design guidance for tab-deck™ composite slabs...

Design Guidance for

TAB-Deck™ Composite Slabs using

SMD Metal Decking reinforced with

ArcelorMittal Steel Fibres

Version 2 Revised October 2008

Design Guidance for TAB-Deck™ Composite

Slabs using SMD Metal Decking Reinforced with ArcelorMittal Steel Fibres

Introduction Steel Fibre Reinforced Concrete is a composite material formed by adding steel fibres into the concrete mix prior to pouring on site. The addition of steel fibres turns the normally brittle concrete into a more ductile material with an enhanced load carrying capacity. The three dimensional nature of the steel fibre reinforcement provides excellent crack control. Use of the TAB-Deck™ system can completely remove the need for traditional mesh reinforcement with all its associated problems of handling, storage and safety. Composite Metal Deck Slabs can be constructed faster and cheaper using the TAB-Deck™ system. ArcelorMittal has been one of the leading developers of steel fibre concrete technology for over 30 years. Steel fibres are already widely used for industrial floors constructed on grade or pile supported. Based on this experience, TAB-Deck™ has been developed by ArcelorMittal Wire Solutions (AMWS) in conjunction with Structural Metal Decks Ltd (SMD) for use with their metal decking profiles. TAB-Deck™ performance data has been fully assessed and approved by The Steel Construction Institute referred to as the SCI in this document. Advantages of using the TAB-Deck™ system

• TAB-Deck™ concrete is ready reinforced and requires little or no mesh fixing

• TAB-Deck™ concrete is easily and safely installed in any location • TAB-Deck™ concrete is faster to install saving time and money • TAB-Deck™ removes the need for storing mesh and accessories on site • TAB-Deck™ removes the need to lift and handle reinforcing mesh • TAB-Deck™ removes the need for mesh, saving fixing time and crane hire

Crack Control Requirements for Concrete The use of ArcelorMittal TAB-Deck™ fibres meets the crack control design requirements specified by BS 5950 part 4 for composite slabs and therefore removes the need for traditional mesh reinforcement. Nominal Reinforcement at Intermediate Supports

Where continuous composite slabs are designed as simply supported, nominal steel fabric reinforcement should be provided over intermediate supports. The cross section area of reinforcement in a longitudinal direction should be not less than 0.1% of the gross cross-section area of the concrete support. TAB-Deck™ solutions using a dosage rate of 30 kg/m3 of HE 1/50 steel fibres meet this requirement. Transverse Reinforcement (Slab)

The cross section area of transverse reinforcement in the form of steel mesh reinforcement should be not less than 0.1% of the cross section area of the concrete above the ribs. TAB-Deck™ fibres meet this requirement. Line Loads and Point Loads

A line load running parallel to the span should be treated as a series of concentrated loads.

Where there are concentrated point or line loads, transverse reinforcement should be placed on or above the profiled steel sheets. It should have a cross section area of not less than 0.2% of the concrete section above the ribs. This transverse reinforcement should be ductile. TAB-Deck™ solutions meet this requirement when used in conjunction with traditional rebar or wire mesh.

For additional advice regarding concentrated loads contact AMWS. Intermediate Supports, Propping or Special Finishes

In situations with a higher risk of cracking such as over intermediate supports, propped construction or where a special floor finish is required additional reinforcement greater than 0.1% of the gross cross section area of the concrete support will be required. CIRIA Report No 91 and BS 8110-2 give methods to determine the amount of reinforcement required to control cracking due to moisture or thermal movement. Additional guidance is given in Eurocode 4, which specifies more severe reinforcement requirements. Depending on circumstances this can require reinforcement of up to 0.4% of the gross cross section area of the concrete support. TAB-Deck™ solutions meet this requirement when used in conjunction with traditional rebar or wire mesh.

Situations when additional reinforcement may be req uired

ArcelorMittal steel fibres can be used to replace the traditional mesh reinforcement used for crack control and fire requirements.

