Mass concrete can be defined as any large volume of cast-in-place concrete with dimensions large enough to require measures to cope with the generation of heat and attendant volume change to minimize cracking. Like regular concrete, mass concrete too is primarily composed of cement, aggregate, and water. Additionally, it has pozzolans and other admixtures to improve its characteristics.

Proper proportioning of mass concrete mixture is aimed at:

1) Achieving economy,

2) Low temperature-rise potential with adequate workability for placing,

3) Adequate strength,

4) durability, and

5) impermeability to serve efficiently the structure in which it is used.

For any concrete placement larger than 4 feet across in any dimension, project specifications typically require temperature monitoring of the concrete in several locations (core, face, etc.). There are usually restrictions placed on how high the temperature can be allowed to go, and also on how much the core temperature can differ from the outside edges . For example, most mass concreting specifications call for an absolute maximum temperature value of not more than 160F, and a core-to-face differential of never more than 35F.

The main reason for this degree of control is to reduce or eliminate cracking that can occur when the concrete gets too hot and the differentials are too great. It is especially important when the massive concrete is being used for things such as containment vessels or bridge piers, where even a single crack could require that the concrete be removed and replaced.

From this, it is clear that accurate monitoring of temperatures in real time can be a vitally important means of staying in compliance of code requirements.