Role of the silica source on the geopolymerization rate

Microstructure and mechanical properties of a metakaolinite-based geopolymer nanocomposite reinforced with carbon nanotubes

“…Based on the simultaneous thermal analysis (STA) of the starting clay (kaolin ZK 2 ), for preparation of metakaolin, dehydration and increases the reaction activity, kaolin ZK 2 was calcined about 700 °C for 12 h. To prepare the specimens, we used a Na 2 Subsequently, the fresh geopolymeric paste is rapidly poured into a cubic Teflon mold (50 mm × 50 mm × 50 mm) and (19 mm × 28 mm × 200 mm) for the measurement of compressive and flexural strengths, respectively. Five iterates were made for each metakaolin-based geopolymer tested.…”

“…The metakaolin-based geopolymers are alumino-silicate polymers that consist of mainly amorphous or semi-crystalline and three dimensional structures formed from geopolymerization of alumino-silicate monomers in alkaline solution [1]. The synthesis of the geopolymer proceeds via polycondensation reactions of metakaolinite (kaolinite calcined at 600-700 °C ) or many natural and artificial silico-aluminates with alkali metal (Na + or K + ) hydroxide and/or silicate [2]. The metakaolin-based geopolymers are interesting because of their excellent properties, but they do not have enough high strength and show brittle behaviour.…”

Feasibility of aluminosilicate compounds from various raw materials: Chemical reactivity and mechanical properties

“…Various samples were synthesized using an alkaline silicate solution (SiO 2 /K 2 O = 1.4 or Si/K = 1.7) noted Si S K 0.7 to investigate the effect of alkaline solution on the aluminosilicate source, as performed in previous works [13]. The alkaline silicate solution was obtained by dissolution of potassium hydroxide pellets (VWR, 85.2% pure) and very fine and highly reactive amorphous silica (denoted S; Aldrich, 99.9% pure) in osmotically purified water.…”

Effect of the addition of ammonium molybdate on metakaolin-based geopolymer formation: Shrinkage and crystallization

“…The alkaline silicate solution was obtained by the dissolution of KOH pellets (85.2% purity) and amorphous silica (99.9% purity) in osmotically purified water at room temperature as described in a previous work [28]. Syntheses were performed by mixing the alkaline silicate solution and metakaolins.…”