65

REFERENCES

[1]. Dhammika K. Wijayasinghe,” a case study of the “Sahaspura” slum relocation

project,” M.S Thesis, Institute for Housing and Urban Development Studies,

Colombo, Sri Lanka,2010.

[2]. Channa Kasturisinghe, (2003, July 8). Invests Rs. 25m in hollow core slab

facility.DailyNewsBusiness(SriLanka).[online].Available:http://archives.dailyn

ews.lk/2003/07/08/bus11.html.

[3]. D. B. P. S. Vidyarathne,” Household Income and Expenditure,” Department of

Census and Statistics, Ministry of Finance and Planning, Sri Lanka, Tech.Rep.

ISBN 978-955-577-719-3, 2009/10.

[4]. W.P.S. Dias, “Useful life of buildings,” Department of Civil Engineering

University of Moratuwa, Sri Lanka, Tech.Rep.4 June 2003.

[5]. R.I.Gilbert and N.C.Mickleborough, Design of Prestressed Concrete. School of

Civil Engineering: Sydney, Australia, 1990.

[6]. Bently Staad.(1999).“Advantages of Post-Tensioning,” [Online].Available:

http://www.ehow.com/info_7932750_advantages-vs-post-tension-slab.html.

[7]. Jim Rogers. (2008, Nov. 25). Post-Tensioned Slab. Webmaster Mag.[Online].

Available: http://www.concreteconstruction.net /concrete-construction /post-

tensioned-slab-on-ground-foundations.aspx.

[8]. Evaluation and Certification Service, LLC. (2006).What is Post-Tensioning.

[Online].Available:http://www.buildersshow.com/Documents/course_handouts

/PostTensioned%20Concrete%20in%20Residential%20Construction.pdf.

[9]. Jim Rogers. (2012 Sep. /Oct.). Concrete Floors. Webmaster Mag.

[Online].Available:http://www.freemagazines.co.za/magazines/floors10/files_f

loors10 /assets/basic-html/page38.html.

[10]. Manamohan R Kalgal, Post-tensioned Concrete in Building Sector [Online].

Available:http://www.sefindia.org/forum/files /pt_in_building_sector_839.pdf.

[11]. Ed Cross, Post-Tensioning in Building Structures. [Online].Available:http://ww

w.ptia.net.au/Documents/Post-tensioning%20%20Building % 20Structures.pdf.

[12]. Boskey Vishal Bahoria and Dhananjay K.Parbat .(2013 ,February).Analysis and

Design of RCC and Post-tensioned Flat Slabs Considering Seismic

Effect.IACSIT International Journel of Engineering and Technology,Vol.5

No.1. [Online]. Available:http://www.ijetch.org/papers/500-C10011.pdf.

66

[13] CCL’s DesignTeam.(2011,Oct).”Post-TensionedSlab,”[online].Available:http:

http://www.cclint.com/sites/default/files ccl_ptslabsbrochureeng.pdf.

[14]. G.D.Palmer, “What are the Advantages & Disadvantages of a Conventional

Concrete Slab Vs. a Post Tension Slab?,” [Online]. Available:

http://www.ask.com/question/what-is-a-post-tension-slab

[15]. Nainar Uma Sentil .(2008-09).”Concrete Basics.org's Newsletter,” [online].

Available: http://www.concretebasics.org/lccb/ptslab.php.

[16]. Kevin. (2007, November). “Post-tensioned or reinforced: Structural

Engineering,”[online]. Available: http://seaint.blogspot.com/2007/11/re-post-

tensioned-or-reinforced.html.

[17]. Dhammika Senarath Kumara, (2011). Post Tensioned Concrete Floors [Online].

Available:http://www.civil.mrt.ac.lk/conference/ICSECM_2011/SEC-11-8.pdf.

[18]. Bijan O. Aalami and Jennifer D.Jurgens. (2003, March). Guidelines for the

Design of Post-Tensioned Floors. Webmasters Mag.

[Online].Available:http://www.adaptsoft.com/resources/Aalami_CI_Mar03_pa

per.pdf.

[19]. Jim Rogers.(2009, September). “Post Tensioning Ironworker Certification

Program,” [online article]. Available : www.ironworkercertification.com.

[20]. B.Dixit Raj .(2011,July). Post Tensioning In Building Structures. Department

of Civil Engineering Gokaraju Rangaraju Institute of Engineering &

Technology Nizampet Road, Hyderabad-500090. [online].

Available:http://grietinfo.in/projects/MINI/civil/Civil_Miniproject_Dixit.pdf.

[21]. Design and Construction, Code of Practice BS 8110: Part 1& Part 3: 1985.

67

Appendix A

Sample Questionnaire

68

Appendix B

Conventional Reinforced Slab

Design Spread Sheet for 7mx9m

Panel for the Live Load of 1.5kN/m2

69

Appendix C

Conventional Reinforced Beam Design

Spread Sheet for 7m Span for the

Live Load of 1.5kN/m2

70

Appendix D

Required Quantities of Materials for

Conventional Reinforced Slabs and Beams for the

Live Load of 1.5kN/m2

71

Appendix E

Unit Rate Calculation for Conventional Reinforced

Slab and Beams for 21mx27m

Area for the Live Load of 1.5kN/m2

72

Appendix F

Post -Tensioned Slab Design

Spread Sheet for 7mx9m Panel for the

Live Load of 1.5kN/m2

73

Appendix G

Conventional Reinforced Beam Design

Spread Sheet for 7m for the

Live Load of 1.5kN/m2 for the Post-Tensioned Slab

74

Appendix H

Required Quantities of Materials for the

Post-Tensioned Slabs and the Conventional Reinforced

Beams for the Live load of 1.5kN/m2

75

Appendix I

Unit Rate Calculation for Post-Tensioned Slab and

Conventional Reinforced Beams for 21m x 27m

Area for the Live Load of 1.5kN/m2

76

Appendix J

Basic Prices for Accessories for the

Post-Tensioned Slab

77

Appendix K

Work Study Spread Sheet for

Three Multi-Storied Buildings

Appendix A- Sample Questionnaire: Study on Viability of adopting Post Tensioned Slab Construction in Sri

