LISESMACS

LISESMACS explores an innovative seismic retrofit strategy based on a lightweight cold‑formed steel exoskeleton installed on the exterior façade of masonry‑infilled reinforced concrete (RC) buildings. The system is composed of modular vertical and horizontal steel profiles arranged in a grid pattern, forming a structural “shell” that enhances the global lateral resistance of the building without intrusive interior interventions.

The experimental program focuses on single‑story, single‑bay RC frames with different types of masonry infills. Each specimen is tested under quasi‑static cyclic in‑plane loading both in its unstrengthened condition and after the installation of the exoskeleton. This allows for a direct comparison of strength, stiffness, deformation capacity, and energy dissipation, providing clear evidence of the exoskeleton’s contribution to seismic performance.

Social Impact

Across many seismic regions, communities live in RC buildings whose infills are highly vulnerable to earthquake damage. Traditional strengthening methods are often invasive, costly, or incompatible with occupied buildings. LISESMACS offers a non‑intrusive, cost‑effective, and architecturally flexible alternative that can significantly improve safety while preserving the building’s functionality and appearance. By enabling rapid strengthening and reducing the need for extensive interior work, the project supports greater seismic resilience, faster recovery after earthquakes, and long‑term protection of communities and local heritage.

Ultimately, LISESMACS contributes to a future where seismic safety is accessible, scalable, and compatible with the realities of existing urban environments.

Practical Implications

LISESMACS aims to deliver a practical, modular, and easily deployable strengthening solution for the vast stock of masonry‑infilled RC buildings constructed before modern seismic codes. The lightweight nature of the exoskeleton reduces installation time, avoids heavy machinery, and minimizes disruption to occupants. Its modular grid layout allows engineers to adapt the system to different building geometries and performance objectives, making it suitable for both emergency post‑earthquake interventions and planned seismic upgrades.

Unstrengthened condition

Strengthened condition