Stress-strain behavior of electric arc furnace slag concrete under uniaxial compression: Short- and long-term evaluation

This work analyzes the experimental behavior of electric arc furnace slag (EAFS) concretes in terms of full stressstrain behavior under uniaxial compression. Tests are carried out on samples cured for 28 days and for more than 6 years, representing both short- and long-term conditions. Results are discussed in terms of main mechanical strength (compressive and indirect tensile strength), deformative properties in the axial and transverse direction, i.e., secant modulus and Poisson's coefficient, stress-strain relations during the load history, damage evolution and critical stress. Furthermore, two models for predicting the stress-strain behavior of concrete under repeated cycles are shown, for both natural aggregate concrete (NAC) and EAFS concrete. Results indicate that EAFS concrete has higher compressive and tensile strength than the reference, as well as better deformative properties. The aggregates type influences the deformability of the concrete also beyond the elastic regime, both in the longitudinal and transverse direction, with a different extent depending on the applied stress. Specifically, EAFS concrete attained higher secant modulus particularly at low-stress levels, while such improvement is less pronounced at high stresses. Instead, no significant differences were recorded concerning Poisson's coefficient between NAC and EAFS concrete. The analytical models proposed hereafter well predict the experimental behavior for both concrete types.