Development of eco-friendly alkali-activated nanocomposites comprising micro-fibers at ambient curing conditions
Ali Raza, Yasser Alashker, Marc Azab, Qaiser uz Zaman Khan, Mirvat Abdallah, Osama Barakat, Khaled Mohamed Elhadi
Abstract
Geopolymers (GOPL) can play a vital role in the sustainability of concrete construction. The addition of nanoparticles and micro-fibers to GOPL can improve the mechanical and microstructural performance by densifying the matrix and providing the bridging effect against the internal cracking mechanism . Therefore, an extensive investigation on the improvement of the various characteristics of the GOPL is required to make it feasible for practical applications. Moreover, the combined effect of nanoparticles and micro-fibers on various features of GOPL needs further insights. This study investigates the microstructural, mechanical, fracture, and toughness performance of micro-basalt fiber (MBF)-reinforced coal ash-made GOPL using different proportions of nano-sodium oxide at ambient curing conditions. The percentage of nano-sodium oxide examined in the present study varied from 0% to 4% by weight. The MBF amount is kept the same for all fabricated samples at 0.5% by weight. Scanning electron microscopy is used for assessing the microstructural cracking and failure behavior of GOPL pastes. The findings of the present study divulged that the usage of 3% nano-sodium oxide in MBF-reinforced GOPL mix presented the highest increase of 29%, 55%, 24%, and 60% for the compression strength , flexure strength, fracture toughness , and impact strength , respectively. Further increase in the content of nano-sodium oxide prompted the agglomeration of nanoparticles leading to a reduction in the performance of the GOPL. The outcomes of scanned electron microscopy delineated that the addition of nano-sodium oxide refined the interfacial regions and promoted the polymerization process of the GOPL which enriched the microstructure and fabricated a highly densified GOPL paste.