Studying the Behavior of Slender Reinforced Lightweight Concrete Columns Subjected to Eccentric Loads

Dr. Eiad Hafiz Zahran

Due to technology and research development on concrete compressive strength over the last years, the use of lightweight concrete has proved to be most popular in terms of economy, superior strength, stiffness and durability. However, strength and ductility are generally inversely proportional. Lightweight concrete is a brittle material causing failure to occur suddenly under excessive applied loads. It is also well known, that axial compression concrete elements (i.e. axially compressed) rarely occurs in practice. The stress concentrations caused by eccentric loading, further reduce the strength and ductility of high- strength concrete columns. The elastic-plastic behavior of pin-ended reinforced concrete slender columns subjected to biaxially eccentric loads is investigated experimentally and theoretically. The ultimate loads, longitudinal and transverse deformations and the behavior up to failure of the columns are examined in detail. This paper presents an experimental and analytically (Ansys14) study to investigate the general deformational behavior of eccentrically loaded slender lightweight reinforced concrete columns. Six long scale lightweight columns with 2000 mm height and three cross sections, rectangular, square and circular cross sections. All specimens connected with two end plates were tested under eccentric and no eccentric loads. Different types of lightweight materials were used. Ansys14 has provided useful insight for future application of a finite element package as a method of analysis. To ensure that the finite element model is producing results that can be used for study, any model should be calibrated with good experimental data. This will then provide the proper modeling parameters needed for later use.