Structural behavior of RC beams containing EAF slag as recycled aggregate: Numerical versus experimental results

In the context of recycled concrete, the use of electric arc furnace (EAF) slag as partial or full replacement of coarse natural aggregates is particularly appealing because of the resulting economic and sustainability implications. Experimental investigation has been carried out on a set of reinforced concrete (RC) beams containing EAF slag as recycled aggregates under four-point bending tests. It has been found that the presence of steel slags leads to a higher flexural and shear capacity than the corresponding traditional RC beams, crack widths are reduced and the overall ductility is increased. Following these experimental findings, a numerical investigation is carried out. In particular, two different three-dimensional finite element procedures are adopted for comparative purposes against the experimental findings. The first procedure is a step-by-step incremental method based on a plasticity model for steel and a nonlinear stress-strain law for concrete in compression, while the post-failure behavior in tension is governed by a smeared-crack model. The second procedure is based on the limit analysis theory and permits one to simulate the limit state solution by carrying out simple elastic analyses in an iterative fashion. Comparison between numerical and experimental results is discussed and the main advantages and drawbacks of the two proposed numerical procedures are outlined.