civil engineering with nanotechnology

7/28/2019 Civil Engineering With Nanotechnology

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New Vision for Civil EngineeringNew Vision for Civil Engineeringwith Nanotechnologywith Nanotechnology


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Physical scale and Examples inPhysical scale and Examples in

Civil Engineering SystemCivil Engineering System


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What is Nanoscale Science andWhat is Nanoscale Science and

EngineeringEngineeringa One nanometer (one billionth of a meter) is

a magical point on the dimensional scale.

a Nanoscale science and engineering here

refer to the fundamental understanding

and resulting technological advances

arising from the exploitation of newsystems that are intermediate in size,

between isolated atoms and molecules and

bulk materials.


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What is NanotechnologyWhat is Nanotechnology

a Nanotechnology is the

creation and utilization of

functional materials, devices,and systems with novel

properties and functions that

are achieved through the

control of matter, atom-by-atom, molecule-by-molecule,

or at the nanoscale or

macromolecular level.


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The Complete Process

Tip Preparation Work piecePreparation

Positional ControlFinal Product


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What Nanotechnology Can DoWhat Nanotechnology Can Do

a Create functional materials, devices and systemsCreate functional materials, devices and systems

with novel functions and properties through thewith novel functions and properties through the

control of matter at the nano-scale.control of matter at the nano-scale.a Exploit properties and phenomena developed atExploit properties and phenomena developed at

the nanometre scale.the nanometre scale.

a Consider a scale in which matter shows a specialConsider a scale in which matter shows a special

behavior due to both the quantum effectsbehavior due to both the quantum effects

(prevailing up to 10 nm) as well as the high(prevailing up to 10 nm) as well as the high

surface/interface effectssurface/interface effects


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Nanotechnology Application inNanotechnology Application in

Civil EngineeringCivil Engineeringa Materials:

ultra-high strength and ductility of steels

polymers composite and concrete

multifunctional materials


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Civil EngineeringCivil Engineeringa Coatings:

new composite materials, photocatalytic

coatings;

corrosion protection coating

and self cleaning coating


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Civil EngineeringCivil Engineeringa Sensors:

intelligent aggregates and coatings acting as

wireless sensors and actuators


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Civil EngineeringCivil Engineeringa Durability:

self-healing structural polymer composite,

pavements


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Civil EngineeringCivil Engineeringa New designs:

infrastructure taking advantage of much

stronger materials, ductile concrete and otheradvances, as such multifunctional or smart

materials


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Civil EngineeringCivil Engineeringa New tools:

giving new understanding of basic materials

structure-property relations, especially forcement


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Future Vision for Civil Engineering withFuture Vision for Civil Engineering with

NanotechnologyNanotechnology

a cracked bridges and potholes in pavement

repair on their own;

a guardrails re-align automatically after

impact;

a bridges adjust their shapes to control

movement caused by winds;


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a coatings make metal structures self clean

to avoid corrosion, and make road sign

never need to be washed;a rearranging and combining alloy particles

could make bridge steel many times more

durable and stronger;


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a MEMS/NEMS sensors could be embeddedMEMS/NEMS sensors could be embedded

into highways or coat an entire bridge forinto highways or coat an entire bridge for

monitoring the processes of deterioration,monitoring the processes of deterioration,and allowing to fix them long before theyand allowing to fix them long before they

are apparent to human inspectorsare apparent to human inspectors


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Apply Nanotecnology to ImproveApply Nanotecnology to Improve

Construction MaterialConstruction Material

a high performance steel for bridges.

With copper nanoparticles forming at the steel

grain boundary, the resulting microstructureschanges make the steel tougher, easier to weld

and more corrosion-resistance


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Nanomaterials Modified ConcreteNanomaterials Modified Concrete

a Concrete is a porous material, ranging from air

voids to nanometers scale pores

a these nanoscale pores control the properties ofthe calcium-silicate-hydrate hydration product,

or C-S-H colloids


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a Exploring and modifying these

nanoscale pores can result in

improved concretea Nano-engineered cement

materials with nano-sized

reaction modifier and

reinforcing materials areunder development



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a These addition could compensate for its

weakness in tension and result in concrete

with greatly improved stress-strainbehavior

a Possibly result in the range of newly

introduced smart properties, such aselectrical conductivity, sensing abilities



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Nanoscale Silica Fume Modifier

a De-icing chemicals could penetrate

concretes porous structure and

oxidize the reinforcing steel andcause cracking and deterioration to

the structure.

a The addition of nanoscale silica

fume operates at a nanoscale andcan improve durability of concrete

structures exposed to de-icing salts.


