Assessment of Strengthening Scheme of Existing Buildings Extended by Adding Additional Floors

Abstract

This study intends to analyze and design existing RC frames, of different concrete compressive strengths when extended by adding more floors to the existing buildings. It may be decided whether a strengthening scheme is feasible or not.In this work, analyses are made of 3 buildings of 14-stories with different compressive strengths in the first 6-floor columns for each building, extended to 16-stories frame by adding 2 stories of Normal weight concrete (NWC) or Steel.A case study is selected which is an existing RC buildings, and the owner requested 2 additional floors. It is assumed that the foundation system is capable of carrying the additional floors. First the capacity of the superstructures must be known, by using data obtained from the previous designs of the existing buildings.After extending the building by NWC or Steel, by using STAAD-pro, it has been shown that a considerable portion of the total number of columns in the superstructure of the existing building couldn’t carry the new loads due to the additional 2 floors, so in order to add two additional floors, strengthening scheme must be planned for the columns which require additional capacity.