Lanka

Research Supervisor : Dr. K. Baskaran, Department of Civil Engineering, University of Moratuwa Page 1

Appendix A- Sample Questionnaire

Research Subject: Study on Viability of adopting Post Tensioned Slab Construction in Sri Lanka

1. Information on Respondent

Please place a tick () as appropriate

a. Your Profession

I. Engineer ( )

II. Architect ( )

III. Quantity Surveyor ( )

Iv. Any other (Please specify) …………………………………………

b. Your Experience in the Construction Industry

I. Less than 5 years ( )

II. Between 5 and 10 years ( )

III. More than 10 years ( )

c. Your current employment is in

I. Government Department ( )

II. State Corporation, Board etc., ( )

III. Private Sector ( )

Iv. Any other (Please specify)………………………………………………

d. Your role in the Construction Sector

I. Contractor ( ) II. Consultant ( ) III. Client ( ) Iv. Any other (Pl specify)…………………………………………..……….

Appendix A- Sample Questionnaire: Study on Viability of adopting Post Tensioned Slab Construction in Sri

Lanka

Research Supervisor : Dr. K. Baskaran, Department of Civil Engineering, University of Moratuwa Page 2

2. Your views on the construction practices of “multi-storied buildings in Sri

Lanka”

Please strike off what is not applicable. Answer could be more than one.

a. What are the main super structure elements in a multi-storied

building?

i. Walls Yes/No

ii. Columns Yes/No

iii. Beams and slab Yes/No

iv. Roof Yes/No

v. Any other (Pl specify)……………………………………………..…

b. In general, what is the most costly super structure element in your

experience?

i. Walls Yes/No

ii. Columns Yes/No

iii. Beams and slabs Yes/No

iv. Roof Yes/No

v. Any other (Pl specify)……………………………………………..…

3. Your views on slab construction in “multi-storied buildings in Sri Lanka”

Please place a tick () as appropriate.

a. What is the main structural material frequently used for slab at

present?

i. Reinforced concrete ( )

ii. Steel ( )

iii. Masonry ( )

iv. Timber ( )

v. Any other (Pl specify)………………………………………………………..…

Appendix A- Sample Questionnaire: Study on Viability of adopting Post Tensioned Slab Construction in Sri

Lanka

Research Supervisor : Dr. K. Baskaran, Department of Civil Engineering, University of Moratuwa Page 3

4. IF the answer to question number 3 is Reinforced Cement Concrete, please answer the following questions Please strike off what is not applicable. Answer could be more than one.

a. What are the advantages in using the Reinforced Cement Concrete

for slabs?

I. Durability Yes/No

II. Less maintenance cost Yes/No

III. Low repair cost Yes/No

vi. Any other (Pl

specify)…………………………………………………………………………..…

b. What are the disadvantages of using Reinforced Cement Concrete for

slabs in your experience?

i. Un-economical beyond certain thickness Yes/No

ii. Un-economical when spans increase Yes/No

iii. Any other (Pl

specify)…………………………………………………………………………..…

5. Please express your involvement in the “Post tensioned slabs”, based on

Your experience in Sri Lanka or Abroad

Please strike off what is not applicable. Answer could be more than one.

a. What is your experience on post tensioned slabs?

I. Designing of “Post Tensioned slabs” Yes/No

II. Construction of “Post Tensioned slabs” Yes/No

III. Any other (Pl

specify)…………………………………………………………………………..…

b. What are the advantages of using “Post Tensioned slabs”, in your

experience?

Please place a tick () as appropriate. Answer could be more than

one.

Appendix A- Sample Questionnaire: Study on Viability of adopting Post Tensioned Slab Construction in Sri

Lanka

Research Supervisor : Dr. K. Baskaran, Department of Civil Engineering, University of Moratuwa Page 4

Advantages Yes No

1 Longer Spans are possible

2 Overall saving on Structural Cost

3 Reduced Floor to Floor Height

4 Deflection Free Slabs

5 Water tight Slabs

6 Early Stripping of formwork

7 Easy handling of materials

8 Lighter foundation designs

9 Speedier of Construction

10 Any other (Please explain below)

…………………………………………………………………………………………………….

……………………………………………………………………………………………………..

…………………………………………………………………………………………………….

……………………………………………………………………………………………………..

c. What are the disadvantages of “Post Tensioned slabs”, in your

opinion?

Please strike off what is not applicable. Answer could be more than

one.

I. Needs the services of trained operatives for

installation and tensioning which involves

additional trade on site

Yes/No

II. Involves additional site works such as drilling

holes on the side shutters and fixing anchorage

blocks to the formwork

Yes/No

III. Special materials such as anchorages, ducts

and tendons will have to be specially procured

and stored on site

Yes/No

Appendix A- Sample Questionnaire: Study on Viability of adopting Post Tensioned Slab Construction in Sri

Lanka

Research Supervisor : Dr. K. Baskaran, Department of Civil Engineering, University of Moratuwa Page 5

IV. Special equipment such as stressing jacks

and grout pumps will have to be

procured initially, maintained and moved

from one position to another within site

and from one site to the other

Yes/ No

V. Any others ………………………..

6. Do you have any idea on cost comparison between

“Reinforced Cement Concrete and Post Tensioned Concrete

slab? Yes/ No

If Yes, please express your views and explain :

……………………………………………………………………………………………

……………………………………………………………………………………………

…………………………………………………………………………………………….

……………………………………………………………………………………………

…………………………………………………………………………………………….

7. Do you think that the post tensioned slab construction in

multi-storied building projects is viable in Sri Lanka?

Yes/ No

If Yes , please express your views and explain :

……………………………………….…………………………………………………

……………………………………………………………………………………………

Appendix B- Conventional reinforced slab design spread sheet for 7mx9m panel for live load of 1.5kN/m2

Sheet No.