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Carbon Nanotubes (CNT)

Reinforced Cement/Concretea A carbon nanotube is a one-A carbon nanotube is a one-

atom thick sheet of graphiteatom thick sheet of graphite

rolled up into a seamlessrolled up into a seamlesscylinder with diameter of thecylinder with diameter of the

order of a nanometer.order of a nanometer.

Single-walled carbon nanotube

Multi-walled carbon nanotube


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Reinforced Cement/Concretea They are one-dimensional nanostructure whereThey are one-dimensional nanostructure where

the length-to-diameter ratio exceeds 10,000.the length-to-diameter ratio exceeds 10,000.

a The Young's modulus of CNTs can be as high asThe Young's modulus of CNTs can be as high as1000 GPa ,5 times higher than steel.1000 GPa ,5 times higher than steel.

a The tensile strength can be up to 63 GPa, 50 timesThe tensile strength can be up to 63 GPa, 50 times

higher than steel.higher than steel.

a They exhibit unique electrical properties, and areThey exhibit unique electrical properties, and are

efficient conductors of heat.efficient conductors of heat.


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Carbon Nanotubes (CNT) Reinforced

Cement/Concretea CNTs hold great promise for the next generation

of high performance and multi-functional

composite materials.a Much research activities have focused on CNTs-

reinforced polymer or ceramic composite

a

Exploration of applications of this new material incement/concrete is underway


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Reinforced Cement/Concretea Plain concrete itself is a

brittle material that is

much stronger incompression than in

tension.

a carbon nanotubes may be

applied to improvemechanical performance of

cement/carbon-nanotube

composite

evidence of reinforcing

mechanisms of CNT in

cement


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polymeric polyvinyl alcohol (PVA)polymeric polyvinyl alcohol (PVA)

fiberfibera nanoscale coating that

controls the chemical

bonding betweenreinforcing PVA fibers and

the mortar matrix

a This nano-enabled

concrete is 500 times

more resistant to cracking

and makes concrete tough

EngineeredCementitious

Composites (ECC)

bending test


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Apply Nanotechnology to ImproveApply Nanotechnology to Improve

sensor for Civil Engineeringsensor for Civil Engineeringa Nanotechnology-based Devices forNanotechnology-based Devices for

Quality Control and Durability MonitoringQuality Control and Durability Monitoring

of Concrete Materialof Concrete Material understanding of the cement hydrationunderstanding of the cement hydration

process, strength development, and damageprocess, strength development, and damage

evolutionevolution

detecting crack initiation under loading, asdetecting crack initiation under loading, as

well as pressure, temperature, chemical,well as pressure, temperature, chemical,

stress, strain for both nondestructivestress, strain for both nondestructive

evaluation and condition-based maintenanceevaluation and condition-based maintenance


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Sensor examplesSensor examples

a A sensor was developed to measure theA sensor was developed to measure the

density and viscosity of uncured concretedensity and viscosity of uncured concrete

in mixing and pumping equipment duringin mixing and pumping equipment duringpouring concrete.pouring concrete.

fresh concrete workability is important andfresh concrete workability is important and

improper workability will prevent concreteimproper workability will prevent concretefully flowing into form and result in porousfully flowing into form and result in porous


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Sensor ExamplesSensor Examples

a NSF currently supports a research of strainNSF currently supports a research of strain

and corrosion sensors for civil structuresand corrosion sensors for civil structures

by exploring the fabrication of carbonby exploring the fabrication of carbonnanotube-polyelectrolyte thin filmsnanotube-polyelectrolyte thin films

a Another NSF funded research is toAnother NSF funded research is to

develop embedded strain sensors, usingdevelop embedded strain sensors, usingnanoscale engineering of ultra-sonicnanoscale engineering of ultra-sonic

consolidationconsolidation


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a Smart dustSmart dust

a wireless sensor builta wireless sensor built

on a small silicon chip,on a small silicon chip,is currently developedis currently developed

these fine particle-sizethese fine particle-size

sensors could besensors could be

distributed over adistributed over a

structure to form astructure to form a

network and monitornetwork and monitor

the entire structurethe entire structure


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a some embedded sensors have beensome embedded sensors have been

developed and applied to verify designsdeveloped and applied to verify designs

a these sensors do not constitutethese sensors do not constitute

nanotechnology, they do illustrate the usenanotechnology, they do illustrate the use

of embedded sensors and give a indicationof embedded sensors and give a indication

of what can be accomplished in the futureof what can be accomplished in the futureas the nanotechnology reduces the sensoras the nanotechnology reduces the sensor

sizesize


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a the Golden Gate Bridge now has anthe Golden Gate Bridge now has an

experimental sensor network ofexperimental sensor network of

approximately 200 small MEMS sensors,approximately 200 small MEMS sensors,a Each sensor can measure movement suchEach sensor can measure movement such

as traffic, wind, or seismic loads.as traffic, wind, or seismic loads.

