Concrete in Cold Store Floors

Summary

Concrete in Cold Store Floors - Concrete floors are usually used in cold stores with temperatures as low as -400C.

Technical Information

Fully matured concrete performs well at constant low temperatures. Immature concrete with a compressive strength of less than 5N/mm2 may be damaged by freezing. Immature concrete with strength of higher than 5N/mm2 may have its strength development curtailed by too early a reduction in temperature. It is therefore essential that that cold store slabs are allowed to mature to develop the required in-situ strength of the concrete under external ambient temperature before the temperature is drawn down. Fourteen days is a minimum and may have to be extended.

Concrete not subject to wetting will resist both continued exposure to temperatures below freezing and freeze-thaw cycles. Therefore there is generally no need to consider enhanced performance.

Air entrainment is normally used to resist damage to exposed saturated concrete by freeze-thaw action and is therefore not applicable to industrial floors. In cold stores the concrete is not saturated and the number of freeze-thaw cycles is very small, so air entrainment is not needed. Importantly, the use of air entrainment in power-trowelled concrete floors should be avoided due to the high risk of delamination.