Prestressed Hollow Core Slabs 250mm
Sectional Information
Cross-section area: 174,855 X 103mm2
Moment of inertia: 1 205,857 X 106mm4
Section modulus top: 9,651 X 106mm3
Section modulus bottom: 9,642 X 106mm3
Total breadth of webs: 468mm
Centroidal axis from bottom: 34,5mm
Conc. 28 day strength: 50MPa
Conc. strength at transfer: 35MPa
Mod. of elasticity of concrete: 34kN/mm2
Stressing of strand / wire: 70%
Check: stresses at transfer: OK
Cover to steel: 30mm
Structural Information
( Wiring Pattern )
MOMENT AND SHEAR CAPACITIES |
G Span | H + 2 span | J +4 span |
|---|---|---|---|
| Service moment | 108,20 kNm | 133,59 kNm | 152,89 kNm |
| Ultimate moment | 167,99 kNm | 230,13 kNm | 273,66 kNm |
| Ultimate shear resist | 214,72 kN | 235,20 kN | 251,11 kN |
Standard Wiring Patterns
G = 10 x 9.53mm strand (over 8m span = 2 x 5mm top wire)
H + 2 = 9 x 9.53mm strand + 3 x 12.5mm strand + 2 x 5mm wires – top (over 9m span – 2 x additional x 5mm top wire)
J + 4 = 4 x 9.53mm strand + 8 x 12.5mm strand + 4 x 5mm wires – top
Load Capacity Table
Live Load
( Wiring Pattern )
kN/m2 |
G Span (m) | H +2 Span (m) | J +4 Span (m) |
|---|---|---|---|
| 0.75 | 11.4 | 12.6 | 13.3 |
| 1.5 | 10.5 | 11.8 | 12.5 |
| 2.5 | 9.8 | 10.9 | 11.6 |
| 4.0 | 8.9 | 9.9 | 10.6 |
| 5.0 | 8.4 | 9.4 | 10.1 |
| 7.5 | 7.5 | 8.3 | 8.9 |
| 10 | 6.9 | 7.7 | 8.2 |