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Int. J. Struct. & Civil Engg. Res. 2014 Er. Tanpreet Singh, 2014

A REVIEW OF NANOMATERIALS IN CIVIL

ENGINEERING WORKS

Er. Tanpreet Singh

1 Department of Civil Engineering, Chandigarh University, Mohali, India.

*Corresponding author:Er. Tanpreet Singh � civil6011@gmail.com

ISSN 2319 – 6009 www.ijscer.com

Vol. 3, No. 1, February 2014

© 2014 IJSCER. All Rights Reserved

Int. J. Struct. & Civil Engg. Res. 2014

Research Paper

INTRODUCTION

Nanotechnology, introduced almost half centuryago and is one of the most active researchareas with both novel science and usefulapplications that has gradually establisheditself in the past two decades. The evolution oftechnology and instrumentation as well as itsrelated scientific areas such as physics andchemistry are making the research onnanotechnology aggressive and evolutional.Not surprisingly, it is observed that expenditureon nanotechnology research is significant. TheUS National Nanotechnology Initiative (NNI)

expenditure exceeds $1 bn each year withpresident’s 2008 budget for NNI at $1.5 bn.The research is mainly moving forwardmotivated by immediate profitable returngenerated by high value commercial products.

The nanotechnologies can be defined asthe design, characterization, production andapplication of structures, devices and systemsby controlling shape and size at the nanoscale.Nanotechnology requires advanced imagingtechniques for studying and improving thematerial behavior and for designing andproducing very fine powders, liquids or solids

The performance of conventional concrete can be improved by applying nanotechnology materialsin constructional industry. The properties of materials actually become affected due to particlesize at the length scale of nanometer, i.e., 10–9 m, based on this view, researchers have beenpursuing to evolve new or alternative materials towards a green and sustainable solution. TheNanotechnology deals at a scale smaller than 100 nm (1 nm = 10-9 m). Due to their reducedsize, nanomaterials properties vary considerably from bulk and thus they present exceptionalmechanical and physical properties. The engineering of complex structure of cement basedmaterials at nano level will definitely result in new generation of concrete, stronger and moredurable with whole range of newly introduced smart properties. The nanotechnology materialshave many unique characteristics but their material cost is very expensive due to noveltytechnology.

Keywords: Nanotechnologies, Nanoscience, Concrete and Civil Engineering Materials

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Int. J. Struct. & Civil Engg. Res. 2014 Er. Tanpreet Singh, 2014

of materials with particle size between 1 and100 nm, known as nanoparticles (Gogotsi,2006). Nanoscience can be divided into threefields (i) Nanostructures; (ii) Nanofabrication;and (iii) nanocharacterization with typicalapplication in nanoelectronics and life scienceand energy. The usage of technology materialswhile being incorporated in constructionalstructures would not help in prolonging in theirlifetime but would also help keep a check onthe energy spent by them at the same timegauging their reaction and reacting to differentagents like fire, corrosion, water penetrationand cracks, etc.

The purpose of reviews is to give clearimage among the nanotechnologydevelopment areas where the constructionprocess would immediately harnessnanotechnology. By specifying clearrecommendations. The information would bebeneficial to both construction, engineeringeducation and research.

BASICS OF NANOTECHNOLOGY

Nanotechnology is the creation of materialsand devices by controlling of matter at the levelsof atoms, molecules, and nanoscale structures(Roco et al., 1999). In other words, it is theuse of very fine particles of materials to createnew large scale materials (Mann, 2006). Thekey is the size of particles because theproperties of materials are dramaticallyaffected under a scale of the nanometer (nm),i.e., 10-9 meter (m). To better understand thedifference among various scales, Table 1shows the categories of scales and its relatedtopics (Balaguru, 2005).

Table 1: Scales Vs. Various Topics

S. No. Scales Various Topics

1. 10-12 Quantum Mechanics

2. 10-9 Molecular Dynamics

Nanomechanics

Biophysics

3. 10-6 Elasticity Plasticity Dislocation

4. 10-3 Mechanics of Materials

5. 10-0 Structural Analysis

The development and application ofnanotechnology are relying on the developmentof other related science and technology suchas physics and chemistry that are commonlynew to break through at that time. Mostpromising developments of nanotechnologyare fullerene (a new form of carbon, C60) andcarbon nanotubes (Sobolev and Gutierrez,2005). The new features of constructionmaterials and elements accordingly changethe material usage and resistance calculationsof project design and its related fieldconstruction operation and management.

APPLICATION OF

NANOTECHNOLOGY IN

CONSTRUCTION

Nanotechnology can be used for design andconstruction processes in many areas due totheir unique characteristics. Thesecharacteristics of nanomaterials cansignificantly fix current construction problemsand may change the requirement andorganization of construction process.

These include products that are for:

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Int. J. Struct. & Civil Engg. Res. 2014 Er. Tanpreet Singh, 2014

• Lighter and stronger structural composites.

• Low maintenance coating.

• Improving pipe joining materials andtechniques.

• Better properties of cementitious materials.

• Reducing the thermal transfer rate of fireretardant and insulation.

• Increasing the sound absorption of acousticabsorber.

