Fibermesh Concrete

We had concrete poured for the garage apron of our new house.  No rebar was used.  About 8 inches of compacted aggregate (I don't know if I am using the correct terminology) was used for the base.  The concrete consisted of fibermesh.  Joints were cut the same day that the concrete was poured by using a cutting device on a long pole.  Within two days, a major crack off of the corner of the garage appeared.  A week later, another crack appeared on an inside curve.  Several other cracks have appeared since with spalling and pealing where the snow run off from the garage hit the ground and concrete pealing on the edges of the joints.  There is fibrous debris on the surface of the concrete.  From what have I read about concrete and fibermesh, if you overwork the concrete containing the fibermesh, more of the fibers will appear at the surface.

I appreciate any information you can give me.

Thank you, CL
Sorry it took me longer than usual.

I understand that we are talking about the apron/driveway leading to the garage.
What you describe sounds wrong.  There should not be any cracks in new concrete like that.

Some possibilities:

1. The concrete is of inferior quality and failed to get the needed strength.

2. The joints were not cut properly.  This is the most likely explanation since the concrete started cracking after 2 days.

  • Joints must be at least 1 third of the depth of the slab.  The deeper the better.
  • The distance between joints is critical.  8-10 feet is probably the maximum for such application.


3. Was it snowing/freezing at the time it was placed?  Concrete needs warmth to harden properly.  At very low temperatures it may not gain strength fast enough to prevent drying cracking.

4.  I do not think that the surface fibers have anything to do with the cracks.  Some are unavoidable.

5.  Concrete spalling and peeling (what does that mean?) sounds bad.  New concrete should not do that.  It may be a result of early freezing.

 I suggest you try to get the builder to replace the slab.  You may want to contact Fibermesh and tell them the story.  They are very sensitive to problems and may help resolve it.

If all else fails you may want to consult an attorney - but I would do anything to avoid that including replacing the slab and trying to get the builder to pay part of the cost.  Litigation is a lose-lose situation. 

Hope that helped a little.  If you want me to look at additional information you are welcome to send it to me.