碳纤维织物增强水泥基复材加固梁加固效率提升机理研究

Fiber Reinforced Cementitious Matrix (FRCM) can be applied as a safe, durable and convenient substitution of Fiber Reinforced Polymer (FRP) for the strengthening of reinforced concrete (RC) or masonry structures. However, the application and spread of FRCM strengthening method are restricted by two main factors: one is the lack of analytical models to cover all the possible failure modes of FRCM strengthened members, another one is lack of methodologies and their fundamental theories of enhancing strengthening efficiency of FRCM strengthened members. In order to efficiently enhance the efficiency of Carbon FRCM (C-FRCM) strengthening, this project will clarify the effect of end-bending anchoring of Carbon fiber grid and U shape FRCM anchoring on the pull-out performance of Carbon fiber grid, the tensile performance of C-FRCM plate, the shear performance of C-FRCM/concrete interface and the flexural performance of C-FRCM strengthened beam. The mothodologies will be raised to predict the pull-out strength of C-FRCM plate and shear strength of C-FRCM/concrete interface. Finally the analytical models considering the material, interfacial properties and anchoring effect will be proposed to predict flexural strength of C-FRCM strengthened beam. The achievements of this project provide theoretical and experimental support to the application and coding of CFRCM strengthening.

纤维织物增强水泥基复合材料（FRCM）可以作为纤维增强复合材料（FRP）安全、耐久、便利的替代，用于混凝土或砌体结构的加固，但FRCM加固技术的应用和推广存在两大瓶颈：一是缺乏涵盖各种破坏模式的FRCM加固构件强度计算模型，二是缺乏提升FRCM加固效率的技术方法及其理论基础。本项目以高效提升碳纤维FRCM（C-FRCM）加固混凝土梁加固效率为研究目标，从材料-界面-构件多层次揭示C-FRCM纤维束网格端部弯折锚固及U型FRCM箍锚固的单一作用和组合作用对碳纤维网格拉拔性能、C-FRCM板拉伸性能、C-FRCM/混凝土界面性能以及C-FRCM加固梁弯曲性能的作用效应和影响机理，提出锚固C-FRCM板拉伸强度及锚固C-FRCM/混凝土界面剪切强度预测方法，建立与材料、界面、锚固效用相关的C-FRCM加固梁性能计算模型。研究成果为FRCM加固混凝土结构的工程应用和规范制定提供理论基础和试验依据。

碳纤维增强水泥基复合材料（C-FRCM）是一种安全、耐久、便利的新型复合材料，可作为纤维增强聚合物复合材料（FRP）的可替代材料用于砌体或者混凝土结构加固。然而，碳纤维/砂浆界面和C-FRCM/混凝土界面常常发生过早破坏降低C-FRCM的加固效率。为了充分发挥C-FRCM中纤维网的拉伸强度，提高C-FRCM的加固效率，本项目基于纤维自身的几何可变特征，将C-FRCM端部纤维进行弯折形成自锚固，以此限制纤维的脱粘滑移并提高纤维复丝的协同受力性能，改善纤维/砂浆界面性能；同时采用U型箍锚固防止C-FRCM和钢筋混凝土梁的分层剥离破坏，保障C-FRCM和钢筋混凝土梁共同工作的可靠性。从材料-界面-构件多层次揭示了C-FRCM纤维束网格端部弯折锚固及U型FRCM箍锚固的单一作用和组合作用对碳纤维网格拉拔性能、C-FRCM板拉伸性能、C-FRCM/混凝土界面性能以及C-FRCM加固梁弯曲性能的作用效应和影响机理，提出了锚固C-FRCM板拉伸强度及锚固C-FRCM/混凝土界面剪切强度预测方法，建立了与材料、界面、锚固效用相关的C-FRCM加固梁性能计算模型。