Benefits of CaCO3 nanoparticles for the strain hardening behavior of high-strength alkali-activated composites based on blast furnace slag and liquid crystal display glass powder

Abstract

This study investigates the effect of CaCO3 nanoparticles on the compressive and tensile behaviors of strain-hardening alkali-activated composites made of blast furnace slag and liquid crystal display glass powder (LCDGP) including 2 % polyethylene fibers. The nucleation effect of small amounts of nano-CaCO3 increased the calcium aluminosilicate hydrates in the hardened paste. The addition of 2 % nano-CaCO3 was most effective for enhancing the compressive strength of alkali-activated composites, yielding maximum compressive strength of 81.5 MPa. Although the tensile strength of alkali-activated composites slightly decreased, its strain and energy absorption capacities were improved by incorporating nano-CaCO3 at dosages up to 5 % because the agglomerated nanoparticles acted as artificial flaws. Compared to plain specimen, almost double the strain capacity and g-value (7.12 % and 281.6 kJ/m3) were obtained at 5 % nano-CaCO3. This also resulted in 37.8 % and 62.3 % higher strength- and energy-based pseudo strain hardening indices, respectively, than in the plain counterpart. The addition of 5 % nano-CaCO3 is recommended to achieve excellent tensile behavior of alkali-activated composites without significant strength deterioration.