No Mesh Construction
Dramix® Steel Fibre Concrete, has been used worldwide in groundworks, for many years. Following extensive test work and analysis by the Steel Construction Institute, it is now available for multi-storey applications. Dramix steel fibres with Multideck 60-V2 have been proven to achieve a full fire performance for 1 – 1.5 hours.

Following further developmental work, Dramix® is now available for use with Multideck 80-V2 with a fire performance of 1 – 1.5 hours and also Multideck 50-V2 with a rating of 1 – 2 hours.

The use of a Dramix® Steel Fibre reinforced Concrete slab provides a “pre-reinforced” concrete slab - no mesh has to be installed.

Construction Advantages

• Pre-Reinforced Concrete
• Simplified process
• No mesh to transport, buy, store, lay etc...
• Time savings on site
• Earlier project completion
• Concrete volume savings
• Reduction in crane hire time

• Pre-Reinforced Concrete
• Simplified process
• No mesh to transport, buy, store, lay etc...
• Time savings on site
• Earlier project completion
• Concrete volume savings
• Reduction in crane hire time

• Pre-Reinforced Concrete
• Simplified process
• No mesh to transport, buy, store, lay etc...
• Time savings on site
• Earlier project completion
• Concrete volume savings
• Reduction in crane hire time

Dramix® Fibres
Dramix® fibres are made from prime quality hard-drawn steelwire to ensure high tensile strength and close tolerances.

Dramix® fibres are added to the concrete during mixing. The gluing of the fibres into bundles guarantees quick and easy mixing with perfectly homogeneous distribution. The hooked ends slowly deforms during pull-out and is generally considered as the best form of anchorage. Dramix® steel fibres are manufactured in accordance with the ISO 9001 quality specifications.

Shear Strength
The shear resistance of Dramix® concrete reinforced with 30kg/m3 RC-65/60-BN / 20kg/m3 RC-80/60-BN exceeds that of mesh reinforced concrete. This means that codified checks for longitudinal shear can be adopted and will not penalise fibre reinforced slabs. For 30kg/m3 the area of fibres crossing a shear plane may be taken as 0.37% of the concrete area.

Shear Stud Capacities
The SCI has established the following design information relating to shear stud strengths from the test data:

• In order to design studs embedded in fibre reinforced concrete with a dosage of 30 kg/m3 of Dramix® RC-65/60-BN or 20 kg/m3 of Dramix® RC-80/60-BN fibres in accordance with BS5950: Part 3: 1990 no shear stud strength reduction factor is applicable.
• In order to design studs embedded in fibre reinforced concrete with a dosage of 30 kg/m3 of Dramix® RC-65/60-BN or 20 kg/m3 of Dramix® RC-80/60-BN fibres in accordance with DD Env 1994-1-1: 1994 no shear stud strength reduction factor is applicable.

Recommendations When Mixing

1. General

• preferably use a central batching plant mixer.
• a continuous grading is preferred.
• mix until all glued fibres are separated into individual fibres. Fibres don’t increase mixing time significantly.
• f special cements or admixtures are used, a preliminary test is recommended.

2. General
2.1 In batching plant mixer

• never add fibres as first component in the mixer.
• fibres can be introduced together with sand and aggregates, or can be added in freshly mixed concrete.
• only for drummixer: unopened degradable bags can be thrown directly in the mixer.

2.2 Truckmixer

• add Dramix® as the final component into the back of the mixer truck.
• run mixer at drum speed: 12-18 rpm.
• adjust slump to a min. of 12 cm (preferably with water reducing agents or high water reducing agents).
• add fibres with maximum speed of 40 kg/min.
• optional equipment: belt-hoist elevator .
• after adding the fibres, continue mixing at highest speed for 4-5 min.

2.3 Automatic dosing

• Fibres can be dosed from bulk at rates up to 3.5 kg/sec with a specially developed dosing equipment.

Should you require further information please contact Bekaert for:

• Composite slab design
• Dramix® data sheet RC-65/60-BN / RC-80/60-BN
• Fire test report
• Composite slab load-span tables
• Composite slab fire resistance tables
• SCI reports