Performance of Alkali-Activated Self-Compacting Concrete with Incorporation of Nanosilica and Metakaolin
Alaa Mohammedameen
Abstract
This study aims to analyze the influence of nano-silica (NS) and metakaolin (MK) as binder replacement materials on the fresh and hardened performance of alkali-activated self-compacting concretes (A-ASCC). Therefore, nine A-ASCC mixes with and without metakaolin were prepared, as well as mixes with and without NS inclusion. Slump flow, v-funnel, L-box, and T50 value tests were used to investigate the fresh properties of A-ASCC. While the hardened performance was examined using compressive strength, bonding strength (pullout test), fracture toughness and flexural tensile strength tests. A relationship analysis was also conducted on the A-ASCC experimental data. The experimental results showed that the addition of NS and MK had a negative influence on the fresh characteristics of fly ash-based A-ASCC mixtures, while the addition of metakaolin had a higher effect. The addition of 1% and 2% NS, on the other hand, significantly enhanced the mechanical performance of the A-ASCC specimens. The use of more than 2% of NS had a negative influence on the mechanical properties of A-ASCC. The mechanical properties of A-ASCC were improved significantly by metakaolin replacement ratios. The A-ASCC bond strength showed the highest improvement. Furthermore, using NS and/or MK significantly increased the A-ASCC setting time and may be used to produce A-ASCC at ambient environment.