Carbon sequestration in Steel Slag-based mortar: investigation of chemical composition and mechanical properties

In the last decades, the use of steel slag as binder in supplementary cementitious materials (SCMs) emerged as a valuable solution to re-use by-product of the steel making industry, and to reduce the use of cement. Moreover, steel slag-based mortar and concrete have proven to be suitable materials for mineral carbon sequestration, capable of permanently storing CO2 during condition-ing in environment rich in carbon dioxide. The study aims at investigating the efficiency of the carbonation of steel slag mortar cylinders by means of thermogravimetric analysis and mechanical compression tests. The results show a high CO2 reactivity of the steel slag mortar capable of storing 69 kg of CO2 per ton of binder and a remarkable improvement of the mechanical properties resulting in a compres-sive strength of 48 MPa, comparable to that obtained using conventional clinker cement.