Two way edge supported Slab( Live load=1.5 kN/m2

)

BS 8110

Part 1:1985 Ly = 9 m

Lx = 7 m

C D

Short Span of the slab Lx = 7 m

Long Span of the slab Ly = 9 m

Density of the concrete s = 24

Concrete compressive strength fcu = 25

Diameter of r/f = 12 mm

Span/Effective depth = 40

Table 3.5 Cover for 1 hour fire resistance = 20 mm

Live load = kN/m2

Partition = kN/m2

Finishes = kN/m2

Effective depth d = mm

Slab thickness h = h= mm

dshort = mm Spacing

dlong = mm

Aspect Ratio = ly/lx ==

Self weight = kN/m2

Design load = kN/m2

kN/m3

0.5

N/mm2

200

Output

1.3

11.22

Date

Reference Calculations

1.5

UNIVERSITY OF

MORATUWA

Course of

Study

M.Eng/PGDip.in Structural

Engineering Design

Component Conventional slab design

4.8

175

200

162

174.0

1.0

Page 1 of 4

Appendix B- Conventional reinforced slab design spread sheet for 7mx9m panel for live load of 1.5kN/m2

Sheet No.

Output

Date

Reference Calculations

UNIVERSITY OF

MORATUWA

Course of

Study

M.Eng/PGDip.in Structural

Engineering Design

Component Conventional slab design

Table 3.15 βsx = One long Edge discontinuous

βsy =

βex =

βey =

msx = kNm/m

msy = kNm/m

mex = kNm/m

mey = kNm/m

Design for reinforcement

Short way mid span

M/bd2

=

From the chart ,Part 3

100As/bd =

As =

Number of bar =

Max.spacing 3d = mm

Asmin = mm2

Provide r/f at = mm spacing Number of bar prov 5 h= mm

Asprov = mm2

Spacing

Check deflection

Table 3.10 BasicSpan/eff.depth =

fs = N/mm2

Modification Factor = F1

F1 = < 2

Allowable Span/eff.depth =

Actual span /eff.depth =

Deflection Criteria Satisfied

250

204

40.2

26

1.8

0.23

48

20.34

0.85

0.028

0.037

25.84

15.39

0.047

0.062

400.2

34.09

260

3.54

522

565.2

mm2

Table 3.27

250

Page 2 of 4

Appendix B- Conventional reinforced slab design spread sheet for 7mx9m panel for live load of 1.5kN/m2

Sheet No.

Output

Date

Reference Calculations

UNIVERSITY OF

MORATUWA

Course of

Study

M.Eng/PGDip.in Structural

Engineering Design

Component Conventional slab design

Short way continuous edge

M/bd2

=

From the chart ,Part 3

100As/bd =

As =

Number of bar =

Max.spacing 3d = mm

Asmin = mm2

Provide r/f at = mm spacing Number of bar prov 5 h= mm

Asprov = mm2

Spacing

Table 3.16 Check Shear

βvx ==

Vsx = kN/m

v = N/mm2

Table 3.9 0.79(100As/bd)1/3

=

=

=

ϒm ==

vc = N/mm2

Long way mid span

M/bd2

=

From the chart ,Part 3

100As/bd =

As = mm2

Number of bar =

Max.spacing 3d = mm

Asmin = mm2

Provide r/f at = mm spacing Number of bar prov 4 h= mm

Asprov = mm2

Spacing

200

300

mm2

1.1

4.46

0.29

300

2.44

452.2

0.17

275.4

0.59

260

486

1.23

0.54

0.47

0.54

1.25

No shear r/f required

Table 3.27

Table 3.27

522

260

504.6

200

(400/d)1/4

(fcu/25)1/3

565.2

1.00

36.9

0.212

Page 3 of 4

Appendix B- Conventional reinforced slab design spread sheet for 7mx9m panel for live load of 1.5kN/m2

Sheet No.

Output

Date

Reference Calculations

UNIVERSITY OF

MORATUWA

Course of

Study

M.Eng/PGDip.in Structural

Engineering Design

Component Conventional slab design

Long way, continuous edge

M/bd2

=

From the chart ,Part 3

100As/bd =

As = mm2

Number of bar =

Max.spacing 3d = mm

Asmin = mm2

Provide r/f at = mm spacing Number of bar prov 4 h= mm

Asprov = mm2

Spacing

Table 3.16 Check Shear

βvx ==

Vsx = kN/m

v = N/mm2

Table 3.9 0.79(100As/bd)1/3

=

(400/d)1/4

=

(fcu/25)1/3

=

ϒm ==

vc = N/mm2

300

452.2

28.3

0.175

0.52

1.00

1.25

0.52

No shear r/f required

300

3.15

260

1.25

0.78

0.36

0.22

356.4

Table 3.27

486

Page 4 of 4

Appendix C-Conventional reinforced beam design spread sheet for 7m for 1.5 kN/m2

Sheet No.

Two way edge supported Slab ( Live load=1.5 kN/m2

)

7m x 9m Panel

Edge Beam(7m)

Short span lx = 7 m

Long span ly = 9 m

Table 3.10 Span/Effective depth = 23 For Span< 10 m

Required effective depth d = mm

Beam height h = mm

Beam width b = mm

Diameter of r/f φ = 16 mm

Cover c = 25 mm

Calculated effective depth de = mm

Concrete compressive strength fcu == 25 N/mm2

Loading from the conventional slab

Live load = kN/m2

Partition = kN/m2

Finishes = kN/m2

Self weight = kN/m2

Table 3.16 Two adjacent edges discontinuous, βvy =

Total dead load from the slab = kN/m

Self wt of beam = 4 kN/m

Total dead load for the beam = kN/m

Total live load from the slab = kN/m

Design load = kN/m

From SAP 2000, Analysis

Msag = kNm

Mhog = kNm

1.5

BS

8110:Part1:

1985

304

600

Conventional beam design

300

567

Reference Calculations Output

UNIVERSITY OF MORATUWA

Component

Course of

Study

M.Eng/PGDip.in Structural Engineering

Design

26.47

1.0

4.8

0.26

11.47

15.8

0.5

2.73

115

130

Page 1 of 5

Appendix C-Conventional reinforced beam design spread sheet for 7m for 1.5 kN/m2

Sheet No.

