Study on chloride transport performance of eco-friendly coral aggregate concrete in marine environment

This study investigates the chloride transport performance of coral aggregate concrete (CAC) in a marine environment. The effects of the aggregate type, strength grade, and fly ash (FA) content on the chloride concentration distribution, surface chloride concentration (C-s), chloride diffusion coefficient (D-a), and porosity are discussed. The results show that the higher the strength grade of CAC is, the lower the C-s and D-a will be. The C-s and D-a of CAC initially decrease and then increase with increasing FA content. The compressive strength of CAC has a negative correlation with the D-a, whereas the porosity is positively correlated with D-a. The D-a of CAC is higher than that of ordinary aggregate concrete (OAC) at the same exposure time. The C-s of CAC increases exponentially with the erosion time. In addition, the attenuation law of D-a with the exposure time can be expressed as a power function. The decay rate of CAC is relatively slow, and the age reduction factor (m) of OAC is 11.95% higher than that of CAC. Furthermore, the age reduction factor is positively correlated with the strength grade and FA content. The content of Friedel's salt decreases gradually with increasing CAC strength grade at the same exposure time; with increasing erosion time, the content of Friedel's salt also increases, but the magnitude of increase is reduced. (C) 2020 Elsevier Ltd. All rights reserved.