STRENGTH AND STIFFNESS CHARACTERISTICS OF AXIALLY LOADED REINFORCED CONCRETE COLUMNS WITH DIFFERENT TYPES OF CONCRETE

The current paper is a report on the preparation and testing of 10 reinforced concrete column specimens of (120x120) mm2 cross section and 1000 mm height, for the experimental clarification of the behavior of columns under the influence of pure axial loads. The research addresses the influences of some parameters and conditions on the mentioned behavior, including concrete type (normal strength, high strength or modified reactive powder concrete), the amount of reinforcement and the percentage of steel fibers. The effects of the above variables on the ultimate capacity, failure mode, stiffness, ductility and axial load-lateral displacement behavior were studied. It has been found that increasing the compressive strength and steel reinforcement ratio lead to increasing the ultimate capacity and stiffness of the tested columns. The effectiveness of increasing the steel fibers ratio is manifest in increasing the ultimate strength, ductility, and decreasing the stiffness and the ductility of the tested columns.