a All sensor readings are correlated, a three-All sensor readings are correlated, a three-dimensional picture is created which maydimensional picture is created which may

portray structural abnormalitiesportray structural abnormalities


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a IntelliRockIntelliRock and iBottom canand iBottom can

be embedded in concrete tobe embedded in concrete to

record the temperature ofrecord the temperature ofcuring concrete.curing concrete.

a Strength of concrete can beStrength of concrete can be

quickly monitoredquickly monitored

a It can speed constructionIt can speed construction

and save cost by removingand save cost by removing

forms earlier, loading theforms earlier, loading the

concrete earlierconcrete earlier

IntelliRock

iBottom


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a Chloride corrodes theChloride corrodes the

reinforcing steel rebarreinforcing steel rebar

in concretein concretea expand the rebarsexpand the rebars

volume and cause thevolume and cause the

surrounding concrete tosurrounding concrete to

crackcrack


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a Smart PebbleSmart Pebble, a long-life, a long-life

wireless sensor can checkwireless sensor can check

chloride ingress and relaychloride ingress and relaythe information wirelesslythe information wirelessly

a This sensor is poweredThis sensor is powered

remotely, so no lifetime-remotely, so no lifetime-

limiting batteries arelimiting batteries arerequiredrequired


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a Smart AggregatesSmart Aggregates,,

contains wireless powercontains wireless power

receiver and datareceiver and datatransmission coilstransmission coils

a A data reader mountedA data reader mounted

on a car powers theon a car powers the

sensors as it passessensors as it passesover them and collectsover them and collects

the sensor datathe sensor data


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Apply Nanotechnology forApply Nanotechnology for

nanocompositenanocompositea Nanomaterials-by-design can deliberatelyNanomaterials-by-design can deliberately

creating materials with uniquecreating materials with unique

functionality for target applicationsfunctionality for target applicationsa Nanocomposites can possess the ability toNanocomposites can possess the ability to

repair themselves after major damage.repair themselves after major damage.

a Nanosensors and multifunctional materialsNanosensors and multifunctional materialscan be built into composite materials tocan be built into composite materials to

produce smart buildingproduce smart building


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Self-Healing NanocompositeSelf-Healing Nanocomposite

a Inspired by biologicalInspired by biological

systems in whichsystems in which

damage trigger andamage trigger anautonomic healingautonomic healing

responseresponse

a A polymer compositeA polymer composite

material that can healmaterial that can healitself when crackeditself when cracked

has been developedhas been developed


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a Incorporate aIncorporate a

microencapsulatedmicroencapsulated

healing agent and ahealing agent and acatalytic chemicalcatalytic chemical

trigger within an epoxytrigger within an epoxy

matrixmatrix

a a structural polymerica structural polymericmaterial can have thematerial can have the

ability to self-healability to self-heal

crackscracks

Microcapsules on computer chip

Ruptured Microcapsules


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a An approaching crackAn approaching crack

ruptures embeddedruptures embedded

microcapsules, releasing amicrocapsules, releasing ahealing agent into thehealing agent into the

crackcrack

a Polymerization of thePolymerization of the

healing agent is triggeredhealing agent is triggeredby contact with theby contact with the

embedded catalyst and willembedded catalyst and will

bond the crack facesbond the crack faces


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Self-Healing Concrete

a The concrete could beThe concrete could be

self-healingself-healing


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a The high fraction ofThe high fraction of

unhydrated cementunhydrated cement

left after the hydrationleft after the hydrationcould be a reservoircould be a reservoir

for further hydrationfor further hydration

Unhydarated

cement grain Cracked

surface


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a When a crackWhen a crack

develops anddevelops and

anhydrous surfacesanhydrous surfacesare soaked in water,are soaked in water,

hydration startshydration starts

again and seal theagain and seal the

crackcrack


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Self-Sensing ConcreteSelf-Sensing Concrete

