Microstructure and strength development of fly ash-based geopolymer mortar: Role of nano-metakaolin

Influence of Glass Silica Waste Nano Powder on the Mechanical and Microstructure Properties of Alkali-Activated Mortars

“…The results indicated that the compressive strength enhanced by including the nano-silica in AAMs mixtures, which is in agreement with the findings of previous studies [46,59,60]. Other research [41,43] indicated that reduced water assimilation and improved structural density, thus affording greater compressive strength, could be achieved by adding 4.0%-6.0% nano-silica by the weight of FA. Nano-silica reacts with lime during the cement hydration process and it generates a C-S-H gel that may improve the mechanical strength and durability of concrete.…”

“…The incorporation of nanomaterials, affording improved qualities, regardless of whether they are fresh or cured, is prioritized by current methods of concrete production. Nanoparticles (e.g., titanium dioxide, silicon dioxide, aluminium oxide, iron oxide, carbon nanotubes/fibres, and nano silica) are capable of filling pores and have a positive pozzolanic reaction, which is why they are widely employed to make concrete and cement perform better [41][42][43][44][45]. At the same time, fast infrastructural development at a global level has led to a growing demand for hybrid materials resembling cement.…”

The Impact of the Amount of Water Used in Activation Solution and the Initial Temperature of Paste on the Rheological Behaviour and Structural Evolution of Metakaolin-Based Geopolymer Pastes

“…In most cases, a higher water/alkaline ratio of the activation solution improves the flowability and workability of the paste [15]. The size, shape and other geometrical properties of the precursor's particles effect the rheological properties of the fresh geopolymer paste [16]. Mixing time and mixing speed have an influence on the rheology of geopolymer pastes as well.…”

“…Mixing time and mixing speed have an influence on the rheology of geopolymer pastes as well. According to the research of Kaur et al [16], the active mixing of raw materials results in increased viscosity of the paste and improved mechanical properties of the hardened samples. This is explained by the input of mixing energy, which can partially break down the size of the raw material "aggregates" which can occur due to agglomeration of the powdered raw materials during milling to allow the complete reaction to continue.…”

“…Mixing is also a temperature-dependent process, which is influenced by the activation energy of raw materials used for geopolymer production. The viscosity and geopolymerisation reaction rate depends on the paste temperature because Brownian motion is slowing down and the dissolution rate of aluminum decreases at lower temperatures [9,16].…”