Bond Properties of Deformed Rebar in Frost-Damaged Recycled Coarse Aggregate Concrete under Repeated Loading

The bond properties of deformed rebar in frost-damaged recycled coarse aggregate concrete (RAC) under repeated loading (R-L) was studied. It is found that the bond failure modes of specimens for R-L is similar to that for monotonic loading (M-L), whereas the crack width for R-L is larger than that for M-L. The bond strength has a tendency to decrease after frost damage, whereas the peak slip has a tendency to increase, whether under R-L or M-L. The bond strength under R-L is lower than that under M-L, whereas the peak slip under R-L is higher than that under M-L. The experimental results of the pullout specimens in water are contrasted with that in salt solution. Through contrasting research, the frost-damage resistance coefficient and the R-L resistance coefficient in salt solution are lower than that in water, whereas the rebar slip in salt solution is higher than that in water. An ultimate bond strength calculation expression of deformed rebar in frost-damaged RAC under R-L is presented.