Rehabilitation of existing concrete structures using externally bonded reinforcement techniques is probably the first application of FRP composites in civil engineering. Fiber reinforced polymers (FRPs) have gained considerable popularity as a sustainable and cost effective rehabilitation materials. Taking into account the properties of advanced composites, FRP strengthening methods can save the world billions of dollars annually. The blog post will discuss some of the applications of FRP composites in bridge engineering.
Composite materials used for retrofitting and strengthening can be used in form of FRP strip or sheet depending on the nature of a project. The prime function of the rehabilitation applications of FRPs in bridge engineering is to increase flexural and shear capacity of beams, girders, and slabs. Adhesive bonding and wet lay-up are some of the methods used to carry out external FRP reinforcement.
The biggest reason why civil engineers were reluctant to use composite materials in the past was the lack of in-practice data and the availability of design codes. Now civil engineers have sufficient data and codes to confidently conclude that FRP composites offer effective ways to improve strength and stiffness of existing concrete members. Following are some of the major applications of advanced composites in bridge engineering:
Seismic retrofitting of concrete bridges
It is important to modify existing bridges and enhance their strength so that they can withstand earthquakes and other natural calamities. Advanced composites offer a level of strength necessary for a concrete structure to handle severe shocks and heavy traffic load. They are used in form of wrapped column to enhance the capacity of a structure to absorb earthquake shocks. Traffic disruption is the major problem engineers face during the retrofitting process. Traditional retrofitting materials are heavy and difficult to install. FRP composites, on the other hand, are lightweight, making it easier for engineers to complete a project quickly without causing major traffic disruptions.
According to stats, thousands of bridges in North America are structurally deficient. Corrosion of steel reinforcement is the primary cause of deterioration of concrete bridges. Advanced composites, such as GFRP bars, are corrosion resistance and proven to be the ideal materials for building durable marine structures. Bridges have to withstand aggressive environmental conditions that can cause spalling of concrete cover. Instead of spending billions of dollar on maintenance and repair, the construction industry should expedite the use of FRP composites.
Bridge deck is the most vulnerable part of a bridge structure. The composite bridge decks offer sustainable and lightweight solutions to bridge engineers. The construction industry in developed countries like Canada, Japan and America is already making a good use of composites in building sustainable bridge infrastructure. GFRP fiberglass bars is the best example of how composite materials can revolutionize the civil engineering.
The advantages of GFRP materials over traditional construction materials are their high strength-to-weight-ratio, ability to be molded into various shapes and sizes, and superior resistance to environment, resulting in low or zero maintenance cost. These properties make GFRP rebar an excellent alternative for sustainable construction.
Consult TUF-BAR to know more about GFRP rebar and its application in bridge engineering.