Quality of water to be used in concrete mix for construction

It is very important to check the water quality for concrete mix. As a slight change in chemical composition of water may result in a drastic change in the chemical behavior of concrete mix. There are different sources of water available. which may or may not be suitable for concrete mix. Such as reclaimed water, groundwater, treated water from sewer and water from ready mix concrete plant etc. As it is a known fact that in many parts of world water is in scarcity or shortage so it is very important to use water efficiently. In such countries, treated effluents are used for concrete mixing, curing and washing of aggregate also. Water from fresh sources like ponds, river etc are also suitable for concrete mixing.

Concrete is a man-made material so it is very much possible for us to change the properties of concrete mix. In the most simplest form concrete is the mixture of coarse aggregate, fine aggregate, water and cement. The mixture of water and cement called as paste act as the binding agent between the coarse and fine aggregate.

By changing the proportion of different materials used, we can alter the properties and will allow us to get the desired quality. The use is not only restricted to only structural application but in the domain of transportation engineering to environmental engineering it is widely used as the construction material.

Common classification

  • Potable water – Water which is suitable for consumption of human being.
  • Recycled water – Water which is treated up to acceptable limit which is suitable for its intended use.
  • Blackish water: Waste water generated from toilet, urinals which are directly contaminated with human excreta.
  • Gray water: Waste water from wash basins, showers, laundries and kitchen.

We should test the quality of water in a laboratory before using in preparing concrete / mortar.

For plain and reinforced cement concrete permissible limits for solids is shown in table as follows:

Type of solid in waterPermissible limits
Organic matter200 mg/l
Inorganic matter3000 mg/l
Sulfates500 mg/l
Chlorides1000 mg/l
Suspended matters2000 mg/l

The pH of water should be between 6 – 8 to use in concrete mix.

Some of the tests for water

The following tests can be done to ensure the quality of water..

  1. Staining properties
  2. Iron in water
  3. Sulfate ion in water
  4. Chloride ion in water
  5. Hydrogen ion concentration of water
  6. Effect of mixing water in compressive strength.

Check this post for different tests available for aggregate.

Leave a Comment