Askouni Paraskevi D, Papanicolaou Catherine Corina G, Azdejkovic Lazar
Department of Civil Engineering, University of Patras, Rio, 26504 Patras, Greece.
Materials (Basel). 2021 Dec 25;15(1):140. doi: 10.3390/ma15010140.
Limited research has focused on the effect of high temperatures on the textile-reinforced mortar (TRM)-to-masonry bond. In this study, masonry prisms that were furnished with double-layered TRM strips were tested under shear bond conditions after their exposure to 200 °C and 400 °C for 1 h using the single-lap/single-prism setup. A total of four TRM systems were applied sharing the same type of textile -a dry AR glass fiber one- and different matrices: two cementitious matrices, namely a normal-weight (TRCNM) and a lightweight (TRCLM) one, and two counterpart alkali-activated matrices (TRAANM and TRAALM) based on metakaolin and fly ash. Specimens' exposure to elevated temperatures did not alter their failure mode which was due to the sleeve fibers' rupture along with core fibers' slippage from the mortar. The residual bond capacity of the TRM systems decreases almost linearly with increasing exposure temperature. The alkali-activated textile reinforced mortars outperformed their cement-based counterparts in terms of bond strength at every temperature. All systems retained close to 50% of their original shear bond strength after heating at 400 °C. Per the type of binder, lightweight matrices resulted in either comparable (cement-based systems) or better (alkali-activated systems) heat protection at the TRM/masonry interface.
有限的研究聚焦于高温对纺织增强砂浆（TRM）与砌体粘结的影响。在本研究中，配备双层TRM条带的砌体棱柱在使用单搭接/单棱柱装置在200℃和400℃下暴露1小时后，在剪切粘结条件下进行测试。总共应用了四种TRM系统，它们使用相同类型的织物——一种干燥的AR玻璃纤维织物——以及不同的基体：两种水泥基基体，即一种普通重量的（TRCNM）和一种轻质的（TRCLM），以及两种基于偏高岭土和粉煤灰的对应碱激活基体（TRAANM和TRAALM）。试件暴露于高温并未改变其破坏模式，该破坏模式是由于套管纤维的断裂以及芯纤维从砂浆中的滑移。TRM系统的残余粘结能力随着暴露温度的升高几乎呈线性下降。在每个温度下，碱激活纺织增强砂浆在粘结强度方面均优于其水泥基对应物。在400℃加热后，所有系统均保留了接近其原始剪切粘结强度的50%。就粘结剂类型而言，轻质基体在TRM/砌体界面处提供了相当（水泥基系统）或更好（碱激活系统）的热防护。
