Self-healing concrete vs. conventional waterproofing systems in underground structures: A cradle to gate LCA comparison with reference to a case study

The use of self-healing concrete in real applications is a challenging opportunity due to its potential to extend the service life of structures by minimizing or even eliminating maintenance and conservation tasks. In this paper the environmental sustainability of self-healing concrete is analyzed. The particular case study deals with the waterproofing and protection of a 24000 m2 underground parking garage of a new shopping center in Novara (Italy). For the construction of the parking a novel waterproofing system was used, consisting of a concrete treated with crystalline admixtures which allows to achieve the aforementioned self-healing capacity by resealing the cracks. In order to evaluate and quantify the environmental benefits and burdens involved in this self-healing ability the Life Cycle Assessment (LCA) methodology has been used. The study assumes a cradleto-gate with options scenario, which includes the stages of the life cycle from extraction of virgin materials to construction phase, corresponding to A1-A5 phases of the EN 15804 standard. The environmental performances of the analyzed structure are then compared to those of a similar construction made of reinforced concrete without the use of crystalline admixtures, but with alternative protective systems.