Electric arc furnace slag (EAFS) is an attractive by-product due to its suitability as a replacement aggregate, the use of which helps to reduce the demand for natural resources. The aim of the present study is to determine the suitability of EAFS as a 50% and 100% replacement for coarse concrete aggregates, by evaluating its physical, mechanical and chemical properties. Slump and workability of concretes with EAFS decreased due to the shape and texture of the aggregate. Compressive strength, flexural strength and modulus of elasticity of concretes with EAFS improved by up to 30.9%, 35.7% and 25.0% over the control series, respectively. Absorption, porosity and ultrasonic pulse velocity were favored as well, and the greater density can be beneficial in some cases; however, thermal conductivity and capillary absorption were slightly affected. Considering the good results, EAFS is considered a viable alternative for use as a coarse aggregate replacement in concretes. © 2023 The AuthorsFondo Nacional de Desarrollo Científico y Tecnológico, FONDECYT, (1211135); Agencia Nacional de Investigación y Desarrollo, ANID