Retrofitting and Strengthening of an RCC Building – A Case Study of Mixed Housing Typology

Abstract

Construction of hybrid or mixed housing typologies with non-engineer solutions has become a common practice in developing countries, such as India. Which in turn affects the service life of the structure and ultimately leads to early failure. However, during the design life of a structure, it is important to investigate the risk posed by multiple parameters such as a sudden change in functional utility, exposure to natural hazards, modifications, and/or expansions in the existing structure. One such case is studied in detail, where a thirty-year-old single-story reinforced concrete building (existing building) is extended to a three-story structure (modified building) leading to multiple structural element damages in the existing building over a period of one year. To evaluate the reasons behind structural elements' damage and reduce the risk of sudden failure, a detailed investigation is carried out based on Non-destructive methods. A numerical model has been developed using Non-destructive testing (NDT) results for estimating the current load-carrying capacity of the structure and results obtained show that there is a load-carrying deficiency in structural elements of the existing building. To enhance both load carrying capacity and service life of the structure, considering site challenges, both composite and encasement retrofitting scheme has been proposed and executed to make the building in a serviceable state.