Review on the Relationship between Nano Modifications of Geopolymer Concrete and Their Structural Characteristics

Abstract

The main objective of this review is to study some important nanomaterials and their impact on the performance of geopolymer concrete. This paper is an investigation into trends and technology in the development of different nanomaterials to develop higher structural performance geopolymer concrete. The effect of the alkaline to binder and sodium silicate to sodium hydroxide ratio on the performances of geopolymer performances is studied. The relationship between setting time and slump is evaluated through the ternary plot, the variation in compressive strength values is evaluated using the kernel density plot, and the relationship between split tensile and flexural strength is investigated using the scattering interval plot. Regression analysis is carried out among water absorption and bulk-density result values obtained from previous literature. As the molarity and alkaline to binder (A/B) ratios increase, the strength development of geopolymer concrete increases up to a specific limit. The addition of a small quantity of nanomaterials, namely, nano silica, nano alumina, carbon nano tubes, and nano clay, led to the maximum strength development of geopolymer concrete. Incorporating these nanomaterials into the geopolymer significantly refines the structural stability, improving its durability. The various products in GP composites emerging from the incorporation of highly reactive SEM, XRD, and FTIR analysis of nanomaterials reveal that the presence of nanomaterials, which enhances the rate of polymerization, leads to better performance of the geopolymer.

A Study on the Cement Gel Formation Process during the Creation of Nanomodified High-Performance Concrete Based on Nanosilica

“…A common method for obtaining high-strength concretes is the addition of carbon nanotubes (CNTs) or multilevel carbon nanotubes (MWCNTs) [ 22 , 23 , 24 , 25 , 26 ]. CNTs modify the failure process in the cement matrix where microcracks are initiated with “significantly improved fracture energy resulting in improved global mechanical properties and a nanosized interfacial transition zone is found which determines the failure of the nanocomposite system” [ 22 ].…”

“…The addition of a small amount of carbon nanotubes with nanosilica, nano-alumina, and nanoclay results in the maximum strength development of geopolymer concrete. The inclusion of these nanomaterials in the geopolymer significantly improves the structural stability, increasing its durability [ 25 ]. Modification of ordinary Portland cement with a suspension of multi-walled carbon nanotubes (MWCNT) with microsilica provided “strong adhesion of additives and cement hydration products” [ 26 ].…”

“…The modification of the following types of additives proved to be effective in improving the characteristics of cement composites: flask, diatomite [ 27 ], ultrafine quartz [ 28 ], nanomethakaolin [ 29 ], nanotitania [ 24 , 27 , 30 ], recycled aggregate [ 23 ], slaked lime [ 13 ], rice husk ash [ 31 ], nanosized cellulose filaments [ 32 ], nanofluid complex additive (graphene/PVA) [ 33 ], boron nanonitride, multilayer graphenes, zirconium oxide [ 24 ], nano-aluminum oxide [ 25 , 34 ], nanoclay [ 25 ], and iron and lead nano-oxides [ 35 ].…”

“…The nano-modification of concrete with nanosilica [ 12 , 13 , 18 , 19 , 23 , 24 , 25 , 35 , 41 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 ] has already shown efficiency in improving the properties of concrete, but still requires a solution for many issues. The main problem associated with the introduction of nanoparticles into cement-based materials is how to evenly distribute them in the matrix [ 23 ].…”

Mechanical Properties of Nano-SiO2 Reinforced Geopolymer Concrete under the Coupling Effect of a Wet–Thermal and Chloride Salt Environment

“…However, the mechanical properties and durability of traditional GPC cannot fully meet the requirements in the engineering in a severe environment [ 21 ]. Therefore, some researchers introduced different kinds of materials to further enhance the durability and toughness of GPC, such as nanomaterials, polyvinyl alcohol fibers, steel fibers and so on [ 26 , 27 , 28 , 29 ]. Adding nanomaterial into the matrix is one of the most effective methods for enhancing the applicability and improving the mechanical properties and durability of GPC.…”