Additional reinforcement may be required in the following situations:

• For continuous slab spans and/or loading conditions, including line loads, which exceed the capacity given by the published load / span tables.

• For single span slabs with over 30 minute fire rating, bottom reinforcement bars will normally be required; size and quantity to be determined by the load / span criteria.

• Cantilever slabs should be designed as reinforced concrete with top reinforcement by the structural engineer.

• Trimming reinforcement around square or round holes with an opening greater than 250mm but not exceeding 700mm. Where holes opening exceed 700mm, additional void trimming beams will be required.

• For edge composite beams when the distance from the edge of the concrete flange to the nearest row of shear connectors is below 300mm, transverse hoop reinforcement bars will be required and are to be detailed by the structural engineer.

• At Construction / Day Joints within the slab pour, adequate continuity reinforcement will be required.

Guidance on forming of Service Holes in Composite D eck Slabs

When it is necessary to form service holes in the composite slab, the following general guidelines should be followed for openings at right angles to the deck span.

1. Up to 250mm opening, no special treatment is required. Prior to casting the concrete the opening is boxed out. When the slab has cured the deck is then cut using a non-percussive tool.

2. Openings greater than 250mm but less than 700mm. Additional reinforcement is required around the opening. The design should generally be in accordance with BS 8110 when forming the hole as described above. Items 1 and 2 relate to isolated single holes and not to a series of holes transverse to the direction of span, which would need to be considered as a single overall opening dimension. In both cases 1 and 2 the metal decking should not be cut until the slab has cured.

3. Greater than 700mm. Structural trimming steelwork is required to be designed by the project engineer and supplied by a steelwork fabricator.

These are guidelines only and the project engineer should check particular requirements. SMD and AMWS cannot take design respo nsibility for any additional framing or slab reinforcement for holes or openings.

TAB-Deck™ Steel Fibre Reinforced Concrete Concrete Mix

The specific mix design will always depend on the local materials available but must follow these basic guidelines:

• Cement – minimum 350kg/m³ of CEM I 42.5 or III

• Aggregates – maximum 20mm

• Fines content – minimum 450kg/m³ of smaller than 200µ including cement

• Water/Cement ratio < 0.50

• Minimum Slump – 50 to 70mm (before the addition of steel fibres or Super-Plasticizer)

AMWS can provide advice on individual mix designs and check their suitability for specific projects. Addition of TAB-Deck™ Fibres to the Concrete Mix

The steel fibres should be added at a rate of 30 kg/m³ into the mixer truck either at the batching plant or on the job site. Some ready-mix suppliers have suitable facilities for loading the fibres into the mixer at the batching plant. Where these do not exist the fibres can be added at the plant or job site using conveyor belts or “blast” machines.

The steel fibres should be added at a rate of 30-40kg per minute. If using a conveyor belt the fibres should be spread on the belt not heaped to avoid clumps of fibres. The maximum drum rotation should be 12-15 revolutions per minute. The truck mixer should be rotated at full speed for 8-12 minutes after adding the fibres.

Adding steel fibres to the concrete mix will typically reduce the slump of the concrete mix by around 35mm. It is recommended therefore that a Super-Plasticiser be added to the concrete before the addition of the fibres to raise the fibre concrete slump to the required level. This is particularly important when the concrete is to be pumped.

Disclaimer: AMWS is to be held harmless in any case where the amount of TAB-Deck™ steel fibres added to the fresh concrete was less than specified in this or any other document relating to TAB-Deck™ applications. The dosage of TAB-Deck™ steel fibres used must be 30kg/m³ of concrete. In order to facilitate this and ease the burden on those adding the steel fibres please refer to the chart below indicating the number of 25kg boxes that should be added to the fresh concrete based on load sizes.

