Experimental studies and analysis on axial compressive properties of full iron tailings concrete columns

The structural properties of iron tailings must be verified for them to be used in reinforced concrete structures. In this study, finely ground iron tailings powder was used as an admixture, and iron tailings gravel and iron tailings sand were used as the coarse and fine aggregates, respectively, to prepare full iron tailings concrete (FITC), which was compared to conventional concrete (CC). Eight concrete column specimens comprising different raw materials were cast. Three slender and three short reinforced FITC columns were designed, tested under axial compression, and compared to the experimental results of the CC columns. The load-bearing and deformation capacities of FITC columns were investigated for the first time. The results indicated that the incorporation of iron tailings reduced the strength and modulus of elasticity of FITC by 7.1–8.8 % and 18.2–19.1 %, respectively. The bearing capacity of three FITC slender columns was 4.6–8.7 % less than that of the CC slender column, and the bearing capacity of three FITC short columns was 10.0–16.7 % less than that of the CC short column. The bearing capacity calculations of the FITC columns indicate that they are safe as per existing Chinese and ACI standards. However, their ductility and stiffness are inferior to those of CC columns. A calculation model for the axial compressive load capacity of FITC columns, which agreed with the test results, was selected.