What is Geopolymer Concrete ?
This article is about Geopolymer concrete and Geopolymer cement. This concrete is another modification of concrete. It is said that Geopolymer concrete and Geopolymer cement are going to be the next future of modern concrete because of its nice characteristics.
There is often confusion between the meanings of the terms ‘geopolymer cement’ and ‘geopolymer concrete’. A cement is a binder, whereas concrete is the composite material resulting from the mixing and hardening of cement with water (or an alkaline solution in the case of geopolymer cement), and stone aggregates. Materials of both types (geopolymer cements and geopolymer concretes) are commercially available in various markets internationally.
Geopolymer cement is an alternative to ordinary Portland cement and is used to produce Geopolymer concrete by adding regular aggregates to a geopolymer cement slurry. It is made from inorganic aluminosilicate (Al-Si) polymer compounds that can utilise 100% recycled industrial waste (e.g. fly ash, copper slag) as the manufacturing inputs resulting in up to 80% lower carbon dioxide emissions. Greater chemical and thermal resistance, and better mechanical properties, are said to be achieved for geopolymer concrete at both atmospheric and extreme conditions.
Geopolymer cement is being developed and utilised as an alternative to conventional Portland cement for use in transportation, infrastructure, construction and offshore applications. It relies on minimally processed natural materials or industrial byproducts to significantly reduce its carbon footprint, while also being very resistant to many common concrete durability issues.
Production of geopolymer cement requires an aluminosilicate precursor material such as metakaolin or fly ash, a user-friendly alkaline reagent(for example, sodium or potassium soluble silicates with a molar ratio MR SiO2:M2O ≥ 1.65, M being Na or K) and water. Room temperature hardening is more readily achieved with the addition of a source of calcium cations, often blast furnace slag.
Geopolymer cements can be formulated to cure more rapidly than Portland-based cements; some mixes gain most of their ultimate strength within 24 hours. However, they must also set slowly enough that they can be mixed at a batch plant, either for precasting or delivery in a concrete mixer. Geopolymer cement also has the ability to form a strong chemical bond with silicate rock-based aggregates. In March 2010, the US Department of Transportation Federal Highway Administration released a TechBrief titled Geopolymer Concrete that states: The production of versatile, cost-effective geopolymer cements that can be mixed and hardened essentially like Portland cement represents a game changing advancement, revolutionizing the construction of transportation infrastructure and the building industry. source : https://en.wikipedia.org/wiki/Geopolymer#Geopolymer_cements.