Use of carbon fibbers for strengthening of the reinforced concrete structures

Abstract

The need for structural rehabilitation of concrete structures all over the world is a wellknown problem and a great amount of research is going on in this field. There can be manyreasons for strengthening such as increased loads, design and construction faults, change ofstructural system, and so on. Economic comparison between the cost of a full or partialreplacing to a building and the intervention of a localized reinforcening makes us give thepriority to the second solution, for reasons like the urban connections, the architecturaleffects, the natural landscapes etc. All these reasons, have pushed the world of technologicalresearch to establish new technics for reinforcening the structures with new compositematerials, mainly reinforced with fibers of different nature.Composite materials heard otherwise with the abbreviation FRP consist in continuedfibers enclosed in a matrix (adhesive substances) of polymers origin. Carbon fibers representa resistant element toward external loads and actions, while the polymer composition has themission to transfer constraints in fibers and between fibers and also protects them from thesurrounding environment. The use of CFRP is a competitive method both regarding structuralperformance and economical aspects which refers to the bonding of a thin carbon fiberlaminate or sheet to the surface of the structure in order to act as an outer reinforcement layer.Mechanical properties of composites depend on several different factors like themechanical properties of the carbon fibers themselves, their nature and the technic used tomanufacture them.Composite materials provide high resistance to traction, excellent resistance tocorrosion and a low specific weight so for they are widely used in the construction field, onreinforced concrete elements, masonry, wood, steel.In this study article will be also shown a numerical implementation of designing a beamin flexing, reinforced with carbon fibers.