A review of retrofit strategies for Large Panel System buildings

A large stock of the 50s-70s buildings with precast concrete Large Panel System (LPS), which consist of load-bearing walls and slabs connected by on-site wet or dry joints, is still present in Europe. This structural typology is inherently vulnerable under extreme loads and prone to progressive collapse because of the lack of integrity mainly due to its weak joints. Although the 1968 Ronan Point partial collapse led to the introduction of robustness concept, LPS buildings still show inadequate safety. Thus, retrofits to increase their reliability have become the goal of ongoing research. A review on latest retrofit strategies is the aim of this paper. Finally, the perspective of life-cycle oriented retrofits is discussed encompassing multi-performance design approaches toward more holistic practices.