Faster slump loss
Hot concrete can lose workability faster, increasing pressure on delivery, discharge, placement, and finishing schedules.
CONCRETE TEMPERATURE CONTROL
Why ice is added
to concrete.
Ice absorbs heat as it melts, making it one of the most effective ways to lower the initial temperature of fresh concrete—while still counting toward the mixture’s total water.
POTENTIAL TEMPERATURE REDUCTION
Chilled waterup to 10°F
Ice as mixing waterup to 20°F
General guidance from NRMCA CIP 12. Actual results depend on the materials, proportions, ambient conditions, and batching process.
THE SIMPLE PHYSICS
Ice cools twice: first as a cold material, then as it melts.
Every component contributes to the temperature of fresh concrete. Ice has an additional cooling effect because it must absorb heat to change from solid to liquid. That heat comes from the other batch materials.
For that reason, a properly engineered ice addition can lower batch temperature more than chilled water alone.
WHY TEMPERATURE MATTERS
Hot concrete changes how a pour behaves.
High initial temperature can create production and placement challenges before the concrete has a chance to perform as intended.
Shorter set time
Accelerated setting can reduce the available window for consolidation and finishing—especially during long hauls or complex placements.
More water demand
Higher concrete temperature can increase the water needed for a target slump, which may affect strength, permeability, and shrinkage.
Thermal risk
In mass concrete, a hotter start can raise peak core temperature and increase the difference between the core and the surface.
BATCHING PRINCIPLE
Ice replaces part of the mixing water. It does not sit on top of it.
Mixing water includes batch water, ice, free moisture on aggregates, and other water introduced to the concrete. The ice quantity should be coordinated with the producer’s approved mixture proportions and quality-control procedures.
TOTAL MIXING WATER
Batch water+Ice+Aggregate moisture+Other water sources
Maintain the specified water-to-cementitious materials ratio and fully melt the ice during mixing.
PLAN BEFORE THE POUR
Make the cooling plan part of production planning.
- 1
Set the target
Start with project specifications, expected weather, haul time, and placement conditions.
- 2
Calculate the substitution
Have qualified mix-design or QC personnel determine the ice and liquid-water amounts.
- 3
Coordinate supply
Confirm bag size, tonnage, staging, truck access, unloading method, and delivery timing.
- 4
Verify the batch
Document the addition, confirm complete melting, and check fresh-concrete temperature.
INDUSTRY REFERENCES
Further reading for production and quality teams.
NRMCA CIP 12Hot Weather Concreting↗
NRMCA TIP 10Mixing Water Quality for Concrete↗
NRMCA TIP 18Managing Concrete Temperature↗
This page is general educational information. Project specifications and decisions by the engineer of record, concrete producer, and qualified quality-control personnel govern each mixture and placement.