A study of the compressive behavior of concrete columns confined with SRP jackets using digital image analysis

This paper describes the results of an experimental study carried out to understand the behavior of short plain concrete prisms with a square cross-section confined by steel reinforced polymer (SRP) jackets subjected to a monotonic concentric compressive load. The effectiveness of the confinement is studied in terms of load-bearing capacity and ultimate strain with respect to unconfined prisms. Test parameters considered in this study are the density of steel fibers, concrete corner condition, concrete surface treatment, SRP jacket height, and number of confinement layers. Digital image correlation (DIC) is used to qualitatively and quantitatively study the displacement and strain fields on the composite surface. SRP confinement is shown to improve the compressive strength and the ultimate strain of concrete prisms relative to the unconfined condition. Increases in fiber density and number of confinement layers are not proportional to increases in confined compressive strength.