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Design of One Way Slab Reference: NSCP 2001 Volume 1 Design of Reinforced Concrete by J.C. McCormac Dimension: Reinforcement: Loads: cc = 20 mm = 12 mm = 2.400 kPa h = 100 mm = 12 mm = 2.000 kPa b = 1000 mm Material Strength: = 1.900 kPa d = 74 mm fc' = 21 Mpa = 9.390 kPa Loads: fy = 276 Mpa = 2.6709 kN-m = 0.9 = 3.0048 kN-m Check if One Way Slab s / l < 0.50 s = 1.600 m l = 4.400 m s = 0.364 one way slab! l when fy = 415 when fy = 415 s / 20 simply supported multiply by: s / 24 one end continuous ### + fy = ### s / 28 two end continuous 415 s / 10 cantilever = s = 57.14 ok! 28 > ### NSCP Section 410.3.7.3 = 0.85 - 0.05 fc' - 30 = 0.85 7 = 0.914 use: = 0.85 > ### ok! NSCP Section 410.4.3 NSCP Section 410.6.1 = = fc' > = 1.4 = 600 4 fy fy fy 600 + fy = 0.0042 < = 0.0051 = 0.0377 use: = 0.0282 = 0.0051 Main Reinforcements Top Bars Bot Bars units Spcg Limitations: m = 0.847 fc' / fy 0.0644 0.0644 - a. Main Reinf. 0.5419 0.6097 Mpa NSCP Section 407.7.5 0.0020 0.0022 - s < 3h = 300 0.0051 0.0051 - s < 450 375.36 375.36 b.Temp Reinf. 113.10 113.10 NSCP Section 407.13 301.30 301.30 pcs s < 5h = 500 300.00 300.00 pcs s < 450 Temperature / Shrinkage Reinforcements NSCP Section 407.13 = 0.002bh = 200 = 565.49 mm Provide = 450 mm Summary: Top Bars 12 @ 300 mm Bot Bars 12 @ 300 mm Temp Bars 12 @ 450 mm main bar q WSLAB temp bar q WDL WLL WU Mutop fM Mubot Solve for hmin hmin hmin Solve fo b1 : a.) if fc' > 30 Mpa ; b.) if fc' < 30 Mpa ; b1 b1 b1 b1 Solve for rmax : Solve for rmin : rmax 0.75 rbal rmin rmin rbal 0.85 b1 fc' rmin rmin rbal rmax rmin R = Mu / fbd 2 rreqd = m - m 2 - 2Rm/fy rsupplied Asreqd = rbd mm 2 As main bar q mm 2 spcgreqd Provide (spcg) Astemp Astemp mm 2 spcgreqd

2.0 Design of Slab

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Page 1: 2.0 Design of Slab

document.xls One Way Slab

Design of One Way SlabReference: NSCP 2001 Volume 1

Design of Reinforced Concrete by J.C. McCormac

Dimension: Reinforcement: Loads:

cc = 20 mm = 12 mm = 2.400 kPa

h = 100 mm = 12 mm = 2.000 kPa

b = 1000 mm Material Strength: = 1.900 kPa

d = 74 mm fc' = 21 Mpa = 9.390 kPaLoads: fy = 276 Mpa

= 2.6709 kN-m = 0.9

= 3.0048 kN-m

Check if One Way Slab s / l < 0.50s = 1.600 ml = 4.400 ms

= 0.364 one way slab!l

when fy = 415 when fy = 415s / 20 simply supported multiply by:s / 24 one end continuous

0.40 +fy

= 1.07s / 28 two end continuous 415s / 10 cantilever

=s

= 57.14 ok!28

> 0.65 NSCP Section 410.3.7.3

= 0.85 - 0.05( fc' - 30 ) = 0.85

7

= 0.914use:

= 0.85 > 0.65 ok!

NSCP Section 410.4.3 NSCP Section 410.6.1

==

fc'> =

1.4

= 600 4 fy fy

fy 600 + fy = 0.0042 < = 0.0051

= 0.0377 use:= 0.0282 = 0.0051

Main Reinforcements Top Bars Bot Bars units Spcg Limitations:m = 0.847 fc' / fy 0.0644 0.0644 - a. Main Reinf.

0.5419 0.6097 Mpa NSCP Section 407.7.5

0.0020 0.0022 - s < 3h = 300

0.0051 0.0051 - s < 450

375.36 375.36 b.Temp Reinf.

113.10 113.10 NSCP Section 407.13

301.30 301.30 pcs s < 5h = 500300.00 300.00 pcs s < 450

Temperature / Shrinkage ReinforcementsNSCP Section 407.13

= 0.002bh

= 200

= 565.49 mmProvide = 450 mm

Summary:Top Bars 12 @ 300 mmBot Bars 12 @ 300 mmTemp Bars 12 @ 450 mm

main bar q WSLAB

temp bar q WDL

WLL

WU

Mutop fM

Mubot

Solve for hmin

hmin

hmin

Solve fo b1 :a.) if fc' > 30 Mpa ; b.) if fc' < 30 Mpa ;

b1b1

b1

b1

Solve for rmax : Solve for rmin :

rmax 0.75 rbalrmin rmin

rbal

0.85 b1 fc'

rmin rmin

rbal

rmax rmin

R = Mu / fbd2

rreqd = m - m2 - 2Rm/fy

rsupplied

Asreqd = rbd mm2

As main bar q mm2

spcgreqd

Provide (spcg)

Astemp

Astemp mm2

spcgreqd

Page 2: 2.0 Design of Slab

document.xls Two Way Slab

Analysis of Two-Way Slab with BeamsReference: NSCP 2001 Volume 1

Design of Reinforced Concrete by J.C. McCormac

NSCP Section 409.6.3.3

= > 125 mm

= > 90 mm

where:

=a = ratio of flexural stiffness of beam section to flexural

stiffness of a width of slab bounded laterally by centerlines of adjacent panels on each side of the beam

a =

= length of clear span in long direction of two-wayconstruction, measured face to face of supports

b = ratio of clear span in long to short direction of two-way slabs

B. Total Factored Static Moment for a Span NSCP Section 413.7.2.2

=8

where:

= length of span in direction that moments are being determined, measured c to c of supports

=of supports

= length of span in direction that moments are being determined, measured face to face of supports

C. Negative & Positive Factored Moments NSCP Section 413.7.3

Negative Factored Moments = 0.65Positive Factored Moments = 0.35

0.75 0.70 0.70 0.70 0.65

0.63 0.57 0.52 0.50 0.35

0.00 0.16 0.26 0.30 0.65

D. Factored Moments in Column Strips NSCP Section 413.7.4

0.50 1.00 2.00

75 75 75

90 75 45

A. Computation of hmin

1. For am greater than 0.20 but not greater than 2.0

hmin

ln ( 0.80 + fy / 1500 )

36 + 5b ( am - 0.20 )

2. For am greater than 2.0

hminln ( 0.80 + fy / 1500 )

