Concrete Curing – How To Do It & What To Avoid
Why is curing concrete correctly important?
Curing (or drying time) is a very important stage during installation, as this is when concrete develops its strength and durability through hydration. However, curing concrete correctly is a delicate process and means controlling the amount and rate of moisture that is lost through evaporation to ensure optimal results.
For example, a well-mixed batch of concrete can be made weaker by poor curing, whilst an average slump that is well cured can produce better durability. It is therefore extremely important for the longevity of your concrete that you follow the correct procedure when curing freshly laid concrete.
Do’s & Dont’s of curing concrete
The first 7-10 days are essential in the curing process, as this is when the concrete will increase in strength the most. During this period, it is essential that your concrete slab does not dry out, especially if it is in direct sunlight. Misting is a technique frequently used and involves spraying a fine mist of water regularly across the surface of the slab to maintain moisture levels and keep the surface damp at all times.
Cover your slab
If it is not realistic for you to employ the misting technique frequently, then covering your concrete slab with a plastic sheet is the most efficient way to prevent surface water from evaporating. When covering your concrete slab, make sure that the sheet extends beyond the edges of the slab by at least double the depth of the slab. Use bricks, rocks or other heavy items to hold the sheet in place. Remove the sheet daily, wet the concrete, and repeat for at least 7 days.
Let your concrete get too hot or cold
The ideal temperature to pour concrete is between 10-15°C. If your freshly laid concrete becomes too cold, then the chemical reactions will also slow down. Your concrete therefore won’t gain strength as quickly (if at all if it’s very cold). Concrete insulating blankets should then be used for the first 2-3 days to avoid damage. If you expect the temperature to be higher than 23°C, it is especially important to ensure that that slab does not dry out too fast – keep it hydrated!
Put too much weight on it too soon
Wait at least 24 hours before allowing light foot traffic on your concrete slab and at least 10 days before heavy traffic, like cars, machinery and heavy furniture.