Moment–curvature behaviour of RC chimney section under monotonic loading–An experimental study

Abstract

The latest revision of IS: 4998 (2015 edition) incorporates the limit state method of design and proposes a new stress–strain model for concrete and steel for RC chimneys. Many apparent differences can be noticed between the stress–strain relationships of these two materials when the methodologies of IS: 4998–2015 and other well-established design codes are compared.In order to investigate these differences and to find out the methodology which uses most precision in depicting the stress–strain relationship of these materials, four hollow circular test specimens of typical RC chimneys with openings have been specially designed, fabricated and laboratory tested for bending under monotonically increasing lateral loading. As the results of the cross-section at the bottom of the opening near the base of the chimney are found to be the most critical, the behaviour at especially this section has been emphasized.Test results include strength, crack pattern, failure mechanism; further, the results obtained from this experimental study have been compared in the form of ultimate strength, curvature ductility and energy absorption by plotting moment–curvature relationships using design guidelines given in IS: 4998–2015, CICIND 2011 and ACI: 307–08.