When it comes to concrete slabs, there is one
fact that must be faced by homeowners, contractors,
and concrete subs alike: Concrete will
crack. Period. The challenge for the concrete sub is
to work with the material and
make it behave in a way that is
acceptable to both the customer
and the contractor. The key to
success is to control where the
concrete is going to crack, and
prepare the customer for the
inevitable.
Brittle Behavior
Concrete does its best work
under compression. It's great for driving cars on,
rolling shopping carts on, even for raising elephants
on. But it doesn't have great tensile strength. Picture
a glass table cover at a restaurant: It works fine