Welcome to E-Z Slab 2006 an interactive spreadsheet for the

design of timber formwork systems for cast in place elevated concrete slabs

Design Load: - Calculated combined dead and live loads to be used for the design Acknowledgements

Plywood - Calculated and practical joist spacing based on plywood properties All formulas, calculations and tables

are based on ACI SP-4,Joist-Stringer Formwork for Concrete, 7th ed.

- Calculated and practical stringer spacing based on joist properties

Stringer-Shore Student Developers - Calculated and practical shore spacing based on stringer properties V. Elliot, A. Murray, D. Reis,

A. Hopkins & E. KingShore

- Calculated axial load & capacity for selected shore size & properties Faculty DeveloperWilliam "Bill" C. Epstein

Horizontal Strut Brace Full Professor, CM Dept.

- Calculated axial load & capacity for selected brace size & properties Cal Poly, San Luis Obispo

Calculation Summary - Bending, deflection, shear, bearing & axial load calculation results

Office: (805) 756-2797

Cell: (805) 459-9087

Email: wepstein@calpoly.edu

General Notes for Best Use of the E-Z Slab 2005 Spreadsheet

1. The E-Z Slab 2005 spreadsheet was designed to run in Microsoft Excel and is best viewed at a screen resolution of 1024 by 768 pixels. Some users may need a higher screen resolution to view the entire tabbed sheet area.

2. Design process of the E-Z Slab 2005 spreadsheet is based on data and procedures given in ACI SP-4

SUMMARY at any point to view the calculation associated with any sheet of interest.

using the "page up" and "page down"keys or by using the mouse wheel.

the slenderness ratios of the lateral braces in both directions.

cell using the arrow keys.

Formwork for Concrete, 7th edition. Beams are calculated using the simplification of three or more continuous spans uniformly loaded. To take full advantage of this spreadsheet, the user should begin with the sheet tabbed LOAD (at the bottom of the screen), and move step by step to the right through the tabs, ending with BRACE LOAD. The user may also click on the CALCULATION

3. Except for the CALCULATION SUMMARY, the sheets are designed for single screen viewing and do not have scroll bars. The CALCULATION SUMMARY has six tables that can be viewed separately

4. The user enters data either by typing directly into the double-blue-lined cells or by selecting alternatives from a list box. Cell values calculated by the computer are bordered by a double red line. The double- green-lined cell in the JOIST-STRINGER sheet checks the bearing between the joists and stringers. The double-green-lined cell in the STRINGER-SHORE sheet checks the bearing between the stringers and shores. The double-green-lined cell in the STRINGER-SHORE sheet checks if the shore passes in axial capacity as well as the slenderness ratio. The double-green-lined cell in the BRACE LOAD sheet checks

5. Sheets which contain more than one double-blue-lined cell will allow the user to navigate from cell to

Pressure

Vertical Load on Formwork

150

50

8

8

8

158.0

Fill in the Following Variables:

Weight of Concrete (lb/cubic foot):

Minimum Construction Live Load (lb/square foot):

i Thickness of Elevated Slab (inches):

i Estimated Weight of formwork (lb/square foot):

Ceiling Height (feet):

i Design Vertical Load (lb/square foot):

Plywood

Plywood Thickness and Joist Spacing

All Plywood is Classified as Plywood B-B Class I Sheathing

Standard

Plywood

Load Duration Thickness

(Inches)

Weak / Strong Direction

Calculated Maximum Joist Spacing: 20.8 Inches

Enter Actual Joist Spacing: 19.2 Inches

Joists-Stringers

Joist Size and Stringer Spacing

Species and Grade Moisture Content

Load Duration

Nominal Size of Joist

Finish of Joist

Calculated Maximum Stringer Spacing: 76.3 Inches

Enter Actual Stringer Spacing: 30.0 Inches

Bearing Check Between Joist and Stringer: pass

0

Stringer-Shore

Stringer Size and Shore Spacing

Species & Grade Moisture Content

Load Duration

Nominal Size of Stringer

Finish of Stringer

Calculated Maximum Shore Spacing: 94.7 Inches

Enter Actual Shore Spacing: 36.0 Inches

Bearing Check Between Stringer and Shore: pass

0

Shore

Shore Size

Note: All Shoring is assumed to be unbraced

Species & Grade Moisture Content

Load Duration

Nominal Size of Shore

Allowable Axial Load: pass

Finish of Shore

Allowable Slenderness Ratio: pass

Shore

Horizontal Strut Brace

Species & Grade Moisture Content

Load Duration

Nominal Size of Strut

Finish of Strut

(DOUGLAS FIR-LARCH) No. 2, 2-4 in. thick, 2 in. and wider(DOUGLAS FIR-LARCH) Construction, 2-4 in. thick, 2-4in. wide(DOUGLAS FIR-SOUTH) No. 2, 2-4 in. thick, 2 in. and wider(DOUGLAS FIR-SOUTH) Construction, 2-4 in. thick, 2-4in. wide(SOUTHERN PINE) No. 2, 2-4 in. thick, 2-4 in. wide(SOUTHERN PINE) No. 2, 2-4 in. thick, 5-6 in. wide(SOUTHERN PINE) No. 2, 2-4 in. thick, 8 in. wide(SOUTHERN PINE) Construction, 2-4 in. thick, 2-4in. wide(SPRUCE-PINE-FIR) No. 2, 2-4 in. thick, 2 in. and wider(SPRUCE-PINE-FIR) Construction, 2-4 in. thick, 2-4in. wide(HEM-FIR) No. 2, 2-4 in. thick, 2 in. and wider(HEM-FIR) Construction, 2-4 in. thick, 2-4in. wide