36 + 9b

am ave. of a

ECBIB

ECSIS

ln

Mowu l2 ln2

l1

l2 length of span transverse to l1, measured c to c

ln

1. Interior Spans

2. Exterior Spans

Exterior Edge Unrestrained

Slabs With Beams

Between All Supports

Slab Without Beams Between Interior Supports Exterior Edge

Fully RestrainedWithout Edge

BeamsWith Edge

Beams

Interior Negative Factored Moment

Positive Factored Moment

Exterior Negative Factored Moment

1. Interior Negative Factored Moments (%)

l2 / l1

a1 l1 / l2 = 0

a1 l1 / l2 > 1

Page 3: 2.0 Design of Slab

document.xls Two Way Slab

0.50 1.00 2.00

100 100 100

75 75 75

100 100 100

90 75 45

0.50 1.00 2.00

60 60 60

90 75 45

Note: NSCP Section 413.7.5

if: > 1.0 85 % - beam15 % - slab

< 1.0 interpolate from 0% to 85%where:

=

= ratio of torsional dtiffness of edge beam section toflexural stiffness of a width od slab equal to span lengthof beam, c to c of supports

=

C = cross-sectional constant to define torsional properties

C = S 1 - 0.63xy 3

E. Slab Reinforcements NSCP Section 413.4

Spacing of reinforcement at critical sections shallnot exceed two times the slab thickness

F. Column Strip and Middle Strip

`

Middle Strip

2. Exterior Negative Factored Moments (%)

l2 / l1

a1 l1 / l2 = 0bt = 0

bt > 2.5

a1 l1 / l2 > 1bt = 1

bt > 2.5

3. Positive Factored Moments (%)

l2 / l1

a1 l1 / l2 = 0

a1 l1 / l2 > 1

a1 l2 / l1

a1 l2 / l1

a1 a in direction of l1

bt y2

x2

bt

ECBCy1

2ECSIS y1 - x2

x3y x1

l2

Column Strip

Column Strip

l1

0.25 l1 or 0.25 l2, which is smaller

Page 4: 2.0 Design of Slab

document.xls

Design of Two-Way Slab with BeamsReference: NSCP 2001 Volume 1

Design of Reinforced Concrete by J.C. McCormacDesign of Concrete Structures by Arthur H. Nilson

= 21 Mpa

= 21 Mpafy = 276 Mpa

= 0.90 4.00 m

= 4.80 kPa b x h

= 2.50 kPa 250 x 400

= 10.92 kPa A

= 4.25 kPa= 15.17 kPa 5.00 m

= 12 mm 300 x 500 C D 300 x 500h = 125 mm

= 93 mm B

= 0.779250 x 400

= 3.00 kPa5.00 m

5.00 m 4.00 m 3.00 m

Side A

= ==

= 21675.58 MPa = 21675.58 MPa

= = = 1.82

= 1.33E+09 = 7.32E+08Side B

= ==

= 21675.58 MPa = 21675.58 MPa

= = = 1.64

= 1.33E+09 = 8.14E+08Side C

= ==

= 21675.58 MPa = 21675.58 MPa

= = = 4.27

= 3.13E+09 = 7.32E+08Side D

= ==

= 21675.58 MPa = 21675.58 MPa

= = = 5.49

= 3.13E+09 = 5.70E+08

=4

= 3.30

B. Check Minimum Thickness = 4.750 m b = 1.284

= > 125 mm

= 125.00 mm

fc'CS

fc'CB

fM

WDL

WLL

WuDL

WuLL

Wu

qbar

deff

la

lb

WSLAB

A. Solve for am

ECB 4730 fc'CB ECS 4730 fc'CSaA

ECBICB

ECB ECS ECSICS

ICB bh3 / 12 ICS bh3 / 12 aA

ICB mm4 ICS mm4

ECB 4730 fc'CB ECS 4730 fc'CSaB

ECBICB

ECB ECS ECSICS

ICB bh3 / 12 ICS bh3 / 12 aB

ICB mm4 ICS mm4

ECB 4730 fc'CB ECS 4730 fc'CSaC

ECBICB

ECB ECS ECSICS

ICB bh3 / 12 ICS bh3 / 12 aC

ICB mm4 ICS mm4

ECB 4730 fc'CB ECS 4730 fc'CSaD

ECBICB

ECB ECS ECSICS

ICB bh3 / 12 ICS bh3 / 12 aD

ICB mm4 ICS mm4

amaA + aB + aC + aD

am

ln

1. For am greater than 0.20 but not greater than 2.0

hmin

ln ( 0.80 + fy / 1500 )

36 + 5b ( am - 0.20 )

hmin

Page 5: 2.0 Design of Slab

document.xls

= > 90 mm

= 100.00 mm

Therefore use: = 100.00 mm ok!

D. Check Slab on Shear ( Coefficient Method )

Va = by linear interpolation Vu Mu(-)

Vb = 0.750 0.7600 1.00 0.500 0.045 0.018 0.027

= 0.7311 kN 0.779 x 0.7311 0.95 0.550 0.050 0.020 0.030

= 0.2689 kN 0.800 0.7100 0.90 0.600 0.055 0.022 0.034Va = 194.91 kN 0.85 0.660 0.060 0.024 0.037Vb = 71.70 kN 0.750 0.2400 0.80 0.710 0.065 0.026 0.041

= 0.779 x 0.2689 0.75 0.760 0.069 0.028 0.045= 362.25 kN ok! 0.800 0.2900 0.70 0.810 0.074 0.030 0.049

0.65 0.850 0.077 0.032 0.053D. Determine Design Moments ( Coefficient Method ) 0.60 0.890 0.081 0.034 0.058

Continuous Edge 0.55 0.920 0.084 0.035 0.062Negative Moments: by linear interpolation 0.50 0.940 0.086 0.037 0.066

Ma = 0.750 0.0690

Mb = 0.779 x 0.0667 1.00 0.500 0.045 0.018 0.027

= 0.0667 kN 0.800 0.0650 0.95 0.450 0.041 0.016 0.025

= 0.0249 kN 0.90 0.400 0.037 0.014 0.022

Ma = 13.85 kN-m 0.750 0.0220 0.85 0.340 0.031 0.012 0.019Mb = 8.52 kN-m 0.779 x 0.0249 0.80 0.290 0.027 0.011 0.017

0.800 0.0270 0.75 0.240 0.022 0.009 0.0140.70 0.190 0.017 0.007 0.012

Positive Moments: by linear interpolation 0.65 0.150 0.014 0.006 0.010

= 0.750 0.0280 0.60 0.110 0.010 0.004 0.007

= 0.779 x 0.0268 0.55 0.080 0.007 0.003 0.006

= 0.0268 kN 0.800 0.0260 0.50 0.060 0.006 0.002 0.004

= 0.0427 kN

= 4.01 kN-m 0.750 0.0450

= 2.48 kN-m 0.779 x 0.0427

= 6.50 kN-m 0.800 0.0410

by linear interpolation

= 0.750 0.0090

= 0.779 x 0.0102

= 0.0102 kN 0.800 0.0110

= 0.0157 kN

= 2.50 kN-m 0.750 0.0140

= 1.51 kN-m 0.779 x 0.0157

= 4.01 kN-m 0.800 0.0170

E. Design Reinforcements:

> 0.65 NSCP Section 410.3.7.3

= 0.85 - 0.05( fc' - 30 ) = 0.85

7

= 0.914use:

= 0.85 > 0.65 ok!

