Strengthening of RC Buildings with Steel Elements

Existing reinforced concrete (RC) buildings often need some strengthening interventions due to different reasons, such as change in usage, repair of visible damage or seismic strengthening. Nowadays, few guidelines and codes that specifically addressing this issue are available in Europe, even though a wide range of research activities and scientific literature is available. As a result, the lack of clarity and guidance from current codes leads most practitioners to rely on their engineering judgment and to resort to assessment procedures that are conceptually suitable to the design of new structures, rather than to the assessment of existing ones. Hence, this chapter aims at providing a brief discussion on the assessment procedures most commonly adopted by practitioners and at clarifying the adequacy of such approaches. Moreover, building on the manifold applications and versatility of steel, the use of steel elements in the strengthening of existing RC buildings is herein addressed. A number of strengthening techniques, from traditional to more innovative solutions, are presented alongside with a brief discussion on the relevant issues characterizing their design and performance.