Conventional beam design

Reference Calculations Output

UNIVERSITY OF MORATUWA

Component

Course of

Study

M.Eng/PGDip.in Structural Engineering

Design

Design for span moment(Sag)

Clause 3.4.4.4 K=M/bd2fcu = <

Compression r/f is not required

Z = < 0.95d

As = mm2

Provide = 3 T16 = 3

Aspro = mm2

Check for deflection

Table 3.10 Basic Span/eff.depth = 23

fs = N/mm2

M/bd2

=

Table 3.11 Modification Factor =

Allowable Span/eff.depth =

Actual span /eff.depth =

Deflection =

Design for support moment(hog)

Clause 3.4.4.4 K=M/bd2fcu = <

Compression r/f is not required

Z = < 0.95d

As = mm2

Provide = 4 T16 = 4

Aspro = mm2

Shear force = kN

Shear Stress v = N/mm2

Clause 3.4.5.3 0.87(fcu)1/2

= N/mm2

>

So, no crushing occurs

Table 3.9 0.79(100As/bd)1/3

=

(400/d)1/4

=

0.156

535.2

537

602.9

256

0.048

1.2

1.430

32.9

12.3

Satisfied

0.054 0.156

531

612

804

112

0.66

4.35

0.62

0.66

1.0

Page 2 of 5

Appendix C-Conventional reinforced beam design spread sheet for 7m for 1.5 kN/m2

Sheet No.

Conventional beam design

Reference Calculations Output

UNIVERSITY OF MORATUWA

Component

Course of

Study

M.Eng/PGDip.in Structural Engineering

Design

=

ϒm =

vc = N/mm2

<

= N/mm2

0.5vc = N/mm2

Table 3.8 < v < vc +0.4

Diameter of a link = 10 mm

Ae = mm

2

fyv = N/mm

2

Asv/sv =

sv = mm

Provide 10 mm Diameter of a link R 10 At

Mild steel at = Spacing stirrups mm

1.25

0.49 0.66

0.89

0.25

0.5vc

78.5

250

vc +0.4

275275 mm

0.55

285

(fcu/25)1/3

1.00

Page 3 of 5

Appendix C-Conventional reinforced beam design spread sheet for 7m for 1.5 kN/m2

Sheet No.

Conventional beam design

Reference Calculations Output

UNIVERSITY OF MORATUWA

Component

Course of

Study

M.Eng/PGDip.in Structural Engineering

Design

All the spans are loaded with the distributed load of 26.5 kN/m (1.4Gk +1.6Qk) on the SAP 2000

modal

Bending Moment Diagram for the distributed load of 26.5 kN/m (1.4Gk +1.6Qk) from the SAP 2000

modal Analysis

Shear Force Diagram for the distributed load of 26.5 kN/m (1.4Gk +1.6Qk) from the SAP 2000 modal

Analysis

Page 4 of 5

Appendix C-Conventional reinforced beam design spread sheet for 7m for 1.5 kN/m2

Sheet No.

Conventional beam design

Reference Calculations Output

UNIVERSITY OF MORATUWA

Component

Course of

Study

M.Eng/PGDip.in Structural Engineering

Design

Bending Moment Diagram for the distributed load of 26.5 kN/m (1.4Gk +1.6Qk) and 15.8 kN/m from

the SAP 2000 modal Analysis

Spans are loaded with the distributed load of 26.5 kN/m (1.4Gk +1.6Qk) and 15.8 kN.m 1.0 Gk on the

SAP 2000 modal

Shear Force Diagram for the distributed load of 26.5 kN/m (1.4Gk +1.6Qk) and 15.8 kN/m from the

SAP 2000 modal Analysis

Page 5 of 5

Appendix D - Required Quantities of Materials for Conventional Reinforced Slabs and Beams for the Live

Load of 1.5 kN/m2

9X9 Panel

( 27 mX27m)

8X9 Panel

( 24 mX27m)

7X9 Panel

( 21 mX27m)

6X9Panel

( 18 mX27m)

5X9Panel

( 15 mX27m)

223 168 148 110 80

Tor bar 25mm Dia(Ton) 6.62376 7.527 4.93308 3.31188 2.70972

Tor bar 20mm Dia(Ton) 2.13408 0 1.24488 1.83768 1.60056

Tor bar 16mm Dia(Ton) 1.16736 0.29184 0.51072 0.3648 0.21888

Tor bar 12mm Dia(Ton) 13.69104 10.23792 6.73728 0.03696 0

Tor bar 10mm Dia (Ton) 3.47988 2.550678 2.372982 5.538192 5.1828

Mild steel 10mm Dia (Ton) 0.799632 0.445474 0.423262 0.469537 0.3702

Quantity of the Steel(Ton) 27.895752 21.052912 16.222204 11.559049 10.08216

666 598 518 453 366

394 309 279 234 183

Required Quantities of Materials for Conventional Reinforced Slabs and Beams for

the Live Load of 1.5 kN/m2

Formwork(m2) for Slab

Formwork(m2) for Beam

Material type

Concrete Grade 25/m3

Page 1 of 1

Appendix E - Unit rate calculation for conventional reinforced slab and beams for

21mx27m area for the live load of 1.5 kN/m2

QuantityCost(Rs)/

unit

Total

cost(Rs)

148 13,250 1961000

4.93308 149,000 735029

1.24488 149,000 185487

0.51072 149,000 76097

6.73728 149,000 1003855

2.372982 149,000 353574

0.423262 149,000 63066

518 1100 569800

279 1250 348750

9342

Supply and placing concrete Grade 25(m3)

Supply and tieing Tor bar 25mm Dia(Ton)

Supply and tieing Tor bar 20mm Dia(Ton)

Supply and tieing Tor bar 16mm Dia(Ton)

Supply and tieing Tor bar 12mm Dia(Ton)

Unit rate calculation for conventional reinforced slab and beams for

21mx27m area for the live load of 1.5 kN/m2

Supply and tieing Tor bar 10mm Dia(Ton)

7X9 Panel ( 21 mX27m)

Supply and tieing mild steel10mm Dia(Ton)

Total cost (Rs) per m2

Items

For Live load of 1.5 kN/m2

Supply , Fixing and Removing Formwork(m2)

for Beam

Supply , Fixing and Removing Formwork(m2)

for Slab

Page 1 of 1

Appendix F-Post-tensioned slab design spread sheet for 7mx9m panel for the live load of 1.5 kN/m2

Sheet No.

