NANOTECHNOLOGYIN BUILDING CONSTRUCTION MATERIAL By: GAURAV JAIN B-TECH (Final yr.)
CONTENTS• Introduction• What nanotechnology is?• Introduction to Nanomaterials• Application of Nanotechnology• Barriers• Conclusion
INTRODUCTION• We are very familiar with the concept of getting raw materials, bringing them together in an organized way and then putting them together into a recognizable form.• This is our role in society and we have performed it well for hundreds or thousands of years. So we can say construction is definitely not a new science or technology and yet it has undergone great changes over its history.• In the same vein, nanotechnology is not a new science and it is not a new technology either. It is rather an extension of the sciences and technologies that have already been in development for many years
What is Nanotechnology ?• Nanotechnology is the use of very small pieces of material by themselves or their manipulation to create new large scale materials.• At the Nano-scale material properties are altered from that of larger scales.• The Nano-scale is the size range from approximately 1nm to 100nm.• Nanotechnology is an enabling technology that allows us to develop materials with improved or totally new properties.
Introduction to Nano-materials Nano-particles:- • It is defined as a particle with at least one dimension less than 200nm. Nano-particles made of semiconducting material(Ex- Silicon) Nano-composites:- • It is produced by adding Nano- particle to bulk material in order to improve its bulk properties
Carbon Nano-tubes:-• They are the form of carbon that was first discovered in 1952 in Russia and then re-discovered in the 1990’s in Japan.• They are cylindrical in shape with Nano-meter diameter.• Production cost of Nano-tubes is high and the price ranges from 20€ to 1000€ per gram depending on quality.• Types of Nano-tubes:- Single-walled carbon Nano-tubesMulti-walled carbon Nano-tubes
Titanium Dioxide (TiO2)• Titanium dioxide is a widely used white pigment.• It can also oxidize oxygen or organic materials, therefore, it is added to paints, cements, windows, tiles etc.• As TiO2 is exposed to UV light, it becomes increasingly hydrophilic (attractive to water), thus it can be used for anti- fogging coatings or self cleaning windows.
Applications of Nano-technology Nanotechnology is widely used in construction material as:• In Concrete• In Steel• In Wood• In Glass• In Coating• In photovoltaic
Nanotechnology in concreteConcrete:- It is a mixture of cement, sandcoarse aggregate and water, The mechanicalbehavior of concrete material depends on thephenomenon that occurs on a micro and Nanoscale.Nanotechnology can modify the structure ofconcrete material and finally improves inproperties of materials as-• Bulk density• Mechanical performance• Volume stability• Durability• Sustainability of concrete
Nanotechnology in concrete• Exploring and modifying these Nano scale pores can result in improved concrete• These addition could compensate for its weakness in tension and result in concrete with greatly improved stress-strain behavior• The addition of Nano scale silica fume operates at a Nano scale and can improve durability of concrete structures exposed to de-icing salts.
Nanotechnology in concreteCNT in CONCRETE:-• The addition of small amount (1%) of CNT improves the mechanical property of concrete• Oxidized MWNTs shows the best improvements in both compressive(+25N/mm2) and flexural strength(+8N/mm2). Research into haematite (Fe2O3) nanoparticles added to concrete has shown that they also increase strength as well as offering the benefit of monitoring stress levels through the measurement of section electrical resistance.
Nanotechnology in SteelNeed of nanotechnology in steel:-• Fatigue is a significant issue that can lead to the structural failure of steel subject to cyclic loading, such as in bridges or towers.• Stress risers are responsible for initiating cracks from which fatigue failure results.• Addition of copper nanoparticles reduces the surface unevenness of steel which then limits the number of stress risers
Nanotechnology in SteelTemperature restriction:-• Above 750 F, steel starts to loose its structural integrity, and at 1000 F, steel loses 50 % of its strength• Infusion of steel with Nano scale copper particles could maintain structural integrity up to 1000 F• New infused steel allows ultra high strength, corrosion resistance and have good surface finish.
Nanotechnology in SteelHigh strength steel cables:-• Current research into refinement of cementite phase of steel to a Nano size has produced stronger cables• A stronger cable material reduce the costs and period of construction, especially in bridges• Sustainability is also enhanced by the use of higher cable strength as this leads to a more efficient use of material• High rise structures require high strength joints and this leads to the need of high strength bolts.
