Flexural Behavior of Reinforced Recycled Aggregate Concrete Beams Strengthened by CFRP

The flexural behavior of concrete beams containing recycled concrete aggregate (RCA) and strengthened externally by CFRP sheets was discussed in this paper. In the experimental program, twelve concrete beams, 150×200 mm in cross-section over an effective span of 1100 mm, with a tensile reinforcement ratio of 0.9%, with four-point load tested. The beams were subdivided into two groups. The first group consists of four beams, one of them is a control beam with natural aggregate (NA), and the others with different RCA ratios (30%, 50%, and 70%), whereas the second group consists of eight beams with a 50% RCA and uses CFRP sheets to strengthen them in various techniques. The externally bonded reinforcement (EBR) method and externally bonded reinforcement on the groove (EBROG) method were both compared. Generally, the test results showed that the flexural strength of RCA beams decreased significantly from 3% to 10.5% as RCA content increased. While the utilization of CFRP sheets to strengthen specimens led to an increase in the flexural strength of RCA beams, where the rate of increase ranged from 5% to 45.6% for the EBR method and 30.5% to 40.4% for the EBROG method.