Glass Fibre Reinforced Polymer (GFRP) bars have been employed as internal reinforcement for concrete members when corrosion of the commonly used steel bars is expected to be an issue. While a good bond is anticipated between GFRP bars and concrete at ambient temperature, the bond performance at high temperature is expected to be reduced due to the physical and mechanical changes that the matrix undergoes at temperatures approaching the glass transition temperature (T_g). Up to date this phenomenon has only been marginally investigated and most of the available bond tests are performed at ambient temperatures after cooling of the heated specimens.

This paper presents the results of an experimental investigation on the bond behaviour of GFRP bars in concrete and exposed to temperature levels ranging from ~20 °C to 300 °C. The test specimens, consisting of an indented GFRP bar embedded in a cylindrical concrete block, were heated in an electric furnace. The pull-out tests were carried out within the furnace only after the temperature level, measured with thermocouples at the interface of GFRP and concrete, stabilized to the desired value.

The paper discusses the effect of temperature on bond behaviour in terms of bond strength, bond stress-slip relationships and failure modes. A contactless technique measuring the free-end slip during pull-out tests at high temperatures was developed and its effectiveness demonstrated. Finally, the experimental results were used to calibrate the parameters of the two most widely used analytical models: mBPE and CMR.

当预期会腐蚀常用的钢筋时，玻璃纤维增​​强聚合物（GFRP）钢筋已被用作混凝土构件的内部钢筋。尽管在环境温度下可以预期GFRP钢筋与混凝土之间具有良好的粘结性，但是由于基体在接近玻璃化转变温度（T _g）的温度下发生的物理和机械变化，因此高温下的粘结性能预计会降低。迄今为止，仅对这种现象进行了很少的研究，并且大多数可用的粘结测试都是在加热试样冷却后在环境温度下进行的。

本文介绍了GFRP筋在混凝土中的暴露行为的实验研究结果，GFRP筋在〜20°C到300°C的温度范围内暴露。由嵌入圆柱形混凝土块中的GFRP锯齿状试样组成的试样在电炉中加热。仅在用玻璃纤维增​​强塑料和混凝土界面处的热电偶测得的温度水平稳定在所需值后，才在炉子内进行拉出试验。

本文从粘结强度，粘结应力-滑动关系和破坏模式等方面讨论了温度对粘结行为的影响。开发了一种非接触式技术，可测量高温下拔出测试期间的自由端滑移，并证明了其有效性。最后，实验结果用于校准两种最广泛使用的分析模型的参数：mBPE和CMR。