Advances in Using Nano Materials in · PDF fileClosed-loop Testing High Strength Concrete...

Center for Advanced Cement-Based Materials Northwestern University McCormick School of Engineering & Applied Science

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Advances in Using Nano Materials in

Construction

Hong Kong Concrete Institute, Hong Kong, Dec 6, 2017

Surendra P. Shah

Walter P. Murphy Professor (Emeritus)

Center for Advanced Cement-Based Materials

Northwestern University

Evanston, IL 60208, USA


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200

0

400

600

800

Max

imu

m h

eigh

t (i

nc.

sp

ire)

[m

]

Water Tower Place, Chicago

(262m)

Petronas twin towers,

Malaysia (452m)

Taipei 101,

Taipei (508m)

Burj Khalifa, Dubai

(828m)

Lake Point Towers, Chicago

(197m)

311 S Wacker, Chicago (293m)

Completion year 1960 1970 1980 1990 2000 2010

Strength of Concrete

Development of building height

High Strength Concrete (HSC)


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Microstructural Changes in High Strength Concrete


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Water Tower Place, Chicago


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High Strength Concrete (HSC): Brittle failure


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Testing With feedback signals

Feedback can be:

- Load

- Axial displacement

- Lateral displacement (circum.)

Closed-loop Testing



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Ultra-high strength

concrete

Normal strength

concrete



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Fiber Reinforced Concrete (FRC)

– Steel

– Polypropylene

– PVA

– Cellulose

– Glass (Alkali resistant)

– Carbon

– Asbestos

Steel Polypropylene

Glass

Carbon

Asbestos

Fiber types


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Fiber Reinforced Concrete

2a

LEFM DOES NOT APPLY

LEFM VALID

a al

f

YS

fICK

a

Critical Stress Intensity FactorICK

Fracture Mechanics – Failure stress of wide plate


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Failure stress of a wide plate

Fibers

Microcracks


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Displacement

Fiber-reinforced (increased ductility)

Normal Strength

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Failure stress of a wide plate

Post-peak Properties

Load


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Deflection

Macro-fiber

Micro-fiber

Matrix

10 MPa

3 MPa

Str

ess



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Weight of beams with equal load carrying capacity (kg/m):

140 112 467 530


Nanotechnology and FRC: Less weight


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Ultra-high Performance Concrete (UHPC)

Hypergreen Tower (Paris, France)

Architect: Jacques Ferrier



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MWCNT

Carbon Nanotubes (CNTs) • A CNT is a sheet of graphite rolled up into a tube structure

– Multi walled (MWNT)

Consist of multiple layers rolled up with diameter of 20-40 mm

Carbon Nanofibers (CNFs) • Carbon Nanofibers are cylinder nanostructures with graphite planes which

extend beyond the diameter of the nanofibers

20

-40

nm

Carbon Nanotubes & Carbon Nanofibers

60

-15

0 n

m

CNFs SEM image of CNFs


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CNT and CNF Mortar Nanocomposites

P-CMOD Curves

0

50

100

150

200

250

300

350

400

450

500

0.00 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08

Lo

ad (

N)

C.M.O.D. (mm)

M0.5+CNFs0.1% (SP/CNFs=4)

M0.5+CNTs0.1% (SP/CNTs=4)

M0.5

28 day specimens

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17

0

0.05

0.1

0.15

0.2

0 24 48 72 96

Hours after casting (h)

CP w/c=0.3

CP+Long CNTs 0.048wt%

Time of setting

Konsta-Gdoutos et al, Cement and Concrete Composites, 2010

Autogenous shrinkage of CNT reinforced concrete



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1

10

100

1000

0 0.05 0.1 0.15 0.2 0.25 0.3

MWNT掺量/wt.%

电阻率

/k_•c

m

Resistivity of CNT reinforced concrete

MWNT content, %

Resis

tivity,

k_ ·

cm



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Han et al., Nanotechnology, 2009


Smart cement based materials using CNTs


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Corrosion Potential

Half Cell

Potential

(mV)

Corrosion

Probability

0-200 No corrosion

200-350 Possible corrosion

350-500 Corrosion

>500 Strongly Corroded


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Corrosion Potential


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Nanoparticles and Sustainability

• Nano-SiO2

• NanoAlO(OH) (Boehmite)

• Nano-limestone

• Nano-clay

• CNT/MWCNT

• TiO2

• Nano CSH


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Nano-SiO2 (NS)

Quercia, Cement and Concrete Composites, 2013, 44: 77-92


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NanoSiO2 on HVFA system -- Hydration and Hardening properties

Hydration and setting are accelerated in the early age;

NS=5% NS=0%

NS=2.25%


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NanoSiO2 on HVFA system -- Hydration and Hardening properties

Higher early-age compressive strength; Comparable or lower at the later age;


