3 Things Concrete Does: Shrinks, Curls and Cracks

Mixing Concrete

Learn more about concrete shrinking, curling, and cracking.

Concrete is made out of three basic components, including water, aggregate, and cement. It is a very durable material, but unfortunately, it can’t last forever. Over time, concrete will show signs of wear and tear by shrinking, curling, and cracking. Learn more about why concrete does these three things and how to maintain your concrete pavement.


Concrete shrinkage describes the aspects of volume changes in concrete due to the loss of moisture. There are four types of shrinkage in concrete, including plastic, drying, autogenous, and carbonation shrinkage. Plastic shrinkage occurs while the concrete is still in the plastic state, and is a result of the loss of water by evaporation or by the absorption by the aggregate. Drying shrinkage occurs because of dry conditions, and concrete made with smaller sized aggregate shrinks more than concrete with bigger sized aggregate. Autogenous shrinkage is the shrinkage of a conservative system, where no moisture movement to or from the paste is permitted. Lastly, carbonation shrinkage is caused by the dissolution of crystals of calcium hydroxide and deposition of calcium carbonate in its place.


Concrete curling can either be upwards or downwards, but both are dangerous and a safety hazard. Upward curling happens when the concrete slab surface is cooler and drier than the base, while downward curling happens when the slab surface is a high temperature and has more moisture than the base. Curling is also affected by shrinkage, as anything that increases drying shrinkage of concrete will also increase curling.


Concrete may crack for many reasons, including excess water in the mix, rapid drying of the concrete if the wrong strength concrete is used, and the lack of control joints. Shrinkage is also a primary cause of cracking, as it causes parts of the slab to be pulled apart.

Concrete Repairs You Can Trust from PTG Enterprises

Located in Linthicum, MD, PTG Enterprises has been in the commercial concrete, masonry, asphalt installation, repair, and paving business for more than a decade. We offer our services throughout Baltimore, Harford, Anne Arundel, Howard, and P.G. Counties. If you are interested in hearing how we can help you, contact us online or give us a call at (410) 636-8777. For more tips and tricks, be sure to follow us on Facebook, Twitter, YouTube, LinkedIn, Google+, and Flickr.

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