What is metakaolin concrete?
What is metakaolin concrete?
Metakaolin is a dehydroxylated form of the clay mineral kaolinite. Metakaolin is commonly used in the production of ceramics, but is also used as cement replacement in concrete. Metakaolin has a smaller particle size (∼1–2 μm) and higher surface area compared with portland cement, but a larger particle size than SF.
Is metakaolin the same as kaolin?
Metakaolin is the anhydrous calcined form of the clay mineral kaolinite. Minerals that are rich in kaolinite are known as china clay or kaolin, traditionally used in the manufacture of porcelain. The particle size of metakaolin is smaller than cement particles, but not as fine as silica fume.
Is metakaolin an admixture?
Metakaolin is one of the most widely used mineral admixtures these days. It helps concrete obtain both higher performance and economy.
Is metakaolin is a geopolymer?
It was found that metakaolin-based geopolymers exhibited high compressive strength and a denser microstructure with a specific Si/Al ratio. The compressive strength tended to increase in proportion to the increasing curing temperature, but beyond a critical temperature, it decreased due to microcracks and shrinkage.
What is the density of metakaolin?
Based on data presented at table 3, it can be seen that all samples have ranged of density between 1.8 to 2.1 gr / cm3. Hence, it is proven that metakaolin levels affect the density of geopolymer paste. The higher MK content in the mixture, the lower density of geopolymer paste produced.
What is in fly ash?
Fly ash consists primarily of oxides of silicon, aluminum iron and calcium. Magnesium, potassium, sodium, titanium, and sulfur are also present to a lesser degree. When used as a mineral admixture in concrete, fly ash is classified as either Class C or Class F ash based on its chemical composition.
What is silica fume used for in concrete?
Silica fume, a by-product of the ferrosilicon industry, is a highly pozzolanic material that is used to enhance mechanical and durability properties of concrete. It may be added directly to concrete as an individual ingredient or in a blend of portland cement and silica fume.
What is the physical properties of metakaolin?
3.1. Manufacturing Process and Chemical Composition
| Physical property | Description |
|---|---|
| Specific gravity | 2.40–2.60 |
| Specific surface area | 8–15 m2/g |
| Brunauer–Emmett–Teller (BET) surface area | 15 m2/g |
| Brightness | 80–82 Hunter L |
How is silica fume made?
Silica fume is a by-product from the production of elemental silicon or alloys containing silicon in electric arc furnaces. At a temperature of approximately 2000°C the reduction of high-purity quartz to silicon produces silicon dioxide vapor, which oxidizes and condenses at low temperatures to produce silica fume.
