Concrete Deterioration

There are a few explanations as to why concrete begins to crack and crumble overtime.

Below is a breakdown on what causes concrete to corrode:

Definitions

Pop-out: A pop-out is a small piece of concrete, which has broken away from the surface leaving a hole in the concrete.   A pop-out can be caused by the expansion of a porous rock after it absorbs water and freezes.  A pop-out can also be the result of a chemical reaction when alkalies in the cement react chemically with the silica found in some fine sands, also causing an expansion. Pop-outs do not affect the life expectancy of concrete.

Concrete Scaling: Scaling is the localized flaking or peeling of a concrete surface exposed to freezing and thawing.

How to Prevent Scaling:

  • Do not use de-icing salts such as calcium, sodium or magnesium chloride. Use sand to provide traction on icy surfaces.
  • Never use ammonium sulfate or ammonium nitrate commonly found in fertilizers as de-icers. Do not allow them to remain on concrete surfaces.
  • Concrete should be allowed to dry for 30 days after curing prior to applying a breathable sealer.
  • Concrete should be protected with silane, siloxane or linseed oil (after 30 days for new concrete) before it comes in contact with de-icers.

Concrete problems: cause and recommended prevention

Problem: Cracking          
Cause: Structural            
Prevention: Concrete should set for a minimum of seven days before vehicles are driven on the new surface. In cooler weather, more time should be allowed.

Problem: Cracking          
Cause: Moisture             
Prevention: Prevent rainwater from collecting under concrete by using drain-tile rain gutters and good landscaping.

Problem:  Surface blemishes     
Cause: Water freezing and thawing numerous times on the surface
Prevention: Apply a protective, penetrating concrete sealer and caulk on all saw cuts and joints. Keep surface clear of snow and ice.

Problem:  Surface deterioration                               
Cause: Use of de-icers and chemical fertilizers
Prevention:  Avoid de-icing chemicals including salts which can cause surface deterioration of your concrete.