Structural Reinforcements with FRP



During his lifetime, the reinforced concrete structure must meet several requirements, which may not be fully known at design moment. Therefore, you may need at some point the structural reinforcement by the following reasons:

  • Increase in load.
  • Damage to structural parts (aging building materials, fire damage, corrosion of reinforcing steel, impact of vehicles).
  • Improving serviceability (limitation of deformations, effort reduction in the steel, reducing the width of the cracks).
  • Modification of the structural system. Design errors or construction calculation. 
    Various methods for strengthening, such as adhesion of steel sheets with epoxy, installing an external prestressing system, increasing the section of concrete with or without additional armor (using shotcrete, for example).


Since 1967, it has been possible to increase the resistance to bending and cutting of existing reinforced concrete structures by means of externally bonded steel bands. Although the method has a "State of the Art", recorded the same advantages and also some disadvantages (Table N ° 1, figures No.1 and No. 2).


Reinforcement with Band Steel 
Weight  low High
Resistance to flexion More High High
Thickness Very low LOW
Corrosión No Yes
Length bands Any Limited
Drive Flexible, easy Dificult, rigid
Load capacity In longitudinal direction only Any direction
Junction Easy complex
outstanding appropriate
Cost of materials High Low
Instalation Low High
Aplication without tools Lifting equipment and fasteners

Table N°1: Advantages and disadvantages of CFRP reinforcement system compared with steel flat bars.

PRFC Bands

Color Negro/blanco
Contenido volumétrico de fibras > 68%
Corrosión Invulnerable
Módulo de elasticidad longitudinal > 4500 - 5500 N/mm2
Resistencia a la tracción > 23 N/mm2
Deformación específica a la rotura > 1.70%
Densidad 1.50g/cm3
Fluencia Inexistente. Rotura frágil
Resistencia a la fatiga Sobresaliente

Table No. 2: Technical data sheets of CFRP


Epoxi formulation

Densidad (A+B) 1.77g/cm3
Pot-life* 30 minutos
Módulo de elasticidad* 4500 - 5500 N/mm2
Esfuerzo de adherencia (húmedo)*

3 N/mm2

Falla del hormigón

Resistencia a la flexión

23 N/mm2

Falla del hormigón 

Resistencia a la tracción 23 N/mm2
Punto de transición al vidrio* 80°C
Resistencia a la compresión 75N/mm2

Table No. 3: Technical data of the epoxy formulation Carbostrip



Adcos Carbotex System

Because of different requirements for tissue reinforcement in composite construction are also used in the form of cloth bonded with an epoxy resin. Adcos Carbotex having carbon fiber fabrics and fibers, respectively, unidirectional fiberglass, high strength and high modulus.

Are saturated at work using the epoxy system Carbotex systems for forming fiber reinforced polymer (FRP) used for reinforcing structural elements.

Among its main applications, highlighting the flexural reinforcement, and compression to cut structural elements of reinforced and prestressed concrete such as beams, columns or walls in buildings, bridges, tunnels, tanks, parking lots, docks, industrial plants, water , energy, etc.. for the following reasons:

Propiedades de la lámina curada
  Carbotex UD 200 Carbotex UD 300
Resistencia a la tracción >450 kN/m >450 kN/m
Módulo de elasticidad >236 Gpa >236 Gpa
Grosor 0,3 mm 0,4 mm
Peso por metro cuadrado 200 g/m2 300 g/m2
Elasticidad >1,6% >1,6%
Longitud por rollo 250 m 250 m
Ancho 300 mm 300 mm



 It can be seen advancing this technology by many tangible advantages: shorter commissioning work (as desired property in many jobs today), retail operators amount work dispensability of skilled and struts and scaffolding work special support, excellent mechanical and chemical resistance, etc.. All this is in fact a general economy in the transport, assembly, maintenance of the structure, etc.., Which could not be visualized by the high initial cost of using CFRP strips and woven fibers.

The use of these technologies in Argentina is quite recent, although there are already many works executed. However in the U.S. and Japan have been working for years with such products; Switzerland also researched, developed and implemented this system in a lot of work and, in hindsight, was introduced in the rest of Europe. A South American level, Colombia leads the field of innovations in reinforcing structures with CFRP numerous works (bridges, office buildings and parking lots).

This method of reinforcement is a tool that the structuralist engineer has at its disposal to reach the technical-economical solution that best suits the conditions, failures and evident in each particular case to resolve technologies.