Due to following reason mention below:

While the idea of geopolymer concrete seems ideal and could be the best thing to come along since Portland concrete, there are still too many unstable issues that can cause major hiccups in the mixing and application process of the concrete.

Though geopolymer based concrete is different from alkali activated materials, you can find summary of limitations associated with these types of material in this paper https://spectrum.library.concordia.ca/984667/1/Main%20file%20-%20ALKALI%20ACTIVATED%20MATERIALS%20REVIEW%20OF%20CURRENT%20PROBLEMS%20AND%20POSSIBLE%20SOLUTIONS.pdf

I think, it's use is tricky and need a trained person. If it is not handled properly, can affect health and Environment.

Due to following reason mention below:

While the idea of geopolymer concrete seems ideal and could be the best thing to come along since Portland concrete, there are still too many unstable issues that can cause major hiccups in the mixing and application process of the concrete.

Valuable discussion.

It is tricky to used and requires skilled workmanship.

Unqualified comments: Concrete or concreting has evolved. Say presently used one is also in concpet like a geopolymer based compared to very conventional of past.

Making things unnecessarily intelligent without identifying purpose is dangerous. Further making things differently intelligent compared to what has been well learned does not mean adequacy/efficiency. It may offer unpredictable performance and add to uncertainty. Repeatable experiments towards a defined purpose and well chosen "additive" may be good start, compared to guessing too many aspects.

I believe that raw materials for the production of this type of concrete are not abundant. And as a result, production costs are high. And the majority prefer to use conventional concrete.

Although this concrete has many advantages in different areas, there is no specialist workforce to implement it. And working with alkaline activators for production requires high safety. In addition, the geopolymer heat treatment works hard to use in large projects.

Valuable discussion

Geopolymer plastic can be used successfully especially where weight is a consideration. It is more expensive than standard construction and typical home builders will not use it.

Using Geopolymer for limited severe exposure condition is more realistic for it's high cost and the required special experience. Such application provides good use of it's high protective performance.

The term "geopolymer" is widely used for slag cements and alkali-activated (slag) cements, too. The production and handling of those systems (without any Ordinary Portland Cement OPC) are neither "difficult to create", have not to be "premixed only" nor "sensitive" at all. Major and fundamental research work and applications have been performed in Russia, China, Ukrania, Japan, India, Spain, Germany and Tschechia since 1990. Intense research about this very competitive product to OPC has been done and patented by P. Krivenko, F. Skvara and J. Gebauer& L. Ko{HOLCIM} and other international cement producers.

Most important is a constant quality of the components for geopolymers:

- Homogenous slags or ashes of consistent/constant quality with high glassy phases

- Proper adjustment of desired slag/ash with alkali source (Sodium or Lithium Sulfate, Sodium Silicates( "water glass"), Sodium Metasilicate, Alkali Hydroxides, Calcium Oxide and/or Hydroxide etc.

Since the constant quality of slag/ash component is necessary, geopolymer production is especially economically in those countries with/or close to a strong heavy metal industry. Geopolymers have a much improved ecological balance (less Carbon Dioxide and dust emissions compared to OPC), very good to excellent compressive strength and much better chemical resistance/durability in comparison to OPC.

The major draw-backs of geopolymers are the lack of standardisation, the strong lobby of the OPC producers....and the still lax legislation on CO2 reduction...but the time for geopolymers will come!

I would be interested in a list of locations where the concrete has been used in Civil Engineering projects.

So true Dr. Aladdin Sharkawi.

Thanks Dr. Omar Al-Khashman for your comment

In general, geopolymers have proven to be much less expensive than ordinary portland cements (OPC), especially when the right qualities and quantities of raw materials (ashes, slags etc.) are available. Relevant studies are kept in the drawers of most OPC producers. Don't get mislead!!

Check the literature properly on "Krivenko"(Ukrania) and other highly-qualified researchers on geopolymers.

There have been several high-rise buildings and other constructions built already with geopolymers, especially in Eastern Europe.

Manfred Hartmut Akstinat your right whenever cheap and good quality raw materials are available . This is very dependent on each country

First of all we must know that geopolymer concrete strength development is temperature dependent process. It has been hugely successful in pre-cast industry applications already and have been implemented at Europe and Australia in larger scale and growing. No toxic effect reported till now. Geopolymer cement is also making its way for commerical acceptance within communities. Hence, geopolymer is breakthrough technology and its high time we should adopt and implement as durability data is promising. However, no proper interest from commercial concrete manufacturers and an opposition lobby of OPC industry are the major hindrances

Obviously, it takes a long time to accept new a technology by industry. To be adopted by industry, any material should have proven characteristics, it should be easy and safe to use. Several studies suggested that geopolymer concrete has superior mechanical and durability properties than OPC concrete. Till date, two-part, liquid sodium hydroxide (NaOH) based geopolymer has been mostly used in research and development works. NaOH based geopolymer has several safety issues in mixing and handling. Using two-part binder is also a difficult process considering its transport and storage. In order to use geopolymer in concrete industry, it is necessary to develop a one-part and NaOH free binder which is physically similar to OPC. In addition, the mixing and handling process also should be easier like OPC.