Sumesh Erikandath Your question brings in a bunch of potential pitfalls:

• If your starting materials are in powdered form then, almost certainly, they will not be 'nano'. They will not contain free, discrete, independent particles < 100 nm in size. If the SSA is > 60 m2/g you may have a defined nano system
• There are many problems with rapidly setting cement (as you're trying to make). Excessive heat production resulting in cracking and other untoward effects
• Incidentally, as an example, if you pull out from the water a concrete bridge that's been under the water for 50 years or more and re-grind the concrete, then you can still make an acceptable cement. That's because much of the original cement goes un-reacted

For more general nano stuff see these webinars:

• May 28th, 2019 Dispersion and nanotechnology https://tinyurl.com/y2wfzed7
• November 3rd, 2015 Adhesion and cohesion http://tinyurl.com/zwb2wlh

Hi, this is most likely possible. By reducing the size to the nano scales, the materials reach a very high surface area, which increases the effective impact surface and thus increases the reaction rate.

Dear all, these same authors RG links provide interesting investigations which deal with the mother subject of the question. My Regards

https://www.researchgate.net/publication/232361939_Pozzolanic_reaction_in_the_presence_of_chemical_activators_Part_I_Reaction_kinetics

https://www.researchgate.net/publication/232361859_Pozzolanic_reaction_in_the_presence_of_chemical_activators_Part_II_Reaction_products_and_mechanism

Dear Sumesh,

Alan already shows that something doesn‘t really work as you might think.

Concrete is system were nano size is almost useless because everything nano means expensive , so not convenient for this product.

If you are referring at UHPC something of little different can have more sense, but lime is already very fine and cheap, there is no need to grind more and also it could be difficult.

Pozzolanic reaction is already quite fast if you use correct ratio between microsilica and hydrate lime. But pay attention, every very fast reaction or flash setting can create bad hydration of minerals (they haven’t the necessary time to develop creating good strength) so you can risk false setting and weaker performances instead of super mechanical properties.

About the study reported by Abdelkader, I don’t understand how this corrosive activators can be useful for concrete. Not only durability of hardened material will be affected but also will be destroyed the rebars used as enforcement.

CSH reaction can be accelerated using other systems more compatible with Portland cement mineralogy. Of course nano materials or colloidal silica can be useful but depends on which level of Concrete you need to produce.

Industrially speaking seems a way expensive, quite dangerous as Alan underlined and not easy to do, thinking on size and mixing equipment , normally used for producing concrete.

Should be interesting if you create a special mixer that can manage all these problems.

Hoping to be useful for your work.

Regards

Alex Reggiani

I concur with Alex's respond. Its practical only in lab set up where very small amount of samples are required.