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Degradation

Cement paste

ref. sample

Sample with

6% nanosilica

Sample with 6%

micro-silica

Compressive Strength in Aggressive

Environment


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• Carbonation

• Microwave

• Heat treatment

• Nano-silica and nano-limestone treatment

Recycled Aggregates Treated by Nano-

particles


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Water absorption of aggregates

N0: untreated, control natural

coarse aggregate

R0: untreated, control recycled

coarse aggregate

R1: recycled coarse aggregate

treated by slurry containing nano-

SiO2 and nano-CaCO3

R2: recycled coarse aggregate

treated by slurry containing cement

and nano-SiO2

1.5

6.4

3.6

4.4

N0 R0 R1 R2

0

1

2

3

4

5

6

7

Wat

er A

bso

rpti

on

(%

)

Aggregate Type

Recycled Aggregates Treated by Nano-

particles


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Surface-treatment with Nano-SiO2

• Surface treatment with TEOS

• Electrochemical Injection Jiri Nemecek, et al

Ismael Diaz, et al

Cardenas, H., et al

Fig.1. Surface treatments classification: (a) hydrophobic impregnations, (b)

impregnations, (c) coatings

1.Baltazar L, Santana J, Lopes B, et al. Surface skin protection of concrete with silicate-based impregnations: Influence of

the substrate roughness and moisture. Constr Build Mater 2014; 70(0): 191-200.

Surface treatments classification: (a) hydrophobic impregnations,

(b) impregnations, (c) coatings1


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– Raw materials

• CNS’ precursor, tetraethoxysilane (TEOS), liquid

2 5 4 2 2 2 5( ) 2 4nSi OC H nH O nSiO nC H OH


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– On the water absorption

• TEOS is capable to reduce water absorption

Mortars, one-month old mortars cured for 14 day after treatment

w/c=0.6, 50oC/95%RH


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Pozzolanic activity of nano silica and silica

fume

CH consuming capacity of CNS/SF


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Modification of Nanostructures

Fig. FTIR of SNPs incorporated

hydrated C3S at different time intervals.

L.P. Singh, etc, Studies on early stage hydration of tricalcium silicate incorporating silica nanoparticles: Part II, Construction and Building

Materials, Volume 102, Part 1, 15 January 2016, Pages 943-949

Nanosilica elongates CSH gel chain length


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Modification of Nanostructures

SEM/EDX micrographs of hydrated C3S at 24 h.

SEM/EDX micrographs of hydrated C3S at 24 h.

Nanosilica reduces the ratio of

Ca and Si.


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Nanoindentation with Hysitron Triboindenter

• Allows both nanoindentation and scanning probe microscopy imaging

• ESEM used to check polishing effectiveness and to find representative areas

• Representative areas also imaged using the Berkovich tip of the triboindenter

• Nanoindentation was performed in a 12×12 grid (10 μm between adjacent grid points)


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Elastic Modulus of Plain Cement Paste (CP) vs

CP modified with nanosilica

Nanoindentation on 6 Months Old Cement

Paste: w/c 0.5


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Nanoclay -- Attapulgite

During mixing, particles break up into much

smaller needle structures


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Self-compacting Concrete (SCC)


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stre

ss (

t)

ty

g shear rate ( )

• Low stress required to initiate flow: low yield stress (ty)

• Low stress required for continuous deformation low viscosity

• Rheology of the matrix must be controlled to avoid particle segregation (i.e. coarse aggregates)

g

t

Conditions for Self-Flowing Suspensions



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• Matrix yield stress and viscosity must be optimized for self-

flowing capability.

Self-flow zone

Poor workability

Particle segregation

Optimum rheology

for self-flow Dr

t y

Dr

Optimum rheology

for segregation resistance

Flow behavior: Rheology


Self-flow zone concept


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Mock Up Test (2007, Dante Galeota, and et al.)

Research in collaboration with Université de Sherbrooke and CTL

Formwork Pressure



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ACI 347: presumed lateral pressure should equal the

hydrostatic pressure until the effect of formwork pressure is

understood

Studies have shown that SCC can have pressure less than

hydrostatic1-3 due to structural rebuilding

1. A. Assaad, et. al, Cement and Concrete Research, v.35, 2005 2. P. Billberg, et. al, Concrete International, v.27 (10), 2005 3. Y. Vanhove, et.al, Magazine of Concrete Research, vol. 56, 2004.


