Structural Strength Performance of Carbon Fiber Reinforced Polymer on High Strength Concrete Beam

The existing public infrastructures of Malaysia has suffered from decades of neglect
and overuse, leading to the accelerated deterioration of bridges, building,
transportation systems, and resulting in a situation that approaching a infrastructure
crisis. This paper investigates the flexural behavior of Carbon Fiber Reinforced
Polymer (CFRP) plates on high strength concrete beams. Eight concrete beam
specimens with dimensions of 150 mm width, 200 mm height and 2150 mm length to
give a clear span length of 2000 mm were manufactured and tested. These eight
beams were grouped by four CB-series beams which were made without fly ash
replacement and four CF-series beams which were made with 30% fly ash
replacement. Six of the reinforced concrete beams were externally strengthened by
pasting CFRP plates at the soffit of the beam, three different lengths, 1333 mm, 1667
mm and 2000 mm which represent 66.7%, 83% and 100% respectively of the total
beam span. The optimum length of the CFRP plate was then established for structural
strengthening in terms of load carrying capacity, ductility and economical factor. The
results have shown that 1667 mm which is 83% of the span length is the optimum
length of the CFRP plate that achieved the highest strength; beyond this length, the
increase in the strength was negligible considering the economical factor. The
behavior of reinforced concrete beams made of 30% fly ash replacement and those
made of normal concrete was similar at first crack and ultimate loads when externally
strengthened with CFRP plates.
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