When working with concrete in hot weather, it’s crucial to understand that higher temperatures accelerate the hydration process of cement. The range of 10°C to 27°C is considered most suitable for hydration. However, in hotter climates, there are certain precautions that need to be taken to ensure the concrete sets properly.
Due to the increased rate of hydration, concrete may begin to set before it’s placed and compacted in its final position. To counteract this, it’s imperative to expedite the placement process after mixing. This ensures that the concrete retains its workability and strength.
To counteract the adverse effects of hot weather, measures can be taken to cool the concrete. One effective approach is to use chilled water and aggregates during the concrete preparation process. This helps maintain the desired temperature and prevents premature setting.
Ideally, the mixer machine should be set up in a shaded area. This helps mitigate the impact of direct sunlight on the concrete mixture.
For situations where concrete needs to be transported over longer distances, it’s advisable to mix the materials in a dry state first. Water can then be added on-site just before placing the concrete, ensuring optimal workability.
When transporting concrete, opt for deep containers. This helps prevent the evaporation of water content, preserving the desired moisture level.
After placement, cover the concrete with wet burlap. This serves a dual purpose of retaining moisture and providing a cooling effect, safeguarding the concrete from the heat.
As soon as the concrete starts to harden, commence the curing process. This is essential for ensuring the concrete attains its intended strength and durability.
The addition of retarding admixtures along with water can help slow down the setting action of concrete. This provides more time for proper placement and finishing.
In cases where ambient temperatures are exceptionally high, consider using ice cubes or refrigerated water. However, it’s crucial to ensure that the ice cubes are fully melted, with no solid ice crystals present in the concrete mixture.
By following these precautions and strategies, concrete work in hot weather conditions can be executed effectively, ensuring the longevity and integrity of the structure.