Like most building products these days, fibrous concrete reinforcements have evolved into something more complex than 15 or 20 years ago.
More than 40 billion square feet of concrete slabs on grade have been completed in that time span utilizing these fibers instead of traditional methods. We now have a much better understanding of what different types of fibers can and cannot do.
Among some of the alternatives that exist in fiber types are monofilament polypropylene, which is virtually invisible on the surface of concrete providing economical crack prevention and control. Fibrillated polypropylene, which is even better at crack prevention and control but is sometimes visible on the surface. Steel fibers, which offer unequalled crack control and impact resistance but are a little more expensive. And, the newest engineered synthetic polymer fibers, which offer the benefits of steel without the possibility of corrosion.
Here are some questions to ask when designing a concrete slab:
- What would the proposed traditional method of reinforcement have been? WWF, secondary rebar, thicker slab or none at all?
- Is the fiber-free surface necessary, or will there be another floor covering on top of the slab?
- What’s more important: tight crack control, extreme load handling or a mirror smooth surface finish? Or is it a combination of factors?
- What are the economic limitations involved?