probably close to no benefit and pretty high costs.

CNTs are hydrophobic and do not like being dispersed. So you would have to do an extraordinary amount of efforts to disperse them (or they don't have a better effect than carbon black). The strengthening effect is probably negligible.

Concrete is the solid composite material and made up of suitable proportion of binding material, fine aggregate, Coarse aggregate and Water. Nanomaterial’s can be defined as those physical substances with at least one dimension between 1 to 100 nm (1 nm = 10–9 m). The nanomaterial’s properties can be very different from the properties of the same materials at micro (10–6 m) or macro scale (10–6 to 10–3 m). The nano-science represents the study of phenomena and the manipulation of materials at nanoscale and is an extension of common sciences into the nanoscale. Nanotechnology requires advanced imaging techniques for studying and improving the material behavior and for designing and producing very fine powders, liquids or solids of materials with particle size between 1 and 100 nm, known as nano-particles, nano materials have four types which are using for concrete Nano silica, carbon nanotube, titanium, carbon fiber the reduced offer of nanoproducts; the lack of detailed informations regarding the nanoproducts content; high costs; the unknowns of health risks associated with nanomaterials.

Carbon nanotubes are seamless, carbon cylinders which have unique mechanical and electronic properties. Carbon nanotubes are a form of carbon having a cylindrical shape, the name coming from their nanometre diameter.

Nanotubes are members of the fullerene structural family and exhibit extraordinary strength and unique electrical properties, being efficient thermal conductors. For example, they have five times the Young’s modulus and eight times (theoretically 100 times) the strength of steel, whilst being 1/6th the density. Expected benefits of carbon nanotubes are: mechanical durability and crack prevention in concrete enhanced mechanical and thermal properties in ceramics and real-time structural health monitoring capacit.

I agree with Florian Stadler. I do not see any benefit from the mechanical properties point of view. However, if your intention is to increase the corrosion resistance of the rebar steel by these additions, then nano cellulose could be beneficial. The corrosion inducing anions (chloride, sulphate etc) could be adsorbed preferentially on the cellulosic surfaces and thus may not react with the rebar steel surface that otherwise would result in corrosion.

cellulose might however increase the fouling, as it is biodegradable, so it might actually decrease the lifetime.

Concrete is an extremely inexpensive product made on site usually. There is absolutely no economic or technical benefit from adding CNT's or nanocellulose to the system. For 'better' properties you need to add something extremely inexpensive (e.g. fly ash) and that means < $10/tonne. You may as well take your money, dig a hole, put the money in followed by a gallon or so of gasoline, and drop in a lighted match.

Dear,Dr. Alan F Rawle

Thank u.for your answer ,

I mean adding CNT or nano cellulose which It is produced from waste and a lot of research has been shown to add to improve the properties by higher percentages

as compared with any pozzlanic material .

Try to test such modified mixtuers to get accurate results ....

Dear,Dr. Rakesh Sonker

thank u.so much for this information.