Influence of novel hybrid nanoparticles as a function of admixture on responses of engineered geopolymer composites: A review

Engineered Geopolymer Composites (EGC) are novel materials and a possible replacement to their cement -based alternatives, Engineered Cementitious Composites (ECC). Portland cement, the binder in Portland Cement Concrete (PCC) which is widely used in concrete structures, is blamed for its negative environmental impact. Engineered Geopolymer Composites (EGC) in civil engineering are one of the most promising alternatives due to sharing peculiar material properties with ECC while aiming for being a more sustainable option. Furthermore, to minimize the environmental impact and massive energy consumption, and carbon footprint of cement production, the option of nanomaterial-based EGC was proposed. The outcome of this research area continued to produce more altered, strong, bendable, durable, and sustainable composites. One option to develop and modify EGCs' extraordinary properties is to add other potential selective materials such as nanoparticles (NPs). The results show that there has been substantial dispute among scholars working on this topic concerning the influence and the optimum amount of nanoparticles addition into the geopolymer composites. In addition to the NPs, other factors such as the type of precursor materials, and efficient dispersity of the nanoparticles also affect the composite's properties such as workability and fluidity. Substantial performance improvements have been observed when NPs added to both EGC and GC. However further research is needed to determine the ideal dosage of nanomaterials to reveal credible results. In general, applications and development of nanotechnology in engineered geopolymer composite remain very limited till these days in comparison with those of geopolymer concrete and traditional Portland cement concrete. Thus, this article presents an overview of the prior studies focused on adding different types of nanoparticles such as nano-ZnO, nano-SiO2, nano-TiO2, nano-Al2O3, nano -carbon black, and some other types of NPs in various EGC and GC composite. In addition to the analysis of carbon emission and cost comparison, the review includes an assessment of flowability, mechanical properties, as well as durability of composite materials under various exposures. The purpose of this review is to provide a comprehensive overview of the current understanding of the use of nano -materials in geopolymer composites. It also aims to determine the acceptable doping rate and methods for controlling the dispersion of nanoparticles in these composites. Additionally, the review explores how these composites respond to applied loads and different environmental exposure conditions. The findings of this review can serve as a valuable reference for future research on the topic of geopolymer composites.