January 30, 2020

Should you cure

…when using Impede® IntraSeal?

It is always a good idea to cure concrete. Curing of concrete is defined as providing adequate moisture, temperature, and time to allow the concrete to achieve the desired properties for its intended use. This would mean maintaining a relative humidity in the concrete of greater than 80 percent, a temperature greater than 50 degrees Fahrenheit, and for a time typically ranging from three to 14 days depending on the specific application. When these recommendations are properly specified and performed in the field, the final properties of the concrete mixture will be achieved.

All curing applications should begin immediately after the last finishing procedure. When using Impede® IntraSeal it is especially critical that water based curing compounds be applied at that time. Shortly after final set the Impede® IntraSeal’s chemical reaction that produces the concretes water repellency begins to form. At that point the concrete becomes hydrophobic, which will cause water to bead on the surface. The results of waiting too long to apply water based material will end up in an uneven blotching of the material. If there is a desire to apply a curing compound or cure and seal after final set it is recommended to use a solvent based acrylic product.

There are other benefits to applying a solvent based acrylic cure and seal beyond curing. First it will help keep the surface of the concrete from drying out due to evaporation caused by low humidity, wind or both. This can protect the concrete surface from the potential of shrinkage cracks or crazing. Secondly, applying a solvent based acrylic cure and seal will create an additional membrane to help keep deicing chemicals from coming into direct contact with the concrete surface. These products will begin to break apart and wear away after one year, however Impede IntraSeal will continue to protect your concrete indefinitely. Concrete continues to gain durability the older it gets so using a belt and suspenders approach to protecting the concrete in its early life will definitely pay dividends down the road.

References

Kosmatka, Steven H., Kerkhoff, Beatrix, and Panarese, William C., Design and Control of Concrete Mixtures, 15th Edition, EB001.15, 2002, 372 pg