5. INTRODUCTION
• Nano technology isone of the most active
research areaswhich haswide applications
in almost all the fields.
• As concrete ismost usable material in.
construction industry it’sbeen required to
improve itsquality.
• Improving concrete properties by addition
of Nano particles have shown significant
improvement than conventional concrete.
6. What isNano?
• The word “Nano” comes from Greek and it means “v
ery small”.
• 1nm=0.000000001m.
• 500000 smaller than a pen line.
• 50000 smaller than a hair.
• 100 smaller than the DNA molecule.
8. Why nanotechnology for
concrete?
Improves the material’s bulk properties.
Ability to control or manipulate materials at
the atomic scale. NANOSCALE ATTACK
ON ASR (ALKALI SILICATE REACTION)
To obtain thinner final products and fast
er setting time. Cost effectiveness.
Lowered levels of environmental
contamination.
9. What is Nano concrete?
A concrete made with Portland cement partic
les that are less than 500nm as a cementing
agent.
Currently cement particle sizes range from a
few Nano-meters to a maximum of about100
micro meters.
10. NANO MATERIALS
Nano materials are defined as a set of substances where at least
one dimension is less than approximately 100 nanometres.
Nanomaterial's are of interest because at this scale unique optical,
magnetic,electrical, and other properties emerge. These emergent
properties have the potential for great impacts in electronics,
medicine, and other fields.
Some of main Nano materials used in concrete:
• Carbon Nanotubes.
• Nano-silica.
• Polycarboxylates.
11. CARBON NANO TUBES
Carbon nanotubes are molecular-scale tubes of
graphitic carbon with outstanding properties.
They can be several millimetres in length and can have one
“layer” or wall (single walled nanotube) or more than one
wall (multi walled nanotube).
15. PROPERTIES
CNT are also highly flexible
Mechanically, CNT appear to be the strongest
material. The smaller diameters.
Stiffest and strongest fibers.
16. NANO SILICA
It Is the first Nano product that replaced the.
micro silica.
Advancement made by the study of concrete
at Nano scale have proved Nano silica much
better than silica used in conventional
concrete.
Nano silica
17. PROPERTIES
High compressive strengths concretes ( 15 M
Pa and 75 MPa at 1 day; 40 MPa and 90 MP
a at 28 days and 48 MPa and 120 MPa at 120
days.)
High workability with reduced water/cem
ent ratio.
Use of super plasticizing additives is unnecessa
ry. Fills up all the micro pores and micro
spaces.
Cement saving upto 35-45%.
18. POLYCARBOXYLATES
• Polycarboxylates or polymer based concrete
admixtures are High Range Water Reducing admi
xture (HRWR).
• low dosage-reduce water as much as high
dosage of conventional admixtures.
• Higher dosage-produce Self Compacting
Concrete (SCC).
• This admixture type is very suitable for under
water anti- washout concrete.
21. RESULTS
Resistance to compression - 40 to 90MPa in 1
day Resistance to compression from 70 a 100 MP
a (or more) in 28 days.
Produces high resistance even with low addition
(1 to 1.5
% of the cements weight) and gives self
compacting characteristics with higher propo
rtions (2.5 %).
Meets the norms of environmental protection.
22. SCOPE
• If Portland cement can be formulated with
nano- size cement particles, it will open up a
large number of opportunities.
• The cement will not only be more economi
cal than organic polymers but also will be
fire resistant.
• A number of investigations have been carried
out for developing smart concrete using carbo
n fibers.
23. •
This will become a reality with nano-cement because
nano- carbontubes are much more effective than
carbon fibers. The thickness of the composite can be
reduced to microns and hence flexible and smart
cement composite can be manufactured.
24. ADVANTAGES OF NANO
CONCRETE
Cessation of contamination caused by micro silica solid
particles.
Lower cost per building site.
Concrete with high initial and final compressive and tensile
strengths.
Concrete with good workability.
Cessation of super plasticizing utilization.
Cessation of silicosis risk.
25. Dis-Advantagesof Nano
concrete
Availability of sources for producing Nano materials is less.
For producing Nano materials there are no such equipment’s
to grain the materialsup to Nano size.
Usage of Nano materials in concrete is difficult to replace.
the materialsin concrete like cement.
26. CONCLUSION
Well dispersed Nano particles increase the
viscosity of the liquid phase, improves the
segregation resistance and workability of th
e system.
Accelerates the hydration.
Better bond between aggregates and cement paste
.
Improves the toughness, shear, tensile
strength and flexural strength of concrete.
27. Reference
1. Abdullah Keyvani, ‘’Huge opportunities for industry of
nano fibrous concrete technology’’, vol.3, No.1, Page N
o 3-10, December 2007.
2. Aiswarya. S, Prince Arulraj.G, AnandNarendran, ’’Exper
imental investigation on concrete containing nano-me
atakaolin’’, vol.3, No.1, Page No180-187, February 201
3.
3. Ali Nazari, ShadiRiahi, SeyedehFatemahShameki and A
. khademo, ‘’Assessment of the effects of cement paste
composite in presence of TIO2 nano particles’’, Page N
o 43-46, February 2010.
4. AlirezaNajigivi, ‘’Investigating the effect of using differe
nt types of SIO2 nano particles on the mechanical prop
ertiesof binary blended concrete’’, Part B 54, Page no 5
2-58, 2013