The accelerating effects of hot weather not only cause concrete to lose workability and finishability faster, they also can reduce long-term strength. There are many simple and effective solutions for avoiding hot-weather concreting problems, such as breaking the job into smaller placements or using more vibrator operators and finishers. The key is to plan construction operations with hot weather in mind. This will help you avoid taking measures on the day of the pour that can make a bad situation worse, such as adding more water to the concrete mix.
Many techniques are available to reduce concrete temperature, such as cooling the mix ingredients or using chilled water, crushed ice, or liquid nitrogen to cool the entire mix. In summer, the cement temperature can be high, so it may be necessary to store cement longer to let it cool. Aggregates can be cooled by spraying them with clean water and storing them in the shade.
It can be even more effective to reduce the heat-generating capacity of the mix by reducing the cement. The hydration of portland cement generates heat, while other materials in the mix absorb heat and reduce the overall temperature gain. Reduced cement contents should be consistent with strength and durability requirements.