NSCP Section 410.4.3 NSCP Section 410.6.1

==

fc'> =

1.4

= 600 4 fy fy

fy 600 + fy = 0.0042 < = 0.0051

= 0.0377 use:

2. For am greater than 2.0

hminln ( 0.80 + fy / 1500 )

36 + 9b

hmin

hmin

la/lb

Ca

CaWulalb Mu(+)DL Mu(+)LL

CbWulalb Ca

Ca

Cb

Cb

fVc 0.85 fc'CS(1000)(deff)fVc

CaWula2 Ca la/lb Cb

CbWulb2

Ca

Cb

Cb

MaDL CaDLWuDLla2 CaDL

MaLL CaLLWuLLla2

CaDL

CaLL

MaDL CaLL

MaLL

MaTOT

MbDL CbDLWuDLlb2 CbDL

MbLL CbLLWuLLlb2

CbDL

CbLL

MbDL CbLL

MbLL

MbTOT

Solve fo b1 :a.) if fc' > 30 Mpa ; b.) if fc' < 30 Mpa ;

b1b1

b1

b1

Solve for rmax : Solve for rmin :

rmax 0.75 rbalrmin rmin

rbal

0.85 b1 fc'

rmin rmin

rbal

Page 6: 2.0 Design of Slab

document.xls

= 0.0282 = 0.0051

Middle StripShort Span Long Span

Top Bars Bot Bars Top Bars Bot BarsDesign Moments 13.85 6.50 8.52 4.01

Bar Diameter 12 12 12 12m = 0.847 fc' / fy 0.0644 0.0644 0.0644 0.0644

1.7791 0.8346 1.0946 0.5154

0.0068 0.0031 0.0041 0.0019

0.0068 0.0051 0.0051 0.0051

632.90 471.74 471.74 471.74113.10 113.10 113.10 113.10

178.70 239.75 239.75 239.75175.00 225.00 225.00 225.00

Column Strip Top Bars Bot Bars Top Bars Bot Bars

262.50 337.50 337.50 337.50250.00 250.00 250.00 250.00

E. Temperature / Shrinkage Reinforcements:As = 0.002bh b.Temp Reinf.

As = 250.00 NSCP Section 407.13

= 12.00 mm s < 5h = 625

= 113.10 s < 450spcg = 450.00 mm

rmax rmin

R = Mu / fbdeff2

rreqd = m - m2 - 2Rm/fy

rsupplied

Asreqd = rbdAs main bar q

spcgreqd

Provide (spcg)

spcgreqd = 3/2(spcgMID-STRIP)Provide (spcg)

mm2

qbar

Asbar mm2

Page 7: 2.0 Design of Slab

document.xls

Design of Two-Way Slab with BeamsReference: NSCP 2001 Volume 1

Design of Reinforced Concrete by J.C. McCormacDesign of Concrete Structures by Arthur H. Nilson

= 21 Mpa b x h

= 21 Mpa 250 x 400fy = 276 Mpa A

= 0.90

= 4.35 kPa

= 1.92 kPa 4.00 m 200 x 400 C D 200 x 400

= 9.45 kPa

= 3.26 kPa B= 12.71 kPa 200 x 400

= 12 mmh = 100 mm

= 68 mm 4.00 m

= 0.477

= 2.40 kPa

2.00 m 2.00 m

Side A

= ==

= 21675.58 MPa = 21675.58 MPa

= = = 8.00

= 1.33E+09 = 1.67E+08Side B

= ==

= 21675.58 MPa = 21675.58 MPa

= = = 3.20

= 1.07E+09 = 3.33E+08Side C

= ==

= 21675.58 MPa = 21675.58 MPa

= = = 6.40

= 1.07E+09 = 1.67E+08Side D

= ==

= 21675.58 MPa = 21675.58 MPa

= = = ###

= 1.07E+09 = 8.33E+07

=4

= 7.60

B. Check Minimum Thickness = 3.775 m b = 2.097

= > 125 mm

= 125.00 mm

= > 90 mm

= 90.00 mm

fc'CS

fc'CB

fM

WDL

WLL

WuDL

WuLL

Wu

qbar

deff

la

lb

WSLAB

A. Solve for am

ECB 4730 fc'CB ECS 4730 fc'CSaA

ECBICB

ECB ECS ECSICS

ICB bh3 / 12 ICS bh3 / 12 aA

ICB mm4 ICS mm4

ECB 4730 fc'CB ECS 4730 fc'CSaB

ECBICB

ECB ECS ECSICS

ICB bh3 / 12 ICS bh3 / 12 aB

ICB mm4 ICS mm4

ECB 4730 fc'CB ECS 4730 fc'CSaC

ECBICB

ECB ECS ECSICS

ICB bh3 / 12 ICS bh3 / 12 aC

ICB mm4 ICS mm4

ECB 4730 fc'CB ECS 4730 fc'CSaD

ECBICB

ECB ECS ECSICS

ICB bh3 / 12 ICS bh3 / 12 aD

ICB mm4 ICS mm4

amaA + aB + aC + aD

am

ln

1. For am greater than 0.20 but not greater than 2.0

hmin

ln ( 0.80 + fy / 1500 )

36 + 5b ( am - 0.20 )

hmin

2. For am greater than 2.0

hminln ( 0.80 + fy / 1500 )

36 + 9b

hmin

Page 8: 2.0 Design of Slab

document.xls

Therefore use: = 90.00 mm ok!hmin

Page 9: 2.0 Design of Slab

document.xls

D. Check Slab on Shear ( Coefficient Method )

Va = by linear interpolation Vu Mu(-)

Vb = 0.750 0.7600 1.00 0.500 0.050 0.027 0.032

= 1.0332 kN 0.477 x 1.0332 0.95 0.550 0.055 0.030 0.035

= -0.0332 kN 0.800 0.7100 0.90 0.600 0.060 0.033 0.039Va = 89.26 kN 0.85 0.660 0.066 0.036 0.043Vb = -2.87 kN 0.750 0.2400 0.80 0.710 0.071 0.039 0.048

= 0.477 x -0.0332 0.75 0.760 0.076 0.043 0.052= 264.87 kN ok! 0.800 0.2900 0.70 0.810 0.081 0.046 0.057

0.65 0.850 0.085 0.050 0.062D. Determine Design Moments ( Coefficient Method ) 0.60 0.890 0.089 0.053 0.067

Continuous Edge 0.55 0.920 0.092 0.056 0.072Negative Moments: by linear interpolation 0.50 0.940 0.094 0.059 0.077

Ma = 0.750 0.0760

Mb = 0.477 x 0.1033 1.00 0.500 0.050 0.027 0.032

= 0.1033 kN 0.800 0.0710 0.95 0.450 0.045 0.024 0.029

= -0.0033 kN 0.90 0.400 0.040 0.022 0.026

Ma = 4.26 kN-m 0.750 0.0240 0.85 0.340 0.034 0.019 0.023Mb = -0.60 kN-m 0.477 x -0.0033 0.80 0.290 0.029 0.016 0.020

0.800 0.0290 0.75 0.240 0.024 0.013 0.0160.70 0.190 0.019 0.011 0.014

Positive Moments: by linear interpolation 0.65 0.150 0.015 0.009 0.011

= 0.750 0.0430 0.60 0.110 0.011 0.007 0.009

= 0.477 x 0.0649 0.55 0.080 0.008 0.005 0.007

= 0.0649 kN 0.800 0.0390 0.50 0.060 0.006 0.004 0.005

= 0.0739 kN

= 1.99 kN-m 0.750 0.0520

= 0.78 kN-m 0.477 x 0.0739

= 2.77 kN-m 0.800 0.0480

by linear interpolation

= 0.750 0.0130

= 0.477 x -0.0034

= -0.0034 kN 0.800 0.0160

= -0.0059 kN

= -0.46 kN-m 0.750 0.0160

= -0.27 kN-m 0.477 x -0.0059

= -0.73 kN-m 0.800 0.0200

E. Design Reinforcements:

> 0.65 NSCP Section 410.3.7.3

= 0.85 - 0.05( fc' - 30 ) = 0.85

7

= 0.914use:

= 0.85 > 0.65 ok!

