Unified Analytical Approaches for Determining Shear Bond Characteristics of FRP-Concrete Interfaces through Pullout Tests
Unified Analytical Approaches for Determining Shear Bond Characteristics of FRP-Concrete Interfaces through Pullout Tests
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DOI：
10.3151/jact.4.133
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发表时间：
2006-02-01
影响因子：
2
通讯作者：
Sato, Yasuhiko
中科院分区：
文献类型：
--
作者：
Dai, Jianguo;Ueda, Tamon;Sato, Yasuhiko
拉拔试验是标定纤维增强聚合物(FRP)-混凝土界面剪切结合特性的常用试验方法。然而，由于FRP片材/带材的弯曲刚度较小，且界面断裂机制高度非线性，尽管进行了广泛的研究，但仍需找到一种公认的分析方法来准确解释拔出试验结果，特别是当目的是校准局部粘结应力-滑移模型时，这对于开发粘结强度和锚固长度模型是必要的，避免使用经验公式。本文介绍了新建立的用于分析拉拔试验中FRP全范围应变分布和界面粘结层剪切应力分布的非线性粘结应力-滑移模型，以及相应建立的新的锚固长度模型和粘结强度模型。与其他现有的键模型相比，本文描述的键模型除了简单之外，还有两个优点：(1)它将所有分析过程中最重要的界面参数，即所谓的界面断裂能，成功地与所有其他重要的键参数联系起来；(2)在frp -混凝土界面非线性分析中首次考虑了粘结层的影响，是一种通用统一的方法。进一步，建立了统一的键应力-滑移表达式，以显示拉拔试验中加载端和自由端局部键应力-滑移关系的差异，从而澄清拉拔试验中使用的键长对界面键应力-滑移模型标定的影响。通过对实验结果和分析结果的综合比较，验证了所提模型的可靠性。
The pullout test is a conventional test method for calibrating interfacial shear bond characteristics of Fiber Reinforced Polymer (FRP)-concrete interfaces. However, due to the small bending stiffness of FRP sheets/strips and the highly non-linear interface fracturing mechanism, a well-recognized analytical approach to the accurate interpretation of the pullout test results remains to be achieved despite extensive studies particularly when the aim is to calibrate a local bond stress-slip model, which is necessary for developing bond strength and anchorage length models avoiding the use of empirical formulations. This paper introduces a newly developed non-linear bond stress-slip model for analyzing full-range strain distributions in FRP and shear bond stress distributions in the interface bond layer during pullout tests, along with a new anchorage length model and bond strength model that were developed accordingly. Compared with other existing bond models, the bond model described here has two advantages besides its simplicity: (1) it incorporates the most important interface parameter, the so-called interfacial fracture energy, in all analytical processes and links it successfully with all other important bond parameters; (2) it is a general and unified approach that allows for the first time consideration of the effects of the adhesive bond layer in non-linear analysis of FRP-concrete interfaces. Further, a unified bond stress versus slip expression is formulated to show the differences in local bond stress-slip relationships at the loaded and free ends in pullout tests, so that the effects of the bond length used in a pullout test on the calibration of the interfacial bond stress-slip model can be clarified. The reliability of all proposed models is verified through a comprehensive comparison of the experimental and analytical results.