Concrete may be one of the hardest building materials on the market, but it can still be damaged by excessive weight or force. To improve the structural integrity, many contractors use fiber-reinforced concrete. As its name implies, such concrete has been bolstered by the addition of special fibers.
These fibers help the concrete resist a variety of problems, from the formation of plastic shrinkage cracks to the tendency to crack or shatter under stress. But not all fiber-reinforced concretes will behave in the same way. By altering certain factors, a savvy contractor can create just the right blend of reinforced concrete for a particular purpose.
If you would like to improve your knowledge of contemporary concrete installation, read on. This article will outline three key factors that affect the performance of fiber-reinforced concrete.
1. Fiber Composition
Concrete reinforcing fibers can be made from either steel or synthetic polymers, such as nylon and polypropylene. Each of these two main categories possesses unique benefits. Steel fibers are prized for their ability to yield stronger, more impact-resistant concrete. In fact, concrete reinforced with steel fibers can often do without secondary forms of reinforcement.
However, steel fibers have certain drawbacks. For one thing, they can negatively impact the concrete’s structural stability in the event of a fire. Specifically, steel fibers increase the concrete’s tendency to develop patches of spalling when exposed to high temperatures. Polymer fibers exhibit much more stable behavior in such conditions.
Steel fibers may also be prone to corrosion. For the most part, such corrosion won’t cause any structural issues. But when corrosion occurs in fibers near or at the surface, rust may discolor the concrete. Finally, polymer fibers tend to be much less expensive than steel fibers due to the fact that they can be manufactured out of recycled materials.
2. Fiber Quantity
Fiber composition isn’t the only factor affecting the ultimate strength of the reinforced concrete. The number of fibers added also plays a huge role in this regard. Generally speaking, the more fibers added, the greater the strength of the concrete. However, this relationship does taper off at a certain level. At which point, an excessive amount of fibers may lead to unwanted segregation during the curing phase.
Greater amounts of fiber also increase the difficulty of mixing. This can lead to insufficiently homogenous concrete – a problem that will largely undermine the benefits of adding reinforcing fibers in the first place. For best results, fibers should be added to the dry mix before any water. Manufacturers often pass the fibers through a mesh basket to help evenly distribute them in the mix.
3. Steel Type
At least five distinct types of steel fiber types exist today. Manufacturers use different fabrication techniques for creating each of these five types. Type I fibers consist of cold-drawn wire. Type II fibers consist of cut sheet metal. Type III consist of melt-extracted fibers. Type IV fibers are mill cut. And Type V fibers consist of modified cold-drawn wire.
Each of these techniques gives the resulting fiber a slightly different profile in terms of its tensile strength. The shape of the fiber also varies from technique to technique. Fibers constructed from cold-drawn wire may also be twisted in order to increase their surface area. In turn, this improves the strengthening properties of the fiber.
As you can see, the world of reinforced concrete possesses a lot of variables. Smart concrete contractors carefully evaluate the needs of a particular project and select the best type of fiber to yield the desired results. For more information on how reinforced concrete can benefit your next building project, contact the pros at Diamond Concrete Supply.
