Concrete Mix Design Criteria

for Tilt-Up Construction in The

Arabian Peninsula

Fadi Elayache, Abu Dhabi May 19th 2010 Fadi Elayache, Abu Dhabi May 19th 2010

Alliance

1

Typical Performance Parameters of A Mix Design

For Tilt-up Cost usually Does

not exceed 300 Dhs/ Cum

For Tilt-up Cost usually Does

not exceed 300 Dhs/ Cum

For Tilt-up, Slump

shall be between

150 + 25 mm

For Tilt-up, Slump

shall be between

150 + 25 mm

2

Outline

Strength

7- Recommendations for a

Concrete Mix Design of Tilt-up

Construction

7- Recommendations for a

Concrete Mix Design of Tilt-up

Construction3

History of Tilt-Up Construction

“Tilt-up construction eliminates the costly,

cumbersome practice of erecting two wooden walls

to get one concrete wall.”

~ Thomas Edison, 1903 ~

4

History of Tilt-Up Construction

Tilt-Up is a cost effectivebuilding method that

achieves the benefits of

solid steel-reinforcedconcrete walls, quickly,and without the need for

wall forms or scaffolding

TILT-UP DIGEST 6,

Steel Reinforcement, Institute of Australia

No Block workNo External PlasterNo Internal PlasterNo Exterior ColumnsNo LintelsNo Bond Beams

5

Current trends of Tilt-Up Construction

50

100

150

200

250

300

1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005

Million SF Tilt-Up Wall

• About 100 million Sqm of Built–up area are constructed with tilt-up every year worldwide. Mainly in the US, Canada, Australia, Mexico and New Zealand

• Tilt-up is growing at about 20 % yearly in the US

• In the ME, First Tilt-up is under construction in Jordan

• The next ones will be in Saudi Arabia and Afghanistan shortly

6

The Tilt-Up Method

7

The Tilt-Up Process

Forming the

Panels on a clean

leveled Slab on

Grade

Forming the

Panels on a clean

leveled Slab on

Grade

8

The Tilt-Up Process

Add Architectural

Rustication if

Required

Add Architectural

Rustication if

Required

9

The Tilt-Up Process

Apply The Bond-

Breaker Agent

Apply The Bond-

Breaker Agent

10

The Tilt-Up Process

Reinforcement &

inserts placement

Reinforcement &

inserts placement

11

The Tilt-Up Process

Concrete Casting

& Consolidation

Concrete Casting

& Consolidation

12

The Tilt-Up Process

Curing 5 to 7 Days

& Preparation for

Tilting

Curing 5 to 7 Days

& Preparation for

Tilting

13

The Tilt-Up Process

Imperative Testing

Compressive &

Bending Strength

Imperative Testing

Compressive &

Bending Strength

14

Lifting , It is a Day You Don’t Want to MissLifting , It is a Day You Don’t Want to Miss

15

Multi-Stories With Tilt-up

16

Temporary Bracing

17

Grouting

18

Structural Roof/ Slab Diaphragm made of

Steel Joist, beams and decking

Braces Remain in-place until the

Engineer of Record confirms they can

be removed

19

Structural Roof/ Slab Diaphragm made of

Hollow Core or CIP Reinforced Concrete Slab

Braces Remain in-place until the

Engineer of Record confirms they can

be removed

20

Cleaning and Painting

21

Creativity With Tilt-up

22

Beacon Pointe, Weston, FL

Creativity With Tilt-up

23

Insulated Sandwich Panels

24

Is Tilt-up the Same as Precast ?

Precast

RC Walls

Cast in plant

Transported to Site

Multiple Handling

Width 3.5 - 4.0 m

Height: Up to 12 m

Weight 5 to 15 ton

Tilt-up Records:Width = 30 mHeight =33 mWeight = 150 Ton

25

Tilt-up

RC Walls

Cast on Site

No Transportation

Single Handling

Width up to 12 m

Height: 22 to 27 m

Weight: 45 to 55 ton

In Service Loadings and Transverse Load Resistance

26

Applied Loadings

Stresses from Lifting Load are most likely to Govern

27

EDGE LIFT

Thick- Panel Height (m) = H ness 2.5 3.0 3.5 4.0 4.5

100 mm 1.58 2.27 120 mm 1.31 1.89 2.57

150 mm 1.05 1.51 2.06 2.69 175 mm 0.90 1.30 1.76 2.30 2.91

200 mm 0.79 1.13 1.54 2.01 2.55

Sample of (1.4) Factored Tilt-up Maximum Flexural Tensile Stress (MPa)

of 1 m wide Solid Panel

28

SINGLE ROW FACE LIFT (2pt) Thick- Panel Height (m) = H

ness 4.0 4.5 5.0 5.5 6.0 6.5 7.0 7.5 100 mm 1.36 1.72 2.12 2.56

120 mm 1.13 1.43 1.77 2.14 2.54 150 mm 0.90 1.14 1.41 1.71 2.03 2.39 2.77

175 mm 0.78 0.98 1.21 1.46 1.74 2.05 2.37 2.72 200 mm 0.68 0.86 1.06 1.28 1.53 1.79 2.08 2.39

Sample of (1.4) Factored Tilt-up Maximum Flexural Tensile Stress (MPa)

of 1 m wide Solid Panel

29

SINGLE ROW FACE LIFT (4 pt) Thick- Panel Height (m) = H

ness 4.0 4.5 5.0 5.5 6.0 6.5 7.0 7.5 100 mm 1.36 1.72 2.12 2.56

120 mm 1.13 1.43 1.77 2.14 2.54 150 mm 0.90 1.14 1.41 1.71 2.03 2.39 2.77

175 mm 0.78 0.98 1.21 1.46 1.74 2.05 2.37 2.72 200 mm 0.68 0.86 1.06 1.28 1.53 1.79 2.08 2.39

