Under seismic action, the most critical part of R/C structures, which were built in the United States before 1970, is beam-column joints. Common deficiencies of these joints could be summarized as; widely spaced column ...

Many of the existing reinforced concrete structures built prior to 1999 have deficient design details due to their non-seismic design or construction flaws. These structures are at risk of collapse under severe earthquakes. ...