Mainly water reducing admixtures are divided into two categories depending upon the amount of dose being use in concrete and in result the decrease in the required weight of water.
- Low range plasticizers or regular plasticizers
- High range or super-plasticizers
Low Range Plasticizers
Low range plasticizers also named as regular plasticizers. These are also called as regular water reducer due to most used in the field. These admixtures are used in a very small amount i.e. almost 0.1% to the total weight of concrete. By using 0.1% dose, slump of concrete increases about 50-85mm and required amount of water also decreases. Required slump will be obtained without increasing water content.
Effects Of Regular Plasticizer
- These admixtures reduce almost 5-10% required amount of water.
- Increase workability of concrete at same water to cement ratio.
- If you want to get best results, than during testing in the laboratories, consider effect of environmental conditions on the properties of that material in the field.
- How concrete will behave in field? This all depends on composition of cement, mix proportions, fines of cement, alkali contents in cement, concrete temperature etc…
Super Plasticizer/High Range Water Reducers
These are the water reducing admixtures, which lessens high amount of required water without any effects on slump value of concrete. Super plasticizers are mostly used where high strength of concrete will be required and this also gives higher slump value without the increment in amount of water content.
These admixtures are mostly used during the construction of commercial areas, like markets, plazas, shopping malls etc…
Amount of doze used in concrete will be higher than low range water reducer. This is because of due to less amount of water, slump value will decrease but super plasticizer tries to resist and add more increment in the value of slump. Slump value shows how workable concrete will be?
If slump value will be less than this mean workability of concrete is less so handling will be bit difficult and also not possible to properly place the concrete. In case when slump value is higher than workability of concrete will be higher, so handling will not be difficult anymore and hence as a result a well compacted, uniform concrete will form.
By using 1 percent of admixtures, increase in value of slump will be greater than 100 and also lessen the 10-20% the required amount of water.