Nobilitation of clay waste from tunneling as building material
Waste reusing is one of the most auspicate practice in order to improve circular economy and industry sustainability, including infrastructures construction works. An integral use of tunnelling excavation material allows to reduce the dumping in the landfills and to limit the quarrying of geo-environmental resources as raw material. Depending from the nature of the extracted rock, tunneling waste can be used in the same infrastructure works. In fact, in cases of hard rocks and unreactive minerals, they are commonly used in the production of aggregate for concrete or road bases. Instead, in many cases, the clay rocks and argillaceus deposits, obligate their dumping in the landfills, due to the bad mechanical properties, plastic behavior and conditioning admixture pollution due to the excavation process. A recent case study, carried out in Italy, shows the possibility to produce construction materials from argillaceous tunneling waste, allowing relevant economic and environmental saving, especially in case of excavation material containing thensioactive admixtures used for clay conditioning during Tunneling Boring Machine excavation (EPB TBM). argillaceous tunneling waste, supplementary cementitious material, pozzolanicity, waste treatment, reusing, cement replacement.