Hi.I know you are looking for the quality of water used for concrete mixes.The quality of water used for concrete is an important factor which determines the strength of the concrete.
We have discussed several other topics which affect strength and quality of concrete in our old articles.Similarly, the quality of water is another important factor in the making of concrete.
Most of the situation we use the water from the site, but there is some limit or criteria for the selection of water from the site.
If the strength of concrete made with site water acquires 90 percent of the strength of concrete made with the pure water then, that water can be acceptable.
But most of the cases these situations are avoided, Usually in India.We will take water directly from the construction site.But there are other situations we cannot be neglected
For the selection of water from the site, we need to get water which should maintain a proper value of Ph.
Ph is an important criterion, if the pH value of water is lying between 6 to 8, then this water is free from organic matter.This water can be adopted for construction purposed
So we should check the ph of the water.If you don’t know how to check Ph, please read this article how to check the PH of the water.
The other factors which affect the water quality are the number of carbonates and bicarbonates present in the water.
Carbonates and bicarbonates of sodium and potassium affect the setting time of concrete, where sodium bicarbonate may cause quick setting.Bicarbonates may accelerate or retard the setting time based on the salt present with bicarbonates
If the salt content is more than 1000ppm, then the test for setting time and strength at 28 days should be carried out.Salt of manganese, Tin, Copper and lead cause reduction in strength of concrete.
Brackish water contains chlorides and sulphates When chloride should not exceed 10000 ppm and sulphate should not exceed 3000ppm.The large quantities of chlorides in the sea water caused efflorescence and dampness.
If you don’t know how to check chloride content in water please read this linked article.
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Use of Sea Water for Mixing Concrete Mixes
Seawater contains a small quantity of sodium and potassium salt.The salinity of seawater is 3.5 percent.These salt can be reacted with reactive aggregate and alkali cement.
Therefore sea water should not be used for the mixing of concrete if the aggregate is potentially reactive.
It is found that the mixing of sea water causes the lesser strength and corrosion to the reinforcement in concrete.The mixing of seawater in non reinforced concrete can be adopted.
The sea water mixing results increase in strength at 3 days, but 28 days of strength is comparatively less( reduces about 15 percent of its strength).Also, the required strength can only be achieved by redesigning the mix.
So, The use of seawater is not advisable for the use of plastering purpose which is going to be painted.
- What are the different types of cement used for construction purpose?
- What are the properties of cement and how cement is manufactured?
Watch the below video how concrete can be compacted