Load Size

TAB-Deck Steel Fibres /M³

25kg Boxes Per Load

1 M³ 30 2 2 M³ 30 3 3 M³ 30 4 4 M³ 30 5 5 M³ 30 6 6 M³ 30 8 7 M³ 30 9 8 M³ 30 10

Note: When pumping TAB-Deck™ steel fibre concrete a minimum 125mm (5”) diameter hose should be used. AMWS does not recommend or advise the use of smaller diameter hoses. AMWS must be consulted prior to the use of a smaller than recommended size with sufficient time to review the case prior to any TAB-Deck™ concrete placement on said project. Installation of TAB-Deck™ Fibre Reinforced Concrete

TAB-Deck™ fibre reinforced concrete should be installed, cured and finished in exactly the same way as non-fibre reinforced concrete. Fire Design of TAB-Deck™ Steel Fibre Reinforced Con crete

The fire resistance of concrete composite slabs reinforced with 30 kg/m³ of HE 1/50 steel fibres has been investigated by SCI.

The conclusions drawn with respect to the structural performance of the TR60, TR80 and R51 composite deck slabs in fire conditions are based on the results of fire tests commissioned by AMWS / SMD and carried out by Warringtonfire in May 2006 and June 2007.

The fire test specimens were tested with an applied load of 5kN/m², in addition to the self weight of the slab and achieved a fire resistance period of 118 minutes for the TR60, 130 minutes for the TR80 and 116 minutes for the R51.

The fire test results have been used to calibrate a structural model developed by SCI. This model was subsequently used to produce fire design tables for composite slabs constructed using SMD TR60, TR80 and R51 decking and concrete reinforced with steel fibres at the same design dosage (30kg/m³) as that used in the test specimens. The following pages include fire design tables for resistance periods of 60 and 90 minutes for the TR60 and R51 profiles and for 60, 90 and 120 minutes for the TR80 profile.

All the tables in this design guide are for Normal Weight Concrete and can conservatively be used for Lightweight Concrete. S hould you require full fire design tables specific to Lightweight Concrete , please contact AMWS or Structural metal Decks Ltd.

x 0.9mm - Normal Weight - 1 hour Fire Rating Fire resistance 60 min Deck Type TR60 Concrete Grade C25/30 Deck Thickness 0.9 mm HE 1.0/50 30 Kg/m3 Deck Strength 350 N/mm2 Concrete Type NW Factored Imposed Load

Depth 2.0 4.0 5.0 6.7 8.0 10.0 12.0 130 3609 3289 3156 2961 2828 2656 2492 140 3891 3555 3406 3180 3031 2813 2625 150 4172 3797 3625 3375 3195 2945 2758 160 4438 4008 3820 3523 3328 3070 2875 170 4688 4227 4000 3664 3461 3203 2992 180 4945 4391 4141 3797 3586 3328 3117 190 5148 4523 4266 3922 3711 3445 3227 200 5328 4648 4398 4047 3836 3563 3344

x 1.0mm - Normal Weight - 1 hour Fire Rating

Fire resistance 60 min Deck Type TR60 Concrete Grade C25/30 Deck Thickness 1.0 mm HE 1.0/50 30 Kg/m3 Deck Strength 350 N/mm2 Concrete Type NW Factored Imposed Load

Depth 2.0 4.0 5.0 6.7 8.0 10.0 12.0 130 3680 3344 3219 3031 2906 2727 2578

140 3961 3617 3484 3258 3117 2906 2727

150 4234 3875 3711 3461 3289 3055 2852 160 4508 4102 3922 3633 3438 3180 2977

170 4758 4313 4109 3781 3570 3305 3094

180 5016 4508 4266 3914 3695 3430 3211

190 5258 4664 4398 4047 3828 3547 3328 200 5445 4781 4523 4164 3938 3664 3438

x 1.2mm – Normal Weight – 1 hour Fire Rating Fire resistance 60 min Deck Type TR60 Concrete Grade C25/30 Deck Thickness 1.2 mm HE 1.0/50 30 Kg/m3 Deck Strength 350 N/mm2 Concrete Type NW Factored Imposed Load

