underwater infrastructure and underwater city of the future · 2017-09-13 · nilsson, l., ngo, m....

Underwater Infrastructure and Underwater City of the Future

New Concrete, Reinforcing Materials and Structural Consideration

School of Civil and Environmental Engineering

Research Team

A/P Susanto Teng

Dr. Liu Yu

Dr. Soerya Widjaja

Mr. Sabet Divsholi Bahador

Dr. Kondraivendhan Balakrishnan

Mr. Lim Tze Yang Darren

Mr. Rhahmadatul Hidayat

Mr. Vu Duc Hieu

Mr. Ng Jun Kai Niki

Mr. Jimmy Chandra

Overview

Topics For Today

1. Durability and Properties of NTU's Ultra

Durable High Performance Concrete

2. Design Considerations for Structural

Members made of Ultra Durable High

Performance Concrete

3. Numerical Modeling of Ultra-Durable

Reinforced Concrete Plates and Shells for

Underwater Structures

Durability and Properties of NTU's Ultra Durable High Performance Concrete (UDHPC)

presented by

Sabet Divsholi Bahador

Research Associate

Mr. Lim Tze Yang Darren

Dr. Kondraivendhan Balakrishnan

Associate Professor Susanto Teng

School of Civil and Environmental Engineering

8th February 2012

Content

• The Criteria for UDHPC

• The Mechanical and Durability Properties

• Service Life Analysis of Our UDHPC

• Development of Durability Guidelines

The Criteria for UDHPC

Fresh Concrete Properties

• Slump and Flowability

• Workability

Heat of Hydration

The Criteria for UDHPC

• Mechanical Properties

Compressive Strength

Flexural Strength

Modulus of Elasticity

Creep Shrinkage Fire Resistance

The Criteria for UDHPC• Durability aspects

Electrical Resistivity Test

Rapid Chloride Migration Test and Rapid Chloride

Permeability Test

Drying Rate Corrosion Rate

What are the Common Ingredients of

UDHPC

Normal Sand 20 mm (aggregate …)

Cement

Superplasticizer

What are the Common Ingredients of

UDHPCMineral Admixtures …

Ground Granulated Blast-Furnace Slag (GGBS) and UFGGBS

Undensified Silica Fume (USF) and Condensed Silica Fume (CSF)

What are the Variables

Water / Cementitious Ratio (w/c)

Aggregate / Cementitious Ratio (a/c)

Mineral Admixture Replacement (type and percentage)

Other Parameters

Types of Rebar (Carbon Steel, Stainless Steel 304 and Stainless

Steel 316)

Steel Fibre PP Fibre

Content





Slump Test

Casting Slab

Filling a Box

Is This Self Compacting Concrete

(SCC)?

• No

• The flowability is similar to SCC.

• The w/c ratio is 0.25 instead of 0.35-

0.45 for SCC.

• We can use normal fine and normal

coarse aggregate.

Mixes studied ….

Mix w/cTotal

CementitiousOPC UFGGBS GGBS USF CSF

1 0.35 448 448 0 0 0 0

2 0.35 444 311 133 0 0 0

3 0.28 522 522 0 0 0 0

4 0.28 518 363 155 0 0 0

5 0.25 585 527 0 0 58 0

6 0.25 580 348 174 0 58 0

Mixes studied ….

Mix w/cTotal


7 0.32 454 454 0 0 0 0

8 0.25 584 409 175 0 0 0

9 0.25 583 320 174 87 0 0

10 0.25 582 320 262 0 0 0

11 0.25 590 590 0 0 0 0

12 0.65 342 342 0 0 0 0

13 0.25 582 320 0 262 0 0

How Good Is Our UDHPC?

0

20

40

60

80

100

120

140

160

0 20 40 60

Co

mp

res

siv

e S

tre

ng

th (

MP

a)

Curing (days)

G 35

UDHPC


0

2

4

6

8

10

12

14

0 20 40 60

UDHPC

G 35

Curing (days)

Fle

xu

ral S

tre

ng

th (

MP

a)

How Good Is Our Concrete?

Rapid Chloride Migration Test (RCMT)

Constant Voltage 10 % NaCl and 0.3 NaOH



0 5 10 15 20

Low

Moderate

High

Very High

Extremly High

D28×10-12

m/s

Resistance to Chloride Penetration

Nilsson, L., Ngo, M. H. and Gjørv, O.E., “High-performance Repair Materials for Concrete Structures in the Port of

Gothenburg”, Second International Conference on Concrete Under Severe Conditions: Environment and Loading, Vol.

