Surface flaking, scaling, delamination and chipping is flaws of concrete flatwork caused by poor construction techniques.
The terms are often used interchangeably and all are variations of concrete desquamation.
Prevention of defects requires adequate selection of materials, correct mixing ratio, moderate temperature and expert finishing techniques.
In addition, improper curing is often a factor in flaking and flaking defects.
Concrete is made of a mixture of cement, an aggregate of gravel and sand, plus water. When these ingredients are mixed, the concrete begins to heal.
Curing is a chemical process that requires constant hydration for a period of five to seven days. Concrete continues to heal and harden for more than a year, but reaches enough strength after four weeks.
Once the concrete is poured, purge water rises to the surface and the heavier particles of cement and sand sink on the bottom of the slab.
Although it seems intuitive to allow the concrete to dry, curing is not a drying process and it is very important that the concrete remains moist during the curing period.
Installing concrete during extremely hot or cold days can cause flaking, peeling or cracking. Concrete should be poured when temperatures are expected to remain between -10 and 20 degrees.
Learn more about how temperature affect concrete setting here.
Wind and heat will cause the top layer of concrete to dry, harden and shrink while the concrete below is hydrated.
The top layer does not bond with the rest of the cured concrete slowly, causing a weak surface that is susceptible to flaking, delamination and scaling.
Cold stops the hydration process and therefore the curing process. Concrete that does not remain hydrated will be weak and brittle, causing it to scale and scale.
Using the proper proportions of aggregate, cement and water is crucial to the strength and integrity of the concrete.
Check the cement bag for the proper proportion. Too much water will make weak concrete susceptible to flaking and cracking.
Choice of ready-mixed concrete allows you to eliminate the measurement step of aggregates and cement. The only necessary step is to add water as specified.
Premixed mixes are labeled for several specific applications.
Freezing and thawing create internal stresses in the concrete, causing peeling and scaling.
Mixing concrete with an air entraining additive will create minute air spaces in cured concrete to provide relief from freeze and thaw pressure.
Deicers containing ammonium sulfate or ammonium nitrate will also cause flaking and peeling and are not recommended.
After the concrete is poured, excess water rises to the top. This bleed water must evaporate before the surface finishes.
If the bleed water is worked towards the concrete surface, the top layer contains too much water, causing a weak and brittle surface layer to break, scale and scale.
The surface should be wet but not covered with water before finishing work.
We recommend to read this article about concrete finish