Two way edge supported Slab

Design of Prestressed Concrete

By

R.I.Gilbert

N.C. Micklebrough

Ly = 9 m

Lx = 7 m

C D

Short Span of the slab Lx = m

Long Span of the slab Ly = m

Thickness of the slab h = mm

Density of the concrete s = kN/m3

Concrete compressive strength = N/mm2

Concrete tensile strength = N/mm2

Elastic Modulus of concrete = N/mm2

Characteristric strength of steel fb = N/mm2

Elastic Modulus of prestressing steel = = N/mm2

Flat Ducted tendons

Strands diametre = N/mm2

Area of a strand Ap = mm2

No of strands per tendons = 3

Reference Calculations Output

UNIVERSITY OF

MORATUWA

Course of

Study

M.Eng/PGDip.in Structural

Engineering Design

Component Post Tensioning slab design Date

35

24

7

9

160

1840

195000

12.7

100

30000

3.5

AS 3600-

1988

Page 1 of 9

Appendix F-Post-tensioned slab design spread sheet for 7mx9m panel for the live load of 1.5 kN/m2

Sheet No.

Reference Calculations Output

UNIVERSITY OF

MORATUWA

Course of

Study

M.Eng/PGDip.in Structural

Engineering Design

Component Post Tensioning slab design Date

Size of the duct

Width = 75 mm

Height = 19 mm

From top to Centre = 7 mm

Conrete cover = 25 mm

Live = kN/m2

Partitions = kN/m2

Finshes = kN/m2

Self weight of floor slab ( Calculated) = kN/m2

0.5

3.84

1.0

1.5

Page 2 of 9

Appendix F-Post-tensioned slab design spread sheet for 7mx9m panel for the live load of 1.5 kN/m2

Sheet No.

Reference Calculations Output

UNIVERSITY OF

MORATUWA

Course of

Study

M.Eng/PGDip.in Structural

Engineering Design

Component Post Tensioning slab design Date

Calculation

The Maximum Depth to CGS for the short -span

dx == mm = mm

= 0 mm

= mm

= mm

The cable drape in the short-span direction

hx = mm

The Maximum Depth to CGS for the Long -span

dy = mm = mm

= mm

= mm

= mm

The cable drape in the Long-span direction

hy = mm

= Dwelling

= 30 %

= kN/m2

The Total sustained load wsus = kN/m2

Alpha = 2

External Balancing load wb = 5 kN/m2

wpx = kN/m2

wpy = kN/m2

Height of CGS above the CGC at the

support on LHS

67

43

64.5

104

43

43

123

0.45

The live load assumed to be

sustained as per AS 3600-1988

5.8

For 1 long edge

discontinuous

Height of CGS above the CGC at the

support on LHS

Height of CGS above the CGC at the

support onRHS

Height of CGS below the CGC at the

span

Height of CGS above the CGC at the

support on RHS 43

Height of CGS below the CGC at the

span 24

The transverse load exerted by the

tendons in the short-span direction

2.89

The transverse load exerted by the

tendons in the Long-span direction

2.11

123

104

Page 3 of 9

Appendix F-Post-tensioned slab design spread sheet for 7mx9m panel for the live load of 1.5 kN/m2

Sheet No.

Reference Calculations Output

UNIVERSITY OF

MORATUWA

Course of

Study

M.Eng/PGDip.in Structural

Engineering Design

Component Post Tensioning slab design Date

Px = kN/m

Py = kN/m

The time dependent losses = 15 %

The prestress in each direction Pxi = kN/m

Pyi = kN/m

The immediate losses at theJack

In the x direction = 8 %

In the y direction = 12 %

The prestress in each direction Pxj = kN/m

Pyj = kN/m

The breaking load per tendon = kN

= kN

The required tendon spacing in each direction

Sx = mm

Sy = mm

Select tendon spacing = = mm

Pxj = Pyi = kN = kN

And at mid span,after all losses,

Px = kN

Py = kN

The load to be balanced is revised

wpx = kN/m2

wpy = kN/m2

Now,the external Balancing load wb = kN/m2

= kN

0.85

0.92

0.88

319

3.5

2.1

Maximum force to be applied to a stress-relieved post

tensioned during the stressing operation,if the limit is applied

on the Jacking forces/tendon

The effective prestress in each

direction 274

323

376

351

427

5.6

427

334

319

The avarage efective prestress after

losses in each direction isassumed

1100

0.85 fbAp 469

552

319

1338

1099

The revised prestressing forces at the jack

per metre width are

427

1100

Page 4 of 9

Appendix F-Post-tensioned slab design spread sheet for 7mx9m panel for the live load of 1.5 kN/m2

Sheet No.

