EAT Crack Control

abc

Project

Delhi Metro MC1B

Client

IMCC External slabs and walls

Made by

Early Age Thermal Crack Control Reinforcement Design

Checked

Location

Date

STS

Page

17-Sep-2013 Revision

Job No

Ref 1: Ref 2:

59120

Early-age thermal crack control in concrete - Ciria Report 91 BS 8007:1987 - Design of concrete structures for retaining aqueous liquids

INPUT Type of Concrete:

Ordinary Portland Cement (OPC) Sulphate Resisting Portland Cement (SRPC) Rapid Hardening Portland Cement (RHPC)

Use of Pozzolanic or Latent Hydraulic Materials: Pulverised Fuel Ash (PFA) Ground Granulated Blastfurnace Slags (GGBS)

SRPC RHPC

PFA GGBS

Cement Content (OPC) = PFA Content =

280 120 0

kg/m³ kg/m³

Concrete Grade = Dominant Movement =

35

N/mm2

Quartzite

Type of Aggregate:

Type of Formwork:

OPC

Steel Formwork 18mm Plywood Formwork

STEEL PLYWOOD

Type of Steel:

415

N/mm²

Diameter of Bars:

201

mm²

1200

mm

Expected Concrete Placing Temperature =

25

°C

Fall in Temperature due to Seasonal Variations (T2) =

15

°C

Maximum Allowable Crack Width (Wmax) =

0.2

mm

Maximum Thermal Expansion Coefficient (x 10-6/°C) =

14.6

USE MAX

Minimum Thermal Expansion Coefficient (x 10-6/°C) = Average Thermal Expansion Coefficient (x 10-6/°C) =

11.7 9.2

USE MIN

Section Thickness =

USE AVERAGE

abc

Project

Delhi Metro MC1B

Client

IMCC External slabs and walls

Made by

Early Age Thermal Crack Control Reinforcement Design

Checked

Location

Date

STS

Page

17-Sep-2013 Revision

Job No

-

59120

CALCULATIONS Temperature Rise Above Mean Ambient Temperature (°C) 35.57 Peak Temperature of Concrete Attributable to the Portland Cement (°C) 50.57 Contribution to the Temperature Rise from PFA in Concrete (°C) 4.80 Contribution to the Temperature Rise from GGBS in Concrete (°C) 0.00 Contribution to the Temperature Rise Increased Placing Temperature (°C) 5.34 Design Mix Tempeature (°C) 60.71

Maximum Spacing of Cracks (Smax) = (fct/fb) x (Ø/2r) fct/fb = 0.67

where

r = As/Ac rcrit = 0.0064 Maximum Crack Width (Wmax) = Smax x (a/2) x (T1 + T2) Rearranging these formulas gives As =

(fct/fb) x

a x (T1 + T2) x Ø x Ac 4 W max a= T1 + T2 =

Required Area of Steel: r=

Data Checks:

T16@ 80mm T16@ 82mm

°C

Ac =

250000

mm2

As =

2440

mm2

0.0098 > rcrit =

= 2513 mm2 = 2440 mm2

x 10-6

60.71

Smax = Steel to be used: or

12

0.0064 549

OK mm

abc

Project

Delhi Metro MC1B

Client

IMCC External slabs and walls

Made by

Early Age Thermal Crack Control Reinforcement Design

Checked

Location

Date

STS

Page

17-Sep-2013 Revision

Job No

-

59120

Range of Temperature Rises Above Mean Ambient Temperature (ºC) 76 74 72 70 68 66 64 62 60 58 56 54 52 50 48 46 44 42 40 38 36 34 32 30 28 26 24 22 20 18 16 14 12 10 8 6 4 2 0

220 (kg/m³) 290 (kg/m³) 360 (kg/m³) 400 (kg/m³) 500 (kg/m³)

35.57

Design Values

0

200

400

600

800

1000

1200

abc

Project

Delhi Metro MC1B

Client

IMCC External slabs and walls

Made by

Early Age Thermal Crack Control Reinforcement Design

Checked

Location

Date

STS

Page

17-Sep-2013 Revision

Job No

Ref 1: Ref 2:

59120

Early-age thermal crack control in concrete - Ciria Report 91 BS 8007:1987 - Design of concrete structures for retaining aqueous liquids

INPUT Type of Concrete:

Ordinary Portland Cement (OPC) Sulphate Resisting Portland Cement (SRPC) Rapid Hardening Portland Cement (RHPC)

Use of Pozzolanic or Latent Hydraulic Materials: Pulverised Fuel Ash (PFA) Ground Granulated Blastfurnace Slags (GGBS)

RHPC

PFA GGBS

Cement Content (OPC) = PFA Content =

300 120 0

kg/m³ kg/m³

Concrete Grade = Dominant Movement =

45

N/mm2

Quartzite

Type of Aggregate:

Type of Formwork:

OPC SRPC

Steel Formwork 18mm Plywood Formwork

STEEL PLYWOOD

Type of Steel:

415

N/mm²

Diameter of Bars:

201

mm²

Section Thickness =

800

mm

Expected Concrete Placing Temperature =

25

°C

Fall in Temperature due to Seasonal Variations (T2) =

15

°C

Maximum Allowable Crack Width (Wmax) =

0.2

mm

Maximum Thermal Expansion Coefficient (x 10-6/°C) =

14.6

USE MAX

Minimum Thermal Expansion Coefficient (x 10-6/°C) = Average Thermal Expansion Coefficient (x 10-6/°C) =

