We do not use sea sand in construction due to the following reasons
1- Sea sand tends to very fine and rounded, Smooth rounded particles would offer less resistance to rearrangement than angular or elongated particles with rough surfaces.
2- In sea water, chloride is present which will cause corrosion of steel and iron which ultimately leads to reducing the carrying capacity of steel and iron, so that the structure built using this may not be sustainable.
3- Sea sand contains a large number of salt particles and also dirt particles like macro microscopic.it is very expensive to remove them and it’s a tedious process.
4- Sea sand does not have high compressive strength, high tensile strength, so it cannot be used in construction activities.
5- Sea sand contains salts which deteriorate the plastered surface and the slab surface and in the long run cause seepage in the building.
6- The salt in sea sand tends to absorb moisture from the atmosphere, bringing dampness.