Bond behavior between steel bar and recycled aggregate concrete after freeze-thaw cycles

- The bond behavior between steel bar and recycled aggregate concrete after freeze-thaw cycles of was studied.
- The influence of freeze-thaw cycles and diameter of deformed steel bar on the bond behavior was studied.
- The bond strength decreased as the freeze-thaw cycles increased.

The bond behavior (failure modes, bond strength, bond stress-slip curves) between steel bar and recycled aggregate concrete after different cycles of freeze-thaw was studied using pullout tests. One recycled aggregate concrete, two types of steel bars: plain steel bars with diameter 12 mm, deformed steel bars with diameter 14 mm, 18 mm, 22 mm and 0, 15, 25, 50, 75 cycles of freeze-thaw were considered in the experiment. Based on the experimental results, the influence of number of freeze-thaw cycles, type of steel bar, and diameter of deformed steel bar on the bond behavior between steel bar and recycled aggregate concrete was studied and analyzed. It was found that the bond strength decreases as the freeze-thaw cycles increased, the drop of bond strength between plain steel bar and recycled aggregate concrete is larger than that between deformed steel bar and recycled aggregate concrete as the freeze-thaw cycles increased, the pullout force and bond strength for deformed steel bar are larger than that for plain steel bar after the same cycles of freeze-thaw.