Nanotechnologies For Cement

Portland cement is a versatile materials andis widely use in construction site. It has beendiscussed that concrete utilizednanotechnology because it contains nanoparticles as ingredient including nano waterparticles and nano air voids. A combination ofnanosilica, sodium aluminate and sodiumhydroxide gives nanocement. Reducing CO2

emissions alongside providing highcompressive strength. 50% replacement ofnanocement along with mortar gives strengthupto 86.97 N/mm2 at the end of 21 days andavoiding air gaps by virtue of large specificsurface area (3582400 cm2/g) are some of theproperties offered by addition of nanocementto the construction materials (Jemimah et al.,2012). Reduction of penetration of water, fillingup air spaces, increasing compressivestrength over a prolonged period of time aresome of the positive results obtained on mixingnanoparticles in the conventional cement.

Nanotechnologies For Concrete

Concrete is one of the most common andwidely used construction materials. Itsproperties have been well studied at macro orstructural level without fully understanding the

properties of the cementitious materials at themicro level. Addition of nanoscales materialsin the cement improves the compressivestrength of cement mortar as well as concretespecimens. The addition of small amounts(1%) of carbon nanomaterial can increase themechanical properties of mixture samples ofconcrete. (Mann, 2006) shows the bestimprovements both in compressive strengthand flexural strength of concrete as comparedto the reference samples with insertion ofnanosilica in concrete. Li (2004) found thatnanosilica could significantly increase thecompressive strength for concrete containinglarge volume fly ash at early age and improvepore size distribution by filling the poresbetween large fly ash and cement particles atnanoscale. CO2 emissions from the globalcement industry are significant and they areincreasing on high scale. Global cementproduction is currently around 1.6 billion tons/year and through the calcinations of limestoneapproximately 0.97 tons of CO2 is producedfor each ton of clinker produced.

Nanotechnologies For SelfCompacting Concrete

Self-Compacting Concrete does not needvibration in order to level off and achieveconsolidation. This represents a significantadvance in the reduction of the energy neededto build concrete structures. In addition SCCcan offer benefits of up to 50% in labor costs,due to it being poured up to 80% faster andhaving reduced wear and tear on formwork.The material behaves like a thick fluid and ismade possible by the use of polycarboxylates.SCC mixes, which contain a high content offine particles, need a very effective dispersingsystem in order to be fluid and workable

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Int. J. Struct. & Civil Engg. Res. 2014 Er. Tanpreet Singh, 2014

overtime at low water/cement ratio (high W/Cratios would lead to risk of segregation) andonly polycarboxylates can meet theserequirements. A fibre sheet (matrix) is used,containing nano-silica particles andhardeners. These nano-particles penetrateand close small cracks on the concrete surfaceand, in strengthening applications, thematrices form a strong bond between thesurface of the concrete and the fiberreinforcement. There is no decrease in themaximum load capacity after repeated cyclesof wetting and drying or scaling.

Nanotechnologies For Steel

Steel is another prominent constructionmaterial and is provided in all the buildingsstructures. The significant properties of steelare tensile strength and corrosive resistance.In India, new low carbon high performancesteel for bridges has been developed. Thiskind of new low carbon steel with high strengthand higher corrosive resistance through theincorporation with nanomaterials reduces thesurface unevenness of steel which then limitsthe number of stress risers and hence stressfatigue cracking.

Nanotechnologies For StructuralComposites

Since, steel is a major construction unit. Itsproperties such as strength, corrosionresistance and weld ability play very importantrole for the design and construction of building.Nanotechnology materials are added to paintsin order to assure the corrosion protectionunder insulation since it is hydrophobic andrepels water from the metal pipe and can alsoprotect metal from salt water attack. It protects

the walls of building for a long period of timewithout need of much maintenance and actsas green product.

Fire resistance of steel structures is oftenprovided by a coating produced by a spray-on cementitious process. Nano-cement (madeof nanosized particles) has the potential tocreate tough, durable, high temperaturecoatings. This is achieved by the mixing ofcarbon nanotubes with the cementiousmaterial to fabricate fibre composites that caninherit some of the outstanding properties ofthe nanotubes.

Micro and nanoporous aerogel materialsare appropriate for being core materials ofvacuum insulation panels and are sensitive tomoisture. As a possible remedy it wasproduced an ultra-thin wall insulation whichuses a hydrophobic nanoporous aerogelstructure. Another application of aerogels issilica based products for transparentinsulation, which leads to the possibility ofsuper-insulating windows. Micro ornanoelectromechanical systems offer thepossibility of monitoring and controlling theinternal environment of buildings and this couldlead to energy savings.

COST

At this moment the nanotechnology materialsand equipment costs very high. This is due tothe novelty of the technology and the complexityof the equipment used for preparation andcharacterization of the materials. However,material cost will cut down over time asmanufacturing technologies will upgrade theirproducts.

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Int. J. Struct. & Civil Engg. Res. 2014 Er. Tanpreet Singh, 2014

CONCLUSION

The application of Nanomaterials andnanotechnologies has attracted considerablescientific interest in civil engineering due to thenew potential uses of particles in nanometerscale. Since the construction industry is heavilyinvolved in economic development andconsumes great amount of resources andenergy and its impact on environment issignificant. Focused research and practiceefforts are needed into nanotechology forconstruction products and therefore saveenergy, reduce resources usage and avoiddamages to environment. This wouldsignificantly help the readers such as civilengineers and contractors to establish asystem environmental friendly and sustainableof construction with nanomaterials and to avoidthe use of harmful materials in future.

REFERENCES

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2. Balaguru P N (2005), “Nanotechnologyand Concrete: Background, Opportunitiesand Challenges.” Proceedings of theInternational Conference – Applicationof Technology in Concrete Design,Scotland, UK; pp. 113-22, 2005.

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