concretebasics.org: your guide to cement & concrete

Hydration

What is heat of hydration?

The heat of hydration can be defined as the quantity of heat, in Joules per gram (or in appropriate units) of unhydrated cement, evolved upon complete hydration at a given temperature.

When Portland cement is mixed with water, heat is liberated. This is due to breaking and making of chemical bonds during hydration. This heat is called the heat of hydration. It is the result of the exothermic chemical reaction between cement and water. The heat generated by the cement’s hydration raises the temperature of concrete.

FAQs

What are the factors affecting the heat of hydration?

Do different compounds of cement have different heat of hydration?

How are concerns regarding heat of hydration taken care of in the Specifications of Cements?

How is heat of hydration determined?

FUAQs

How does total heat of hydration compare with the sum of heats of hydration of individual compounds of cement?

What is the relation between the heat of hydration and the cementing properties of the individual compounds?

What is more important: “total heat of hydration” or “the rate of heat evolution”?