• CONCRETE COOLING
• HOW TO CHOOSE
• RECOMMENDED EQUIPMENT

Considerations for Concrete Cooling

When mass pour concrete projects call for specific low temperature concrete placement temperatures, North Star flake ice is the reliable, low-cost way to cool concrete mixtures. Flake ice replaces up to 100% of the water in the mix and offers the most efficient ways to meet your concrete placement requirements.

NORTH STAR FLAKE ICE ADVANTAGES

• North Star ice systems give consistent control of the cooling from the first mix of the day through each succeeding mix throughout the day. There is no waiting for start-up, for containments and iron to cool, or for pumps and compressors to come on stream.
• If there is a delay in concrete production for any reason, North Star subcooled ice does not lose its cooling power. Chilled aggregate will pick up heat if not immediately used, or mixed; and therefore, cannot be used and must be disposed of promptly or be re-chilled. Temperatures in most climates normally increase from morning to mid-afternoon. Thus, cooling requirements also increase proportionately. This increase in cooling activity is immediately supplied to each mix by the addition of the proper amount of North Star flake ice. Changing specifications are easily satisfied and no flake ice needs to be wasted.
• North Star ice makers produce ice 30% more efficiently in terms of energy and horsepower savings than any other ice maker. There are over 17,000 square feet (1,600 square meters) of heat transfer surface in a ton of North Star flake ice available for heat absorption.
• North Star ice measures approximately 1/16" (1.5mm) thick and will melt quickly and completely as water in the mix with no delay in mixing time. There are no large unmelted ice particles left in the mix to result in voids and rejected concrete.

North Star flake ice provides a better option for concrete cooling than these other less effective, more expensive methods:

• Chilled water addition to the mixer.  Gives extremely limited cooling possibilities.  Example:  45ºF (7º) water will cool the average mix a maximum of 5º to 7ºF (3º to 4ºC).
• Water spraying of aggregate piles.  Gives limited cooling, with excessive waste water disposal. Does not give uniform cooling because it is related to the wet bulb temperature, and adds free water to the mix.
• Vacuum cooling of aggregate in a containment, or cooling by chilled air. A batch operation: This involves excessive cost in construction of vacuum chambers and bins and costly handling equipment. Slow start-up.
• Chilled water cooling of aggregate in containment. Batch operation involves high containment costs and costly handling equipment. Involves difficulties in disposal of waste, and loss of residual cold water in that waste material.
• Plate or crushed block ice.  High cost of purchase, transportation, meltage, crushing, weighing. Also delays the mixing cycle to insure that all large pieces of ice are melted in the mixer.
• Cooling the coarse aggregate by spraying cold water as it travels on a conveyor belt.  It is effective, but requires both space for the conveyor and a system of settling tanks for clearing the cooling water. A pause in the placement will allow stored aggregate to warm up. Creates poblems removing large quantities of mud from settling tanks.