Feasibility of glass/basalt fiber reinforced seawater coral sand mortar for 3D printing

In remote islands and coastal areas, where there are no freshwater and river sand, the use of locally available seawater and marine sediments in mortar and concrete for building construction may be a better solution. Moreover, if there are no local materials for fabricating the formwork, 3D mortar/concrete printing may be considered. However, study on 3D printing using mortar/concrete made of seawater and marine sediments is still lacking. In this study, a series of mortar mixes made of seawater, coral sand, and glass or basalt fibers were produced to test their fresh and hardened properties for the purpose of developing 3D printable glass/basalt fiber reinforced seawater coral sand mortars. It was found that by adjusting the water reducer dosage, all the mortar mixes exhibited good buildability. The addition of glass or basalt fibers improved the flexural strength to some extent but slightly reduced the compressive strength. However, the flexural and compressive strengths of the printed specimens were significantly lower than those of the standard un-printed specimens. Overall, the fiber reinforced seawater coral sand mortar exhibits great potential to be applied as 3D printable cement-based material for use in remote areas.