Transcript
Page 1: Global Manager, Dams & Hydropower - ESI-Africa.com · Mark Cordell Global Manager, Dams & Hydropower High quality consulting and development solutions worldwide

Mark Cordell

Global Manager, Dams & Hydropower

High quality consulting and development solutions

worldwide

Page 2: Global Manager, Dams & Hydropower - ESI-Africa.com · Mark Cordell Global Manager, Dams & Hydropower High quality consulting and development solutions worldwide

Major Dams ≥60mUnder Construction in 2009

Source: 2009 World Atlas & Industry Guide

Page 3: Global Manager, Dams & Hydropower - ESI-Africa.com · Mark Cordell Global Manager, Dams & Hydropower High quality consulting and development solutions worldwide

Major Dams ≥60mUnder Construction in 2009 - Worldwide- Africa

Source: 2009 World Atlas & Industry Guide

Page 4: Global Manager, Dams & Hydropower - ESI-Africa.com · Mark Cordell Global Manager, Dams & Hydropower High quality consulting and development solutions worldwide

RCC Mix DesignAn Introduction and Case Study

• Introduction

• RCC and Dam Construction Today

• RCC Mix Constituents

• RCC Design Philosophies

• Options Using Various ‘Quality’ Aggregates

­ A Case Study

Page 5: Global Manager, Dams & Hydropower - ESI-Africa.com · Mark Cordell Global Manager, Dams & Hydropower High quality consulting and development solutions worldwide

RCC Mix Constituents

Roller Compacted Concrete – RCC – is a Concrete

• Dry enough to

support vibratory

roller

• Wet enough to

permit adequate

distribution of

paste

Page 6: Global Manager, Dams & Hydropower - ESI-Africa.com · Mark Cordell Global Manager, Dams & Hydropower High quality consulting and development solutions worldwide

RCC Design Philosophies

“High Paste”

• High cementitious content (typ. 180­240kg/m3)

• Relatively large quantities of Pozzolan as

substitute for natural fines

• Workable material

• Low permeability

• “Premium” concrete

Page 7: Global Manager, Dams & Hydropower - ESI-Africa.com · Mark Cordell Global Manager, Dams & Hydropower High quality consulting and development solutions worldwide

RCC Design Philosophies

“Low Paste”

• Low cementitious content (typ. 70­90kg/m3)

• Relies on continuous dense grading envelope to

fine fraction for its density

• Lower workability

• Higher permeability

• Need for Upstream Membrane?

Page 8: Global Manager, Dams & Hydropower - ESI-Africa.com · Mark Cordell Global Manager, Dams & Hydropower High quality consulting and development solutions worldwide

Location• Dak Nong

Province,Vietnam

Services• Technical Appraisal• RCC Mix Lab Tests/Trial Embankment• Construction Assistance

Main Features• 108m RCC dam• 180MW Power house• 607GWh/annum

Dong Nai 3 Hydroelectric Project, Vietnam

DONG NAI 3 HEP

Page 9: Global Manager, Dams & Hydropower - ESI-Africa.com · Mark Cordell Global Manager, Dams & Hydropower High quality consulting and development solutions worldwide

Project Status

• Feasibility Studies completed in March 2000

• Design further developed by Power Engineering

Consulting Company No.2 (PECC2) with

assistance from an International Consultant Firm

• SMEC engaged to undertake Independent

Technical Appraisal of Dong Nai 3 and Dong Nai

4 RCC Dam Designs in January 2006

• SMEC’s appointment in accordance with GoV

policy for technical oversight on large RCC Dams

Page 10: Global Manager, Dams & Hydropower - ESI-Africa.com · Mark Cordell Global Manager, Dams & Hydropower High quality consulting and development solutions worldwide

Project Status

Following the Independent Technical Appraisal,

SMEC were engaged to:

•Supervise the RCC Trial Mix Programme,

including the Trial Embankment

•Supervise the establishment of the Aggregate

Quarry

•Provide ongoing Construction Assistance for

Dong Nai 3 and Dong Nai 4 RCC Dams

Page 11: Global Manager, Dams & Hydropower - ESI-Africa.com · Mark Cordell Global Manager, Dams & Hydropower High quality consulting and development solutions worldwide

Principal Objectives of Technical Appraisal

• Review the proposed design concept of the RCC

dams

• Review the proposed RCC dam construction

methodology

• Assess geological conditions of the dam sites

and proposed quarries

• Inspect and comment on concrete laboratory

and hydraulic modelling facilities used for design

development of the Projects

Page 12: Global Manager, Dams & Hydropower - ESI-Africa.com · Mark Cordell Global Manager, Dams & Hydropower High quality consulting and development solutions worldwide

