The use of UHDC to strengthen reinforced concrete columns

Abstract

The use of concrete in building construction during the last century has increased greatly. Throughout this period, several structures such as bridges, high-rise buildings and industrial buildings have been constructed with this material. The development of these structures involves a substantial investment of resources, and therefore it becomes essential to preserve their structural integrity. It is a well-known phenomenon that concrete experiences some damage throughout its lifetime. Deterioration is mainly caused by gradual degradation brought about by physical and chemical processes. It is important to have an understanding of the underlying causes of concrete deficiencies to perform a meaningful evaluation for structural repair. An overview of different types of structural repair and rehabilitation will be discussed, with particular importance given to the use of Ultra High-Durability Concrete (hereinafter referred to as UHDC) with self-compacting characteristics as a repairing and strengthening material for concrete columns. The effectiveness of UHDC for jacketing of concrete columns in repair and strengthening shall be assessed through the production of cylindrical specimens to be tested under compressive loading. A strengthening method using a UHDC jacket will be used to improve the performance of concrete with reference to the following test variables: assessment of UHDC confinement to ordinary concrete, and load application method on samples to assess improvement in axial strength and confinement.