Effects of Ageing on the Bond Properties of Carbon Fiber Reinforced Polymer/Concrete Adhesive Joints: Investigation Using a Modified Double Shear Test
Effects of Ageing on the Bond Properties of Carbon Fiber Reinforced Polymer/Concrete Adhesive Joints: Investigation Using a Modified Double Shear Test
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DOI：
10.1520/jte20160587
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发表时间：
2017-11
影响因子：
1.2
通讯作者：
M. Quiertant;K. Benzarti;J. Schneider;Fabrice Landrin;Mathieu Landrin;F. Boinski
中科院分区：
文献类型：
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作者：
M. Quiertant;K. Benzarti;J. Schneider;Fabrice Landrin;Mathieu Landrin;F. Boinski
尽管外部粘合碳纤维增强聚合物（FRP）复合材料现在通常用于钢筋混凝土结构的加固和修复，但混凝土/复合材料界面粘合的耐久性仍然是一个研究问题，并且仍然是评估FRP加固方法的长期性能需要解决的关键问题。该论文旨在介绍加速老化的混凝土/复合材料组件粘合强度随时间演变的研究结果。通过在长达 1 年的几个老化中间阶段进行双搭接剪切试验来研究这种演变，同时分别通过拉伸和压缩试验研究最弱的构成材料（即聚合物粘合剂和混凝土）的机械性能变化。考虑到老化样品转移长度的增加可以抵消老化引起的散装粘合剂机械性能的下降，并最终导致接头的剪切能力不变，因此提出了一种新的双剪切试样几何形状。这种几何形状涉及较小的键合长度，因此限制了老化期间转移长度的可能增加。此外，它们尺寸的减小允许在标准气候室中存储大量样品。设计了特定的锚固装置，以便可以使用传统的万能试验机进行双搭接剪切试验。所得结果表明，基于这种原始设置的剪切试验能够揭示混凝土/复合材料组件在各种加速老化条件下的粘结强度和破坏模式的演变。发现这些老化条件对样品的机械特性仅产生轻微的有害影响，并且最终观察到部分恢复。
Although externally bonded carbon fiber reinforced polymer (FRP) composites are now commonly used for the strengthening and repair of reinforced concrete structures, the durability of the adhesive bond at the concrete/composite interface is still a matter of investigation and remains a critical issue to be addressed in order to assess the long-term performance of FRP strengthening methods. The proposed paper aimed at presenting the results of an investigation on the time evolution of the adhesive bond strength of concrete/composite assemblies exposed to accelerated ageing. Such an evolution was studied by performing double lap shear tests at several intermediate periods of ageing up to 1 year, while changes in the mechanical properties of the weakest constitutive materials, namely polymer adhesive and concrete, were investigated by means of tensile and compressive tests, respectively. Considering that an increase in the transfer length of aged samples can counterbalance the ageing-induced degradation of the mechanical properties of the bulk adhesive and can finally lead to an unchanged shear capacity of the joint, a new geometry of double-shear test specimens was proposed. This geometry involved a smaller bonded length and consequently restricted the possible increase in transfer length during ageing. Moreover, their reduced size allows the storage of a large number of samples in standard climatic chambers. A specific anchorage device was designed, so that double lap shear tests could be carried out using a conventional universal testing machine. The obtained results showed that the shear tests based on this original setup are able to reveal the evolutions of both the bond strength and the failure mode of concrete/composite assemblies subjected to various accelerated ageing conditions. These ageing conditions were found to have only slight detrimental effects on the mechanical characteristics of samples, and finally a partial recovery was observed.