Sunday, June 28, 2020

QUICK SETTING CEMENT & USES

Quick Setting Cement & Uses.

Quick setting cement is a the types of cement as the name indicates,these types of cement are used where quick setting is required.In this cement setting time is very high as compare to ordinary portland cement. Initial setting time is 5 min and final set achived in 30 min. 

The quick setting cement is manufactured by grinded cement clinkers with aluminium sulfate,which accelerates the setting time of cement.Aluminium sulphate is used as an accelerating admixture (1% to 3%) by weight of cement clinkers.

The mechanism of function of aluminium sulphate is that it increases the rate of hydration of Tricalcium silicate (C3S) and Tricalcium aluminate (C3A) phase of cement,thereby providing earlier heat evolution and strength development.It acts as a catalyst in the hydration of tricalcium silicate (C3S) and Tricalcium aluminate(C3A). 

Concrete specimens with varying percentage of aluminium sulphate were tested for compressive strength,splitting tensile strength and flexual strength.


Uses of Quick Setting Cement

1.It is used in underwater constructions.
2.It is used in river bridge constructions.
3.It is used for fixing concrete steps.
4.It is used where quick strength is required in short duration.
5.Used in higher temperature where water evaporates easily.
6.It is used in cold and rainy weather conditions.

Advantages of Quick Setting Cement

1.Quick setting cement has high resistance towards water.
2.The amount of water required during hydration is also low.
3.Work can be finished in short period of time.

Disadvantages of Quick Setting Cement

1.Due to the quick setting property it should be placed quickly within its initial setting time (5min) otherwise the concrete paste start setting and is very difficult to place concrete.
2.Due to quick setting a large amount of heat emitted during hydration of cement which may leads to shrinkage cracks.
3.Due to the present of sulphur in the cement may leads sulphate attack on the  reinforcement.
4.It is costly as compared to OPC.
5.It is not widely available.

No comments:

Post a Comment

If you have any doubts, Please let me know.

SOIL STABILISATION AND TYPES

Soil Stabilisation Soil stabilisation is the process of improving the engineering properties of the soil and thus making it more stable.It i...