Durability of concrete structures in tropical atoll environment

作者：Yu, Hongfa^*; Da, Bo; Ma, Haiyan; Zhu, Haiwei; Yu, Qiang; Ye, Haimin; Jing, Xianshuang

来源：Ocean Engineering, 2017, 135: 1-10.

DOI：10.1016/j.oceaneng.2017.02.020

• Tropical atoll environment
• Ordinary Portland-cement concrete
• Coral aggregate concrete
• Durability
• Chloride diffusion

A literature investigation and field surveys were made to explore the durability to destruction of Ordinary Portland cement Concrete (OPC) and Coral Aggregate Concrete (CAC) structures in a tropical atoll environment. The surface free Cl- concentrations (C-s) and apparent chloride diffusion coefficients (D-a) were calculated and the calculation method of D-a in a one-dimensional half-infinite-body concrete structure was explored. The results show that the complex and severe environment of tropical atolls corrodes concrete structures badly and that the reinforcement corrosion rate is high. For a concrete structure in a tropical atoll, C-s of OPC is generally smaller than that of CAC. At the same time, the D-a of concrete calculated by the least squares method is the most reliable according to Fick's second law of diffusion. The calculated results demonstrate that the value of D-a is generally smaller in OPC than in CAC. Smaller water-to-binder ratios and higher strengths cause decreases in D-a for CAC. When OPC is not available in tropical atoll projects, the water-to-binder ratio should be decreased and the strength should be enhanced in CAC, which should improve the durability of the concrete effectively and decrease the C-s and D-a of the concrete structure.

• 出版日期2017-5-1
• 单位南京航空航天大学