Reference Calculations Output

UNIVERSITY OF

MORATUWA

Course of

Study

M.Eng/PGDip.in Structural

Engineering Design

Component Post Tensioning slab design Date

=

Final shrinkage strain =

Dead load = kN/m2

ψs =

wu = kN/m2

β = Ref Page 387

The maximum moment MCD = kNm/m

I = mm4

Z = mm3

Check for cracking

Stress at top = N/mm2

Compression

Stress at Bottom = N/mm2

Compression

Average compressive stress level 2.0- 3.0 Mpa Satisfied

Check for deflection

Maximum total deflection

wus = kN/m

Short term deflection v = mm

The sustained portion of unbalanced load = kN/m

Deflection due to vsus = mm

Creep induced deflection vcr = 0 mm

Shrinkage-induced curvature xsh = mm

Shrinkage-induced deflection vsh = mm

vtot = = mm

9E-07

0.6

-1.6

-2.40

0.36

341333333

0.6

0.4

5.34

0.057

2.5

In the x-direction over support CD,the concrete stresses in the

top and the bottom fibres are

4266666.7

0.10

0.1

5.0

4.1

Under this unbalanced load,the maximum moment occurs over

the beam support CD by using the moment coefficiants for

edge-supported slabs in Table 10.2

Final Creep coefficient for concrete in

post tension slab

v+vcr+vsh

-1.7

0.0005

The maximum unbalanced transverse load to be

considered for short-term serviceability for

Page 5 of 9

Appendix F-Post-tensioned slab design spread sheet for 7mx9m panel for the live load of 1.5 kN/m2

Sheet No.

Reference Calculations Output

UNIVERSITY OF

MORATUWA

Course of

Study

M.Eng/PGDip.in Structural

Engineering Design

Component Post Tensioning slab design Date

The maximum panel deflection vtot = mm

= mm

K = Page 427

The unbalanced load wu = kN/m2

The sustained part of the unbalanced load

wus = kN/m2

Le/D <=

[wu+3wus]1/3

[(vtot/Le)1000Ec]1/3

=

[wu+3wus]1/3

=

Le/D <=

D = mm Satisfied Satisfied

Check for Flexural Strength

Dead load = kN/m2

Live load = kN/m2

The Factored design load as per AS 3600-1988

w* = kN/m2

βx = Page 386

βy =

The deflection at the centre of the slab panel will be

approximately 30% less than this owing to the torsional stiffness

of the slab which has been ignored in the above analysis.

137

5.34

The design moments at mid=span in each direction are

obtained are obtained from Eq 10.7 with values taken

from Table 10.1

0.046

0.028

3.83

It is of value to examin the slab thickness

predicted,if the limiting deflection is taken

For this edge-supported slab panel,the slab

system factor is taken from table 11.4 ,K

2.4

1.5

8.9

0.6

51

3.83

0.4

25.3

1.19

K[(vtot/Le)1000Ec]1/3

Page 6 of 9

Appendix F-Post-tensioned slab design spread sheet for 7mx9m panel for the live load of 1.5 kN/m2

Sheet No.

Reference Calculations Output

UNIVERSITY OF

MORATUWA

Course of

Study

M.Eng/PGDip.in Structural

Engineering Design

Component Post Tensioning slab design Date

= kNm/m

= kNm/m

The maximum design moment occurs over the beam support CD

= kNm/m

Depth to neutral axis at ultimate

h = Ap = mm2

b = Ep = N/mm2

h' = 43 Ec = N/mm2

i = mm4

ece =

Pe = kN/m ept = 0.003(R62-dn)/dn

epe =

epu = 0.00612+0.003(R62-dn)/dn

c = 0.85X35X1000X0.800Xdn= 23800 dn

The resultant tensile force T = Apσpu

Horizontal equilibrium requires that C=T

= 87.3dn

σpu(N/mm2)

21

The depth to the neutral axis at ultimate = mm

However, the maximum limitting value =

= mm

The tensile force in the steel = kN/m

Mu = kNm/m

φMu = kNm/m

> kNm/m

Hence,Conventional r/f is not required to supplement the

prestressed steel over the beam support CD

0.4d

49.2

500

57.3

45.88

26.2

0.0207 1835

Trial dn epu

σpu

21.0

273

195000

0.00600

12.25

0.00012

1000 mm

mm

341333333

30000

319

MDC 26.15

160 mm

Mx*

My*

20.12

Page 7 of 9

Appendix F-Post-tensioned slab design spread sheet for 7mx9m panel for the live load of 1.5 kN/m2

Sheet No.

Reference Calculations Output

UNIVERSITY OF

MORATUWA

Course of

Study

M.Eng/PGDip.in Structural

Engineering Design

Component Post Tensioning slab design Date

Checking for strength at other critical section

At mid-span in the x-direction:

= kNm/m

= kNm/m

d = mm

Hence,no additional r/f is required

At mid-span in the y-direction:

= 21 mm

However, the maximum limitting value =

= mm

The tensile force in the steel = kN/m

Mu = kNm/m

=

> kNm/m

Hence,no additional r/f is required

At the short continuos supports;

= kNm/m

φMu = kNm/m

> 16 kNm/m

Hence,no additional r/f is required

Ckeck Shear strength

V* = Lx w*/2

= kN/m

s = Pe

A

= N/mm2

Q =

Q/Ib =

t = Q Vt/Ib

s1 = 0.33(fc)1/2

s1 = N/mm2

From the equation 5.11 from the text book

The depth to the neutral axis at

ultimate

20.1

φMu

Mx*

57.3

φMu 38.27

12.2

My* 16

45.88

31

-2.08

3200000

0.4d

41.6

500

47.8

1.95

9.38E-06

123

Page 8 of 9

Appendix F-Post-tensioned slab design spread sheet for 7mx9m panel for the live load of 1.5 kN/m2

Sheet No.

Reference Calculations Output

UNIVERSITY OF

MORATUWA

Course of

Study

M.Eng/PGDip.in Structural

Engineering Design

Component Post Tensioning slab design Date

(s1- s /2 )2

= Eqn----1

(s /2)2

= Eqn----2

Eqn---1 -Eqn---2 =

t2

=

t =

Vt =

= kN/m

f =

= kN/m

Clearly V* is much less than fVuc

and the shear strength is ample here

Shear strength at all other sections are also satisfactory.

Shear is rarely a problem in edge-supported slabs.

