Repairing of reinforced concrete continuous beams by CFRP sheets

Abstract

Although continuous beams may be found in a range of projects such as garages, bridges, and multi-story structures, studies have been still restricted to a limited field. Flexural cracks are a common issue in continuous beams; therefore, this article outlines an investigation study used to assess the performance of two-span reinforced concrete beams repaired by attaching (CFRP) sheets. The program included seven beam specimens with a length of 2800mm and rectangular cross sections of 150*250mm. All beams were strengthened externally on the tension zones via CFRP-sheet considering changing the ratio of sheet length to beam span which is 0.5, 0.7, and 0.9 except one was chosen as a reference beam. Repaired beams were preloaded with damage ratios of 45% and 65% with respect to the reference beam. The findings showed that using style 0.7L for both positive and negative regions achieve an appropriate restored percentage of ultimate capacity of about 101.7% and 98.2%. In addition, eliminating the sheet length in the positive moment regions gives higher stiffness. it is also found that when the CFRP sheet length in the tension part is increased, the tensile rupture of the sheet was the dominant failure mode.