Thermal Control Plans Service

What are thermal control plans about

These plans mainly show:

• The initial placement temperature of concrete.
• The required system to be implemented (thermal insulation, heating system, piping, etc…) to control the differential temperature between the core and the surface of concrete so that it does not exceed the acceptable limits.
• Duration for monitoring the temperature.
• The maximum allowable concrete temperature.
• Shrinkage limits of concrete.
• The maximum allowable differential temperature.
• Frequency of temperature measurements.
• Type and specifications of sensors.
• The number of temperature monitoring sensors.
• The location of temperature monitoring sensors.
• Cooling method and rate.

The importance of thermal control plans

Temperature matters

When addressing temperature in mass concrete, we are mainly concerned about two parameters, the core temperature and the surface temperature. In general, the hydration mechanisms of cement, mix design, temperature of constituent materials, and mixing regime, mainly influence the former. Whereas, the weather conditions and temperature of the base material or forms mainly affect the latter.

Based on that, one of the concerns in mass concrete is the differential temperature. In fact, when the difference between the core temperature and the surface temperature is high enough to produce tensile stresses that exceed the bearing capacity at that time, concrete will crack. Hence, it is crucial to control the differential temperature and keep it within the allowable range. However, in addition to this, it is also crucial to control the temperature of concrete, else other problems can occur. Specifically, even if the differential temperature is controlled, but the temperature is high, the micro-structure of concrete can be affected leading to a higher permeability. In addition, if the temperature is considerably high, the formation of delayed ettringite can be of a concern. Hence, thermal control plans are essential.