IS code for geopolymers has been drafted on 10th October 2019. it will be available online in few months. large scale use for geopolymers won't take much long now. lets hope for the best.

Despite the huge environmental advantage of geopolymers/alkali activated materials, some major limitations still persists which limits its wide scale application. You can go through the paper below to preview a summary of some of these major challenges associated with this material.

https://spectrum.library.concordia.ca/984667/1/Main%20file%20-%20ALKALI%20ACTIVATED%20MATERIALS%20REVIEW%20OF%20CURRENT%20PROBLEMS%20AND%20POSSIBLE%20SOLUTIONS.pdf

alkaline activators are expensive, corrosive and the highest contributor of embodied energy and carbon to AAMs.

I think adeyemi's article correctly pointed out all the obstacles to using gpc.

Dear all,

I think that OPC has long history and technicians learned how to modify properties of mortars and concretes . This process needed more than 2 centuries and now seems quite easy to use OPC . But if we see at the early years after its invention , Portland cement was initially bad seen in comparison with already used materials principally lime based .

Prof. Davidovits showed that Pyramids were built using ancient geopolymer mortars of humid earth consistency , but process wasn’t easy to industrialize . When he invented the therm geopolymer, he wanted to solve problems linked to plastic materials , about fire resistance, not to substitute Portland cement as binder for concrete. Only in secondary moment he tested that using geopolymer binder concrete became more resistant to acid / base attack, saving lot of CO2 production and after more than 30 years (Pyrament was produced in the 80’ ) , now I learned from him how to produce geopolymer concrete really low cost reducing at best liquid hardener amount and using only user friendly ones. I use silicates that are not corrosives , only irritant like Portland cement or lime waters , we sell in cubes using normal trucks , without ADR , IMDG or IATA codes.

For my company GeoMITS I have patented automatic mixing machines for geopolymer mortars and concretes from laboratory scale to industrial. So, in my opinion , the limit of diffusion of Geopolymer concrete is still linked to these 3 factors :

1. Geopolymer products aren’t alkali activated materials, because Geopolymerization creates 3D network that after hardening results insoluble in water, because Alkali are inside the matrix and no water is in the new minerals after hardening (under water the mechanical properties are the same found by air curing ) ; while with alkali activation materials don‘t harden creating any polymerization of minerals, but they dry only , when water evaporates. For this reason if under water, their alkali salts , very soluble and not involved in the matrix of material , are leached out and AAM break or lose lot of mechanical strength. Lot of people still do AAM but they are convinced to realize geopolymer materials.

2. Mix design of Geopolymer products isn’t the same of Portland based concrete or AA concrete . I needed to patent new type of mixing machines to be sure to obtain ,every time, real geopolymer products assuring the necessary stability to Geopolymerization process to be industrialized.

3. Raw materials to create geopolymer binder specific for concrete industry are several and cheap. It’s possible to use not only fly ash type F, that isn’t worldwide diffuse and at ambient temperature hasn’t high performance. Concrete industry needs low costs so ordinary metakaolins are too expensive and also too sticky to be used, but world is rich on silicon aluminate sources , so is possible to use rock based geopolymer binder and lot of other very cheap raw materials to promote the reaction. Isn’t necessary any activator , because powders are super reactive due to proper low temperature calcination or in case of wastes , have been already burned . Considering that geopolymer concrete doesn’t need any particular additive (for OPC concrete you usually use : retarders, accelerants, superplasticizer, defoamers , air entrance additives, thixotropic agents, anti segregation additives and so on) because recipes of binder can be manage depending on needs and you could add the same type of Alkali resistant fibers (glass, PVA, PP, PAC, steel ) to increase when necessary flexural strength, final costs can be comparable with OPC concrete, with lower CO2 production , similar or superior strength and more long durability .

I think finally that GPC will increase its diffusion when a big company will invest money and marketing to enter in concrete market at the best way possible.

Progress can’t wait more time. I‘m working on Portland technology from more than 15 years , but from 4-5 I‘ve changed my focus on geopolymer binders because we must think to planet Earth health and CO2 production must be reduced or within a generation we will leave at our sons very sick planet .

Best regards

Alex Reggiani

Major limitations:

1. No universal code/regulations till now.

2. Efflorescence

3. Hugely Temperature dependent

4. No commercial expressions of interest

However, times are changing and improvements are happening slowly.