General Information
Prestressed concrete is used in a wide range of building and civil structures where its improved concrete performance will allow for longer spans, reduced structural thickness and materials savings to be realised compared to reinforced concrete. Choosing to use Ducon Concrete Ltd. for your prestressed slabs offers you, the customer a number of advantages:
- Prestressed Slabs Design Process – Submit your plans to Ducon Conrete Ltd and we will calculate, measure, specify and manufacture slabs to suit your project.
- Construction Process – You benefit from a faster build time based on the speed of manufacture & selection of prestressed slabs.
- Quality Controlled Products – Prestressed slabs are CE approved and manufactured in a controlled environment.
- Units are supplied with pre-stressing strands complying with BS 5896: 1980.
- Openings and notches can be incorporated into the slab design allowing for services etc. to pass from floor to floor.
- All units achieve one hour standard fire resistance in accordance with TB 4.4, BS 8110, Part 2 – 1985. This may be increased to two hour fire resistance on request. Please consult our technical office for additional details.
- Joints between units must be adequately grouted using 3:1 sand/cement mortar or 30 N/10 concrete, prior to the addition of any service loading or structural screed where appropriate.
- Where slabs are to be temporarily supported during construction, this shall be done in accordance with the details on the relevant slab layout drawing, and within the provisions of section 6.9, BS8110, Part 1 – 1985.
Benefits of using prestressed slabs
- Higher load capacity – long spans making it structurally efficient.
- Provides high levels of inherent fire resistance
- Provides excellent sound resistance
- Quick installation ensures a reduction in building programme time.
- Slabs can be grouted immediately after installation providing a stable floor suitable for working off.
- Progress on site is not weather dependent.
Cross sections
HOLLOWCORE SECTION PROPERTIES
| UNIT TYPE | |||||||
|---|---|---|---|---|---|---|---|
| mm2 | 150mm | 200mm | 250mm | 300mm | 400mm | ||
| Property | 15R7 | 20E11 | 25E6 | 30E11 | 40E6 | ||
| A mm2x103 | 124 | 151 | 167 | 212 | 223 | ||
| Self-Weight Kg/m2 | 254 | 298 | 330 | 418 | 438 | ||
Hollowcore load span tables
- Allowable spans refers to distances between support centres. These are maximum figures for each floor depth calculated with consideration of stresses induced from handling and transportation, in addition to flexural design. Further consideration of camber and deflection may also be required, consult our technical office for details.
- Figures tabulated include an allowance for self-weight and structural screed where appropriate. No allowance is taken for floor finishing screeds, partitions, services, ceilings, etc.
- Tables are not intended as a substitute for design. Please consult our Technical Office to discuss all design considerations.
| Table 1 | Allowable Spans (m) for Superimposed loadings kn/m2 | ||||||
|---|---|---|---|---|---|---|---|
| CASE A | UNIT ONLY | ||||||
| Unit | Superimposed loading kn/m2 allowing for self-weight only | ||||||
| Depth | 1.50 | 2.00 | 3.00 | 4.00 | 5.00 | 7.50 | 10.00 |
| 150 | 7.20 | 7.20 | 7.00 | 6.45 | 6.00 | 5.10 | 4.60 |
| 200 | 9.75 | 9.75 | 9.55 | 8.85 | 8.25 | 7.10 | 6.40 |
| 250 | 10.40 | 10.00 | 9.65 | 9.30 | 8.40 | 7.30 | 6.95 |
| 300 | 12.00 | 12.00 | 12.00 | 11.30 | 10.60 | 9.40 | 8.40 |
| 400 | CONSULT TECHNICAL DEPARTMENT | ||||||
| Table 2 | Allowable Spans (m) for Superimposed loadings kn/m2 | ||||||
|---|---|---|---|---|---|---|---|
| CASE B | Unit + 50 mm structural screed | ||||||
| Unit | Superimposed loading kn/m2 allowing for self-weight + 50mm screed | ||||||
| Depth | 1.50 | 2.00 | 3.00 | 4.00 | 5.00 | 7.50 | 10.00 |
| 150 | 7.20 | 7.20 | 7.05 | 6.60 | 6.30 | 5.65 | 5.20 |
| 200 | 9.75 | 9.75 | 9.65 | 8.90 | 8.45 | 7.65 | 7.00 |
| 250 | 10.40 | 10.40 | 10.00 | 10.00 | 8.50 | 7.70 | 7.40 |
| 300 | 12.00 | 12.00 | 12.00 | 11.95 | 11.75 | 10.75 | 8.70 |
| 400 | CONSULT TECHNICAL DEPARTMENT | ||||||
| Table 3 | Allowable Spans (m) for Superimposed loadings kn/m2 | ||||||
|---|---|---|---|---|---|---|---|
| CASE C | Unit + 75 mm structural screed | ||||||
| Unit | Superimposed loading kn/m2 allowing for self-weight + 75mm screed | ||||||
| Depth | 1.50 | 2.00 | 3.00 | 4.00 | 5.00 | 7.50 | 10.00 |
| 150 | 7.20 | 7.15 | 7.10 | 6.60 | 6.35 | 5.75 | 5.35 |
| 200 | 9.75 | 9.75 | 9.15 | 8.85 | 8.45 | 7.70 | 7.15 |
| 250 | 10.40 | 10.40 | 10.40 | 10.25 | 9.50 | 8.05 | 7.85 |
| 300 | 12.00 | 12.00 | 12.00 | 12.00 | 11.85 | 10.80 | 9.75 |
| 400 | CONSULT TECHNICAL DEPARTMENT | ||||||
