Project Job Ref.
Section Sheet no./rev.
1
Calc. by Date Chk'd by Date App'd by Date
D 8/20/2017
RC TWO-WAY SLAB DESIGN (ACI318-11)
TEDDS calculation version 1.2.01
lx x
Column strip
Middle strip
ly
Column strip
Column strip Middle strip Column strip
TWO-WAY SLAB PANEL
147 mm
175 mm
250 mm
Section at middle strip along X axis
Slab definition
Slab thickness; h = 175 mm
Span along x dir; lx = 6000 mm
Span along y dir; ly = 3000 mm
Long span to short span ratio less than 2, hence two-way slab
Clear cover to positive reinforcement; cc = 20 mm
Clear cover to negative reinforcement; cc = 20 mm
Effective flanged beam section
Flange width; bf = 1000 mm
Beam depth; hb = 650 mm
Beam width; bw = 450 mm
Materials
Specified compressive strength of concrete; fc = 28 MPa
Specified yield strength of reinforcement; fy = 415 MPa
Modulus of elasticity; ESACI = 199948MPa
Concrete type; Normal weight
Project Job Ref.
Section Sheet no./rev.
2
Calc. by Date Chk'd by Date App'd by Date
D 8/20/2017
Concrete modification factor; = 1.00
Loads
Total factored ultimate load on slab; wu = 15.00 kN/m2
Check for the depth of slab provided
Clear span x dir (13.6.2.5); lnx = max(0.65 lx, (lx - bw / 2 - bw / 2)) = 5550 mm
Clear span y dir (13.6.2.5); lny = max(0.65 ly, (ly - bw / 2 - bw / 2)) = 2550 mm
Ratio; = max(lnx, lny) / min(lnx, lny) = 2.176
Moment of inertia of beam; Ib = 14628994381 mm4
Moment of inertia of slab along x axis; Isx = 1339843750 mm4
Moment of inertia of slab along y axis; Isy = 2679687500 mm4
Flexural stiffness ratio along x axis; fx = Ib / Isx = 10.918
Flexural stiffness ratio along y axis; fy = Ib / Isy = 5.459
Average flexural stiffness ratio; fm = (fx 2 + fy 2) / 4 = 8.189
Minimum depth required (9.5.3); hmin = 110 mm
PASS - slab thickness provided is sufficient for deflection
Moment computation (x direction)
Width of column strip (half) (13.2.1); lcol_stp = min(0.25 lx, 0.25 ly) = 750 mm
Width of middle strip (13.2.2); lmid_stp_x = ly - 2 lcol_stp = 1500 mm
Factored moment (Eqn 13-4); Mox = wu ly lnx2 / 8 = 173.26 kNm
Moment distribution for interior panel (13.6.3.2); Mux = 0.65 Mox = 112.62 kNm
Mux = 0.35 Mox = 60.64 kNm
Moment distribution in column and middle strips
ly / lx = 0.50
fx ly / lx = 5.46
Moment distribution factors; fx_neg = 0.90
fx_pos = 0.90
Total column strip design moments; Mx_col_stp = fx_neg Mux = 101.36 kNm
Mx_col_stp = fx_pos Mux = 54.58 kNm
Column strip beam moments; Mx_beam = 86.16 kNm
Mx_beam = 46.39 kNm
Column strip slab moments; Mx_slab = Mx_col_stp - Mx_beam = 15.20 kNm
Mx_slab = Mx_col_stp - Mx_beam = 8.19 kNm
Total middle strip design moments; Mx_mid_stp = (1 - fx_neg) Mux = 11.26 kNm
Mx_mid_stp = (1 - fx_pos) Mux = 6.06 kNm
Required flexural nominal strength in column strip per 1 m width of slab
Mnx_col = Mx_slab / (0.9 (2 lcol_stp - bf)) = 33.79 kNm/m
Mnx_col = Mx_slab / (0.9 (2 lcol_stp - bf)) = 18.19 kNm/m
Required flexural nominal strength in middle strip per 1 m width of slab
Mnx_mid = Mx_mid_stp / (0.9 lmid_stp_x) = 8.34 kNm/m
Mnx_mid = Mx_mid_stp / (0.9 lmid_stp_x) = 4.49 kNm/m
Moment computation (y direction)
Width of column strip (half) (13.2.1); lcol_stp = min(0.25 lx, 0.25 ly) = 750 mm
Width of middle strip (13.2.2); lmid_stp_y = lx - 2 lcol_stp = 4500 mm
Factored moment (Eqn 13-4); Moy = wu lx lny2 / 8 = 73.15 kNm
