The damping capacity of recycled concrete members at inelastic stage
mostly depends on the damage degree. Taking the recycled coarse aggregate
replacement ratio and size distribution as controlling factors, the pseudo-static
test and free vibration damping test were conducted to study the damping capacity
of cantilever beams damaged at different levels. The influence of crack development
on damping and damage evaluation were also discussed and the quantitative
relationship between damping ratio and damage index of cantilever beam was built.
The test results show that the damping ratio of recycled concrete cantilever beam
first sharply increases and then decreases with the damage index. The peak damping
ratio is about 2 times that at elastic stage. For the same damage index, the
damping ratio increases with the coarse aggregate replacement ratio, while
decreases with the aggregate size. The physical and mechanical properties of
recycled aggregate, replacement ratio and size distribution all have significant
impacts on the damping ratio and damage index of recycled concrete member. The
evolution of damping capacity and damage index of recycled concrete member is
related to the crack number, density and length.
