The degree of hydration of cement can be determined by different means. But, unfortunately, the application of these method to commercial cements is by no means simple. These methods are :
a) The amount of chemically combined water.
b) The amount of unhydrated cement present ( using X-ray quantitative analysis ).
c) The amount of Ca(OH)2 present in the paste.
d) The specific gravity of the paste.
e) The heat evolved by hydration.
f) Indirectly from the strength of the hydrated pasted.
g) Thermogravimetric techniques and continuous X -ray diffraction scanning of wet pastes undergoing hydration gives an idea about early reactions.
h) Back-scattered electron imaging in a scanning electron microscope also can help to study on the microstructure of hydrated cement paste.