EFFECTS OF SALT IN CONCRETE

Salt has different results when mixed in concrete, different results is due to different chemical substances (elements) that it contains, so chlorides salts has different effects to sulfates salts.

When Sulfates Salt is Added to Concrete Has the Following Effects

• When the concrete is mixed and / or cured by sulfates salt ( present in seawater), the concrete will have higher early strength (at 7 to 14 days) compared to concrete mixed by fresh water because at first salt acts as accelerator. But after 14 and 28 days and as time goes on there is reduction in concrete strength the strength of concrete.
• The salt can cause fretting (heave and cracks) due to salt attack this happens when salt crystallize on drying, this process is repeated as re-wets and dries (water curing).

When Chlorides Salt is Added to Concrete Has the Following Effects

• The chlorides salt can be used as accelerator at early stage ( on early strength gaining) but after 14 to 28 days the will have same strength and strength increase as that mixed and cured by fresh water.
• the use of chloride salt as accelerator can be applied to plain concrete but not to reinforced concrete because, when using in reinforced concrete your concrete will start cracking as bars will start rusting. It takes just a little salt  to start off  the rusting because the normal protection against rusting afforded by the alkaline environment is compromised by even a little salt.