The current research is focused on developing a geopolymer binder using rice husk ash–derived silica nanoparticles. Four types of rice husks were collected directly from various rice fields of Bangladesh in order to evaluate the pozzolanic activity and compatibility of the derived rice husk ashes with precursors of sodium-based geopolymers. Silicon carbide whiskers were introduced into sodium-based geopolymers in order to evaluate the response of silicon carbide whiskers to the interfacial bonding and strength of sodium-based geopolymers along with rice husk ashes. Compression, flexural and short beam shear tests were performed to investigate the synergistic effect of rice husk ashes–derived silica and commercially available silicon carbide whiskers. Results show that rice husk ashes–derived spherical silica nanoparticles reduced nano-porosity of the geopolymers by ∼20% and doubled the compressive strength. The simultaneous additions of rice husk ashes and silicon carbide whiskers resulted in flexural strength improvement by ∼27% and ∼97%, respectively. The increase in compressive strength due to the inclusion of silica nanoparticles is related to the reduction in porosity. The increase in flexural strength due to simultaneous inclusion of silica and silicon carbide whiskers suggest that silica particles are compatible with the metakaolin-based geopolymers, which is effective in consolidation. Finally, microscopy suggest that silicon carbide whiskers are effective in increasing bridged network and crack resistance.

中文翻译：

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稻壳二氧化硅和碳化硅晶须对钠地聚合物力学性能和形貌的同时影响

目前的研究重点是使用稻壳灰衍生的二氧化硅纳米粒子开发地质聚合物粘合剂。为了评估衍生的稻壳灰与钠基地质聚合物前体的火山灰活性和相容性，直接从孟加拉国的各个稻田收集了四种类型的稻壳。将碳化硅晶须引入钠基地质聚合物中，以评估碳化硅晶须对钠基地质聚合物和稻壳灰的界面结合和强度的响应。进行压缩、弯曲和短梁剪切试验以研究稻壳灰衍生的二氧化硅和市售碳化硅晶须的协同效应。结果表明，稻壳灰衍生的球形二氧化硅纳米粒子将地质聚合物的纳米孔隙率降低了约 20%，并将抗压强度提高了一倍。同时添加稻壳灰和碳化硅晶须使弯曲强度分别提高了约 27% 和约 97%。由于包含二氧化硅纳米粒子，压缩强度的增加与孔隙率的降低有关。由于同时包含二氧化硅和碳化硅晶须，弯曲强度增加表明二氧化硅颗粒与偏高岭土基地质聚合物相容，这在固结方面是有效的。最后，显微镜表明碳化硅晶须可有效增加桥接网络和抗裂性。同时添加稻壳灰和碳化硅晶须使弯曲强度分别提高了约 27% 和约 97%。由于包含二氧化硅纳米粒子，压缩强度的增加与孔隙率的降低有关。由于同时包含二氧化硅和碳化硅晶须，弯曲强度增加表明二氧化硅颗粒与偏高岭土基地质聚合物相容，这在固结方面是有效的。最后，显微镜表明碳化硅晶须可有效增加桥接网络和抗裂性。同时添加稻壳灰和碳化硅晶须使弯曲强度分别提高了约 27% 和约 97%。由于包含二氧化硅纳米粒子，压缩强度的增加与孔隙率的降低有关。由于同时包含二氧化硅和碳化硅晶须，弯曲强度增加表明二氧化硅颗粒与偏高岭土基地质聚合物相容，这在固结方面是有效的。最后，显微镜表明碳化硅晶须可有效增加桥接网络和抗裂性。由于包含二氧化硅纳米粒子，压缩强度的增加与孔隙率的降低有关。由于同时包含二氧化硅和碳化硅晶须，弯曲强度增加表明二氧化硅颗粒与偏高岭土基地质聚合物相容，这在固结方面是有效的。最后，显微镜表明碳化硅晶须可有效增加桥接网络和抗裂性。由于包含二氧化硅纳米粒子，压缩强度的增加与孔隙率的降低有关。由于同时包含二氧化硅和碳化硅晶须，弯曲强度增加表明二氧化硅颗粒与偏高岭土基地质聚合物相容，这在固结方面是有效的。最后，显微镜表明碳化硅晶须可有效增加桥接网络和抗裂性。