Original Design Concept for RCC Dam

• RCC mix design based on high cementitious

content 170kg/m³

(60kg/m³ cement; 110kg/m³ pozzolan)

• Metasediment aggregate source

• Central Vietnam commercial pozzolan source

­ relatively high transportation cost

Page 13: Global Manager, Dams & Hydropower - ESI-Africa.com · Mark Cordell Global Manager, Dams & Hydropower High quality consulting and development solutions worldwide

Locally Available Aggregate Options- Metasediment Aggregate Source

Page 14: Global Manager, Dams & Hydropower - ESI-Africa.com · Mark Cordell Global Manager, Dams & Hydropower High quality consulting and development solutions worldwide

Locally Available Aggregate Options- Basalt Aggregate Source

Page 15: Global Manager, Dams & Hydropower - ESI-Africa.com · Mark Cordell Global Manager, Dams & Hydropower High quality consulting and development solutions worldwide

Characteristics of Basalt Quarry - Solid Basalt

Page 16: Global Manager, Dams & Hydropower - ESI-Africa.com · Mark Cordell Global Manager, Dams & Hydropower High quality consulting and development solutions worldwide

Characteristics of Basalt Quarry- Vesicular Basalt

Page 17: Global Manager, Dams & Hydropower - ESI-Africa.com · Mark Cordell Global Manager, Dams & Hydropower High quality consulting and development solutions worldwide

Characteristics of Basalt Quarry- Dirt Seams

Page 18: Global Manager, Dams & Hydropower - ESI-Africa.com · Mark Cordell Global Manager, Dams & Hydropower High quality consulting and development solutions worldwide

Thermal Expansion and Thermal Stress

• Critical property of concrete for dams

• If stiffness (Modulus of Elasticity) and creep

similar, thermal stress and related potential for

cracking essentially proportional to coefficient of

thermal expansion

• This property of RCC dependent of aggregate

properties

Page 19: Global Manager, Dams & Hydropower - ESI-Africa.com · Mark Cordell Global Manager, Dams & Hydropower High quality consulting and development solutions worldwide

Thermal Expansion and Thermal Stress

At Dong Nai 3:

• Metasediment 10.7 x 10­6/°C

• Basalt 4.6 x 10­6/°C

The Basalt aggregate offered much more

favourable thermal properties – low thermal

stresses

Page 20: Global Manager, Dams & Hydropower - ESI-Africa.com · Mark Cordell Global Manager, Dams & Hydropower High quality consulting and development solutions worldwide

Unit Weight, Density and Air Voids

• Initial concern with vesicular nature was effect

the basalt aggregate would have on RCC density

• When crushed to less than 13mm, specific

gravity of the two aggregates essentially same

(≈2.72)

• Coarser aggregates had a lower specific gravity

for 25­50mm particles (2.64 vs 2.76)

Page 21: Global Manager, Dams & Hydropower - ESI-Africa.com · Mark Cordell Global Manager, Dams & Hydropower High quality consulting and development solutions worldwide

Unit Weight, Density and Air Voids

• However, the coarse aggregates only

represented 20% of total aggregate – impact on

the overall density not significant

• The vesicular basalt exhibited greater

absorption, but the mix proportions were based

on saturated aggregates, so essentially no effect

Page 22: Global Manager, Dams & Hydropower - ESI-Africa.com · Mark Cordell Global Manager, Dams & Hydropower High quality consulting and development solutions worldwide

Gradation

• Initial gradation of aggregates adjusted to be

consistent with efficient RCC mixes (greater

strength per kg of cementitious material)

• Better mixability

• Less segregation for mixes of same cementitious

content

• Less void space in compacted aggregates

• Less need for cement and pozzolan to fill void

space

0

1 0

2 0

3 0

4 0

5 0

6 0

7 0

8 0

9 0

1 0 0

0 .0 1 0 .1 0 1 .0 0 1 0 .0 0 1 0 0 .0 0

S ize (m m )

% P

assi

ng

In it ia l M e ts S a nd s ton e La b M ix G r ad a t io n

S M E C M ix e d B as a lt La b M ix G r ad a tio n

S M E C B as a lt A t In ita l La b M ix G r ad a tio n

Page 23: Global Manager, Dams & Hydropower - ESI-Africa.com · Mark Cordell Global Manager, Dams & Hydropower High quality consulting and development solutions worldwide

Comprehensive Mix Design Studies

• Many mixes assessed ­ varying cement and

pozzolan contents, including mixes with no

pozzolan

• Control mixes – ‘initial’ gradation

• Most mixes used improved gradation

• Base mixes used ‘mixed basalt’ – 70% solid

basalt; 25% vesicular basalt; 5% dirty material

• 100% crushed vesicular basalt mix made for

comparison

Page 24: Global Manager, Dams & Hydropower - ESI-Africa.com · Mark Cordell Global Manager, Dams & Hydropower High quality consulting and development solutions worldwide