NSCP Section 410.4.3 NSCP Section 410.6.1

==

fc'> =

1.4

= 600 4 fy fy

fy 600 + fy = 0.0042 < = 0.0051

= 0.0377 use:= 0.0282 = 0.0051

la/lb

Ca

CaWulalb Mu(+)DL Mu(+)LL

CbWulalb Ca

Ca

Cb

Cb

fVc 0.85 fc'CS(1000)(deff)fVc

CaWula2 Ca la/lb Cb

CbWulb2

Ca

Cb

Cb

MaDL CaDLWuDLla2 CaDL

MaLL CaLLWuLLla2

CaDL

CaLL

MaDL CaLL

MaLL

MaTOT

MbDL CbDLWuDLlb2 CbDL

MbLL CbLLWuLLlb2

CbDL

CbLL

MbDL CbLL

MbLL

MbTOT

Solve fo b1 :a.) if fc' > 30 Mpa ; b.) if fc' < 30 Mpa ;

b1b1

b1

b1

Solve for rmax : Solve for rmin :

rmax 0.75 rbalrmin rmin

rbal

0.85 b1 fc'

rmin rmin

rbal

rmax rmin

Page 10: 2.0 Design of Slab

document.xls

REINFORCEMENTSShort Span Long Span

Cont. Discont. Cont. Discont.

Middle Strip Top Bars Bot Bars Top Bars Top Bars Bot Bars Top BarsDesign Moments 4.26 2.77 0.92 -0.60 -0.73 -0.24

Bar Diameter 12 12 12 12 12 12m = 0.847 fc' / fy 0.0644 0.0644 0.0644 0.0644 0.0644 0.0644

1.0227 0.6648 0.2216 -0.1444 -0.1752 -0.0584

0.0038 0.0025 0.0008 -0.0005 -0.0006 -0.0002

0.0051 0.0051 0.0051 0.0051 0.0051 0.0051

344.93 344.93 344.93 344.93 344.93 344.93113.10 113.10 113.10 113.10 113.10 113.10

327.89 327.89 327.89 327.89 327.89 327.89Provide (spcg) 200.00 200.00 200.00 200.00 200.00 200.00

Column Strip Top Bars Bot Bars Top Bars Top Bars Bot Bars Top Bars

300.00 300.00 300.00 300.00 300.00 300.00Provide (spcg) 200.00 200.00 200.00 200.00 200.00 200.00

E. Temperature / Shrinkage Reinforcements:As = 0.002bh b.Temp Reinf.

As = 200.00 NSCP Section 407.13

= 12.00 mm s < 5h = 500

= 113.10 s < 450spcg = 450.00 mm

R = Mu / fbdeff2

rreqd = m - m2 - 2Rm/fy

rsupplied

Asreqd = rbdAs main bar q

spcgreqd

spcgreqd = 3/2(spcgMID-STRIP)

mm2

qbar

Asbar mm2

Page 11: 2.0 Design of Slab

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Design of Two-Way Slab with BeamsReference: NSCP 2001 Volume 1

Design of Reinforced Concrete by J.C. McCormacDesign of Concrete Structures by Arthur H. Nilson

= 21 Mpa b x h

= 21 Mpa 250 x 400fy = 276 Mpa A

= 0.90 long span

= 4.80 kPa

= 2.50 kPa 3.70 m 300 x 500 C D 300 x 500

= 10.92 kPa

= 4.25 kPa B= 15.17 kPa 250 x 400

= 12 mmh = 125 mm 4.00 m 4.00 m

= 93 mm

= 0.932

= 3.00 kPa

Side A

= ==

= 21675.58 MPa = 21675.58 MPa

= = = 4.43

= 1.33E+09 = 3.01E+08Side B

= ==

= 21675.58 MPa = 21675.58 MPa

= = = 4.43

= 1.33E+09 = 3.01E+08Side C

= ==

= 21675.58 MPa = 21675.58 MPa

= = = 4.80

= 3.13E+09 = 6.51E+08Side D

= ==

= 21675.58 MPa = 21675.58 MPa

= = = 9.60

= 3.13E+09 = 3.26E+08

=4

= 5.81

B. Check Minimum Thickness = 3.700 m b = 1.072

= > 125 mm

= 125.00 mm

= > 90 mm

= 90.00 mm

Therefore use: = 90.00 mm ok!

fc'CS

fc'CB

fM

WDL

WLL

WuDL

WuLL

Wu

qbar

deff

la

lb

WSLAB

A. Solve for am

ECB 4730 fc'CB ECS 4730 fc'CSaA

ECBICB

ECB ECS ECSICS

ICB bh3 / 12 ICS bh3 / 12 aA

ICB mm4 ICS mm4

ECB 4730 fc'CB ECS 4730 fc'CSaB

ECBICB

ECB ECS ECSICS

ICB bh3 / 12 ICS bh3 / 12 aB

ICB mm4 ICS mm4

ECB 4730 fc'CB ECS 4730 fc'CSaC

ECBICB

ECB ECS ECSICS

ICB bh3 / 12 ICS bh3 / 12 aC

ICB mm4 ICS mm4

ECB 4730 fc'CB ECS 4730 fc'CSaD

ECBICB

ECB ECS ECSICS

ICB bh3 / 12 ICS bh3 / 12 aD

ICB mm4 ICS mm4

amaA + aB + aC + aD

am

ln

1. For am greater than 0.20 but not greater than 2.0

hmin

ln ( 0.80 + fy / 1500 )

36 + 5b ( am - 0.20 )

hmin

2. For am greater than 2.0

hminln ( 0.80 + fy / 1500 )

36 + 9b

hmin

hmin

Page 12: 2.0 Design of Slab

document.xls

D. Check Slab on Shear ( Coefficient Method )

Va = by linear interpolation Vu Mu(-)

Vb = 0.750 0.8800 1.00 0.710 0.071 0.033 0.035

= 0.8070 kN 0.932 x 0.8070 0.95 0.750 0.075 0.036 0.038

= 0.1930 kN 0.800 0.8600 0.90 0.790 0.079 0.039 0.042Va = 156.28 kN 0.85 0.830 0.083 0.042 0.046Vb = 37.37 kN 0.750 0.1200 0.80 0.860 0.086 0.045 0.051

= 0.932 x 0.1930 0.75 0.880 0.088 0.048 0.055= 362.25 kN ok! 0.800 0.1400 0.70 0.910 0.091 0.051 0.060

