Durability of concrete structures in tropical atoll environment

Affiliation of Author(s):航空学院

Journal:OCEAN ENGINEERING

Key Words:Tropical atoll environment Ordinary Portland-cement concrete Coral aggregate concrete Durability Chloride diffusion

Abstract: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.

ISSN No.:0029-8018

Translation or Not:no

Date of Publication:2017-05-01

Co-author:dabo,mhy,Zhu, Haiwei,Yu, Qiang,Ye, Haimin,Jing, Xianshuang

Correspondence Author:yhf

Date of Publication:2017-05-01