New methodology predicts service life of marine concrete structures

A recent study published in Engineering presents an innovative approach to predicting the service life of concrete structures in marine environments. The research, led by Taotao Feng, Jinyang Jiang and colleagues from Southeast University in China, introduces a comprehensive methodology that leverages multiscale modeling and extensive datasets to efficiently assess the durability of marine concrete structures.

Concrete structures in marine environments face significant challenges due to prolonged exposure to chloride ions, which can lead to corrosion of internal steel reinforcements. Traditional methods for analyzing the durability of these structures are often complex and time-consuming, relying heavily on long-term exposure tests and experimental methods. This new study aims to address these limitations by developing a more efficient and reliable approach to service life assessment.

The researchers utilized a multiscale modeling technique, ranging from the microscale to the macroscale, to calculate the chloride diffusion coefficient of concrete. They constructed three-dimensional (3D) heterogeneous models of cement-based materials, incorporating detailed simulations of chloride transport behavior at different scales. The study began with the microscale analysis of hardened paste, where the CEMHYD3D model was employed to reconstruct hydration microstructures. The chloride diffusion coefficients for high-density and low-density calcium silicate hydrate (C-S-H) gels were determined through numerical simulations using ABAQUS software.

At the mesoscale, the researchers developed a 3D packing model of fine aggregates to simulate the transport properties of mortar. The diffusion coefficients for mortar were calculated based on the results from the hardened paste simulations. Finally, at the macroscale, a 3D packing model of coarse aggregates was established to simulate chloride transport in concrete. The chloride diffusion coefficients for concrete were derived from these simulations and validated against experimental data.

To further enhance the accuracy of the service life assessment, the researchers analyzed a dataset containing over 2000 groups of marine concrete. This dataset was used to determine the values and distribution types of relevant durability parameters, such as the time-dependent index of the chloride diffusion coefficient, the critical chloride concentration, and the chloride binding capacity. The study focused on the marine environment of Northeast Asia, where the values of these parameters were carefully examined and incorporated into the theoretical model of chloride diffusion.

The service life of marine concrete structures was then evaluated using the chloride diffusion theory combined with reliability theory. The results indicated that the service life of concrete structures with different water-binder ratios varied significantly. For example, under a 5% corrosion probability, the service life of concrete structures with a water–binder ratio of 0.35 (A35) was 11.2 years, while for those with a water–binder ratio of 0.45 (A45), it was only 0.5 years. This highlights the importance of optimizing concrete mix proportions to enhance durability.

This study offers a novel and efficient methodology for predicting the service life of marine concrete structures. By integrating multiscale modeling with extensive datasets, the researchers were able to bypass the lengthy process of conventional exposure testing, significantly improving the efficiency of durability assessment. This approach provides valuable insights for the design and maintenance of concrete structures in marine environments, contributing to the development of sustainable and high-performance structural materials.

The paper “Prediction Methodology for the Service Life of Concrete Structures in Marine Environment: From Materials to Performance,” is authored by Taotao Feng, Yanchun Miao, Yongshan Tan, Zhiqiang Yang, Tongning Cao, Fengjuan Wang, Jinyang Jiang. Full text of the open access paper: https://doi.org/10.1016/j.eng.2025.03.010. For more information about Engineering, visit the website at https://www.sciencedirect.com/journal/engineering.