0.65 0.930 0.093 0.054 0.064D. Determine Design Moments ( Coefficient Method ) 0.60 0.950 0.095 0.056 0.068

Continuous Edge 0.55 0.960 0.096 0.058 0.073Negative Moments: by linear interpolation 0.50 0.970 0.097 0.061 0.078

Ma = 0.750 0.0880

= 0.0807 kN 0.932 x 0.0807 1.00 0.290 - 0.027 0.032Ma = 14.57 kN-m 0.800 0.0860 0.95 0.250 - 0.024 0.029

0.90 0.210 - 0.021 0.025Positive Moments: by linear interpolation 0.85 0.170 - 0.017 0.022

= 0.750 0.0480 0.80 0.140 - 0.015 0.019

= 0.932 x 0.0371 0.75 0.120 - 0.012 0.016

= 0.0371 kN 0.800 0.0450 0.70 0.090 - 0.009 0.013

= 0.0404 kN 0.65 0.070 - 0.007 0.010

= 4.82 kN-m 0.750 0.0550 0.60 0.050 - 0.006 0.008

= 2.04 kN-m 0.932 x 0.0404 0.55 0.040 - 0.004 0.006

= 6.86 kN-m 0.800 0.0510 0.50 0.030 - 0.003 0.005

by linear interpolation

= 0.750 0.0120

= 0.932 x 0.0229

= 0.0229 kN 0.800 0.0150

= 0.0269 kN

= 3.43 kN-m 0.750 0.0160

= 1.57 kN-m 0.932 x 0.0269

= 5.00 kN-m 0.800 0.0190

E. Design Reinforcements:

> 0.65 NSCP Section 410.3.7.3

= 0.85 - 0.05( fc' - 30 ) = 0.85

7

= 0.914use:

= 0.85 > 0.65 ok!

NSCP Section 410.4.3 NSCP Section 410.6.1

==

fc'> =

1.4

= 600 4 fy fy

fy 600 + fy = 0.0042 < = 0.0051

= 0.0377 use:= 0.0282 = 0.0051

la/lb

Ca

CaWulalb Mu(+)DL Mu(+)LL

CbWulalb Ca

Ca

Cb

Cb

fVc 0.85 fc'CS(1000)(deff)fVc

CaWula2 Ca la/lb Cb

Ca

MaDL CaDLWuDLla2 CaDL

MaLL CaLLWuLLla2

CaDL

CaLL

MaDL CaLL

MaLL

MaTOT

MbDL CbDLWuDLlb2 CbDL

MbLL CbLLWuLLlb2

CbDL

CbLL

MbDL CbLL

MbLL

MbTOT

Solve fo b1 :a.) if fc' > 30 Mpa ; b.) if fc' < 30 Mpa ;

b1b1

b1

b1

Solve for rmax : Solve for rmin :

rmax 0.75 rbalrmin rmin

rbal

0.85 b1 fc'

rmin rmin

rbal

rmax rmin

Page 13: 2.0 Design of Slab

document.xls

REINFORCEMENTSShort Span Long Span

Cont. Discont. Discont.

Middle Strip Top Bars Bot Bars Top Bars Bot Bars Top BarsDesign Moments 14.57 6.86 2.29 5.00 1.67

Bar Diameter 12 12 12 12 12m = 0.847 fc' / fy 0.0644 0.0644 0.0644 0.0644 0.0644

1.8720 0.8813 0.2938 0.6421 0.2140

0.0072 0.0033 0.0011 0.0024 0.0008

0.0072 0.0051 0.0051 0.0051 0.0051

668.01 471.74 471.74 471.74 471.74113.10 113.10 113.10 113.10 113.10

169.31 239.75 239.75 239.75 239.75Provide (spcg) 150.00 225.00 225.00 225.00 225.00

Column Strip Top Bars Bot Bars Top Bars Bot Bars Top Bars

225.00 337.50 337.50 337.50 337.50Provide (spcg) 225.00 250.00 250.00 250.00 250.00

E. Temperature / Shrinkage Reinforcements:As = 0.002bh b.Temp Reinf.

As = 250.00 NSCP Section 407.13

= 12.00 mm s < 5h = 625

= 113.10 s < 450spcg = 450.00 mm

R = Mu / fbdeff2

rreqd = m - m2 - 2Rm/fy

rsupplied

Asreqd = rbdAs main bar q

spcgreqd

spcgreqd = 3/2(spcgMID-STRIP)

mm2

qbar

Asbar mm2

Page 14: 2.0 Design of Slab

document.xls

Design of Two-Way Slab with BeamsReference: NSCP 2001 Volume 1

Design of Reinforced Concrete by J.C. McCormacDesign of Concrete Structures by Arthur H. Nilson

= 21 Mpa b x h

= 21 Mpa 250 x 400fy = 276 Mpa A

= 0.90

= 4.80 kPa 5.00 m

= 2.50 kPa 300 x 500 C D 300 x 500

= 10.92 kPa

= 4.25 kPa B= 15.17 kPa 250 x 400

= 12 mmh = 125 mm

= 93 mm 6.00 m short span

= 0.779

= 3.00 kPa

4.00 m

Side A

= ==

= 21675.58 MPa = 21675.58 MPa

= = = 3.28

= 1.33E+09 = 4.07E+08Side B

= ==

= 21675.58 MPa = 21675.58 MPa

= = = 1.49

= 1.33E+09 = 8.95E+08Side C

= ==

= 21675.58 MPa = 21675.58 MPa

= = = 9.60

= 3.13E+09 = 3.26E+08Side D

= ==

= 21675.58 MPa = 21675.58 MPa

= = = 9.60

= 3.13E+09 = 3.26E+08

=4

= 5.99

B. Check Minimum Thickness = 4.750 m b = 1.284

= > 125 mm

= 125.00 mm

= > 90 mm

= 100.00 mm

fc'CS

fc'CB

fM

WDL

WLL

WuDL

WuLL

Wu

qbar

deff

la

lb

WSLAB

A. Solve for am

ECB 4730 fc'CB ECS 4730 fc'CSaA

ECBICB

ECB ECS ECSICS

ICB bh3 / 12 ICS bh3 / 12 aA

ICB mm4 ICS mm4

ECB 4730 fc'CB ECS 4730 fc'CSaB

ECBICB

ECB ECS ECSICS

ICB bh3 / 12 ICS bh3 / 12 aB

ICB mm4 ICS mm4

ECB 4730 fc'CB ECS 4730 fc'CSaC

ECBICB

ECB ECS ECSICS

ICB bh3 / 12 ICS bh3 / 12 aC

ICB mm4 ICS mm4

ECB 4730 fc'CB ECS 4730 fc'CSaD

ECBICB

ECB ECS ECSICS

ICB bh3 / 12 ICS bh3 / 12 aD

ICB mm4 ICS mm4

amaA + aB + aC + aD

am

ln

1. For am greater than 0.20 but not greater than 2.0

hmin

ln ( 0.80 + fy / 1500 )

36 + 5b ( am - 0.20 )

hmin

2. For am greater than 2.0

hminln ( 0.80 + fy / 1500 )

36 + 9b

hmin

Page 15: 2.0 Design of Slab

document.xls

Therefore use: = 100.00 mm ok!hmin

Page 16: 2.0 Design of Slab

document.xls

D. Check Slab on Shear ( Coefficient Method )

Va = by linear interpolation Vu Mu(-)

