Fiber Reinforced Polymers
Fiber-reinforced polymers (FRP) (also fiber-reinforced plastics) is a composite material made of a polymer matrix reinforced with fibers. Externally or internally installed, FRP is engineered to increase the load capacity, strength and potentially provide protection from external environmental attack. FRP is also an effective way of regaining structural integrity in structures where internal reinforcing has been damaged, compromised or has been installed incorrectly. FRP can be applied to strengthen the beams, columns and slabs in buildings and bridges. It is possible to increase the strength of these structural members, even after severe damage due to loading conditions. For strengthening beams, two techniques are adopted. The first is to paste FRP plates to the bottom (generally the tension face) of the beam. This increases the strength, deflection capacity and stiffness (load required to make unit deflection) of the beam. Alternatively, FRP strips can be pasted in a ‘U’ shape around the sides and bottom of a beam, resulting in higher shear resistance. Columns in buildings and bridges can be wrapped with FRP to achieve higher strength. This is called “wrapping” of columns. The technique works by restraining the lateral expansion of the column from vertical loads. Slabs may be strengthened by pasting FRP strips on their bottom (tension) face. This will result in better performance, since the tensile resistance of slabs is supplemented by the tensile strength of the FRP.
Change of occupancy to increase load capability
Upgrade load bearing capacities of concrete and masonry structures
Restore capacity of concrete structures loss due to deterioration
Correct design/construction errors
Environmental protection for concrete members exposed to environmental attack