Seismic Upgrading of RC Wide Beam–Column Joints Using Steel Jackets

Giuseppe Santarsiero,Angelo Masi

doi:10.3390/buildings10110203

Abstract

This study is devoted to experimentally investigate the seismic behaviour of reinforced concrete (RC) wide beam–column joints equipped with a steel jacketing seismic strengthening solution. To this end, three identical full-scale specimens have been tested under cyclic loading, one in the as-built condition and two after the application of the strengthening solutions. Details of selected solutions are described in the paper along with the experimental results which confirm how the application of simple and feasible steel interventions can effectively improve the seismic capacity of wide beam–column connections in RC frames, especially in terms of lateral load carrying capacity and energy dissipation.

Highlights

Performances of public and private buildings in the last Italian seismic sequences have not been satisfactory since many structures and critical infrastructures like hospitals lost their serviceability, reporting significant damage up to the collapse [1]
The main aim of this study is to explore the possibility of applying the steel jacketing technique to strengthen wide beams in reinforced concrete (RC) frame buildings by using the well-known CAM system
The proposed approach is based on exploiting the exceedance of flexural strength that columns typically have with respect to framing wide beams

Summary

Introduction

Performances of public and private buildings in the last Italian seismic sequences have not been satisfactory since many structures and critical infrastructures like hospitals lost their serviceability, reporting significant damage up to the collapse [1]. There are ideal conditions to invest in buildings’ renovation considering structural and energy upgrading needs of Italian buildings, with special attention to reinforced concrete (RC) ones, where most of the population lives. 55% of RC buildings were constructed before 1980 which is the year when a large part of the Italian territory became seismically classified. Most of those buildings were designed without any seismic provision, with respect to gravity loads only. A significant share of those RC frame buildings was realized using wide beams (having the depth equal to the slab thickness) for the internal spans, due to the architectural need of having a plane ceiling surface

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