Formwork Pressure


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Pressure Sensors

(capacity: 50psi = 344kPa)

Lab formwork (V~20 Liter, H= 45cm, D=23 cm)

Loading Cell

Simulation Range: Real

scale column heights up

to 20 m, and casting rates

ranging from 0 m/hr to

25m/hr ( and more)

Formwork Pressure: Laboratory set-up for measurement


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*Slump flow: 60 2cm

0% nanoclay

0.33% nanoclay

Formwork Pressure: Clay effect


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Chord length

Laser

Focusing Lens

Sapphire Window

Rotating Optics

Coupling Lens

Fiber

Fiber-Optic

Coupler

Gives information about Floc size

indirect indication of flocculation

Scans highly focused laser beam across suspension and measure time duration of back scattered light

Cluster range: 0.5 – 1200 μm


Laser Backscattering

Measurement of Floc Size


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3D Printing with Cement Material


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Metaconcrete

Processing Microstructure Property

1. Traditional

2. Metaconcrete

Property Hierarchical

Architecture Fabrication

Greer, J.R.(2015), Materials by design: Using architecture and nanomaterial size effect to attain unexplored properties. Bridge. 45(4), 37-44.


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Prairie Hosts Industry Experts at Concrete Roundtable


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Motivation

How to obtain 8 million psi (58 GPa) of modulus of elasticity?

Lake Point Tower in

Chicago


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Nanofiber Reinforced Concrete


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CP-MWCNT-nanocomposites--Young`s modulus

8.8

14.3

29.3

14.0

27.5

45.7

0

10

20

30

40

50

CP M Con

E (

GP

a)

Cement paste Mortar

28d

CP w:c=0.485:1.0

*striped bar diagram: Neat matrix

**solid bar diagram:

Matrix+MWCNTs 0.1% wt

Fiber count:

CP: 8.3×1011 MWCNTs

+59%

+92%

+56%

MWCNT reinforced CP, M and Concrete--Young`s modulus


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CP vs. M-MWCNT-nanocomposites--Young`s modulus

8.8

14.3

29.3

14.0

27.5

45.7

0

10

20

30

40

50

CP M Con

E (

GP

a)

Cement paste Mortar Concrete

28d

CP w:c=0.485:1.0

M w:c:s=0.485:1.0:2.75


**solid bar diagram: Matrix+MWCNTs

0.1% wt

Fiber count:


M: 3.6×1011 MWCNTs

+59%

+92%

+56%



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8.8

14.3

29.3

14.0

27.5

45.7

0

10

20

30

40

50

CP M Con

E (

GP

a)

Cement paste Mortar Concrete

28d

CP w:c=0.485:1.0

M w:c:s=0.485:1.0:2.75

Con w:c:s:a=0.51:1.0:2.63:2.04


**solid bar diagram: Matrix+MWCNTs

0.1% wt

Fiber count:


M: 3.6×1011 MWCNTs

Con: 2.5×1011 MWCNTs

+59%

+92%

+56%



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Young’s Modulus

(GPa)

Compressive Strength

(MPa)

Plain Concrete 29.3 45.9

Concrete+0.1 wt% CNT 45.7 48.2

Mechanical Properties of CNT Reinforced Concrete

Mechanical Properties of Concrete with or without CNTs


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Nanofiber Reinforced Concrete


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rGO synthesized using Modified Hummers’ method


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Nanomechanical properties

Nanoindentation results of the 28 days cured

paste specimens

“Influence of 2D rGO nanosheets on the properties of OPC

paste”, Cement and Concrete Composites, 70, 48-59, 2016. (M.,

Murugan, M., Santhhanam, S. S., Gupta, T., Pradeep, S.P.,

Shah)


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Modification with Nano-SiO2

– Raw materials

• CNS’ precursor, tetraethoxysilane (TEOS), liquid

2 5 4 2 2 2 5( ) 2 4nSi OC H nH O nSiO nC H OH


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Modification with Nano-SiO2

– On the water absorption

The use of tetraethyl orthosilicate silane (TEOS) for surface-treatment of hardened cement-based materials: a comparison study

with normal treatment agents, Construction and Building Materials (Pengkun, Hou, S.P. Shah)

Silane has a good performance of keep water out


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Synthesis of Silane@SiO2

Synthesis of Silane@SiO2

Nano-SiO2

Silane

Materials：

tetraethyl orthosilicate (TEOS)

Polymethylhydrosiloxane(PMHS)

Deionized water Guo et al., J COLLOID INTERF SCI.446(2015) 155-162


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Water absorption cement mortar (w/c=0.6)

Control

TEOS

Silane@SiO2

Silane

Performance of Silane@SiO2

Research in progress in University of Jinan


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• Nano-silica

• High volume fly ash

• Calcium leaching

• Recycled concrete aggregate

• Surface treatment

• Nanostructure modification

• Nano-clay

• Highway construction

• Formwork pressure

• Chloride diffusion

• Freeze thaw resistance

• CNT

• Mechanical properties

• Autogenous shrinkage

• Corrosion resistance

• Meta-material

• High modulus concrete

• Reduce graphene oxide

• Core shell nanoparticles

• Nano-composites hydrogels

Summary


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Thank you

Advances in Using Nano Materials in · PDF fileClosed-loop Testing High Strength Concrete...

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