Performance of blended cement SCC filled steel tubes for repair/rehabilitation of structural columns of buildings, bridges and deep foundations

Abstract

Research on structural performance of confined self-consolidating concrete tubes as columns is scarce and there is little data available. Similarly, there is little research on use of blended cement containing agricultural waste, i.e. rice husk ash as cementitious material in normal/high strength concrete. Limited research has shown better performance of such blended cements with increased strength by up to 30 and improved durability, reduced permeability and shrinkage. Its behaviour under confined conditions is still to be studied. This paper provides valuable research in this area with special focus on the use of blended cement SCC confined in steel tubes applicable for rehabilitation/ replacement of columns of old bridges and buildings as well as in deep foundation applications. This paper presents an experimental study on the behaviour of short, SCC, with blended cement containing 75 ordinary Portland cement and 25 rice husk ash, filled steel tubular columns axially loaded in compression to failure and compares the results with testing on similar hollow tubes and tubes filled with normal concrete. Almost 350 to 460 increase in strength was observed by filling steel tubes with SCC (containing blended cement) in square and circular tubes respectively. Failure strains were also reduced by 40 to 45. Smaller steel sections and use of blended cement containing rice husk ash reduces the costs of repairs/renovation works along with reducing the disposal problems of this massively produced agricultural waste in the rice growing regions.