A thermal control plan is the temperature monitoring procedure that a contractor intends to follow when placing concrete in hot weather, cold weather, or for mass placements. Some specifications require development and approval of a thermal control plan prior to construction.
As part of the plan, contractors must determine the maximum allowable concrete temperature and temperature differential that will prevent concrete cracking during the heat dissipation period. In addition, the contractor must identify the type of equipment, location, and frequency of concrete temperature measurements. Plans are often specific to a particular mix design and type of project.
A project’s plan must conform to the governing agency’s requirements, but in general, temperature monitoring sensors should be placed at critical locations in the concrete such as on outer faces, on corners, and on surfaces. Sensors should monitor concrete temperatures at regular intervals for as many as several days after placement. After the concrete begins to cool and/or the temperature differential remains within the specified range for several consecutive days, temperature is usually read less frequently.