Abstract
This paper presents the rate-dependent cyclic compressive properties, and the compressive and splitting tensile impact properties of rubberised slag-based alkali-activated concrete. Crumb rubber particles of up to 60% replacement by volume of the total natural aggregates are considered. For the rate-dependent cyclic response, three different strain-rates accounting for quasi-static, moderate seismic and severe seismic conditions are investigated using a servo-hydraulic machine. The compressive and splitting tensile impact properties are performed in an instrumented drop-weight loading rig. Three impact velocities of 5, 10 and 15 m/s are considered, giving a range of strain-rates between 3 and 270 s-1. The cyclic and impact mechanical properties, including the compressive strength, elastic modulus, and splitting tensile strength, reduce with higher rubber content, and are shown to be strain-rate sensitive. The unloading and reloading curves in the cyclic stress-strain response fall within the monotonic curves. Rubber addition increases the impact duration under compressive loading and alters the compressive stress-strain response under impact, resulting mainly in two main peaks and a delay in the axial crushing strain. Analytical expressions are presented to predict the unloading modulus, residual plastic strain, and unloading-reloading curves in the cyclic stress-strain response. Formulations for the dynamic increase factors of the compressive strength, elastic modulus, axial crushing strain and splitting tensile strength under a varied range of strain-rates are also provided. The results help characterise the fundamental cyclic and impact properties of rubberised alkali-activated concrete.