Concrete self-healing for sustainable buildings. A focus on the economic evaluation from a life cycle perspective.

Concrete is one of the world’s most used and produced materials, based on its dominant role in the construction sector, both for the construction of new structures and for the repair, restoration, and retrofit of built ones. Recently, research has been focused on the development of innovative solutions to extend the service life of reinforced-concrete structures, specifically by introducing self-healing properties aimed at reducing the necessary maintenance interventions and, conse-quently, the environmental impacts. These solutions imply costs and financial feasibility impacts, which must be measured and evaluated to support the ranking of preferable alternatives. Thus, this paper proposes a methodology capable of supporting the selection of material/product op-tions from the early design stages in the construction sector. Assuming a life cycle perspective, the Life Cycle Costing (LCC) approach (Standard ISO 15686-5:2008) is proposed for comparing three material solutions applied to the case study of a wall component, – hypothesized to be used in building construction in Turin (Northern Italy). Namely, a traditional standard concrete and two different self-healing concrete types were evaluated through the Global Cost calculation of each solution. The focus is on the material service life as a crucial factor, capable of orienting invest-ment decisions given its effects on the required maintenance activities (and related investments) and the obtainable residual value. Thus, according to a performance approach, LCC is combined with the Factor Method (FM) (ISO 15686—part 1:2000). Assuming the capability of lifespan to affect the Global Cost calculation, the results give full evidence of the potential benefits due to the use of self-healing materials in construction, in terms of reduction of maintenance costs, increase in the durability of buildings and structures, and related residual values, and, consequently, re-duction of the environmental impacts.