11.7 9.2

USE MIN USE AVERAGE

abc

Project

Delhi Metro MC1B

Client

IMCC External slabs and walls

Made by

Early Age Thermal Crack Control Reinforcement Design

Checked

Location

Date

STS

Page

17-Sep-2013 Revision

Job No

-

59120

CALCULATIONS Temperature Rise Above Mean Ambient Temperature (°C) 34.62 Peak Temperature of Concrete Attributable to the Portland Cement (°C) 49.62 Contribution to the Temperature Rise from PFA in Concrete (°C) 4.62 Contribution to the Temperature Rise from GGBS in Concrete (°C) 0.00 Contribution to the Temperature Rise Increased Placing Temperature (°C) 5.19 Design Mix Tempeature (°C) 59.43

Maximum Spacing of Cracks (Smax) = (fct/fb) x (Ø/2r) fct/fb = 0.67

where

r = As/Ac rcrit = 0.0064 Maximum Crack Width (Wmax) = Smax x (a/2) x (T1 + T2) Rearranging these formulas gives As =

(fct/fb) x

a x (T1 + T2) x Ø x Ac 4 W max a= T1 + T2 =

Required Area of Steel: r=

Data Checks:

T16@ 80mm T16@ 84mm

°C

Ac =

250000

mm2

As =

2389

mm2

0.0096 > rcrit =

= 2513 mm2 = 2389 mm2

x 10-6

59.43

Smax = Steel to be used: or

12

0.0064 561

OK mm

abc

Project

Delhi Metro MC1B

Client

IMCC External slabs and walls

Made by

Early Age Thermal Crack Control Reinforcement Design

Checked

Location

Date

STS

Page

17-Sep-2013 Revision

Job No

-

59120

Range of Temperature Rises Above Mean Ambient Temperature (ºC) 76 74 72 70 68 66 64 62 60 58 56 54 52 50 48 46 44 42 40 38 36 34 32 30 28 26 24 22 20 18 16 14 12 10 8 6 4 2 0

220 (kg/m³) 290 (kg/m³) 360 (kg/m³) 400 (kg/m³)

34.62

500 (kg/m³) Design Values

0

200

400

600 Element Thickness

800

1000

1200

abc

Project

Delhi Metro MC1B

Client

IMCC External slabs and walls

Made by

Early Age Thermal Crack Control Reinforcement Design

Checked

Location

Date

STS

Page

17-Sep-2013 Revision

Job No

Ref 1: Ref 2:

59120

Early-age thermal crack control in concrete - Ciria Report 91 BS 8007:1987 - Design of concrete structures for retaining aqueous liquids

INPUT Type of Concrete:

Ordinary Portland Cement (OPC) Sulphate Resisting Portland Cement (SRPC) Rapid Hardening Portland Cement (RHPC)

Use of Pozzolanic or Latent Hydraulic Materials: Pulverised Fuel Ash (PFA) Ground Granulated Blastfurnace Slags (GGBS)

SRPC RHPC

PFA GGBS

Cement Content (OPC) = PFA Content =

320 80 0

kg/m³ kg/m³

Concrete Grade = Dominant Movement =

35

N/mm2

Granite

Type of Aggregate:

Type of Formwork:

OPC

Steel Formwork 18mm Plywood Formwork

STEEL PLYWOOD

Type of Steel:

500

N/mm²

Diameter of Bars:

201

mm²

1200

mm

Expected Concrete Placing Temperature =

25

°C

Fall in Temperature due to Seasonal Variations (T2) =

10

°C

Maximum Allowable Crack Width (Wmax) =

0.2

mm

Maximum Thermal Expansion Coefficient (x 10-6/°C) =

10.3

USE MAX

Minimum Thermal Expansion Coefficient (x 10-6/°C) = Average Thermal Expansion Coefficient (x 10-6/°C) =

8.1 9.2

USE MIN

Section Thickness =

USE AVERAGE

abc

Project

Delhi Metro MC1B

Client

IMCC External slabs and walls

Made by

Early Age Thermal Crack Control Reinforcement Design

Checked

Location

Date

STS

Page

17-Sep-2013 Revision

Job No

-

59120

CALCULATIONS Temperature Rise Above Mean Ambient Temperature (°C) 40.43 Peak Temperature of Concrete Attributable to the Portland Cement (°C) 55.43 Contribution to the Temperature Rise from PFA in Concrete (°C) 3.80 Contribution to the Temperature Rise from GGBS in Concrete (°C) 0.00 Contribution to the Temperature Rise Increased Placing Temperature (°C) 6.06 Design Mix Tempeature (°C) 60.29

Maximum Spacing of Cracks (Smax) = (fct/fb) x (Ø/2r) fct/fb = 0.67

where

r = As/Ac rcrit = 0.0064 Maximum Crack Width (Wmax) = Smax x (a/2) x (T1 + T2) Rearranging these formulas gives As =

(fct/fb) x

a x (T1 + T2) x Ø x Ac 4 W max a= T1 + T2 =

Required Area of Steel: r=

Data Checks:

T16@ 100mm

°C

Ac =

250000

mm2

As =

1858

mm2

0.0074 > rcrit =

= 2011 mm2

x 10-6

60.29

Smax = Steel to be used:

9.2

0.0064 721

OK mm

abc

Project

Delhi Metro MC1B

Client

IMCC External slabs and walls

Made by

Early Age Thermal Crack Control Reinforcement Design

Checked

Location

Date

STS

Page

17-Sep-2013 Revision

Job No

-

59120

Range of Temperature Rises Above Mean Ambient Temperature (ºC) 76 74 72 70 68 66 64 62 60 58 56 54 52 50 48 46 44 42 40 38 36 34 32 30 28 26 24 22 20 18 16 14 12 10 8 6 4 2 0

220 (kg/m³) 290 (kg/m³)

40.43

360 (kg/m³) 400 (kg/m³) 500 (kg/m³) Design Values

0

200

400

600 Element Thickness

800

1000

1200