Durabilità di strutture armate realizzate con calcestruzzi sostenibili aventi materie prime contaminate da cloruri

In recent decades concrete industry had to respond to a growing demand for infrastructures for which it has been necessary a substantial exploitation of the environment, in terms of non-renewable resources and of atmospheric emissions. Cementitious materials field not only has important environmental consequences, connected to resource consumption, pollution and the production of demolition waste, but it also offers interesting prospects for reducing this impact through recycling of materials. Moreover, a further strategy to solve the environmental problems is connected to the durability of constructions: designing structures with longer life cycle allows to reduce the quantity of concrete to be produced and disposed of. Within the SEACON project, financed by the Infravation program, several experimental tests have been carried out aimed at demonstrating the safe utilization of seawater and chloride contaminated raw materials (such as cement or recycled aggregates) for the production of a sustainable concrete when combined with non-corrosive reinforcement to construct durable and economical concrete infrastructures. Laboratory tests in progress from about 3 years and presented partially in this note showed that the use of chloride-contaminated materials in concrete did not negatively influence its microstructural features. Moreover, the protection conditions are guaranteed for austenitic stainless steel rebars (304L) in the studied mixes regardless of the chlorides contamination even when concrete is carbonated or subjected to the further penetration of chlorides.