Vb = 0.750 0.5600 1.00 0.290 - 0.027 0.032

= 0.5195 kN 0.779 x 0.5195 0.95 0.330 - 0.031 0.036

= 0.4805 kN 0.800 0.4900 0.90 0.380 - 0.035 0.040Va = 138.50 kN 0.85 0.430 - 0.040 0.045Vb = 128.11 kN 0.750 0.4400 0.80 0.490 - 0.045 0.051

= 0.779 x 0.4805 0.75 0.560 - 0.051 0.056= 362.25 kN ok! 0.800 0.5100 0.70 0.620 - 0.058 0.063

0.65 0.690 - 0.065 0.070D. Determine Design Moments ( Coefficient Method ) 0.60 0.760 - 0.073 0.077

Continuous Edge 0.55 0.810 - 0.081 0.085Negative Moments: by linear interpolation 0.50 0.860 - 0.089 0.092

Mb = 0.750 0.0440

= 0.0481 kN 0.779 x 0.0481 1.00 0.710 0.071 0.033 0.035Mb = 16.45 kN-m 0.800 0.0510 0.95 0.670 0.067 0.031 0.032

0.90 0.620 0.062 0.028 0.029Positive Moments: by linear interpolation 0.85 0.570 0.057 0.025 0.026

= 0.750 0.0510 0.80 0.510 0.051 0.022 0.023

= 0.779 x 0.0475 0.75 0.440 0.044 0.020 0.020

= 0.0475 kN 0.800 0.0450 0.70 0.380 0.038 0.017 0.017

= 0.0531 kN 0.65 0.310 0.031 0.014 0.014

= 7.10 kN-m 0.750 0.0560 0.60 0.240 0.024 0.012 0.011

= 3.09 kN-m 0.779 x 0.0531 0.55 0.190 0.019 0.009 0.009

= 10.19 kN-m 0.800 0.0510 0.50 0.140 0.014 0.007 0.007

by linear interpolation

= 0.750 0.0200

= 0.779 x 0.0212

= 0.0212 kN 0.800 0.0220

= 0.0217 kN

= 5.21 kN-m 0.750 0.0200

= 2.08 kN-m 0.779 x 0.0217

= 7.30 kN-m 0.800 0.0230

E. Design Reinforcements:

> 0.65 NSCP Section 410.3.7.3

= 0.85 - 0.05( fc' - 30 ) = 0.85

7

= 0.914use:

= 0.85 > 0.65 ok!

NSCP Section 410.4.3 NSCP Section 410.6.1

==

fc'> =

1.4

= 600 4 fy fy

fy 600 + fy = 0.0042 < = 0.0051

= 0.0377 use:= 0.0282 = 0.0051

la/lb

Ca

CaWulalb Mu(+)DL Mu(+)LL

CbWulalb Ca

Ca

Cb

Cb

fVc 0.85 fc'CS(1000)(deff)fVc

CbWulb2 Cb la/lb Cb

Cb

MaDL CaDLWuDLla2 CaDL

MaLL CaLLWuLLla2

CaDL

CaLL

MaDL CaLL

MaLL

MaTOT

MbDL CbDLWuDLlb2 CbDL

MbLL CbLLWuLLlb2

CbDL

CbLL

MbDL CbLL

MbLL

MbTOT

Solve fo b1 :a.) if fc' > 30 Mpa ; b.) if fc' < 30 Mpa ;

b1b1

b1

b1

Solve for rmax : Solve for rmin :

rmax 0.75 rbalrmin rmin

rbal

0.85 b1 fc'

rmin rmin

rbal

rmax rmin

Page 17: 2.0 Design of Slab

document.xls

REINFORCEMENTSShort Span Long Span

Discont. Cont. Discont.

Middle Strip Bot Bars Top Bars Top Bars Bot Bars Top BarsDesign Moments 10.19 3.40 16.45 7.30 2.43

Bar Diameter 12 12 12 12 12m = 0.847 fc' / fy 0.0644 0.0644 0.0644 0.0644 0.0644

1.3097 0.4366 2.1129 0.9375 0.3125

0.0049 0.0016 0.0082 0.0035 0.0011

0.0051 0.0051 0.0082 0.0051 0.0051

471.74 471.74 760.17 471.74 471.74113.10 113.10 113.10 113.10 113.10

239.75 239.75 148.78 239.75 239.75Provide (spcg) 225.00 225.00 125.00 225.00 225.00

Column Strip Bot Bars Top Bars Top Bars Bot Bars Top Bars

337.50 337.50 187.50 337.50 337.50Provide (spcg) 250.00 250.00 175.00 250.00 250.00

E. Temperature / Shrinkage Reinforcements:As = 0.002bh b.Temp Reinf.

As = 250.00 NSCP Section 407.13

= 12.00 mm s < 5h = 625

= 113.10 s < 450spcg = 450.00 mm

R = Mu / fbdeff2

rreqd = m - m2 - 2Rm/fy

rsupplied

Asreqd = rbdAs main bar q

spcgreqd

spcgreqd = 3/2(spcgMID-STRIP)

mm2

qbar

Asbar mm2

Page 18: 2.0 Design of Slab

document.xls

Design of Two-Way Slab with BeamsReference: NSCP 2001 Volume 1

Design of Reinforced Concrete by J.C. McCormacDesign of Concrete Structures by Arthur H. Nilson

= 21 Mpa

= 21 Mpafy = 276 Mpa

= 0.90 6.00 m

= 4.80 kPa b x h

= 2.50 kPa 300 x 500

= 10.92 kPa A

= 4.25 kPa long span= 15.17 kPa 6.00 m

= 12 mm 300 x 500 C D 300 x 500h = 125 mm

= 93 mm B

= 1.000300 x 500

= 3.00 kPa6.00 m

6.00 m 5.70 m

Side A

= ==

= 21675.58 MPa = 21675.58 MPa

= = = 3.20

= 3.13E+09 = 9.77E+08Side B

= ==

= 21675.58 MPa = 21675.58 MPa

= = = 3.20

= 3.13E+09 = 9.77E+08Side C

= ==

= 21675.58 MPa = 21675.58 MPa

= = = 6.40

= 3.13E+09 = 4.88E+08Side D

= ==

= 21675.58 MPa = 21675.58 MPa

= = = 3.28

= 3.13E+09 = 9.52E+08

=4

= 4.02

B. Check Minimum Thickness = 5.700 m b = 1.000

= > 125 mm

= 101.79 mm

fc'CS

fc'CB

fM

WDL

WLL

WuDL

WuLL

Wu

qbar

deff

la

lb

WSLAB

A. Solve for am

ECB 4730 fc'CB ECS 4730 fc'CSaA

ECBICB

ECB ECS ECSICS

ICB bh3 / 12 ICS bh3 / 12 aA

ICB mm4 ICS mm4

ECB 4730 fc'CB ECS 4730 fc'CSaB

ECBICB

ECB ECS ECSICS

ICB bh3 / 12 ICS bh3 / 12 aB

ICB mm4 ICS mm4

ECB 4730 fc'CB ECS 4730 fc'CSaC

ECBICB

ECB ECS ECSICS

ICB bh3 / 12 ICS bh3 / 12 aC

ICB mm4 ICS mm4

ECB 4730 fc'CB ECS 4730 fc'CSaD

ECBICB

ECB ECS ECSICS

ICB bh3 / 12 ICS bh3 / 12 aD

ICB mm4 ICS mm4

amaA + aB + aC + aD

am

ln

1. For am greater than 0.20 but not greater than 2.0

hmin

ln ( 0.80 + fy / 1500 )

36 + 5b ( am - 0.20 )

hmin

Page 19: 2.0 Design of Slab

document.xls

= > 90 mm

= 124.64 mm

Therefore use: = 124.64 mm ok!

