Substances in water:

1. Suspended particles

2. Inorganic salts

3. Acids and Alkalis

4. Algae

5. Sugar content

6. Mineral oil

Effects of deleterious materials on concrete:

1. Suspended particles: If the mixing of water contains suspended particles more than 0.02% by weight of total water un concrete, then it affects all properties other than strength of concrete.

2. Inorganic salts: The inorganic salts like zinc chloride lead nitrate, sodium phosphate etc. reduces strength whereas sodium and potassium carbonates results very rapid setting of concrete. The presence of calcium chloride in water more than 1.5% of total weight of cement results reduces rate of setting of concrete. The salt content in sea water reduces the concrete strength about 10-20% and also affects curing in the form of efflorescence.

3. Acids and Alkalis: The acids and alkalis present in industrial waste water results in undesirable alkaliaggregate reaction giving cracks on concrete surface.

4. Algae: The algae present in water reduces bond between

5. Cement and aggregate: hence reduces strength of concrete.

6. Sugar content: The sugar content in water between 0.05- 0.15% by weight of water results in retarding setting time and early strength of concrete. The sugar more than 0.20% will give fast setting but reduces ultimate strength of concrete.

7. Oil content: Mineral oil more than 8% reduces strength of concrete and vegetable oil shows detrimental effects on concrete strength at its later stages.