Depth 2.0 4.0 5.0 6.7 8.0 10.0 12.0 130 3813 3469 3336 3156 3039 2867 2719 140 4078 3734 3602 3398 3258 3063 2883 150 4344 3992 3844 3609 3445 3227 3023 160 4617 4250 4070 3805 3625 3375 3156 170 4891 4484 4289 3984 3781 3500 3281 180 5156 4695 4477 4141 3914 3625 3398 190 5414 4883 4633 4266 4039 3750 3516 200 5633 5023 4758 4383 4148 3859 3617

x 0.9mm - Normal Weight - 90 minute Fire Rating


Depth 2.0 4.0 5.0 6.7 8.0 10.0 12.0 140 3258 2906 2773 2570 2422 2234 2086 150 3523 3133 2969 2719 2563 2367 2211 160 3750 3320 3133 2859 2695 2492 2336 170 3953 3469 3266 2992 2828 2617 2453 180 4148 3625 3422 3141 2969 2750 2578 190 4320 3758 3547 3266 3086 2867 2688 200 4469 3898 3688 3398 3219 2992 2805



Depth 2.0 4.0 5.0 6.7 8.0 10.0 12.0 140 3328 2977 2836 2633 2500 2305 2148 150 3586 3195 3039 2797 2633 2438 2273 160 3828 3398 3219 2945 2773 2570 2398 170 4031 3563 3359 3070 2898 2688 2516 180 4227 3719 3508 3219 3039 2820 2641 190 4406 3844 3625 3336 3156 2930 2750 200 4563 3984 3766 3469 3289 3055 2867


Fire resistance 90 min

Deck Type TR60 Concrete Grade C25/30

Deck Thickness 1.2 mm HE 1.0/50 30 kg/m3

Deck Strength 350 N/mm2 Concrete Type NW

Factored Imposed Load

Depth 2.0 4.0 5.0 6.7 8.0 10.0 12.0

140 3445 3094 2953 2758 2625 2438 2273

150 3711 3328 3172 2938 2773 2563 2398

160 3945 3523 3352 3086 2906 2688 2516

170 4164 3711 3516 3219 3039 2813 2641

180 4367 3883 3656 3359 3172 2945 2758

190 4555 4008 3789 3484 3297 3063 2875

200 4727 4148 3922 3609 3422 3180 2984

x 0.9mm - Normal Weight - 1 hour Fire Rating Fire resistance 60 mins Deck Type R51 Concrete Grade C30/35 Deck Thickness 0.9 mm HE 1.0/50 30 kg/m3 Deck Strength 350 N/mm2 Concrete Type NW Factored Imposed Load

Depth 2.0 4.0 5.0 6.7 8.0 10.0 12.0 101 6578 5461 5086 4602 4313 3961 3680 110 6773 5664 5289 4789 4500 4133 3852 120 6969 5875 5500 4992 4695 4320 4031 130 7156 6078 5695 5188 4883 4500 4203 140 7320 6250 5867 5359 5047 4664 4359 150 7477 6430 6047 5531 5219 4828 4516 160 7617 6578 6203 5688 5367 4977 4656 170 7758 6742 6359 5844 5531 5125 4805 180 7883 6875 6500 5992 5672 5266 4938

x 1.0mm - Normal Weight - 1 hour Fire Rating Fire resistance 60 mins Deck Type R51 Concrete Grade C30/35 Deck Thickness 1.0 mm HE 1.0/50 30 kg/m3 Deck Strength 350 N/mm2 Concrete Type NW Factored Imposed Load

Depth 2.0 4.0 5.0 6.7 8.0 10.0 12.0 101 6844 5688 5297 4789 4484 4117 3828 110 7047 5906 5508 4992 4688 4305 4008 120 7250 6117 5719 5195 4883 4500 4195 130 7445 6320 5922 5398 5078 4680 4375 140 7609 6500 6109 5578 5258 4852 4531 150 7781 6688 6289 5758 5430 5023 4703 160 7922 6844 6453 5914 5586 5180 4844 170 8070 7008 6617 6078 5750 5336 5000 180 8195 7148 6758 6227 5891 5477 5133

x 1.2mm - Normal Weight - 1 hour Fire Rating Fire resistance 60 mins Deck Type R51 Concrete Grade C30/35

