Lightweight vaulting systems in the early 19th century, from Naples to Europe. Knowledge for conservation of an adaptive built heritage

In the Kingdom of Naples, as well as in Europe, the Early 19th century was a period of deep experimentations in relation to innovative lightweight ‘mixed’ vaulting systems. The strong interlace between scientific culture and empirical knowledge, together with a renovated constructive Neoclassicism, represented crucial aspects for the definition and diffusion of building systems which were alternative to a heavy constructive practice, well established and much better-known. The technical competence which was developed in those years was extraordinary and demonstrated the capacity of architects and engineers to learn from the past and to propose innovating and unusual building vaults. They are structures made up of lightweight materials such as wood, concrete with light and volcanic aggregates, bricks laid lengthwise and cylindrical hollow clay bricks. An interesting aspect is related to the widespread diffusion of this technical competence, from Naples to European countries such as France and Germany. This ongoing PhD research explores the level of progress which the 19th century building yard proves in the evolution of lightweight construction techniques – with particular reference to vaulting systems – by evaluating the adaptability and vulnerability as well as the resilience capacity compared with extreme events such as earthquakes. This research – by starting from an historical study that inevitably interlaces direct surveys – comes to envision the conservation project by encouraging further reflection about issues related to vulnerability and adaptability of these constructive systems. Our main goal is to devise an exhaustive framework of knowledge, which is necessary for defining possible intervention approaches for these particularly vulnerable systems. In fact, the lacking knowledge of historical construction techniques can cause wrong and damaging restoration projects. It is necessary, instead, to find methods for a sustainable restoration, by using ‘compatible’ materials and adaptive techniques and by safeguarding the monumental value. The current state of the art for these construction systems requires further in depth-analysis and new practical applications aiming at supporting an aware project of restoration.