2, 1998, pp. 1193–1198.



10.2

7.9

6

3.8

1.71

0.11 0.07 0.010

2.5

5

7.5

10

12.5

3 28 56 90

G 70

UDHPC

Extremely High

Very High

High

Moderate

98.6% Reduction


Rapid Chloride Permeability Test (RCPT)

Understanding AASHTO T277 and ASTM C1202 Rapid Chloride Permeability Test, Concrete Bulletin


(RCPT)- Chloride Permeability

27002500

2000

1750

870

120 98 470

500

1000

1500

2000

2500

3000

3 28 56 90

G 70

UDHPC

Negligible

Very Low

Low

Moderate

95.2% Reduction


Electrical Resistivity (Corrosion rate)

0 5 10 15 20 25

Low

Moderate

High

Very High

KΩ.cmACI Committee 222, Protection of Metals in Concrete Against Corrosion, ACI

222R-01, 2001, pp. 41.


Electrical Resistivity (Corrosion rate)

30

70

1700

1

10

100

1000

10000

90 days

G 70

Durable Concrete

UDHPC

56 times increase


Direct Electrical Resistivity

G 70 at 90 days of water curing 8 kΩcm

UDHPC at 90 days of water curing 448 kΩcm

56 times increase

When we apply 60 Volts to 50 mm thick

concrete, the current passing is:

117.8 mA for G70

2.1 mA for UDHPC

Study on Creep and Shrinkage

Study on Heat of Hydration

Future Mixes…

Mix w/cTotal


14 0.25 579 232 347 0 0 0

15 0.25 579 232 0 347 0 0

16 0.25 582 320 175 0 0 87

17 0.25 582 320 0 175 0 87

18 0.25 582 320 0 175 87 0

19 0.25 580 261 0 261 58 0

20 0.25 580 261 0 261 0 58

Why Various Mixes…

Few Alternatives

• Cost Consideration

• Different Mixes for Various Exposure Conditions

Increased Safety

• Concrete Cover

• Concrete Quality

• Types of Steel Rebar

Content





Deterioration of a Concrete Structure

due to Steel Corrosion

e

Service Life Analysis

All the parameters have uncertainties

• Cover Depth, Chloride Permeability, Critical Chloride

Content, Curing Duration and Time of Exposure

• Sea Water Chloride Content and Temperature

The Resistance to

withstand the

loads (R)

Monte Carlo SimulationThe

Environmental

Loads (S)


Mix Design G 70 UDHPC

Design life 500 years

Cover depth 50 (2) mm

Temperature 30ºC

DcoefΧ10-12 m/s 7.91 (1.22) 0.11 (0.01)

t0 (age when tested) 28 days

te (age when exposed) 28 days

α (age factor) 0.4 (0.08)

Ccr (critical chloride content) 0.4 (0.08)

Cs (surface chloride content) 3.8 (0.9)


0.00

10.00

20.00

30.00

40.00

50.00

60.00

70.00

80.00

90.00

100.00

0 100 200 300 400 500

Pro

bab

ilit

y o

f fa

ilu

re (

%)

Years

G 70

UDHPC

‘Nye Tjuvholmen’, Oslo (2005-?)Owner requested for 300 years design life


Mix Design Oslo (b) Oslo (SS) UDHPC

Design life 500 years

Cover depth 100 (10) mm 50 (2) mm

Temperature 30ºC

DcoefΧ10-12 m/s 2 (0.4) 0.11 (0.01)

t0 (age when tested) 28 days

te (age when exposed) 28 days

α (age factor) 0.4 (0.08)

Ccr (critical chloride

content)0.4 (0.08) 2 (0.5) 0.4 (0.08)

Cs (surface chloride

content)3.8 (0.9)


0

10

20

30

40

50

60

70

80

90

100

0 100 200 300 400 500

Pro

bab

ilit

y o

f fa

ilu

re (

%)

Years

Oslo (b)

Oslo (SS)

UDHPC

Content





Durable Concrete Structures for the

Marine Environment

1- Durability Specifications

2- General Guidelines for Durability Design,

Quality Assurance and Preventive

Maintenance

In Collaboration with Em. Professor Odd E. Gjørv

Department of Structural Engineering, Norwegian

University of Science and Technology

Acknowledgment

o BASF Asia Pacific Pte Ltd

o EnGro Corporation Limited

o Proceq Asia Pte Ltd

o Elkem Materials SEA Pte Ltd

o Bekaert Singapore Pte Ltd

Thank You ….

underwater infrastructure and underwater city of the future · 2017-09-13 · nilsson, l., ngo, m....

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