On the response to hygrothermal aging of pultruded FRPs used in the civil engineering sector
On the response to hygrothermal aging of pultruded FRPs used in the civil engineering sector
复制标题
DOI：
10.1016/j.matdes.2016.02.026
复制
发表时间：
2016-04-15
影响因子：
8.4
通讯作者：
Papanicolaou, George C.
中科院分区：
文献类型：
--
作者：
Grammatikos, Sotirios A.;Evernden, Mark;Papanicolaou, George C.
本文介绍了湿热老化对拉挤平板的耐久性的影响，该平板在 25 摄氏度、40 摄氏度、60 摄氏度或 80 摄氏度的蒸馏水中浸泡 224 天。升高的温度显着增加水分扩散系数和吸湿行为。 28、56、112 或 224 天后检查拉伸和面内剪切机械性能的测量变化。拉伸性能实际上不受老化影响，而基体主导的剪切性能显示出初始下降，在进一步湿热老化后在很大程度上恢复。记录了由于塑化、附加交联等叠加机制引起的粘弹性性能变化。扫描电子显微镜显微照片表明，即使在最剧烈的热/湿老化之后，纤维/基体界面实际上仍保持完整。 X 射线能量色散光谱分析显示纤维增强表面没有发生化学降解事件，红外光谱显示老化基质中出现表面化学变化。光学显微镜显示在 80 摄氏度老化 112 天的样品中出现基体裂纹。最后，未老化材料的计算机断层扫描显示内部缺陷，这无疑增强了水分传输。在 60 摄氏度下老化 112 天后，计算机断层扫描检测到优先位置的水袋。 (C) 2016 年作者。由爱思唯尔有限公司出版
This paper presents the effects of hygrothermal aging on the durability of a pultruded flat sheet, immersed in distilled water at 25 degrees C, 40 degrees C, 60 degrees C or 80 degrees C for a period of 224 days. Elevated temperatures noticeably increase the moisture diffusion coefficient and moisture uptake behaviour. Measured changes in the tensile and in-plane shear mechanical properties were examined after 28, 56, 112 or 224 days. Tensile properties remained practically unaffected by aging whereas matrix dominated shear properties revealed an initial drop which was recovered to a substantial degree after further hygrothermal aging. Visco-elastic property changes due to the superimposing mechanisms of plasticization, additional cross-linking etc. were recorded. Scanning Electron Microscopy micrographs indicate that the fibre/matrix interface remained practically intact, even after the most aggressive hot/wet aging. X-ray Energy Dispersive Spectroscopy analysis showed no chemical degradation incidents on the fibre reinforcement surfaces and infrared spectroscopy revealed superficial chemical alteration in the aging matrix. Optical microscopy revealed matrix cracking in samples aged at 80 degrees C for 112 days. Lastly, Computed Tomography scans of un-aged material showed internal imperfections that undoubtedly enhanced moisture transport. After aging at 60 degrees C for 112 days, Computed Tomography detected preferentially situated water pockets. (C) 2016 The Authors. Published by Elsevier Ltd.