Utilization of seawater and seasand in concrete structures, current situation, experimentnl evidence and development prospects

Abstract

Concrete is the most widely used construction material today due to its versatility, durability, and cost-effectiveness. Rapid urbanization and infrastructure development—particularly in Asia-have significantly increased the demand for concrete, thereby placing substantial pressure on natural resources and the environment. In conventional concrete, river sand and freshwater are essential components. However, prolonged river sand mining and the growing scarcity of freshwater caused by climate change and saltwater intrusion have led to serious environmental and socio-economic consequences. In this context, the search for sustainable alternative materials has become an urgent necessity. Sea sand has been utilized in several countries, such as the United Kingdom, Japan, and China, where relatively comprehensive standards and quality control procedures have been established [1–3].
In Vietnam, facing a severe depletion of river sand and freshwater resources, the country’s coastline-extending over 3,260km-offers abundant sea sand and seawater that could serve as promising resources for the development of seawater sea-sand concrete, particularly for coastal and island infrastructure projects. Nevertheless, the marine environment, characterized by high concentrations of chloride and sulfate ions, can accelerate reinforcement corrosion and compromise long-term structural durability. Although desalination of sea sand using freshwater can mitigate these risks, this solution increases construction costs and further consumes scarce freshwater resources. In recent years, numerous studies have evaluated the feasibility of directly using sea sand and seawater in concrete. However, the findings remain fragmented and do not fully reflect the tropical monsoon climate and aggressive coastal exposure conditions typical of Vietnam.
Therefore, this paper presents a systematic review of research on seawater and sea-sand concrete, focusing on mechanical properties, strength development, durability performance, reinforcement corrosion behavior, and the potential application of fiber-reinforced polymer (FRP) reinforcement systems. The objective is to identify existing research gaps and propose future development directions to support sustainable coastal and island infrastructure construction in Vietnam.