Frequently Asked Questions

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Applications

Questions:


Yes. Fiber reinforcement has become a desirable construction practice for a wide range of concrete project applications. The ease of addition and the uniform distribution have given fibers distinct job site advantages over non-structural wire mesh. These advantages are even more valuable on projects where the concrete is delivered by a pumping process. The use of integral fiber reinforcement eliminates the wire mesh hassle encountered by the pump-line labor force, and allows the nozzle-man an unencumbered field in which to operate. In lieu of hoisting rolls of mesh onto upper-level deck projects, FORTA-reinforced concrete can simply be pumped into place, offering significant time and labor savings to the project. Though fibers tend to change the "visual appearance" of the concrete, the pump operators typically notice more consistent and slightly lower pump pressures are required for fiber concrete. There are certain recommended precautions at the grate when pumping high dosages of macro/structural fibers — contact FORTA® for the list of "Pumping Pointers."
Yes. The definition of a precast concrete member is simply an item that is "cast before" — one that is cast and cured in a form other than its final position. This concrete product application might include a wide variety of items: patio stones, splash blocks, step units, septic tanks, architectural facade panels, median barriers, railroad ties, burial vaults, utility boxes, bridge beams, grade rings, pipes, hollow-core slabs, manholes, and fence posts, as well as hundreds of different decorative ornamental items. It is very important for the precast producer to find methods to increase the toughness and early strength of his concrete products to reduce waste, minimize callbacks and returns, and aid in the item's long-term durability. If precasters are able to strip the forms and move "green" products to a curing area without breakage, the fiber reinforcement is obviously fulfilling its initial performance obligation. In addition, precasters notice less breakage, chipping, and spalling during handling, delivery, and placement of their products due to the unique three-dimensional FORTA® coverage. The use of higher dosages of macro/structural fibers allows the precaster to replace a higher level of conventional steel — contact FORTA® for engineering assistance.
Yes. The term 'shotcrete' is generally used to describe concrete or mortar that is placed or shot at a high velocity onto a given surface by means of compressed air. The reinforcement used in typical shotcrete applications is expected to provide resistance to shear, flexure, and bending loading that may result from soil or rock movement, or from local hydrostatic pressures. The placement of wire mesh on typical irregular shotcrete surfaces is both cumbersome and costly with regards to labor. Synthetic fibers may be used as alternate materials that offer the necessary toughness-index and residual strength levels required, without the hassle and labor costs associated with mesh.
Yes. There are a number of terms used to describe elevated slab systems, such as slab-on-metal deck and composite deck. The elements of this system are the metal deck, Portland cement concrete, and in most cases, some form of reinforcement. The metal deck can be classified in three categories – structural (composite), form, and roof deck. The first step is to select the proper metal deck for the application. Typically, in most multi-story structures, the composite (structural) floor deck is used, wherein the deck acts as the primary or positive reinforcement. Conversely, in a non-composite deck system, the metal deck is only used as the form; therefore the primary or positive reinforcement will be incorporated within the concrete slab. In the composite steel deck system, welded wire fabric is sometimes used as a temperature or secondary reinforcement. The Welded Wire Fabric calculation for temperature and shrinkage reinforcement per the Steel Deck Institute is 0.00075 times the area of concrete above the deck, however, SDI goes on to state that, "if welded wire fabric is used with a steel area given by the above formula, it will generally not be sufficient to be the total negative reinforcement". This consideration allows that FORTA® network fibers be used as a replacement for welded wire fabric as the secondary reinforcement. These fibers provide uniform, three-dimensional secondary reinforcement that is superior to any other form of temperature/secondary reinforcement, and are safer and more economical to use. In any above grade applications FORTA® engineering should be consulted for reinforcement calculation assistance.
Yes. An overlay is defined as a layer of concrete or mortar, seldom thinner than 1 inch (25 mm.), placed on, and usually bonded onto, the worn or cracked surface of a concrete slab. The overlay is usually designed to either restore or improve the function of the previous surface. Similarly, a topping is also defined as a layer of concrete or mortar placed to form a floor surface on a concrete base, yet is not necessarily bonded to the existing slab. Although deterioration of the old surface or severe cracking of the old slab is most often the reason for a topping course, other reasons might include a lack of floor levelness, improper elevation or plane, inadequate skid or slip resistance, or a lack of wear resistance. Regardless of the reasons, slab toppings and overlays can provide a cost-effective method of restoring an existing slab into serviceable condition, without the expense of removal and replacement. In addition to the normal difficulties of placing mesh in flatwork applications, there are additional related complications when toppings and overlays are placed. Naturally, the steel wire mesh requires sufficient cover within the concrete (usually a minimum of 2" or 5 cm.) to prevent corrosion-related spalling and unsightly mesh lines. Obviously, this cover becomes impossible in thin concrete toppings. In unbonded overlay applications, the placement of wire mesh becomes equally difficult without disrupting or damaging the bond-breaking layer or sheeting. One of the most important negatives with regards to mesh is the lack of uniform reinforcement coverage. The mesh is obviously located in one plane only in these thin applications that demand reinforcement to counter problems caused by one-directional bleeding, differential shrinkage, and curling.

FORTA's three-dimensional fiber coverage offers an excellent and easy alternative to the cumbersome mesh in these topping and overlay applications.