满足100年耐久性设计的自密实海工高性能混凝土寿命评价技术研究

Study on durability design of 100 years' life evaluation technology for high performance self- compacting concrete

分析了海工混凝土结构的腐蚀机理,并对海工混凝土结构的腐蚀危险性进行了评估,表明氯离子对混凝土结构内钢筋的腐蚀是混凝土结构与构件耐久性的主要控制因素。确定了菲克第二扩散定律的解析解中表面氯离子浓度、临界氯离子浓度和保护层厚度等参数的取值,获得了不同矿物掺合料自密实海工高性能混凝土满足100年耐久性设计年限要求的有效氯离子扩散系数控制指标,并表明掺合料的种类和掺量在合理的范围时,自密实海工高性能混凝土的耐久性可满足设计使用年限100年的耐久性要求。

In this work, the corrosion mechanism of marine concrete structures is analyzed and the risk of corrosion for reinforced steel is assessed, the results show that the corrosion of reinforced steel is the main controlling factor of durability of concrete structures, which lead by the penetration of chloride ions into the concrete cover. Furthermore, the surface chloride concentration, the critical chloride con- centration and the concrete cover thickness are determined, and the control targets of chloride diffusion coefficient for self - compacting concretes are analyzed in this study ,the results show that the durability of self - compacting concretes can meet the 100 - year durability design requirements when the admixture type and dosage in the range of reasonable.