Authors:
Heebok Choi;
Abstract:
In this study, 12 specimens with three different lateral reinforcement ratios (ρ = 0.022, 0.012 and 0.007) and four RG replacement ratios (0%, 30%, 50% and 100%) were prepared and tested under pure axial load, in order to investigate the influence of recycled coarse aggregate (RG) and lateral tie reinforcement ratio (ρ) on the
compressive behavior of a confined recycled aggregate concrete (RAC) column. The results showed that the effect of RG on the compressive behavior of the RAC was negligible at low stress level and that it began to appear as the load increased at load levels above about 35% of the peak, regardless of ρ. The slope of the normalized compressive strength (f’cc / f’co) and normalized corresponding strain (εcc / εco) against ρ showed that the lateral reinforcement exerted the greatest effect on the stress and strain enhancement in the RG-30
series and the smallest effect in the RG-50 series. The ratios of experimental values to those predicted from Mander’s model, f’cc_exp / f’cc_model and εcc_exp / εcc_model, showed that the model tended to give unconservative strain (εcc) values for the RAC column. For proper estimation of f’cc and εcc by the existing model in case of
RAC column, the main reinforced bars would be more efficient in the center of the sides as well as the corner of the rectangular column section.
Keywords:
Recycled aggregate, Volumetric ratio of tie hoop, Compressive stress-strain behavior, Confined concrete, Rectangular column