An enhanced system for the combined seismic and energy retrofit of masonry buildings

The Italian existing building stock is characterized by low-performance levels in terms of energy efficiency and seismic safety. The development of retrofit solutions fulfilling both targets is therefore of strong interest, as proven by a series of fiscal incentives recently approved, in Italy, to encourage the implementation of both energy and seismic intervention. Nevertheless, energy and seismic retrofitting techniques often present specific features that make it difficult to pursue both objectives. In this framework, an innovative solution is proposed, focused on the enhancement of unreinforced masonry buildings using expanded-clay blocks infill walls. Expanded-clay block walls technique has proven to provide excellent energy performance and ensure high seismic safety in new buildings. This technique's feasibility and efficiency as a retrofit solution were analysed when applied to a representative case-study building, analysed in the current condition and after the application of the retrofit system. Dynamic thermal simulations were carried out to evaluate the hygrothermal performance, showing a general decrease in the overall thermal transmittance and an improvement in the indoor thermal comfort for the retrofitted configuration. The seismic behaviour was assessed according to actual standards, showing an increased capacity of the building towards horizontal actions post-retrofit application.