Horizontal Load for Bracing Design90 ft

<------Joists------>

60 ft 194.4 plf

N

129.6 plf

North-South Direction East-West Direction

129.6

36.0(Shore Spacing)

pass

27.7

2% of Concrete DL (lb):

2% of Formwork DL (lb):

Lateral Force in N/S Direction (plf): Lateral Force in N/S Direction (plf):

Maximum Unbraced Length (in): i Maximum Unbraced Length (in):

Allowable Slenderness Ratio: Allowable Slenderness Ratio:

i Maximum Tributary Length (ft): Maximum Tributary Length (ft):

Horizontal Load for Bracing Design

90.0

60.0

10800.0

864.0

East-West Direction

194.4

30.0(Stringer Spacing)

pass

24.4CONTROLLING

i Length of Slab (ft):

i i Width of Slab (ft):

2% of Concrete DL (lb):

2% of Formwork DL (lb):

i Joist Orientation:

Lateral Force in N/S Direction (plf):

i Maximum Unbraced Length (in):

Allowable Slenderness Ratio:

Maximum Tributary Length (ft):

CALCULATION SUMMARY

Page 11

Allowable Plywood Spans Determine Joist Spacing

Bending 24.6 Rolling Shearsize: 3/4" size: 3/4"Fb: 1545 Fs: 57

S: 0.412 lb/Q: 6.762w: 158.00 w: 158.00

Adjustment: 1.25 Adjustment: 1.25

Alternate Fb: Alternate Fs:

l / 360 Deflection 20.8 Deflectionsize: 3/4" size: 3/4"

E: 1500000 E: 1500000I: 0.197 I: 0.197

w: 158.00 w: 158.00Adjustment: 1 Adjustment: 1

Alternate E: Alternate E:

Minimum Value: 20.8

Allowable Joist Spans Determine Stringer Spacing

Bending 76.3 Shearsize: 3x6 size: 3x6Fb: 975 Fv 150

S: 12.6 d 5.5w: 252.80 w: 252.80

Adjust (Moisture): 1 bd: 13.75Adjust (Use): 1 Adjust (Moisture): 1Adjust (size): 1 Adjust (Use): 1

Alternate Fb: Alternate Fv:

l / 360 Deflection 95.1 Deflection

D = 1/16''

D = 1/4''

CALCULATION SUMMARY

Page 12

size: 3x6 size: 3x6E 1300000 E 1300000I: 34.66 I: 34.66

w: 252.80 w: 252.80Adjust (Moisture): 1 Adjust (Moisture): 1

Adjust (Use): 1 Adjust (Use): 1

Alternate E: Alternate E:

Minimum Value: 76.3

Allowable Stringer Spans Determine Shore Spacing

Bending 94.7 Shearsize: 3x8 size: 3x8Fb: 900 Fv 180

S: 21.9 d 7.25w: 395.00 w: 395.00

Adjust (Moisture): 1 bd: 18.12Adjust (Use): 1.25 Adjust (Moisture): 1Adjust (size): 1.2 Adjust (Use): 1.25

Alternate Fb: Alternate Fv:

l / 360 Deflection 115.8 Deflectionsize: 3x8 size: 3x8

E 1600000 E 1600000I: 79.39 I: 79.39

w: 395.00 w: 395.00Adjust (Moisture): 1 Adjust (Moisture): 1

Adjust (Use): 1 Adjust (Use): 1

Alternate E: Alternate E:

Minimum Value: 94.7

D = 1/4''

CALCULATION SUMMARY

Page 13

Bearing Joists-Stringers Bearing Stringers-Shores

w: 632.00 w: 1185.00Width of Joist: 2.5 Width of Stringer: 2.5

Width of Stringer: 2.5 Width of Shore: 3.5Contact Area: 6.25 Contact Area: 8.75

Actual Stress (psi): 101.12 Actual Stress (psi): 135.43Allowable Stress (psi): 405 pass Allowable Stress (psi): 625

(not adjusted) (not adjusted)

SHORESAxial Load and Slenderness Test

E: 1,500,000

Alternate E:

Fc: 1,650

Alternate Fc:d 2.5

le: 96.00le/d: 38.40 pass

Fc Adjust (Moisture): 1Adjust (Use): 1.25Adjust (size): 1

x: 0.1480

CALCULATION SUMMARY

Page 14

Cp: 0.1432Area: 8.75

axial Load Capacity: 2583.9 pass

Total Load 1185.0

HORIZONTAL BRACES

Axial Load, Slenderness Test & Tributary Length

North-South Direction East-West Direction

E: 1500000 E: 1500000

Alternate E: Alternate E:

Fc: 1650 Fc: 1650

Alternate Fc: Alternate Fc:d 1.5 d 1.5

le: 36.00 le: 30.00le/d: 24.00 pass le/d: 20.00

Fc Adjust (Moisture): 1 Fc Adjust (Moisture): 1Adjust (Use): 1 Adjust (Use): 1Adjust (size): 1 Adjust (size): 1

x: 0.4735 x: 0.6818Cp: 0.4147 Cp: 0.5485

Area: 5.25 Area: 5.25Axial Load Capacity: 3592.5 Axial Load Capacity: 4751.6

Max. Tributary Length: 27.7 Max. Tributary Length: 24.4

CALCULATION SUMMARY

Page 15

Allowable Plywood Spans Determine Joist Spacing62.5

21.2

Allowable Joist Spans Determine Stringer Spacing

119.8

93.9

CALCULATION SUMMARY

Page 16

Allowable Stringer Spans Determine Shore Spacing124.6

108.8

CALCULATION SUMMARY

Page 17

Bearing Stringers-Shores

pass

CALCULATION SUMMARY

Page 18

HORIZONTAL BRACES

Axial Load, Slenderness Test & Tributary Length

East-West Direction

pass

CONTROLLING