Nanotechnology in SteelBolted connection:-• The capacity of high strength bolts is realized generally through quenching and tempering CONNECTIONS• Vanadium and molybdenum nanoparticles delays the problems associated with high strength bolts and also improving the steel’s micro- structure BOLTEDWelding connection:-• The addition of nanoparticles of magnesium and calcium makes the HAZ(Heat Affected WELDED Zone) grains finer in plate steel and this leads to an increase in weld toughness.
Nanotechnology in SteelThere are two international product:-• Sandvik Nanoflex has both the desirable qualities of a high Young’s Modulus and high strength and it is also resistant to corrosion due to the presence of very hard nanometer-sized particles in the steel matrix.• MMFX2 steel, while having the mechanical properties of conventional steel, has a modified Nano-structure that makes it corrosion resistant and it is an alternative to conventional stainless steel, but at a lower cost.
Nanotechnology in Wood• Wood is also composed of nanotubes or “Nano fibrils”; namely, lignocellulose (woody tissue) elements which are twice as strong as steel.• Researchers have developed a highly water repellent coating based on the actions of the lotus leaf as a result of the incorporation of silica and alumina nanoparticles and hydrophobic polymers.
Nanotechnology in Glass• Most of the glass used on the exterior surface of buildings to control light and heat in order to control the building environment and contribute to sustainability.• Titanium dioxide (TiO2) is used as nanoparticle form to coat glazing since it has sterilizing and anti-fouling properties. conventional self-cleaning glass glass
Nanotechnology in Glass• Glass incorporating this self cleaning technology is available on the market today.• Fire-protective glass is another application of nanotechnology. This is achieved by using a layer sandwiched between glass panels (an interlayer) formed of fumed silica (SiO2) nanoparticles which turns into a rigid and opaque fire shield when heated.
Nanotechnology in Coatings• Coating is an area of significant research in nanotechnology• Nanotechnology is being applied to paints and insulating properties, produced by the addition of Nano-sized cells, pores and particles.• The TiO2 will break down and disintegrate organic dirt through powerful catalytic reaction.• This research opens up the intriguing possibility of putting roads to good environmental use.
Nanotechnology in Fire-Resistance• This is achieved by the mixing of carbon nanotubes with the cementious material to fabricate fibre composites that can inherit some of the outstanding properties• Polypropylene fibres are also being considered as a material for increasing fire resistance and this is a cheaper option than conventional insulation.
Nanotechnology in Photovoltaic• Predominant photovoltaic material is silicon, but an emerging technology involves the use of dye-sensitized nano- TiO2.• Large surface area of Nano TiO2 greatly increases photovoltaic efficiency.• Also has potential for lower material and processing costs relative to conventional solar cells.
Barriers Regulatory, legal, political and ethical issues. Competition with established micro scale technologies. License of proof-of-concept Nano tools, and delivery system. Safety and toxicity. Implementation cost of plant.
Barriers cont… 1. FABRICATION 2. HEALTH 3. ENVIRONMENT 4. COST• 1. FABRICATION Current efforts in the field of nanotechnology are focussed on the fabrication,characterization and use of these materials on a Nano scale.• 2. HEALTH Nanotechnology based construction products might be harmful to health. example, thenanotubes might cause lung problems to the workers.
Barriers cont..• 3. ENVIRONMENT The effect of various nanomaterials on the natural environment is hotlydebated in nanotechnology and environmental research. Moreover it will create a new category of Nano-waste which has to be extracted and treated.• 4. COST The cost of most nanotechnology materials and equipment are relativelyhigh. In comparison to traditional method.It’s a challenge for construction engineer to provide a facility to the generalpublic at a reasonable cost.
Real life Examples… • Building made by using self-cleaning concrete (Church ‘‘Dives in Misericordia”, Rome, Italy) • TiO2 coating on roads for pollution reduction
Real life Examples… Nano house , Australia:- University of Technology ,Sydney (UTS) have developed a model house that shows how new materials, products and processes that are emerging from nanotechnology research and development might be applied to our living environment.
CONCLUSION• Present day we are in great search for alternate materials this can effectively be achieved through the emerging field of Nanotechnology.• Nanotechnology is not exactly a new technology, rather it is an extrapolation of current ones to a new scale.• The main limitation is the high costs of nanotechnology, also concerns with the environmental and health effects.• There is wide scope of research for application of nanotechnology in the building industry and it shall help in conserving the material resources.