Fiber Reinforced Polymer- Higher Strength, Lower Cost
If Superman were a creation of the 21st Century, rather than of the 20th, he might well be known as “The Man of FRP”, rather than, “The Man of Steel”. Compared to steel, “FRP” (Fiber Reinforced Polymer) can provide greater strength and it also offers a number of other advantages.
As an example, if “The Man of Steel” was left out in the rain, he would rust, whereas “The Man of FRP”, would not. That same characteristic is of vital importance when selecting materials for increasing the strength of or repairing a structure. Elimination of rust and corrosion issues, combined with overall cost advantages has made FRP the material of choice for most projects initiated to strengthening or repair concrete and masonry structures.
FRP has been in use in a wide variety of industries for many years. Its most well-known application outside of construction is in the automotive industry, specifically in the construction of high performance and race cars. Offering extremely high strength, combined with lightweight, carbon fiber-based FRP is now widely used in place of steel, aluminum, and fiberglass.
Formulations of fiber reinforced polymers are specific to the intended use; FRP components can be specific not only for construction projects but for structure location, (above ground, underwater, areas of high seismic activity) and the type of structural members to which they will be applied. Tendon Systems has been using FRP materials for a number of years and has found that carbon fiber is the preferred material for most projects as it offers higher load-handling capacities. Fiberglass FRP is the material of choice when greater elasticity and deformability must be accommodated. Laminates, epoxies, and anchors may be further refined to better suit unique environmental conditions.
Formerly, structural reinforcement and strengthening were accomplished by bonding steel plates to of concrete slabs, beams, and columns. Over time, degradation of steel reinforcements resulting from rust or corrosion, or bond degradation, can significantly reduce the strength provided by a repair or upgrade project. Steel bonding is also expensive and time-consuming, adds a considerable amount of weight, and may have a significant negative impact on appearance. Repairs or upgrades incorporating steel bonding also tend to reduce usable space and clearance.
In contrast, fiber reinforced polymer offers extremely high tensile strength, is relatively lightweight and economical, and is not subject to corrosion. FRP reinforcement has been used to improve the strength of virtually every type of concrete structure including buildings, parking structures, bridges, pipelines, tunnels, tanks, silos, piers, wharfs, and underwater structures. Another advantage offered by FRP reinforcement is that it can usually be applied without having to take a structure out of service.
Although strengthening and reinforcement projects are often necessary when a structure has been damaged or has deteriorated over the years, they may be required for different reasons. Carbon fiber FRP is frequently used to compensate for substandard construction where adequate reinforcement rebar or beams were not included in a structure during construction. FRP strengthening is also ideal for accommodating newly increased loading requirements.
Although FRP is not “cheap” when evaluated on a cost per square foot basis, it typically offers a significant overall project cost advantage. That is easily seen when the expense of materials and labor of other strengthening and repair methods, combined with the need for section enlargement, or partial demolition are compared to the total expense of an FRP-based project.
In spite of the numerous advantages it offers, use of FRP may not be the best choice for some projects. In some instances, a combination of FRP and steel reinforcement may be the best solution. Tendon Systems is highly experienced in all types of structural strengthening and repair and is dedicated to providing the most suitable and cost-effective solutions for any type of construction project.