Glass fiber-reinforced polymer (GFRP) has demonstrated great potential in civil engineering. It offers several advantageous properties comparing with other traditional reinforcing materials. One of the distinguishing properties of GFRP bars is the unprecedented durability when subjected to aggressive environment.
Initially, it was the lack of validated data that delayed the worldwide acceptance of GFRP as the ideal environment-resistant and durable material for structural concrete applications. Since steel is prone to corrosion, GFRP concrete reinforcement has been developed as an alternative to steel reinforcement. GFRP bars can be used both as internal and external reinforcement.
The use of GFRP as an external reinforcement has increased considerably over the past few years. The rapid deterioration of concrete infrastructure is largely associated with corrosion and ruptured steel. Because of the worldwide corrosion issue and the inability of steel to fight corrosive agents, civil engineers now have shown faith in GFRP as a step to eliminate corrosion-related issues. The non-corrosive nature of fiberglass bars help engineers restore the integrity of deteriorated concrete structures.
In external reinforcement, the material is generally bonded externally in forms of jackets, plates, fabrics etc. In rehabilitation applications, fiber-reinforced polymers are used to confine concrete, enhance the shearing capacity, and flexural strength of a concrete member. FRP is commonly used for repair and restoration of structurally deficient concrete members.
Corrosion is probably the biggest civil engineering issue that forces builders, governments, and contractors to spend billions of dollars on the rehabilitation of steel-reinforced concrete structures. The leading advantage of using fiberglass bars as an internal reinforcement is that it enables concrete structures to achieve long service life without any major maintenance. Following are some of the advantages of using fiberglass bars:
- Ease of installation: The fiberglass bars are one-fourth the weight of steel bars, making it easier for engineers to complete a project within time restraints.
- Environmental durability: Fiberglass bars, as mentioned earlier, are corrosion-resistant which enables engineers to build durable concrete structures in the chloride-rich environment. Marine structures, therefore, should be built with GFRP reinforcement bars.
- Electrically and thermally non-conductive: Since fiberglass bars do not contain any metal, they are thermally and electrically con-conductive. This property makes fiberglass reinforcement an ideal material for sensitive buildings like research facilities, health facilities, power plants, etc.
- Lower life-cycle cost: Initial cost of reinforcing concrete with GFRP could be relatively high. However, the ability to sustain harsh environment makes fiberglass bars a cost-effective building material.
The use of GFRP in civil engineering enables engineers to achieve better functionality, safety, and economy of construction. Following are some of the new construction applications of GFRP bars:
- Highway applications (bridges, overpasses, etc.)
- Marine applications (seawalls, retaining walls, etc.)
- Mining and tunneling
- Transport infrastructure (bus stops, runways, etc.)
From highway to marine structures, GFRP has proven and tested to be the best construction material available in the global rebar market.