a The inclusion of electricallyThe inclusion of electrically

conducting short fibers can makeconducting short fibers can make

concrete sense elastic andconcrete sense elastic and

inelastic deformation and fractureinelastic deformation and fracturenecessarynecessary

a The electrical resistance (ER)The electrical resistance (ER)

increase is due to conducting fiberincrease is due to conducting fiber

pullout in the elastic regime,pullout in the elastic regime,conducting fiber breakage in theconducting fiber breakage in the

inelastic regime, and crackinelastic regime, and crack

propagation at fracturepropagation at fracture


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Self-Sensing ConcreteSelf-Sensing Concrete

a Correlations existCorrelations existbetween concrete ERbetween concrete ERand its strain or damageand its strain or damagecondition:condition: Reversible change in ERReversible change in ER

is for elastic deformationis for elastic deformation

Irreversible change in ERIrreversible change in ER

is for inelasticis for inelasticdeformationdeformation

Irreversible dramaticIrreversible dramaticchange in ER is forchange in ER is forfracture.fracture.


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Use ECC for Concrete Self-HealingUse ECC for Concrete Self-Healing

a Engineered Cementitious Composites (ECC)Engineered Cementitious Composites (ECC)

are developed and reinforced by polymericare developed and reinforced by polymeric

polyvinyl alcohol (PVA) fiber or other fiberspolyvinyl alcohol (PVA) fiber or other fibersa It results in smaller crack in concreteIt results in smaller crack in concrete

a Hollow fibers with sealing agent couldHollow fibers with sealing agent could

repair cracks after fibers break due torepair cracks after fibers break due tocrackingcracking


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Use ECC for Concrete Self-HealingUse ECC for Concrete Self-Healing


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Advanced Smart ConcreteAdvanced Smart Concrete

a Sensing strain and damageSensing strain and damage

a Self-healing after crackingSelf-healing after cracking

Electrically conducted hollowed fibersElectrically conducted hollowed fibers

inclusion for sensinginclusion for sensing

Fill hollowed fiber with sealing agent forFill hollowed fiber with sealing agent for

sealing the crackssealing the cracks


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Self-Cleaning Nano-CoatingSelf-Cleaning Nano-Coating

a In some Eastern

cultures, the lotus

plant is a symbol ofpurity.

a Even lotuses emerge

from muddy ponds or

lakes, its leaves andflowers remain

uncontaminated and

pure.


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a lotus leaves have a fine surfacelotus leaves have a fine surface

with wax crystals of around 1 nmwith wax crystals of around 1 nm

in diameterin diametera The contact area between theThe contact area between the

water and surface is reduced towater and surface is reduced to

only 2-3% of the droplet-coveredonly 2-3% of the droplet-covered

surfacesurfacea Dirt and grime can be collectedDirt and grime can be collected

by water drops and rinses offby water drops and rinses off


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a Nanotechnology isNanotechnology is

being used to mimicbeing used to mimic

the lotus leaf surfacethe lotus leaf surfaceand create new no-and create new no-

stick painting orstick painting or

coatingcoating

(C) treated surface with silica

nanoparticles. (D) Water droplet

on this surface. (Zhai et al.)


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a Development of lotus-effect aerosolDevelopment of lotus-effect aerosol

spray is underwayspray is underway

a It combines nanoparticles withIt combines nanoparticles withhydrophobic polymers and propellanthydrophobic polymers and propellant

gas, and develops a nanostructuregas, and develops a nanostructure

through self-assembly.through self-assembly.

a It particularly suits rough surfacesIt particularly suits rough surfaces

such as paper, leather, textiles andsuch as paper, leather, textiles and

masonrymasonry

Treated wood

surface with

waterrepelling

capacity


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a The Lotus-Effect exteriorThe Lotus-Effect exterior

coating or paint oncoating or paint on

traffic signs or controltraffic signs or controldevices:devices:

require no labor-require no labor-

intensive and periodicintensive and periodic

washing to remove roadwashing to remove roadgrimegrime

enhance visibility andenhance visibility and

safetysafety


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a The commercial Lotus-EffectThe commercial Lotus-Effect

exterior coating or paint areexterior coating or paint are

available in U.S. for buildingavailable in U.S. for buildingfacades:facades:

Water and dirt flow offWater and dirt flow off

immediatelyimmediately

Resists the growth of mold,Resists the growth of mold,mildew, and algaemildew, and algae

The facade remains dry andThe facade remains dry and

attractiveattractive Sto Lotusan


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A Schematic View of a Smart Bridge


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civil engineering with nanotechnology

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