针对玄武岩纤维增强树脂基复合筋（BFRP筋）海水海砂混凝土海工结构的长期服役性能问题，本项目拟采用试验测试、理论分析与数值模拟相结合的方法，研究海水海砂混凝土内BFRP筋、BFRP筋-混凝土界面及BFRP筋海水海砂混凝土梁在海洋环境下的性能演化，提出BFRP筋海水海砂混凝土梁的耐久性设计方法。首先，研究混凝土内碱环境对BFRP筋力学性能影响，探索实际海洋暴露与实验室加速环境下BFRP筋退化的等效关系；其次，研究混凝土保护层厚度、BFRP筋直径及粘结长度对界面粘结强度、破坏模式及粘结-滑移关系的影响，建立考虑BFRP筋性能退化的BFRP筋-海水海砂混凝土界面粘结强度计算模型；最后，基于混凝土内BFRP筋及其与混凝土界面粘结退化模型，结合有限元分析与试验验证，明确BFRP筋海水海砂混凝土梁的长期性能演化规律。本研究将为BFRP筋海水海砂混凝土结构在海洋环境下的设计与应用提供理论基础与决策支撑。

In view of the long-term durability problem of basalt fiber reinforced polymer (BFRP) bars reinforced seawater and sea sand concrete structures in marine structure, the properties of BFRP bars in concrete, BFRP-concrete interface and BFRP reinforced seawater and sea sand concrete beam will be studied through a comprehensive study of experimental tests, theoretical study and numerical analysis. Based on the achievement in this study, a design method of the durability of seawater and sea sand concrete beams reinforced with BFRP bars will be proposed. Firstly, the effect of alkaline environment on BFRP bars in concrete, and the equivalent relationship between actual marine immersion and laboratory acceleration on the performance of BFRP bars will be studied. Secondly, the effects of concrete cover thickness, diameter of BFRP bars and the bond length on the bond strength, failure mode and bond-slip relationship of BFRP-concrete interface will also be illustrated, and a new calculation model for the bond performance of long-term BFRP-concrete interface based on the deterioration of BFRP bars will be developed. Finally, the long-term performance of BFRP reinforced seawater and sea sand concrete beams will be further evaluated based on the degradation mechanisms of BFRP bars in concrete and BFRP-concrete interface degradations well as finite element analysis results. This study aims to provide further insights for the design and application of BFRP bars reinforced seawater and sea sand concrete structures in marine environment.