D. Check Slab on Shear ( Coefficient Method )

Va = by linear interpolation Vu Mu(-)

Vb = 1.000 0.3300 1.00 0.330 0.033 0.020 0.028

= 0.3300 kN 1.000 x 0.3300 0.95 0.380 0.038 0.022 0.031

= 0.6700 kN 0.950 0.3800 0.90 0.430 0.043 0.025 0.035Va = 162.65 kN 0.85 0.490 0.049 0.029 0.040Vb = 330.23 kN 1.000 0.6700 0.80 0.550 0.055 0.032 0.044

= 1.000 x 0.6700 0.75 0.610 0.061 0.036 0.049= 362.25 kN ok! 0.950 0.6200 0.70 0.680 0.068 0.040 0.054

0.65 0.740 0.074 0.044 0.059D. Determine Design Moments ( Coefficient Method ) 0.60 0.800 0.080 0.048 0.065

Continuous Edge 0.55 0.850 0.085 0.052 0.070Negative Moments: by linear interpolation 0.50 0.890 0.089 0.056 0.076

Ma = 1.000 0.0330

Mb = 1.000 x 0.0330 1.00 0.670 0.061 0.023 0.030

= 0.0330 kN 0.950 0.0380 0.95 0.620 0.056 0.021 0.027

= 0.0610 kN 0.90 0.570 0.052 0.019 0.024

Ma = 16.26 kN-m 1.000 0.0610 0.85 0.510 0.046 0.017 0.022Mb = 30.07 kN-m 1.000 x 0.0610 0.80 0.450 0.041 0.015 0.019

0.950 0.0560 0.75 0.390 0.036 0.013 0.0160.70 0.320 0.029 0.011 0.014

Positive Moments: by linear interpolation 0.65 0.260 0.024 0.009 0.011

= 1.000 0.0360 0.60 0.200 0.018 0.007 0.009

= 1.000 x 0.0360 0.55 0.150 0.014 0.005 0.007

= 0.0360 kN 0.950 0.0320 0.50 0.110 0.010 0.004 0.005

= 0.0490 kN

= 12.77 kN-m 1.000 0.0490

= 6.77 kN-m 1.000 x 0.0490

= 19.54 kN-m 0.950 0.0440

by linear interpolation

= 1.000 0.0130

= 1.000 x 0.0130

= 0.0130 kN 0.950 0.0150

= 0.0160 kN

= 4.61 kN-m 1.000 0.0160

= 2.21 kN-m 1.000 x 0.0160

= 6.82 kN-m 0.950 0.0190

E. Design Reinforcements:

> 0.65 NSCP Section 410.3.7.3

= 0.85 - 0.05( fc' - 30 ) = 0.85

7

= 0.914use:

= 0.85 > 0.65 ok!

NSCP Section 410.4.3 NSCP Section 410.6.1

==

fc'> =

1.4

= 600 4 fy fy

fy 600 + fy = 0.0042 < = 0.0051

= 0.0377 use:

2. For am greater than 2.0

hminln ( 0.80 + fy / 1500 )

36 + 9b

hmin

hmin

la/lb

Ca

CaWulalb Mu(+)DL Mu(+)LL

CbWulalb Ca

Ca

Cb

Cb

fVc 0.85 fc'CS(1000)(deff)fVc

CaWula2 Ca la/lb Cb

CbWulb2

Ca

Cb

Cb

MaDL CaDLWuDLla2 CaDL

MaLL CaLLWuLLla2

CaDL

CaLL

MaDL CaLL

MaLL

MaTOT

MbDL CbDLWuDLlb2 CbDL

MbLL CbLLWuLLlb2

CbDL

CbLL

MbDL CbLL

MbLL

MbTOT

Solve fo b1 :a.) if fc' > 30 Mpa ; b.) if fc' < 30 Mpa ;

b1b1

b1

b1

Solve for rmax : Solve for rmin :

rmax 0.75 rbalrmin rmin

rbal

0.85 b1 fc'

rmin rmin

rbal

Page 20: 2.0 Design of Slab

document.xls

= 0.0282 = 0.0051rmax rmin

Page 21: 2.0 Design of Slab

document.xls

REINFORCEMENTSShort Span Long Span

Cont. Discont. Cont.

Middle Strip Top Bars Bot Bars Top Bars Top Bars Bot BarsDesign Moments 16.26 19.54 6.51 30.07 6.82

Bar Diameter 12 12 12 12 12m = 0.847 fc' / fy 0.0644 0.0644 0.0644 0.0644 0.0644

2.0895 2.5101 0.8367 3.8624 0.8764

0.0081 0.0098 0.0031 0.0160 0.0033

0.0081 0.0098 0.0051 0.0160 0.0051

751.14 915.74 471.74 1485.57 471.74113.10 113.10 113.10 113.10 113.10

150.57 123.50 239.75 76.13 239.75Provide (spcg) 150.00 100.00 225.00 75.00 225.00

Column Strip Top Bars Bot Bars Top Bars Top Bars Bot Bars

225.00 150.00 337.50 112.50 337.50Provide (spcg) 225.00 150.00 250.00 100.00 250.00

E. Temperature / Shrinkage Reinforcements:As = 0.002bh b.Temp Reinf.

As = 250.00 NSCP Section 407.13

= 12.00 mm s < 5h = 625

= 113.10 s < 450spcg = 450.00 mm

R = Mu / fbdeff2

rreqd = m - m2 - 2Rm/fy

rsupplied

Asreqd = rbdAs main bar q

spcgreqd

spcgreqd = 3/2(spcgMID-STRIP)

mm2

qbar

Asbar mm2

Page 22: 2.0 Design of Slab

document.xls

Design of Two-Way Slab with BeamsReference: NSCP 2001 Volume 1

Design of Reinforced Concrete by J.C. McCormacDesign of Concrete Structures by Arthur H. Nilson

