混凝土剥离是加固混凝土梁的主要早期破坏形态。为研究混凝土梁不同受力阶段对界面粘结失效或混凝土剥离的影响程度,针对实际加固工程中常见的混凝土梁损伤状况并结合室内试验结果,分别研究了粘贴碳纤维片加固完整梁及不同开裂程度梁在不同受力阶段中的界面应力分布与剥离机理,指出了加固梁的开裂或裂缝扩展是导致界面或粘贴基面混凝土剥离的主要原因。最后,结合实际混凝土梁的损伤特点,提出了加固设计施工过程中的注意事项及应采取的技术措施。

     

    Abstract: The existing experimental results and failure modes indicate that cover delamination or FRP debonding from RC beams strengthened with CFRP will limit the overall effectiveness of the bonded FRP system, and result in premature failure in addition to the conventional modes of failure observed in unstrengthened RC beams. The main objective of this study is to assess the effects of flexural cracks in the midspan tension zone of the plated beams on interfacial stresses. Based on experimental results and crack patterns of RC beams strengthened with externally bonded CFRP sheets, the distribution of interfacial stresses of CFRP strengthened un-cracked and pre-cracked RC beams is discussed. It is shown that cracks or cracking in substrate along the CFRP-strengthened RC beams causes the shear stress concentrations, which are believed to be responsible for the premature failure observed in CFRP-strengthened beams. Finally, on the basis of failure modes of aging structures, general design recommendations for CFRP anchorage are proposed for preventing or delaying premature failures of CFRP-strengthened beams.

     

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