| Title |
Bond Performance between Reinforcing Bars and Recycled Coarse Aggregate Concrete with Respect to Reinforcement Location |
| Authors |
Lee Min-Jung ; Yun Hyun-Do ; Kim Sun-Woo ; Choi Ki-Sun ; You Young-Chan ; Kim Keung-Hwan |
| Keywords |
Recycled Coarse Aggregate ; Locations of Deformed Bar ; Bond Behavior ; Pull-out Failure |
| Abstract |
This study investigated the bond behavior between recycled coarse aggregate (RCA) concrete and deformed reinforcing bars. The positions (i.e., vertical, horizontal) and the locations (i.e., 375mm, 225mm and 75mm) of deformed bar were considered as a main test parameter in this paper. The ready mixed RCA concrete with specified strength of 21MPa was prepared with different replacement levels (i.e 0%, 30%, 60% and 100%) of recycled coarse aggregate. For the pull-out test, each specimen was in the form of a cube, with each side of 150mm in length and a deformed bar, 16mm in diameter, was embedded in the center of each specimen. From the test results, it was found that maximum bond strength was slightly decreased as the RCA replacement ratio increased. And as the location of rebar was higher, maximum bond strength was decreased and slip at maximum bond strength was increased. Especially, the specimen with recycled coarse aggregate concrete, bar embedded horizontally 225mm above from base could not satisfy bond strength requirement provided in CEB-FIP code although ACI code consider reinforcement location factor α=1.3 to reflect height of reinforcement more than 300mm. In this specimen, the bond strength provided by bearing stress and wedging action of concrete was not observed. It was caused by the fact that bonded area at the bottom of horizontal reinforcement was significantly reduced by the poring water and laitance. |