= 21 Mpa b x h

= 21 Mpa 250 x 400 short spanfy = 276 Mpa A

= 0.90

= 4.80 kPa

= 2.50 kPa 300 x 500 C D 300 x 500 5.00 m

= 10.92 kPa

= 4.25 kPa= 15.17 kPa

= 12 mm Bh = 125 mm 250 x 400

= 93 mm 5.00 m

= 0.779

= 3.00 kPa

5.00 m 4.00 m 3.00 m

Side A

= ==

= 21675.58 MPa = 21675.58 MPa

= = = 3.28

= 1.33E+09 = 4.07E+08Side B

= ==

= 21675.58 MPa = 21675.58 MPa

= = = 1.64

= 1.33E+09 = 8.14E+08Side C

= ==

= 21675.58 MPa = 21675.58 MPa

= = = 4.27

= 3.13E+09 = 7.32E+08Side D

= ==

= 21675.58 MPa = 21675.58 MPa

= = = 5.49

= 3.13E+09 = 5.70E+08

=4

= 3.67

B. Check Minimum Thickness = 4.750 m b = 1.284

= > 125 mm

= 125.00 mm

= > 90 mm

= 100.00 mm

fc'CS

fc'CB

fM

WDL

WLL

WuDL

WuLL

Wu

qbar

deff

la

lb

WSLAB

A. Solve for am

ECB 4730 fc'CB ECS 4730 fc'CSaA

ECBICB

ECB ECS ECSICS

ICB bh3 / 12 ICS bh3 / 12 aA

ICB mm4 ICS mm4

ECB 4730 fc'CB ECS 4730 fc'CSaB

ECBICB

ECB ECS ECSICS

ICB bh3 / 12 ICS bh3 / 12 aB

ICB mm4 ICS mm4

ECB 4730 fc'CB ECS 4730 fc'CSaC

ECBICB

ECB ECS ECSICS

ICB bh3 / 12 ICS bh3 / 12 aC

ICB mm4 ICS mm4

ECB 4730 fc'CB ECS 4730 fc'CSaD

ECBICB

ECB ECS ECSICS

ICB bh3 / 12 ICS bh3 / 12 aD

ICB mm4 ICS mm4

amaA + aB + aC + aD

am

ln

1. For am greater than 0.20 but not greater than 2.0

hmin

ln ( 0.80 + fy / 1500 )

36 + 5b ( am - 0.20 )

hmin

2. For am greater than 2.0

hminln ( 0.80 + fy / 1500 )

36 + 9b

hmin

Page 23: 2.0 Design of Slab

document.xls

Therefore use: = 100.00 mm ok!hmin

Page 24: 2.0 Design of Slab

document.xls

D. Check Slab on Shear ( Coefficient Method )

Va = by linear interpolation Vu Mu(-)

Vb = 0.750 0.8600 1.00 0.670 0.061 0.023 0.030

= 0.8426 kN 0.779 x 0.8426 0.95 0.710 0.065 0.024 0.032

= 0.1574 kN 0.800 0.8300 0.90 0.750 0.068 0.026 0.036Va = 224.66 kN 0.85 0.790 0.072 0.028 0.039Vb = 41.96 kN 0.750 0.1400 0.80 0.830 0.075 0.029 0.042

= 0.779 x 0.1574 0.75 0.860 0.078 0.031 0.046= 362.25 kN ok! 0.800 0.1700 0.70 0.890 0.081 0.033 0.050

0.65 0.920 0.083 0.034 0.054D. Determine Design Moments ( Coefficient Method ) 0.60 0.940 0.085 0.036 0.059

Continuous Edge 0.55 0.950 0.086 0.037 0.063Negative Moments: by linear interpolation 0.50 0.970 0.088 0.038 0.067

Ma = 0.750 0.0780

Mb = 0.779 x 0.0763 1.00 0.330 0.033 0.020 0.028

= 0.0763 kN 0.800 0.0750 0.95 0.290 0.029 0.017 0.025

= 0.0157 kN 0.90 0.250 0.025 0.015 0.022

Ma = 15.84 kN-m 0.750 0.0140 0.85 0.210 0.021 0.013 0.020Mb = 5.39 kN-m 0.779 x 0.0157 0.80 0.170 0.017 0.010 0.017

0.800 0.0170 0.75 0.140 0.014 0.007 0.0130.70 0.110 0.011 0.006 0.011

Positive Moments: by linear interpolation 0.65 0.080 0.008 0.005 0.009

= 0.750 0.0310 0.60 0.060 0.006 0.004 0.007

= 0.779 x 0.0298 0.55 0.050 0.005 0.003 0.006

= 0.0298 kN 0.800 0.0290 0.50 0.030 0.003 0.002 0.004

= 0.0437 kN

= 4.46 kN-m 0.750 0.0460

= 2.54 kN-m 0.779 x 0.0437

= 7.00 kN-m 0.800 0.0420

by linear interpolation

= 0.750 0.0070

= 0.779 x 0.0087

= 0.0087 kN 0.800 0.0100

= 0.0153 kN

= 2.15 kN-m 0.750 0.0130

= 1.47 kN-m 0.779 x 0.0153

= 3.62 kN-m 0.800 0.0170

E. Design Reinforcements:

> 0.65 NSCP Section 410.3.7.3

= 0.85 - 0.05( fc' - 30 ) = 0.85

7

= 0.914use:

= 0.85 > 0.65 ok!

NSCP Section 410.4.3 NSCP Section 410.6.1

==

fc'> =

1.4

= 600 4 fy fy

fy 600 + fy = 0.0042 < = 0.0051

= 0.0377 use:

= 0.0282 = 0.0051

la/lb

Ca

CaWulalb Mu(+)DL Mu(+)LL

CbWulalb Ca

Ca

Cb

Cb

fVc 0.85 fc'CS(1000)(deff)fVc

CaWula2 Ca la/lb Cb

CbWulb2

Ca

Cb

Cb

MaDL CaDLWuDLla2 CaDL

MaLL CaLLWuLLla2

CaDL

CaLL

MaDL CaLL

MaLL

MaTOT

MbDL CbDLWuDLlb2 CbDL

MbLL CbLLWuLLlb2

CbDL

CbLL

MbDL CbLL

MbLL

MbTOT

Solve fo b1 :a.) if fc' > 30 Mpa ; b.) if fc' < 30 Mpa ;

b1b1

b1

b1

Solve for rmax : Solve for rmin :

rmax 0.75 rbalrmin rmin

rbal

0.85 b1 fc'

rmin rmin

rbal

rmax rmin

Page 25: 2.0 Design of Slab

document.xls

REINFORCEMENTSShort Span Long Span

Cont. Cont. Discont.

Middle Strip Top Bars Bot Bars Top Bars Bot Bars Top BarsDesign Moments 15.84 7.00 5.39 3.62 1.21

Bar Diameter 12 12 12 12 12m = 0.847 fc' / fy 0.0644 0.0644 0.0644 0.0644 0.0644

2.0347 0.8996 0.6920 0.4652 0.1551

0.0079 0.0033 0.0026 0.0017 0.0006

0.0079 0.0051 0.0051 0.0051 0.0051

730.06 471.74 471.74 471.74 471.74113.10 113.10 113.10 113.10 113.10

154.91 239.75 239.75 239.75 239.75150.00 225.00 225.00 225.00 225.00

Column Strip Top Bars Bot Bars Top Bars Bot Bars Top Bars

225.00 337.50 337.50 337.50 337.50225.00 250.00 250.00 250.00 250.00

E. Temperature / Shrinkage Reinforcements:As = 0.002bh b.Temp Reinf.

As = 250.00 NSCP Section 407.13

= 12.00 mm s < 5h = 625

= 113.10 s < 450spcg = 450.00 mm

R = Mu / fbdeff2

rreqd = m - m2 - 2Rm/fy

rsupplied

Asreqd = rbdAs main bar q

spcgreqd

Provide (spcg)

spcgreqd = 3/2(spcgMID-STRIP)Provide (spcg)

mm2

qbar

Asbar mm2