表面涂覆胶黏剂对碳纤维拉挤板材耐湿热性能的影响

发布时间：2018-01-06 14:44

本文关键词：表面涂覆胶黏剂对碳纤维拉挤板材耐湿热性能的影响　出处：《哈尔滨工业大学》2015年硕士论文　论文类型：学位论文

【摘要】：碳纤维增强环氧树脂(CFRP)复合材料是性能优异的新型结构材料,近年来被广泛应用于土木工程结构的改造、加固及新建结构的建设。土木工程结构的服役环境(如温度、湿度、紫外光、干湿循环等)恶劣,会导致碳纤维复合材料的性能发生退化,因此,为保证碳纤维复合材料在土木工程结构中安全设计与应用,需要系统研究碳纤维复合材料在各种服役环境下的耐久性能。CFRP板材应用于混凝土结构外粘结加固,CFRP板材与混凝土间通过胶黏剂粘结,该粘结剂的存在,将阻隔水分子或强碱性混凝土渗出水对碳纤维板材的侵蚀,从而可能对CFRP板材的耐久性能有正面作用。前期的碳纤维板材耐久性能研究,均未考虑胶黏剂涂层的作用,这可能导致研究结果与实际退化情况不一致。因此,本文将研究表面涂覆胶黏剂的CFRP材在水或强碱溶液浸泡条件下的水吸收与力学性能演化,以期得到更接近服役状态的碳纤维拉挤板材的耐久性能。研究发现,对未涂覆胶黏剂的CFRP板材,随着温度升高,其吸水速率逐渐升高;强碱溶液浸泡环境中,CFRP拉挤板的吸水速率高于水浸泡;对浸泡于60 oC强碱溶液中的CFRP板材,树脂发生水解反应。表面均匀涂覆胶黏剂后,同样浸泡时间内,CFRP拉挤板的水吸水率明显降低。Abaqus有限元软件模拟结果与实验测试得到的水吸收曲线结果基本吻合。对于未涂覆胶黏剂的CFRP拉挤板,在水及强碱溶液浸泡条件下,其拉伸性能均缓慢下降,但面内剪切强度相对下降更为明显,如在60 oC蒸馏水与强碱溶液浸泡三个月后,CFRP拉挤板的面内剪切强度分别下降了18.8%和48.8%。涂覆胶黏剂后,在同样浸泡条件下,CFRP板的拉伸强度保持不变,但面内剪切强度仍有一定的退化,60 oC蒸馏水与强碱溶液浸泡三个月后CFRP板面内剪切强度退化达29.1%和32.8%。
[Abstract]:Carbon fiber reinforced epoxy resin (CFRP) composite is a new type of structural material with excellent properties, which has been widely used in civil engineering in recent years. The service environment of civil engineering structure (such as temperature, humidity, ultraviolet light, dry-wet cycle, etc.) is bad, which will lead to the degradation of the properties of carbon fiber composites. In order to ensure the safety design and application of carbon fiber composites in civil engineering structures. It is necessary to systematically study the durability of carbon fiber composites in various service environments. CFRP sheets are applied to the external bond strengthening of concrete structures and bonding between CFRP sheets and concrete through adhesive. The presence of the binder will block water molecules or strong alkaline concrete seepage water on carbon fiber sheet erosion. Therefore, it may have a positive effect on the durability of CFRP sheet. The previous study on durability of carbon fiber sheet did not consider the effect of adhesive coating. Therefore, the water absorption and mechanical properties of CFRP coated with adhesive in water or strong alkali solution were studied in this paper. It is found that the water absorption rate of the uncoated CFRP sheet increases with the increase of temperature. The water absorption rate of CFRP pultrusion plate in strong alkali solution was higher than that in water immersion. For the CFRP plate soaking in 60oC strong alkali solution, the resin was hydrolyzed, and the surface was evenly coated with adhesive, and the same soaking time was obtained. The water absorbency of CFRP pullout plate is obviously decreased. The results of finite element software simulation are in good agreement with the water absorption curve obtained by the experiment. For the CFRP extruded plate with uncoated adhesive, the water absorption rate of the extruded plate is obviously reduced. After soaking in water and strong alkali solution, the tensile properties of the samples decreased slowly, but the in-plane shear strength decreased more obviously, for example, after soaking in 60oC distilled water and strong alkali solution for three months. The in-plane shear strength of CFRP extruded plate decreased by 18.8% and 48.8.The tensile strength of CFRP plate remained unchanged under the same soaking conditions. However, the in-plane shear strength is still degraded to a certain extent. The in-plane shear strength of CFRP plate degenerates to 29.1% and 32.8% after soaking in 60 OC distilled water and strong alkali solution for three months.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB332

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