Compressive Strength Development [MPa]

0

5

10

15

20

25

30

35

40

1 10 100 1000

Co

mp

res

siv

e S

tre

ng

th (M

Pa

)

Age (Days)

170-65-4.2 (7) 1x (SMEC Gradation - Metasediment) VB1=11 Sec170-65-4.2 (4) 1x (Initial Gradation-Metasediment) VB1= 23 Sec170-65-4.2 (8) 1x (SMEC Mixed Basalt) VB1=15 Sec

Cementitious Content (kg/m3)-% Pozzolan-% Moisture Content (% Fines) Admix Dose

Accelerated Cure

Accelerated Cure

Page 25: Global Manager, Dams & Hydropower - ESI-Africa.com · Mark Cordell Global Manager, Dams & Hydropower High quality consulting and development solutions worldwide

Basalt vs Metasediment – No Pozzolan

0

5

10

15

20

25

30

35

40

1 10 100 1000

Co

mp

res

siv

e S

tre

ng

th (M

Pa

)

Age (Days)

90-0-4.2 (8) 1x : VB1=15 Sec, Mixed Basalt

90-0-4.2 (7) 1x : VB1=15 Sec, Metasediment

Cementitious Content (kg/m3)-% Pozzolan-% Moisture Content (% Fines) Admix Dose

SMEC Gradation

Page 26: Global Manager, Dams & Hydropower - ESI-Africa.com · Mark Cordell Global Manager, Dams & Hydropower High quality consulting and development solutions worldwide

Effectiveness of Pozzolan vs Aggregate Fines

0

5

10

15

20

25

30

35

40

1 10 100 1000

Co

mp

ress

ive

Str

eng

th (M

Pa)

Age (Days)

60-0-4.2 (8) 1x : VB1=12 Sec

120-0-4.2 (8) 1x : VB1=18 Sec

120-50-4.2 (8) 1x : VB1=13 Sec

170-65-4.2 (8) 1x: VB1=15 Sec

Cementitious Content (kg/m3)-% Pozzolan-% Moisture Content (% Fines) Admix Dose

60 kg Cement + 60 kg Cement

60 kg Cement + 60 kg Pozz

60 kg Cement + 00 kg Pozz

60 kg Cement + 110 kg Pozz

SMEC Mixed BasaltSIKA TM 25 Admix

Accelerated Cure

Page 27: Global Manager, Dams & Hydropower - ESI-Africa.com · Mark Cordell Global Manager, Dams & Hydropower High quality consulting and development solutions worldwide

Effect of Dirty Material on Strength

0

5

10

15

20

25

30

35

40

1 10 100 1000

Co

mp

ress

ive

Str

eng

th (M

Pa)

Age (Days)

90-0-4.2 (8) 1x : VB1=15 Sec, 5% Dirty Basalt90-0-4.2 (8) 1x : VB1=15 Sec, No Dirty Basalt

Cementitious Content (kg/m3)-% Pozzolan-% Moisture Content (% Fines) Admix Dose

Page 28: Global Manager, Dams & Hydropower - ESI-Africa.com · Mark Cordell Global Manager, Dams & Hydropower High quality consulting and development solutions worldwide

RCC Trial Embankment

Page 29: Global Manager, Dams & Hydropower - ESI-Africa.com · Mark Cordell Global Manager, Dams & Hydropower High quality consulting and development solutions worldwide

RCC Trial Embankment

Page 30: Global Manager, Dams & Hydropower - ESI-Africa.com · Mark Cordell Global Manager, Dams & Hydropower High quality consulting and development solutions worldwide

Mix 110 + 60 (Basalt)

Page 31: Global Manager, Dams & Hydropower - ESI-Africa.com · Mark Cordell Global Manager, Dams & Hydropower High quality consulting and development solutions worldwide

Mix 75 + 00 (Basalt)Mix 90 + 00 (Basalt)

Page 32: Global Manager, Dams & Hydropower - ESI-Africa.com · Mark Cordell Global Manager, Dams & Hydropower High quality consulting and development solutions worldwide

Dong Nai 3 RCC Dam - Nearing Completion

Page 33: Global Manager, Dams & Hydropower - ESI-Africa.com · Mark Cordell Global Manager, Dams & Hydropower High quality consulting and development solutions worldwide

Thank You

Mark CordellGlobal Manager, Dams & [email protected]

High quality consulting and development

solutions worldwide www.smec.com


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