In the last 20 years, there have been a series of seismic events in Italy that have caused serious damage to civil and building structures. This has led to a significant increase in the use of concrete for the reconstruction of new structures and the repair of existing structures damaged by earthquakes. At the same time, the concrete industry is responsible for the most significant environmental damage during the life cycle of the built environment. The environmental disadvantages characterizing the concrete industry are related to the constant growth of the exploitation of natural aggregates. Therefore, it is necessary to use alternative and innovative aggregates that provide good concrete performance and lower environmental impacts. In this study, a very promising route from an environmental point of view is given by the use of artificial aggregates from industrial waste as substitutes for natural aggregates. An innovative low-cost and energy-saving granulation process has been employed to produce lightweight aggregates using fly ash from the incineration of municipal solid waste and ground granulated blast furnace slag. The final aim of this research is to demonstrate the environmental sustainability of artificial aggregates, through a comparison of three different mixtures.

Italy is one of the countries with the greatest seismic risk in the Mediterranean, due to the frequency of earthquakes that have historically affected its territory and the intensity that some of them have reached, resulting in a significant social and economic impact. Earthquakes and telluric phenomena are frequent and have affected various regions from North to South. Emilia Romagna, L’Aquila, and all of central Italy are just some of the locations of the most recent earthquakes, which unfortunately have left collapsed structures on the ground, swept away entire villages, and caused a dramatic loss in terms of human lives. Moreover, earthquakes have caused substantial economic damage, estimated for the last forty years at around 135 billion euros, which were used for the restoration and post-event reconstruction. To this must be added the consequences for the historical, artistic, and monumental heritage.

In Italy, the ratio between the damage produced by earthquakes and the energy released during the events is much higher than that which normally occurs in other countries with high seismicity, such as California or Japan. For example, the 1997 earthquake in Umbria and Marche produced a picture of damage with an economic damage of about 10 billion euros comparable to that of California in 1989 with 14.5 billion US $, even though it was characterized by about 30 times lower energy. This is mainly due to the high population density and the considerable fragility of our building stock.

The most recent regulations have acknowledged the presence of a widespread seismic hazard that does not spare areas that the previous classifications declared free from a probability of seismic events of any significance. This circumstance has accentuated the presence on the Italian territory of buildings, even quite recent ones, which although built according to the law, do not meet the requirements of seismic zones.

For this reason, the need to build buildings resistant to seismic phenomena—or to adapt existing ones by improving their resistance—is spreading more and more, to prevent damage caused by the earthquake. In this regard, over the past twenty years, earthquake science and in particular seismic engineering have undergone a technical-scientific transformation with respect to earthquake resistance and the first seismic regulations for the protection of new buildings. The first innovative aspect concerns the buildings and lies in the recognition of the importance of the seismic protection of the existing heritage. Especially in Italian towns, but also in Europe, the existing built heritage, even the minor one, is in many cases of great historical and cultural importance and fits into environmental contexts that are also of considerable value.