Why Concrete Cracks

It is a fact that concrete is the best and most widely used building material.  It is far more durable that wood or asphalt and generally requires a lot less maintenance during its lifespan than other types of material.  While we understand the hardness and durability of concrete, we are also aware that it has the tendency to crack. 

Concrete contractors know this and work to mitigate many of the controllable conditions that create the cracks.  They use preventative methods when laying the concrete that can reduce and control the amount and type of cracks.  According to the Portland Cement Association, the most common type of cracks is caused by tensile stresses that develop with the slight change of volume as concrete dries.  This is the reasons that joints are placed in concrete pavement which allows for the shrinkage in a controlled manner, thus reducing cracking.

In most cases, cracks are not structurally damaging and are to be expected in foundations and slabs.  The three basic reasons for cracking are thermal temperatures difference, plastic cracking, and shrinkage cracking.

When cracks occur before the hardening is complete, it is most likely a result of settling or shrinkage in the volume.  The Concrete Foundation Association says that shrinkage of the surface (plastic-shrinkage cracks) is caused by loss of water while the concrete is still plastic.   The types of cracks that occur after the hardening process is completed are generally the result of drying shrinkage, thermal contraction, or subgrade settlement. 

Experienced concrete contractors know all of this and much more.  They understand the proper mix and type of concrete to help eliminate cracking and to prepare the concrete to withstand all the weather conditions it will face over the years.  

Conco is a leading supplier of concrete services for the Western United States. We got our start in the Bay Area in 1959 by offering clients the best value on a wide range of concrete services and products.  Since that time, we have steadily taken a leading role as one of the Bay Area’s top concrete contractors.