The solidification of concrete is an exothermic process. As large quantities of heat are released inside the concrete structure, it is important that temperature changes are monitored and influenced, in particular:
In cases with high quality requirements for concrete such as bridges, tunnels and storage tanks.
In cases requiring large volumes of concrete such as dams, large foundations.
In hot climates.
There are several factors that can cause heat accumulation inside the concrete structure with a high temperature gradient:
Hot aggregates caused by hot weather.
Cement with a temperature of up to 70 oC.
Hydration heat that is released in the chemical process during a period of 2 weeks.
The cooling of the concrete after setting produces tensile stresses within the concrete structure which may result in the formation of cracks.
Solution cooling with liquid nitrogen has proved to be an effective and cheap method. One particular advantage is that coolant costs are generated only if cooling is really needed.
Nitrogen cooling can be applied in different ways:
To cool the aggregates
To cool the mixing water
To cool the mobile mixer
The use of the best cooling method for the specific task minimizes costly interruptions during the process.
Advantages:
Low investment cost
Short lead times, flexible cooling capacity
Alternative cooling methods to suit the production process
Simple operation and maintenance
