Rate and temperature dependent relations for CFSTs and CFFTs subject to post-impact fire conditions.

Abstract Experimental research on the behaviour of conventional construction materials subject to extreme loading condition of post-impact-fire has indicated the effect of rate dependent loading history on the temperature performance of these materials. In order to analyse and design structures to withstand such combined loading, it is desirable to develop models that can reflect the mechanical properties of materials under initial impulsive loading and subsequent elevated temperature. In this study, a rate-pre-damage-temperature dependent empirical expression is proposed to predict the residual strength of partially damaged steel-concrete and fibre rein-forced polymer-concrete composite materials, in the form of concrete-filled steel tubes (CFST) and Concrete filled carbon-fibre reinforced polymer tubes (CFFT), at high temperatures up to 600 °C. The developed model is calibrated and validated on the basis of actual experimental data published by the authors. The proposed expression proves to be capable of successfully reproducing material strengths by considering the extent of high strain rate induced pre-damage together with temperature exposure. Highlights • Post-fire low-velocity impact behaviour of CFSTs and CFFTs is investigated. • A rate-pre-damage-temperature dependent expression is proposed. • Model is calibrated and validated against experimental data published by the authors. • Proposed expression proves capable of reproducing residual strengths of materials. [ABSTRACT FROM AUTHOR]