Geopolymer Concrete

The building industry uses concrete as a material. Concrete is formed when water and cement are mixed with aggregates. Therefore, concrete is usually called “manmade stone,” as Badea states. When hydrated, the cement, water, and aggregate become solid. Therefore, energy consumption is the most critical environmental aspect of cement and concrete production. NRMCA (Concrete CO₂ Fact Sheet. NRMCA Publication, 2012) discussed two mechanisms that result in CO₂ generation during cement manufacturing as fossil fuels must be burned.

Geopolymer concrete is a new building material that is environmentally benign and an alternative to conventional Portland cement concrete. The fundamentals of the process: a binder is formed using alkali-activated aluminosilicate ingredients (for instance, fly ash and metakaolin). To activate the aluminosilicate materials, a process known as geopolymerization requires silica and either alumina or silica–alumina species to dissolve in a highly alkaline environment, then condense and rearrange to form a three-dimensional network structure. The geopolymerization process is generally initiated by combining aluminosilicate precursors with alkaline activators like sodium hydroxide (NaOH) or potassium hydroxide (KOH), and frequently sodium or potassium silicate. The aluminosilicate materials break down upon activation in a manner that transports reactive silica and alumina species into the solution. These species are then recombined into oligomers, which finally polymerize into a gel-like structure as their reaction progresses. The final geopolymer matrix is formed when this gel gradually hardens and crystallizes. This binder synthesis process produces a geopolymer binder with superior mechanical qualities, durability, and fire resistance. For strength development, geopolymer concrete relies on the formation of aluminosilicate gel rather than calcium silicate hydrate (C–S–H) gel. Because of its special chemistry and ability to provide high early strength, minimal shrinkage, and—above all—great chemical attack resistance, geopolymer concrete is appropriate for a variety of applications in aggressive environments. The main advantage of geopolymer concrete over traditional Portland cement concrete is that it is much further from generating a significant carbon footprint, making it the perfect choice if you care about it.

Benefits: Geopolymer concrete has many benefits compared to conventional concrete. GPC has the potential to become an alternative infrastructure material because it has several advantages, such as very high resistance against acid (sulfate) attack, good early strength gain, moderate drying shrinkage, and low creep. Geopolymer concrete is recognized as a preferable alternative to traditional concrete (Song et al. in J Mater Sci 35:249–257, 2005; Duxson et al. in Cem Concr Res 37:1590–1597, 2007a, J Mater Sci 42:2917–2933, b). Geopolymer represents the effective use of various waste materials. Consequently, the most compelling option for the concrete sector to meet the present CO₂ targets is to transition to sustainable materials.

Geopolymer concrete is an alternative to Portland cement concrete that is green and sustainable and has properties that are increasingly attracting the construction industry. This smart concrete has several distinct characteristics that set it apart from regular concrete.

This chapter discusses the different design and specification considerations for geopolymer concrete, including mix design, strength requirements, and other relevant design factors of M20 and M50 grade of GPC with an example. This includes components, testing methods etc.

This chapter discusses the uses in different construction projects and their performance in different environmental conditions. Geopolymer concrete has been successfully implemented in numerous construction projects globally, demonstrating its versatility and efficacy across diverse environmental conditions. This innovative material has garnered significant attention in the construction industry due to its superior performance characteristics and reduced environmental impact compared to traditional Portland cement concrete.

This chapter discussed the opportunities for new applications and the requirement for more R&D. Geopolymer concrete has significant potential as a future material to be used in various industries, for example, in sustainable construction and infrastructure areas. With a focus on sustainability and greener construction coming into play, geopolymer concrete can find a place more frequently in mega projects like bridge construction, highways, and high-rise buildings. This could make it an attractive choice for marine structures, chemical plants, and other facilities that are exposed to corrosive environments because of their potentially improved durability and resistance to harsh conditions.

Geopolymer concrete is a very new and sustainable option compared to Portland cement concrete. It employs industrial waste materials, such as fly ash or blast furnace slag, as the main binder, thus recycling materials that would otherwise be in the form of a waste product. This not only reduces the carbon footprint caused by concrete production but also provides an answer to industrial waste management and severity issues.