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GEOPOLYMER TECHNOLOGY

Cement is one of the most widely consumed material in the modern world. It is estimated that concrete is the second most consumed material after water. The material is so ubiquitous that we rarely notice its presence, but its carbon footprint is enormous, and it is one of the prime drivers of climate change along with coal power plants and other uses of fossil fuels.


An alternative for Portland cement is therefore a pressing need of the times. Fortunately, Portland cement is going to be obsolete within probably two decades. A better alternative, Geopolymer has been invented in the 1960s and the technology is now tested and proven, being used for many projects the world over.


The term Geopolymer was coined by the inventor Prof. Joseph Davidovits, a French Scientist, to denote the polymerization of Aluminous and Silicious materials into molecular chains and network to form a hardened binder. The Alumina and Silica are provided by thermally activated natural materials like volcanic ash or industrial by-products like fly ash and / or blast furnace slag and is activated by an alkaline solution which initiates the polymerization. This binder replaces cement while the aggregates
remain the same as in ordinary concrete or mortar.

Geopolymer basics.jpg

Geopolymer concrete (GPC) outperforms Cement concrete (CC) in almost all parameters.
• GPC gains its characteristic strength much faster than CC, thereby saving on time required for de-shuttering.
• GPC is proven to be better resistant to corrosive environments like that of marine structures.
• The drying shrinkage is much lesser than that of CC, making it ideal for heavily restrained structural members.
• Heat of hydration is much lower than that of CC.
• This concrete has low chloride permeability, which offers better protection to steel reinforcement than traditional CC.
• This concrete has also very high acid resistance under test conditions.

Global Change Institute, University of Queensland, Australia, completed in 2013, is the first building done fully with Geopolymer Concrete. It is four floor structure with about 50,000 Sq,ft built up area, made with prefabricated components, constructed by M/S Wagners, a major construction firm in Australia, doing projects with Geopolymer concrete branded as Earth Friendly Concrete.

Apart from concrete, Geopolymer is also used for stabilizing soil blocks, instead of cement. Prof. Davidovits had also developed a Low temperature Geopolymer Stabilization (LTGS) technology for producing clay bricks which offers much better compressive strength than country burnt bricks. The major advantage of LTGS is that the energy footprint is drastically reduced. Compressive strengths in the range of 25 kg/sq.cm can be produced by baking the bricks below the boiling point of water, at about 75 degrees. The strength can be increased to a certain limit by increasing the temperature. Thus, LTGS technology can reduce a lot of embodied energy of bricks and building blocks.

Other applications of Geopolymer concrete by Wagners

Images courtesy : Wagners, Australia.

R&D in Geopolymer applications

I have developed a prefabricated structural system which is modular in composition and monolithic in structural action, combining the advantages of prefab construction and the resilience of a shear wall structure. I envisage the use of geopolymer concrete for that system which is now in the patenting and prototype stage.


As a part of my R&D, I had attended the 10th International Geopolymer camp held at The Geopolymer Institute, St. Quentin, France, as a representative of my former employer Habitat Technology Group. – Architect Jos Conil

LIGHT GAUGE STEEL FRAME

 (LGSF) TECHNOLOGY

LGSF is a type of prefabricated steel framed construction that is fast gaining popularity all over the world. In India, it is already used widely in many cities in the North. Though the technology is relatively new to Kerala, it is backed by decades for research, development, and trials. It is now a time tested and proven technology with a cost factor on par with the conventional RCC framed systems but comes packed with a lot of advantages.


LGSF has a fundamental difference with structural steelwork, using I sections etc, as in PEB structures. Unlike structural steel work that uses hot formed and rather heavy sections readily available in the market, this technology uses a cold formed process that is used to create low weight high strength steel sheets that are fully coated with a zinc alloy that imparts much higher corrosion resistance to the steel. These steel sheets are shaped into box or channel sections in a computer controlled based on a fully automated system with everything - the screws, bolts and the service line passage, all pre-planned and provided for right at the time of the manufacture of the structural members.


The walls are load bearing with a skeleton of LGSF and a core of mineral wool or aerated concrete, covered on both sides with fiber reinforced cement boards and a vapor barrier for weather protection. The slabs are made of steel deck sheets on joists, topped with a layer of concrete.


Construction in LGSF is economical and sustainable in the long run. It drastically reduces the labor content and enables faster construction, two fundamental criteria for construction works in these times of a global pandemic. Also, you get more carpet area than in the conventional system, for the same plinth area as the walls are of
almost half the thickness.

Images courtesy : Forms Ezy Build Solutions

The advantages of LGSF technology are as follows:
• Saves substantially on construction time. A villa can constructed and finished within three to four months.
• Drastically saves on the labor content, making it an ideal choice in these times of labor shortage.
• Drastically reduces the dead weight of the structure, thereby saving on the foundation costs.

• Saves up to 10% more carpet area for the same plinth area when compared with the conventional systems.
• Provides excellent finish which does not need plastering.
• Offers better thermal insulation than brick or concrete block masonry if mineral wool infill is used.
• A green building option as it saves on lot of concrete aggregates and energy intensive cement.
• Offers better seismic and cyclone resistance than conventional systems.

The seismic resistance of steel framed structures have been well demonstrated in a test conducted on the world’s largest outdoor shake table. Watch video >

Cold formed steel framed buildings are also suitable for high rise apartments, as demonstrated in this video.

Eco Concord has entered into a project collaboration with “Forms Ezy Build Solutions”, a Calicut based company, to promote the technology as well as execute projects all over Kerala.

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