Use of sea-sand and seawater in concrete construction: Current status and future opportunities

This paper presents a critical review of existing studies on the effects of using sea-sand and/or seawater as raw materials of concrete on the properties of the resulting concrete, including its workability, short- and long-term strength as well as durability. It has been shown by existing research that concrete made with sea-sand and seawater develops its early strength faster than that of ordinary concrete, but the former achieves a similar long-term strength to the latter. Existing studies have also shown that the use of sea-sand and seawater may have a significant effect on chloride-induced steel corrosion but has only a negligible effect on the carbonation process of concrete. Strong evidence exists that a combination of mineral admixtures for the concrete and reinforcement with fiber reinforced polymer (FRP) can effectively solve the durability problem associated with the abundance of chloride ions in sea-sand seawater concrete (SSC). Such use of SSC also offers a good opportunity for the incorporation of recycled coarse aggregate (RCA) in concrete, particularly those that have been chloride-contaminated, as has been demonstrated by some preliminary research. The current understanding of the behavior of SSC, as summarized in the present paper, provides a solid basis for further research in the area to enable the wide use of SSC in concrete construction worldwide, particularly when combined with FRP as the reinforcing material. (C) 2017 Elsevier Ltd. All rights reserved.