Client
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S1 Design Of Two-way Restrained Slab (IS456:2000) Slab Group
1 Conc Concrete rete Strength Strength (fck)
20 Mpa
2 Reinforc Reinforcement ement Strength Strength (fy)
415 415 Mpa Mpa
3 Asuumed Over all Thickness of slab
125 mm
4 Clear Cover 5 Length along along X-dir (SHORT (SHORT SPAN)( Lx) 6 Length along along Y-dir (LONG SPAN)(Ly) 7 αx (P ut for or - Moments) 8 αy (Put f or or - Moments) 9 De ad l oad (KN/m2) 10 Li ve l oad (KN/m2) Effective Depth of Slab 11 Adopted effective depth
20 mm mm 4m 4.7 m 0.058 0.047 5.75 KN /m2 2 KN /m2 mm
Suggestion
CHECK For
[1] or [0]
Revisi on
1= ok Check for effective depth
125,150.175,200
1
20,25,30
0=fail,increse depth of slab
(IS456-2000;C 24.2;C37.1.2) ANNEX-D Table26;C D1 and C24.4.1 (IS456-2000;C 24.2;C37.1.2) ANNEX-D Table26;C D1 and C24.4.2
64
105 mm
1= ok Check for spacing of bars along SHORT span (Middle Strip)
Spacing of bar (SHORT) Middle Strip
13 Adopt Spacing of bar (SHORT SPAN) 14 Used Φ bar (SHORT)
125 mm 10 mm mm
128 mm or l e ss Check for spacing of bars along LONG span (Middle Strip)
150 mm 8 mm
300 mm 8 mm mm
1 0=fail,increase bar dia or decrease spacing along short span 1= ok
175 175 mm or Less
Check for spacing of bars along ANY span (Column Strip)
2. Reinforcement in Edge (COLUMN) strip
17 Adopt Spac Spacing ing (ANY SPAN) SPAN) 18 Used bar Φ *ANY SPAN++
0=fail,increase bar dia or decrease spacing along short span 1= ok
8,10,12,16
Spacing of bars in 1 meter strip [LONG] Span,Middle Strip
15 Adopt Spac Spacing ing (LONG SPAN) 16 Used bar Φ*LONG+ Span
1
1 0=fail,increase bar dia or decrease spacing along short span
399 mm or l e ss 8,10,12
3. Curtailment upto distance from CENTREof SUPPORT 19 Along short short span span 20 Along long Span
1= ok Check for curtailment 411 Length
500 mm 500 mm
1 1
481
4. Check For Shear at Short Edges Thickness factor (k) for shear strength of 21 Slab
22 23 Permissible shear stress stress in concrete concrete Increased Shear strength of concrete due to sl ab acti on
0=fail,increase curtailment length 1= ok
1.3
1.3 for slab up to 150mm overal thickness
Check for Shear criterion
125 125 mm of Slab have k= 0.25 N/ N/mm2 Pe rce nt Te nsi on ste e l ( = 100As/bd 0.325 N /mm2
Concre te Mpa
6. Corner Reinforcement for Torsion
Slab-
Torsion reinforcements need not be provided at any comer contained by edges over both of which the slab is continuous.
IS456:2000,Annex D D1.9 page 90
Corner Type-I, {2-open,2-close} Corner Type-II, {1-open,3-close} Corner Type-III, {0-open,4-close} Type-I numbers of 8 mm Φ
1
0=fail,increase bar dia or thickness of slab 1.3 IS456-2000;Annex-B;Clause B5.2.1.1;page 85 0.32 % 20 MPA
S1
Reinforcement area required along X along Y
D1.8
461 mm2 215 mm2
9 4
87 (= 0.75*Atx) 186 (= 0.75*Aty)
min 100 mm and maximum 150mm (in ge neral)
Length extension from edge and paralle to edge along X 800 mm along Y 800 mm Type-II numbers of 8 mm Φ number of layers bars per layer Reinforcement area required along X along Y
230 mm2 107 mm2
Code IS456:2000 annex D D1.9
spacing (mm) 5 2
174 373
min 150 mm and maximum 200 mm (in general)
Length extension from edge along X 800 mm along Y 800 mm Type-II numbers of 8 mm Φ number of layers bars per layer Reinforcement area required along X 0 mm2 along Y 0 mm2 Length extension from edge along X 0 mm along Y 0 mm Bottom bar continuity (Not reqd at the support side upto distance) X-dir (mm) Continuous side of Slab 1000 Terminating side of Slab 600
Code IS456:2000 annex D D1.10
spacing (mm) 0 0
0 0
0 0
0 0 Code IS456:2000 annex D , D1.4
Y-dir (mm) 1175 705
Tension(negative moment)reinforcement at support Continuous edge Reinforcement area required numbers( not less than spacing (not more than) along X 307 mm2 4 153 along Y 143 mm2 3 247 Length extension from edge along X 600 mm along Y 705 mm
Code IS456:2000 annex D, D1.5
Non-Continuous edge Reinforcement area required numbers( not less than spacing (not more than) along X 307 mm2 4 102 along Y 143 mm2 3 165 Length extension from edge along X 400 mm along Y 470 mm
Code IS456:2000 annex D, D1.6
oncrete Percentage of steel(%) At
MPA
20
0.32
τ
c
(N/mm2)
of steel(%) At
< 0.15
20MPA 25MPA 0.18 0.25 0.22
0.19 0.23
30MPA 0.2 0.23
0.5
0.3
0.31
0.31
0.75 1
0.35 0.39
0.36 0.4
0.37 0.41
1.25 1.5
0.42 0.45
0.43 0.46
0.45 0.48
1.75 2 2.25
0.47 0.49 0.51
0.49 0.51 0.53
0.5 0.53 0.55
2.5
0.51
0.55
0.57
2.75 3.00 and above
0.51 0.51
0.56 0.57
0.58 0.6
For solid slab τ'c =kτc Overal Depth Of Slab (mm) Factor k
300 or more
275.000
250.000
225.000
200.000
1.00
1.05
1.10
1.15
1.20
Adopted Overal depth (mm) value of k taken 125.000
1.300 Check right value taken or not
175.000 150 or less 1.25
1.30