Deck Thickness 1.2 mm HE

1.0/50 30 kg/m3 Deck Strength 350 N/mm2 Concrete Type NW Factored Imposed Load

Depth 2.0 4.0 5.0 6.7 8.0 10.0 12.0 101 7289 6063 5648 5102 4781 4391 4086 110 7523 6305 5883 5336 5008 4602 4289 120 7750 6539 6117 5563 5227 4813 4484 130 7961 6758 6336 5773 5430 5016 4680 140 8141 6961 6539 5969 5625 5195 4852 150 8320 7156 6734 6164 5813 5375 5031 160 8477 7328 6906 6336 5984 5539 5188 170 8633 7500 7078 6508 6156 5711 5352 180 8758 7648 7234 6656 6305 5859 5492

x 0.9mm - Normal Weight - 90 minute Fire Rating Fire resistance 90 mins Deck Type R51 Concrete Grade C30/35


1.0/50 30 kg/m3 Deck Strength 350 N/mm2 Concrete Type NW


Depth 2.0 4.0 5.0 6.7 8.0 10.0 12.0 110 4484 3758 3508 3180 2984 2750 2563 120 4664 3938 3688 3352 3148 2906 2711 130 4813 4094 3836 3500 3297 3039 2844 140 4945 4234 3977 3641 3430 3172 2969 150 5086 4375 4117 3773 3563 3297 3086 160 5227 4523 4266 3914 3695 3430 3211 170 5336 4641 4383 4031 3813 3539 3320 180 5484 4789 4531 4172 3953 3672 3453





Depth 2.0 4.0 5.0 6.7 8.0 10.0 12.0 110 4664 3906 3641 3305 3102 2852 2664 120 4844 4086 3820 3477 3266 3016 2813 130 4992 4242 3977 3625 3414 3156 2945 140 5133 4391 4125 3773 3555 3289 3078 150 5266 4531 4266 3906 3688 3414 3203 160 5398 4664 4398 4039 3820 3539 3320 170 5539 4820 4555 4188 3961 3680 3453 180 5664 4945 4680 4313 4086 3797 3563





Depth 2.0 4.0 5.0 6.7 8.0 10.0 12.0 110 4984 4172 3891 3523 3313 3047 2836 120 5172 4367 4086 3711 3492 3219 3000 130 5328 4531 4250 3875 3648 3367 3141 140 5477 4680 4398 4023 3789 3508 3281 150 5609 4828 4547 4164 3930 3641 3406 160 5758 4984 4703 4313 4078 3781 3547 170 5883 5117 4836 4445 4203 3906 3664 180 6000 5242 4961 4570 4336 4031 3781

x 0.9mm - Normal Weight - 1 hour Fire Rating Fire resistance 60 mins Deck Type TR80 Concrete Grade C28/35


Deck Strength 350 N/mm2 Concrete Type NW Factored Imposed Load

Depth 2.0 4.0 5.0 6.7 8.0 10.0 12.0 150 4945 4125 3852 3492 3273 3008 2805 160 5172 4359 4078 3703 3484 3211 2992 170 5367 4563 4273 3898 3672 3391 3164 180 5539 4742 4453 4070 3844 3555 3320 190 5680 4891 4609 4219 3984 3695 3453 200 5797 5023 4742 4352 4117 3820 3578 210 5906 5141 4859 4469 4234 3930 3688 220 6008 5258 4977 4586 4352 4047 3797 230 6117 5375 5094 4703 4461 4156 3906 240 6219 5484 5211 4820 4578 4266 4016 250 6320 5594 5320 4930 4688 4375 4117



