Triaxial compression experiments on plain concrete

This M.E. project report describes the main aspects and findings of an experimental research project on triaxial compression of plain concrete. The main focus of the research is to study the behavior of plain concrete under increasing axial compression while maintaining different levels of constant lateral confinement. Twenty-two mechanical property tests---four unconfined compression tests, and 18 triaxial compression tests---were completed. The triaxial compression tests exhibited a continuous increase in ultimate compressive stress and strain at failure with increasing confining stress. An empirical failure envelope based on a linear correlation of the compressive strength experimental data obtained through this research is presented. Experimentally determined full stress-strain curves are also presented from standard triaxial tests. These curves are used to determine mechanical properties of the plain concrete such as initial Poisson's ratio and initial tangential modulus, and to provide empirical evidence of the effect that lateral confinement will have on these properties. All findings were compared to previously published data or empirical models and in general were found to be in good agreement.