Answers to Two Common Questions About Steel-Fiber Concrete

Posted on: 2 September 2016

Pouring a concrete slab or foundation is a big job, one that nobody wants to see undermined by cracks, crumbling, or other trouble down the line. A great way to ensure a durable, long-lasting surface is to utilize steel-fiber concrete. If you would like to learn more about this useful innovation, read on. This article will answer two common questions about steel-fiber concrete.

What is steel-fiber concrete?

Steel-fiber concrete is distinguished from other types of concrete by the addition of short steel fibers, also often referred to as steel wire. This improves the durability and crack-resistance of the concrete. The wire that is added may be one of five different types:

  • cold-drawn wire
  • cut-sheet fiber
  • melt-extracted fiber
  • mill-cut fiber
  • modified cold-drawn wire

The main difference between these fiber types is their relative tensile strength. Tensile strength, which may vary from between 50,000 to 445,000 psi, determines the wire's resistance to deformation or breakage. Surfaces that will be exposed to higher amounts of surface stress tend to benefit from a steel fiber with a higher psi rating.

The effectiveness of steel-fiber concrete is also affected by the length of the added wires, which vary from roughly 1/4" to 2". In general, longer fibers add a greater amount of strength to the concrete. That said, they are also more difficult to mix evenly into the wet concrete mix.

What are the specific benefits of steel-fiber concrete?

As noted above, steel fiber is used to boost the lifespan of a concrete surface. It does this primarily by reducing the frequency and severity of crack formation, specifically plastic shrinkage cracks. These cracks tend to form during the curing process, as evaporating water causes the concrete to draw apart. Steel fiber increases the tensile strength of the concrete, helping it to overcome the dehydrating effects of curing.

The strengthening effects provided by steel fiber reduce the need for concrete expansion joints. Such joints, cut in the wet concrete using a concrete saw, are used to help reduce the likelihood of cracks occurring. Steel-fiber concrete allows the number of such joints to be drastically reduced, thus lowering the overall amount of site labor required.

The benefits of steel-fiber concrete don't stop there, however. Steel fibers also act to increase the overall weight capacity of the fully-cured concrete. This means that slab thickness can be reduced without compromising its strength, thereby lowering material and installation costs. 

Visit sites such as to look at various concrete options.