Life cycle assessment for concrete kerbs manufactured with recycled aggregates

A study on the use of sand aggregates from an energetic and environmental point of view is presented hereby. The aggregates come from the recoveries produced at the construction of buildings and demolition wastes (C&DW) and are reused as substitutes of the natural sand aggregates in the fabrication of concrete kerbs. A ‘life cycle assessment’ of the particular elements has been carried out, determining the energetic consumptions of all the processes that take part in order to reach the final product. Several studies on waste recycling procedures have been conducted in the last decades, but not so many deal with applications on the concrete industry. In the present application, concrete kerbs with 0% up to 50% replacement of the natural aggregate were manufactured. It must be pointed out that a significant energy saving has been promoted together with a relevant decrease in the emissions. The energy consumption data together with the contaminant emissions produced in the whole processes have been analyzed for a fixed and mobile recycling plants and compared with the natural aggregates manufacture. The environmental impact has been measured in terms of natural environmental impact. There would also be a decrease by a lower use of the natural resources, and also in terms of neighbourhood noises and sightseeing impact, although these last ones have not specifically been measured and cannot be quantified. As a conclusion, a procedure to manufacture kerbs from recycled concrete has been established. On the energetic consumption point of view, the emission reduction and the minimization of the studied impact categories have been obtained.