The time taken by the poured concrete to dry and attain its full strength is called concrete drying. The process of concrete drying includes the evaporation of the water inside it through its surface. The process continues till the air in the vicinity cannot hold the water vapours any more.
It is a long-term process that may take a month or more to complete. Read the blog to explore trusted tips you can use in your construction project to avoid an extensive waiting period.
Concrete Drying vs Concrete Curing
Many people confuse concrete drying with concrete curing. Concrete curing means maintaing the optimum moisture content to let the concrete achieve its maximum compressive strength. This process starts as soon as the concrete is poured. Typically, the concrete starts drying itself, enabling it to be ready for foot traffic within 24 to 48 hours. Unlike complete drying, which may take months for completion, concrete curing is completed within 14-28 days on average.
To patiently wait for concrete drying is essential to ensure structural stability. The waiting part is hard to endure and can prolong the time required to complete the project. However, you may be relieved to know that there are ways to boost the concrete drying time and increase its strength and efficiency.
Here, we have included some comprehensive and reliable tips that you can follow to ensure faster concrete drying:
Before Pouring Concrete
Work in suitable weather conditions
If you are not in a hurry to start your construction project right away, then it is advisable to wait till summer. The more dry and hot the weather will be the more quickly concrete will dry. If you can’t wait till summer, then at least ensure it’s not the rainy season or extremely cold weather that may significantly delay the drying process.
The right amount of water in the mixture
As explained above, the concrete continues drying as the water keeps evaporating. So, if you add less water, less time will be required to evaporate the inside water completely, hence quicker drying. However, make sure the water ratio is optimal. Too much less water isn’t beneficial either, as it can compromise concrete strength and fluidity.
To save from the complications of getting a precise cement-water ratio, there are two solutions. First, you can add water-reducers. They are specialised assistants similar to retarders that can minimise the water content in the concrete mix by 5-10% while enhancing the fluidity and strength of the concrete mix. The second option is to seek professional services from expert companies like K M Flow Screed.
Choose the right type of aggregates
Consider switching to synthetic aggregate. Unlike lightweight aggregates, synthetic ones don’t absorb water, hence reducing the drying time. Moreover, avoid using sealing, curing or bond-breaking agents as they may increase the drying time by inhibiting the evaporation process.
Add calcium chloride
Just adding calcium chloride into the wet concrete mix is an efficient way to stimulate the concrete solidification time. Such self-desiccation agents hold the specialised ability to expedite cement hydration. It helps to minimise the concrete drying time to a significant extent. It is an excellent alternative to adding more cement as a high cement ratio concrete is prone to many risks, i.e. cracks due to shrinkage.
Add warm water
Adding slightly warm water acts as a catalyst and speeds up the chemical reactions that harden the concrete. It accelerates the process of concrete hydration significantly. However, avoid using boiling water as it has adverse effects.
After Pouring Concrete
Use a heater
You can use external heating sources like heaters or heating mats to provide extra warmth that will ultimately accelerate the drying time. However, avoid high temperatures as it may be disastrous.
Hard Trowelling
Hard trowelling causes increased pressure that makes the concrete compact and reduces the air spaces and vent. Resultantly, the escape of water molecules becomes harder hence prolonging the drying time.
Dehumidifiers
Portable dehumidifiers and even fans can be rented for use. Dehumidifiers expedite concrete drying by reducing the humidity in the air, which ultimately accelerates evaporation.
How to Know the Concrete Is Dry?
Gone are the days when people used to stress about concrete drying. Since the 1960s, various concrete moisture tests have been used to check whether the concrete has dried or not. These tests measure the moisture content in the concrete using specialised sensors injected at certain depths, i.e. 20% or 40%, depending on the requirements.