EXPERIMENTAL INVES rIGATIONS INTO CIRCULAR TUBES WITH FIBRE-BASED CONCRETE INFILLS

Abstract

Steel columns are extensively used in high-rise buildings wherein very high axial loads and moments are to be transferred. These steel sections have traditionally been open sections such as I-section or.H-section. During the past a decade or so, however, tubular sections in high strength steel have facilitated the use of steel in high-rise buildings much to its advantages. The hollow space within the tube has been further used to advantage by filling it with concrete. This has given rise to a composite section for column which primarily is in steel and supplemented by concrete with a minor amount of reinforcement to take care of problems related to creep and shrinkage. This type composite section has been popularly used in developed countries wherein availability of steel and welding technology is no problem. In the present thesis work, columns are required to transfer small amount of axial load and moment arising in low cost housing units. Single or 2- storey buildings as dwelling units for low income groups of people needs appropriate kind of technology so as to make the buildings durable and cost-effective. PVC pipes readily available for piping work, is intended to be studied for its effectiveness in being used as columns. This type of columns is generally referred to as Concrete-Filled Tube (CFT). Performance of such CFT's is the main stay of study in this thesis. A total of 12 samples were cast and effects of different diameter to thickness and length to diameter ratios on axial load behavior were studied. As a result the study on short columns was made possible.