0.8

fVuc 240

7.882

7.882

2.807

t/Q/Ib

299

8.968

1.087

Page 9 of 9

Appendix G-Conventional reinforced beam desin spread sheet for the live load of 1.5 kN/m2

for the post tensioned slab

Sheet No.

7m x 9m Panel

Edge Beam(7m)

Short span lx = 7 m

ly = 9 m

Table 3.10 Span/Effective depth = 26 For Span< 10 m

Required effective depth d = mm

Beam height h = mm

Beam width b = mm

Diameter of r/f φ = 16 mm

Table 3.4 Cover c = 35 mm

Calculated Effective depth de = mm

Concrete compressive strength fc == 35 N/mm2

Loading from the post-tensioned slab

Live load = kN/m2

Partition = kN/m2

Finish = kN/m2

Self weight = kN/m2

Table 3.16 Two adjacent edges discontinuous, βvy =

Total dead load from the slab = kN/m

Total live load from the slab = kN/m

Self wt of beam = kN/m

Total Dead load for the beam = kN/m

Total live load from the slab = kN/m

Design load = kN/m

BS

8110:Part1:

1985

2.73

23.52

550

1.0

3.84

0.26

Reinforced Beam Design

Reference Output

UNIVERSITY OF

MORATUWA

Component

9.72

Course of

Study

M.Eng/PGDip.in Structural Engineering

Design

3.96

0.5

300

13.7

507

2.73

Two way edge supported post tensioned Slab

for the Live load of 1.5 kN/m2

1.5

269

Page 1 of 5

Appendix G-Conventional reinforced beam desin spread sheet for the live load of 1.5 kN/m2

for the post tensioned slab

Sheet No.

Reinforced Beam Design

Reference Output

UNIVERSITY OF

MORATUWA

Component

Course of

Study

M.Eng/PGDip.in Structural Engineering

Design

From the sap 2000, analysis Msag = kNm

Mhog = kNm

Design for Span moment(Sag)

K=M/bd2fcu = <

Compression r/f is not required

Z = < 0.95d

As = mm2

Provide = 3 3

Aspro = mm2

Check for deflection

Table 3.10 Basic Span/eff.depth = 26

fs = N/mm2

M/bd2

=

Table 3.11 Modification Factor =

Allowable Span/eff.depth =

Actual span /eff.depth =

Deflection =

Design for Support moment(hog)

K=M/bd2fcu = <

Compression r/f is not required

Z = < 0.95d

As = mm2

Provide= 4 4

Aspro = mm2

Shear force = kN

Shear Stress v = N/mm2

0.87(fcu)1/2

= N/mm2

>

So, no crushing occurs

T16=

T16=

482

13.8

5.15

Satisfied

484.5

0.65

0.043

115

0.65

36.0

0.156

596

99

804

0.038 0.156

531

253

1.3

1.384

602.9

103

Clause

3.4.4.4

Clause

3.4.4.4

Clause

3.4.5.3

Page 2 of 5

Appendix G-Conventional reinforced beam desin spread sheet for the live load of 1.5 kN/m2

for the post tensioned slab

Sheet No.

Reinforced Beam Design

Reference Output

UNIVERSITY OF

MORATUWA

Component

Course of

Study

M.Eng/PGDip.in Structural Engineering

Design

Table 3.9 0.79(100As/bd)1/3

=

(400/d)1/4

=

=

ϒm =

vc = N/mm2

<

= N/mm2

0.5vc = N/mm2

Table 3.8 < v < vc +0.4

Diametre of a link = 10 mm

Ae = mm

2

fyv = N/mm

2

Asv/sv =

sv = mm

Provide 10 mm Diameter of a link R 10 At

Mild steel at = Spacing stirrups250 mm

0.65

0.29

0.97

0.64

1.25

0.57

1.12

1.0

250

0.55

285

(fcu/25)1/3

250

vc +0.4

0.5vc

78.5

Page 3 of 5

Appendix G-Conventional reinforced beam desin spread sheet for the live load of 1.5 kN/m2

for the post tensioned slab

Sheet No.

Reinforced Beam Design

Reference Output

UNIVERSITY OF

MORATUWA

Component

Course of

Study

M.Eng/PGDip.in Structural Engineering

Design

All the spans are loaded with the distributed load of 23.5 kN/m (1.4Gk +1.6Qk) on the SAP

2000 modal

Bending Moment Diagram for the distributed load of 23.5 kN/m (1.4Gk +1.6Qk) from the

SAP 2000 modal Analysis

Shear Force Diagram for the distributed load of 23.5 kN/m (1.4Gk +1.6Qk) from the SAP

2000 modal Analysis

Page 4 of 5

Appendix G-Conventional reinforced beam desin spread sheet for the live load of 1.5 kN/m2

for the post tensioned slab

Sheet No.

Reinforced Beam Design

Reference Output

UNIVERSITY OF

MORATUWA

Component

Course of

Study

M.Eng/PGDip.in Structural Engineering

Design

Spans are loaded with the distributed load of 23.5 kN/m (1.4Gk +1.6Qk) and 13.7kN.m 1.0

Gk on the SAP 2000 modal

Bending Moment Diagram for the distributed load of 23.5 kN/m (1.4Gk +1.6Qk) and 13.7

kN/m from the SAP 2000 modal Analysis

Shear Force Diagram for the distributed load of 23.5 kN/m (1.4Gk +1.6Qk) and 13.7kN/m

from the SAP 2000 modal Analysis

Page 5 of 5

Appendix H - Required quantities of materials for post-tensioned slabs and beams for

the live of 1.5 kN/m2

9X9Panel

( 27 mX27m)

8X9 Panel

( 24 mX27m)

7X9Panel

( 21 mX27m)

6X9 Panel

( 18 mX27m)

5X9 Panel

( 15 mX27m)

