Stopping of cement hydration by various methods

الملخص EN

Cement hydration stopping is very important process to study the kinetics of hydration.

There are different methods for the stopping of hydration such as drying at 105ºC for 24 hrs, freezedrying and the use of organic solvent to drive off the free water.

But these methods have some drawbacks.The drying of the cement paste at 105 ºC for 24 hrs leads to accelerate the rate of hydration of cement paste.

Therefore, the free water diminishes and the combined water increases in comparison with the other methods of stopping of hydration.

On the other side, The stopping of hydration by using organic solvent cannot absorb all of the free water, then the free water icreases on the expense of combined water.

Microwave is a kind of electromagnetic radiation with the wavelength of 1 mm-1m of an ultra high frequency to be used as an energy source for heating.

The nature and quantity of hydration products depend on the method of stopping.

The hydration of OPC and pozzolanicas well as filled cement pastes were stopped using three methods, namely oven drying, organic solvents and microwave oven.

The results showed that, the microwave technique can certainly be considered as a very powerful and recognized tool for cement hydration stopping.

This method doesn’t consume time, easer, inexpensive and environment friendly.