Life cycle assessment of mortars and concretes with recycled construction and demolition wastes

The increasing demand for infrastructure and construction works generates high consumption of building materials, especially concrete. The high CO2 emissions of cement and other environmental impacts of concrete life cycle has encouraged the development of more sustainable concretes. Among alternatives, there are cement and aggregates partial replacement for recycled construction and demolition wastes (CDW). The aim of this study was to assess the environmental performance of mortars and concretes with CDW considering performance properties, as strength and durability. The methodology adopted was the Life Cycle Assessment (LCA), established by ISO 14.040 and 14.044 standards. SimaPro (R) was utilized to evaluate the environmental impacts of these products. The results showed that the performance indicators are decisive in environmental assessments. Mortars with 20% cement replacement by CDW had their environmental impacts reduced about 80%. Meanwhile, concretes with 40% coarse aggregates replacement by recycled concrete aggregates had their environmental impacts increased up to 30%.