Evaluating the Performance of Green Mortar Based on Alkali-Activated Slag – CaO and Sea Sand

This study examines the performance of green mortar including with various nano-aluminum oxide (nano<tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\text{Al}_{2} \mathrm{O}_{3}$</tex>) based on alkali-activated slag - CaO incorporating sea sand. Mortar mixtures were formulated with nano- <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\text{Al}_{2} \mathrm{O}_{3}$</tex> dosages of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$0 \%, 1 \%, 2 \%, 3 \%$</tex>, and 5 % (by binder mass) at a fixed water-to-binder ratio of 0.6. The findings reveal that increasing the nano- <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\text{Al}_{2} \mathrm{O}_{3}$</tex> content adversely affects mortar flowabitiy. Optimal mechanical performance, including compressive strength, flexural tensile strength, and ultrasonic pulse velocity (UPV), was observed at 28 days with a 3 % nano- <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\text{Al}_{2} \mathrm{O}_{3}$</tex> dosage. However, electrical surface resistivity (ESR) exhibited a continuous decline with increasing nano- <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\text{Al}_{2} \mathrm{O}_{3}$</tex> content across all tested ages.