Use of Sea Sand as an Alternative to Fine Aggregate in the Construction Industry of Sri Lanka - A Review

River sand is the commonly used fine aggregate for concrete production in Sri Lanka. However, the over-extraction of this resource has caused numerous environmental issues. Globally, sea sand is the most frequently used alternative for river sand. Based on its geography, Sri Lanka has great potential for using sea sand to fulfill the fine aggregate demand in the future. Despite it being used for several large-scale projects in Sri Lanka, sea sand remains underutilized in the local construction sector due to concerns about chloride contamination and impurities such as seashell fragments. This study aims to assess the current utilization of sea sand in Sri Lanka and evaluate the performance of sea sand concrete based on the current literature. A field study was conducted at the Muthurajawela main sand yard, other sea sand distribution sites, and testing laboratories, to understand the current practice. Currently, commercial-scale sea sand mining is carried out by the Sri Lanka Land Reclamation and Development Corporation (SLLRDC). Extracted sea sand is treated to remove the chloride and seashells at the Muthurajawela main sea sand yard. Following the Sri Lankan Standards, various quality control and quality assurance tests, such as water-soluble chloride content, shell content, and particle size distribution, are carried out before releasing sand to the market. This quality testing process ensures that sea sand is suitable for any construction application comparable to the use of river sand and exhibits comparable mechanical and durability performance to river sand concrete, as supported by various studies. According to the SLLRDC data, commercial utilization of sea sand peaked during the post-COVID-19 pandemic period and dropped due to the country's economic downturn. Moreover, using sea sand as an alternative to river sand offers several advantages, including availability on a large scale, which helps mitigate the issues of uncontrolled sand mining and diminishing river sand reserves. Altogether, sea sand presents a technically and economically viable solution for fine aggregate use in the Sri Lankan construction industry.