189 146 124 92 75

6.0216 6.99432 4.09932 2.70972 2.70972

1.06704 0 1.06704 1.7784 1.42272

1.16736 0.29184 0.7296 0.29184 0.32832

0.805802 0.686721 0.322691 0.318989 0.299862

0.799632 0.447325 0.702146 0.389944 0.3702

1.50 1.45 1.35 1.20 1.07

4.1 3.7 2.8 2.5 1.6

56 53 44 44 44

56 53 44 44 44

168 159 132 126 88

168 159 132 126 88

1512 1347 1082 909 896

12 12 12 12 12

666 598 518 450 366

394 304 276 230 178

2 2 2 2 2

Formwork(m2) for Slab

Tor bar 25mm Dia(Ton)

Formwork(m2) for Beam

Tor bar 20mm Dia(Ton)

Tor bar 16mm Dia(Ton)

Tor bar 10mm Dia(Ton)

Mild steel bar 10mm

Dia(Ton)

Live end Anchor block(nos)

Multi Strands Jacks/Month

Required quantities of materials for post-tensioned slabs and beams for the

live of 1.5 kN/m2

Labours for PT work( laying

duct,inserting stands and

Jacking)

Sheath/Duct (m)

Concrete Grade 35(m3)

Material Items

Minimum R/F Tor steel

10mm Dia(Ton)

12.7mm Strand(Ton)

Recess former (nos)

Wedges(nos)

Dead end Anchor block(nos)

Page 1 of 1

Appendix I - Unit rate calculation for the post-tensioned slab and beams for

21mx27m area for the live of 1.5 kN/m2

Quantity Cost(Rs)/

unit

Total

cost(Rs)

124 14,750 1829000

4.09932 149,000 610799

1.06704 149,000 158989

0.7296 149,000 108710

0.322691 149,000 48081

0.702146 149,000 104620

1.35 149,000 201333

2.8 150,000 426563

44 1700 74800

44 280 12320

132 120 15840

132 1000 132000

1082 170 183940

12 1200 14400

518 1100 569800

276 1250 345000

2 20000 20000

8548

Multi Strands Jacks(RS)/Month

7X9Panel ( 21 mX27m)

Labours for PT work( laying duct,inserting

stands and Jacking)

Suppy Sheath/Duct (m)

Supply , Fixing and Removing

Formwork(m2) for Slab

Total cost (Rs)/m2

Items

Supply and tieing mild steel 10mm

Dia(Ton)

Minimum R/F Tor steel 10mm Dia(Ton)

Suppy 12.7mm Strand(Ton)

Supply Live end Anchor block(nos)

Supply recess former (nos)

Supply wedges(nos)

Supply Dead end Anchor block(nos)

Unit rate calculation for the post-tensioned slab and beams for 21mx27m

area for the live of 1.5 kN/m2

Supply and tieingTor bar 20mm Dia(Ton)

Supply and tieingTor bar 16mm Dia(Ton)

For Live load of 1.5kN/m2

Supply , Fixing and Removing

Formwork(m2) for Beam

Supply and placingConcrete Gr35(m3)

Supply and tieing Tor bar 25mm Dia(Ton)

Supply and tieingTor bar 10mm Dia(Ton)

Page 1 of 1

Appendix J- Basic Prices for Accessories for Post-Tensioned Slab

P a g e 1 o f 1

Basic Prices received from an Engineer who worked at the post -

tensioned slab construction site in Colombo.

1. 7-wire strand super grade –Nominal diameter 12.7 mm. (1840MP) 1 Ton Rs

150,000.00

2. Live end Anchor Block set for four strand holes with grouting pipe Rs -1700

each.

3. Wedges-Rs 120 each.

4. Recess former-Rs 280 .0 each plastic.

5. Duct/sheath for four number strands (19mm-50mm)- 5.5m long duct Rs 900

6. labours strength for erecting form work, fixing post tension cables and placing

concrete for a floor Fw - 25, PT works 12, Concrete 35.

7. Hydraulic Jack that was used in that project - two multi strand jacks. 20,000.0

each per month.

8. Did you use cement grouting or any other grouting to fill the sheath of

strands?? Ducts grouted after stressing using cement grout.

9. What is the cost to make a dead end anchorage? - Just make dead end

approximately Rs 1000.0

10. How many days were taken to complete a floor? 7 days cycle.

Appendix K-Work study spread sheet for three multi-storied buildings

ELEMENTS

Foundation 7,499,630.70 22% 6,673,239.00 10% 5,285,039.87 19%

Concrete 4,135,008.50 4,179,520.00 2,124,575.12

Reinforcement 3,043,207.20 2,067,616.00 2,553,362.36

Formwork 321,415.00 426,103.00 607,102.39

Beam 9,284,630.00 27% 19,512,586.20 31% 6,601,751.19 24%

Concrete 3,295,577.00 6,106,523.00 2,711,584.84

Reinforcement 4,631,628.00 9,441,403.20 3,189,758.75

Formwork 1,357,425.00 3,964,660.00 700,407.60

Slab 8,133,341.40 24% 21,951,555.50 34% 9,298,514.71 34%

Concrete 3,582,119.40 7,777,962.50 3,190,875.38

Reinforcement 3,440,174.00 8,386,828.00 5,224,750.12

Formwork 1,111,048.00 5,786,765.00 882,889.21

Shaft wall 2,211,592.25 6% 4,388,115.00 7% 1,602,413.46 6%

Concrete 1,264,844.25 2,501,225.55 913,375.67

Reinforcement 481,536.00 965,385.30 352,530.96

Formwork 465,212.00 921,504.15 336,506.83

Columns 6,962,848.45 20% 11,343,503.00 18% 4,776,854.47 17%

Concrete 1,306,169.25 2,423,772.00 1,035,862.97

Reinforcement 4,760,503.20 6,763,251.00 2,871,730.30

Formwork 896,176.00 2,156,480.00 869,261.20

(Beam + Slab)

cost per m2 7,207.31 6,379.10 6,697.02

HOSPITAL SHOPPING

ARCHADEOFFICE COMPLEX

Work study spread sheet for three multi-storied buildings

Page 1 of 1