Made By: Mukul Srivastava Roll No. : 131000138 (36) Section : A2 NANO CONCRETE Made By: Mukul Srivastava Roll No. : 131000138 (36) Section : A2

INTRODUCTION Nano-technology is one of the most active research areas which has wide applications in almost all the fields. As concrete is most usable material in construction industry it’s been required to improve it’s quality. Improving concrete properties by addition of nano particles have shown significant improvement than conventional concrete.

Why nanotechnology for concrete? Improves the material’s bulk properties. Ability to control or manipulate materials at the atomic scale. To obtain thinner final products and faster setting time. Cost effectiveness. Lowered levels of environmental contamination.

Building made By Nano Technology Building made by self cleaning concrete (“Church Dives in Misericordia”,Rome,Italy) TiO2 Coating on Roads for Pollution Reduction

What is nano concrete? A concrete made with portland cement particles that are less than 500nm as cementing agent. Currently cement particle sizes range from a few nano-meters to a maximum of about 100 micro meters.

Carbon Nanotubes. Nano-silica. Polycaboxylates. NANO MATERIALS Carbon Nanotubes. Nano-silica. Polycaboxylates.

CARBON NANO TUBES Nano tubes are the members of the fullerene structural family. They align themselves into “ropes” held together by van der Waals forces. Carbon nanotubes are molecular-scale tubes of graphitic carbon with outstanding properties. They can be several millimeters in length and they can have one “layer” or wall (single walled nanotube) or more than one wall (multi walled nanotube)

SINGLE WALLED CARBON NANO TUBE

MULTI WALLED CARBON NANO TUBES

PROPERTIES CNTs have Electrical conductivity.(107A/cm2) CNTs have a low thermal expansion coefficient. CNTs have very high tensile strength. CNT are highly flexible(honeycomb lattice). Mechanically, CNT appear to be the strongest material. Stiffest and strongest fibers.

NANO SILICA 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.

MICROSCOPIC IMAGE OF NANO SILICA

PROPERTIES High compressive strength concretes. High workability with reduced water/content ratio. Use of super plasticizing additives is unnecessary. Fills up all the micro pores and micro spaces. Cement saving up to 35-40%. CONCRETE MIX DESIGN

POLYCARBOXYLATES Polycarboxylates or polymer based concrete admixtures are high range water reducing admixture (HRWR) without affecting workability. They are used as dispersants to avoid particle segregation .Low dosage-reduce water as much as high dosage of conventional admixtures. Higher dosage-produce self compacting concrete (SPC). This admixtures type is very suitable for underwater anti-washout concrete.

MOLECULAR DIAGRAM OF POLYCABOXYLATE

RESULTS Resistance to compression 40 to 90MPa in 1 day. Resistance to compression from 70 to 100 MPa (or more) in 28 days. Produces high resistance even with low addition (1to 1.5% of the cements weight) and gives self compacting characteristics with higher proportions (2.5%) Meets the norms of environmental protection. 70% less use of additives as traditional silica, super plasticizer or traditional fibers.

BENEFITS OF NANO CONCRETE Concrete is more stronger, lighter and more durable. Concrete with good workability. Lower cost per building site. Cessation of contamination caused by micro silica solid particles. Concrete with high initial and final compressive and tensile strengths. Cessation of super plasticizing utilization. Cessation of silicosis risk.

CONCLUSION Well dispersed nano particles increase the viscosity of the liquid phase, improves the segregation resistance and workability of the system. Accelerates the hydration. Better bond between aggregates and cement paste. Improves the toughness,shear,tensile strength and flexural strength of concrete.

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 economical than organic polymers but also will be fire resistant. A number of investigations have been carried out for developing smart concrete using carbon fibers. This will become a reality with nano cement because nano-carbon tubes are much more effective with carbon fibers.

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