The American Concrete Institute (ACI) recognizes the use of macro-synthetic fibers as a suitable replacement for reinforcing bars and welded wire mesh when used to control drying shrinkage cracking and thermal changes (ACI 544.4R).
There are two types of synthetic fibers, “micro” and “macro” fibers.
Micro-synthetic fibers, along with proper curing after finishing, are used to reduce the effects of plastic shrinkage cracking. Plastic shrinkage cracking occurs when the surface of the concrete dries out during finishing operations.
Macro-synthetic fibers can be used as a replacement for rebar and welded wire mesh when used to control cracking caused by drying shrinkage cracking and thermal changes in driveways and interior slabs on ground.