Sample of (1.4) Factored Tilt-up Maximum Flexural Tensile Stress (MPa)

of 1 m wide Solid Panel

30

DOUBLE ROW FACE LIFT Thick- Panel Height (m) = H

ness 6.5 7.0 7.5 8.0 8.5 9.0 9.5 10.0 10.5

100 mm 1.60 1.86 2.13 2.42 120 mm 1.33 1.55 1.78 2.02 2.28 2.56

150 mm 1.07 1.24 1.42 1.62 1.83 2.05 2.28 2.53 175 mm 0.91 1.06 1.22 1.39 1.56 1.75 1.95 2.16 2.39

200 mm 0.80 0.93 1.07 1.21 1.37 1.53 1.71 1.90 2.09

Sample of (1.4) Factored Tilt-up Maximum Flexural Tensile Stress (MPa)

of 1 m wide Solid Panel

31

All of the above shall not exceed the flexural strength of concrete as obtained by ASTM C78 third

point Loading at the time of lifting

Consists of:1.Self Weight of Panel2.Suction Load between Panel and Casting Surface3.Dynamic Load at the time of lifting between the panel and the casting surface

Suction and Dynamic loadings

are usually estimated at 40 % of panel self weight

Design Loadings During Lifting

32

For Normal Concrete Construction Mr = Modulus of Rupture (ROM by ACI)=

7.5√ f’c in PSI0.71 √f’c in MPa

Correlation between Flexural &

Compressive Strength

For Tilt –up Construction, Mr= Modulus of Rupture (ROM) =

4.0√ f’c in PSI0.4 √f’c in MPa

At Early Age 5 to 7 day, Mr shall be obtained by testing via ASTM C78

33 34

Climatic Conditions

Max & Min Temperature

0

5

10

15

20

25

30

35

40

45

50

Jan

Mar

May

July

Sept

Nov

Month

Te

mp

era

ture

De

gre

e c

Mean Min TempMean Max Temp

(Max – Min )Temp ~ 20 Deg C

35

Climatic Conditions

Daily Sunshine

0

2

4

6

8

10

12

JanM

arM

ay

JulySep

tNov

Month

Ho

urs

Daily Sunshine

Daily Sunshine in July = 11 hrs

36

Climatic Conditions

Min & Max Relative Humidity

010

2030

4050

6070

8090

100

JanM

arM

ayJu

lySe

ptNov

Month

RH

%

Mean Min RH

Mean Max RH

RH variation in a Typical Day is

about 60%

37

Climatic Conditions

Rainfall & Evaporation

0

1

2

3

4

5

6

7

8

Jan

Mar

May

July

Sept

Nov

Month

Millim

ete

rs

Ave Daily RainfallAve Daily Evaporation

On an average Less 0.5 mm

daily rainfall with 5 mm of

evaporation

38

Climatic Conditions

Gulf Salinity

• High Temperature

• High Daily Sunshine

• High Evaporation

• Low Rainfall

• Shallow water of the Gulf

High Salinity

45%0

35%0

38%0

39

Micro Climatic Conditions

Temperature & Relative Humidity

0

5

10

15

20

25

30

35

0 3 6 9 12 15 18 21 24

Daily Timing

Tem

pera

ture

Deg

ree C

0

20

40

60

80

100

Re

lati

ve

Hu

mid

ity

%

Temperature Relative Humidity

Variation of RH and Temperature

During a Typical Day in April,

(Sharjah, UAE)

40

Durability Challenge –Chloride ingress into

Concrete 1st stage

During Wetting Cycle (high RH), the near –surface concrete absorbs

the chloride solution from exposed surface

Concrete Cover

41

During dry period (low RH), water evaporates from surface and high chloride

concentration forms. Moist gas in the inner concrete carries the Cl ions deeper

into concrete due to vapor pressure and temperature gradients.

Durability Challenge –Chloride ingress into

Concrete 2nd stage

Concrete Cover

42

Durability Challenges and Remedy

To Minimize the chloride ingress Into Concrete,

1.Concrete cover shall be crack free

2.Reduce the porosity of Mortar Fraction

3.Reduce the Mortar Fraction Volume in the mix

MF = 50 % MF = 67 %

(Ref: G. R Summers, Gulf Construction, Sep 2001)

MF=∑ of Volume (Air, water, cement, and sand) in %

43

Concrete Mix Design Criteria for Tilt-up Construction in the Arabian Peninsula

f’c (cube) = 40 to 45 MpaSlump = 150 + 25 mm

Sand Type: Well Graded

Aggregate Type : Crushed Max Aggregate Size = 20 mm

Water Cement Ratio = 0.42 to 0.45

depending on exposure conditionCement Type: I or II

Max cement Content = 400 kgMax Water Content = 150 liter per m3 of mix

MF = 50 to 55 %

Cement Supplement: None Heat inducing Air Content : 2 to 3 %

Concrete Cover = 40

to 50 mm

44

References

1- CON/STEEL LJB Library

2- “Guide to the Construction of Reinforced Concrete in the Arabian Peninsula” CIRIA C577

3- R.G Summers, Gulf construction, Sep 20014- Fadi Elayache, Samir Chidiac, Nabil Kallas,

“ Concrete Durability Issues for the Gulf RegionICPCM, Feb 18, 2003

5- TCA, “Tilt-up Construction & engineering Manual” 6th Edition, 2007

6- “Tilt-up Concrete Buildings, Design and Construction Guide”, British Cement Association,

19987- “ Technical Manual TM34”Cement & Concrete

Association of New Zealand, 2004

45

Q & A

ThanksThanks

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