PSI - Issue 78

Available online at www.sciencedirect.com

ScienceDirect

Procedia Structural Integrity 78 (2026) 2169–2175

© 2025 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of XX ANIDIS Conference organizers Keywords: seismic vulnerability; masonry;retrofit. Abstract Italian existing building heritage largely involves unreinforced masonry structures. In last decades, a growing research focus is directed toward retrofit solutions that can simultaneously enhance seismic performance and improve energy efficiency. In line with this objective, the paper offers insight into partial outcomes of a laboratory test campaign, actually ongoing, on an innovative retrofit system. The proposed system involves a lightly reinforced concrete wall cast within expanded clay formwork blocks: owing to their design, these blocks allow for the integration of a high-performance insulation layer, enhancing thermal efficiency. The retrofitted wall is strategically connected to the existing masonry wall at the levels of the horizontal floors. The resulting system can be conceptualised as a parallel configuration of two walls: the existing wall primarily resists also to vertical loads, and the new reinforced concrete one is able to absorb part of the horizontal seismic action, relieving the existing wall too. The paper presents some preliminary results of the experimental ongoing tests on the combined system with a specific typology of masonry, and the calibration of numerical refined models useful for the optimization of the further tests and parametric analysis. 1. Introduction The rehabilitation of buildings is a fundamental process aimed at maintaining construction quality and extending the service life of existing structures. Over time, the criteria guiding rehabilitation have evolved beyond the sole necessity of ensuring structural safety, incorporating goals related to sustainability, reduced emissions, and enhanced thermal efficiency. This shift reflects global discussions surrounding the energy and environmental performance of buildings, highlighting the need not only for safe and durable structures but also for reduced environmental impact and lower dependence on heating and cooling systems. While achieving these targets is already challenging for newly XX ANIDIS Conference Combined seismic and energy retrofit of masonry structures Francesca Mattei a *, Federica Del Carlo a , Silvia Caprili a , Walter Salvatore a a University of Pisa, Department of Civil and Industrial Engineering, Largo L. Lazzarino, 56122 Pisa (IT)

* Corresponding author. E-mail address: francesca.mattei@unipi.it

2452-3216 © 2025 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of XX ANIDIS Conference organizers 10.1016/j.prostr.2025.12.276