Loading–unloading curves of interlocking grouted stabilised sand-flyash brick masonry

Abstract

Loading–unloading and reloading stress–strain curves of interlocking grouted stabilised sand-flyash brick masonry under uniaxial cyclic compressive loading are presented. Five cases of loading at 0°, 22.5°, 45°, 67.5° and 90° to the bed joints are considered. The brick units and masonry system developed by Prof. S.N. Sinha is used in present investigation. A mathematical model to describe the Loading–unloading–reloading response of this masonry system is proposed. The model accounts for the effect of residual strain on the cyclic compressive behaviour. The model uses simple polynomial functions. The loading and unloading curves are transformed to a normalised co-ordination system on which all the curves plot within a narrow range. A parent polynomial is developed to fit the curve on this coordinate system. Then individual reloading and unloading curve are obtained by transferring the parent equation to the stress–strain coordinate system. The present model for Loading–unloading and reloading curves compare well with the experimental data for five cases of loading under consideration.