CARBON FIBERS AND THEIR APPLICATION IN CIVIL ENGINEERING 4 from 7

That does not mean that the deficient bridges are unsafe; they are classified administratively to indicate they require some form of maintenance or major rehabilitation to restore them to their original condition or to their original load carrying capacity Retro- fitting is popular in many instances as the cost of replacing the deficient struc- ture can greatly exceed its strength- ening using CFRP.

Typically, a concrete bridge deck has a 25 to 40 years life span.

Old concrete bridge decks that were reinforced with unprotected steel reinforcement are deteriorating rapidly.

The CFRP composite deck systems have the potential to fill the need of bridge deck replacement and extend the service life of existing structures.

The advantages of a CFRP induced deck are – lightweight, high strength and high performance, chemical and corrosion resistant, easy construction and handling, rapid project delivery, and in most cases, high quality shop fabrication.

wrapping around bridge sections can also enhance the ductility of the section, greatly increasing the resistance to collapse under earthquake loading.

Such ‘seismic retrofit’ is the major application in earthquake-prone areas, since it is much more economic than alternative methods.

The fiber wrap systems are also being used to repair deteriorated concrete piers, pier caps, concrete arch, and damaged beams.

Bonded concrete repair using CFRP

laminates, rods and wet lay-up fabrics is alsoa very popular repair technique. The surface mounted composites have been used in numerous concrete bridge strengtheningand repair applications.

This technique is cost effective, easily to design, install and inspect.

Compo- sites here are applied to the soffit of existing concrete decks.

Carbon fiber’s chimney repair applications are also very important.

The aged chimneys require some repair and strengthening to continue their safe operation today.