Deck Strength 350 N/mm2 Concrete Type NW

Factored Imposed Load Depth 2.0 4.0 5.0 6.7 8.0 10.0 12.0

150 5500 4586 4273 3867 3633 3336 3109 160 5750 4844 4523 4109 3859 3555 3320 170 5938 5047 4727 4305 4055 3742 3492 180 6109 5227 4914 4492 4234 3914 3656 190 6250 5383 5070 4641 4383 4063 3797 200 6375 5523 5211 4781 4523 4195 3930 210 6484 5648 5336 4914 4648 4320 4047 220 6594 5766 5461 5031 4773 4438 4164 230 6703 5891 5578 5156 4891 4555 4281 240 6797 6000 5695 5266 5000 4664 4383

250 6891 6102 5797 5375 5109 4766 4492

x 0.9mm - Normal Weight - 90 minute Fire Rating Fire resistance 90 mins Deck Type TR80 Concrete Grade C28/35



Depth 2.0 4.0 5.0 6.7 8.0 10.0 12.0 160 3531 2984 2789 2539 2391 2211 2063 170 3797 3227 3031 2766 2602 2406 2250 180 4055 3469 3266 2984 2813 2602 2438 190 4266 3672 3461 3172 3000 2773 2602 200 4430 3836 3617 3328 3141 2914 2734 210 4625 4023 3805 3500 3313 3078 2891 220 4750 4164 3938 3633 3445 3203 3016 230 4875 4289 4063 3758 3563 3320 3125 240 5000 4414 4188 3875 3688 3438 3234 250 5117 4531 4313 4000 3797 3547 3344

x 1.2mm - Normal Weight - 90 minute Fire Rating Fire resistance 90 mins Deck Type TR80 Concrete Grade C28/35



Depth 2.0 4.0 5.0 6.7 8.0 10.0 12.0 160 3875 3273 3063 2789 2625 2422 2258 170 4156 3523 3305 3016 2836 2625 2453 180 4406 3773 3547 3242 3055 2828 2648 190 4617 3977 3742 3430 3242 3008 2813 200 4781 4141 3906 3586 3391 3148 2953 210 4945 4305 4070 3742 3547 3297 3094 220 5086 4453 4211 3883 3680 3422 3219 230 5195 4570 4336 4008 3805 3547 3336 240 5320 4695 4461 4133 3922 3656 3445 250 5430 4813 4570 4242 4031 3766 3547




Depth 2.0 4.0 5.0 6.7 8.0 10.0 12.0 170 3328 2836 2664 2430 2289 2117 1984 180 3594 3078 2891 2648 2500 2313 2164 190 3844 3313 3117 2859 2703 2508 2352 200 4031 3492 3297 3031 2867 2656 2492 210 4188 3648 3453 3180 3008 2797 2625 220 4359 3820 3617 3336 3164 2945 2766 230 4500 3961 3758 3469 3297 3070 2891 240 4648 4109 3898 3609 3430 3203 3016 250 4773 4227 4016 3727 3547 3313 3117




Depth 2.0 4.0 5.0 6.7 8.0 10.0 12.0 170 3633 3094 2906 2648 2500 2313 2164 180 3891 3336 3141 2875 2711 2508 2352 190 4125 3555 3352 3078 2906 2695 2523 200 4305 3734 3523 3234 3063 2844 2664 210 4461 3883 3672 3383 3203 2977 2797 220 4633 4055 3836 3539 3359 3125 2938 230 4750 4180 3969 3664 3477 3242 3047 240 4867 4305 4086 3781 3594 3352 3156 250 5023 4453 4234 3930 3734 3492 3289

Composite Beam Design with TAB-Deck™ Steel Fibre Reinforced Concrete

Shear Stud Connectors for SMD TR60 Deck

From tests on a total of 12 push tests it has been demonstrated that the resistance of stud connectors was similar in specimens using concrete reinforced with a dosage of 30 kg/m³ of TAB-Deck™ fibres, compared to identical specimens using conventional reinforcement bars. The presence of fibres resulted in a significant enhancement to the ductility, for single and pairs of studs, which was equivalent to a 61% and 51% improvement in slip capacity. Stud Design Rules

For 19mm diameter studs through deck welded in a favourable position within 0.9mm gauge TR60, TR80 and R51 sheeting, the following rules should be used in design: Eurocode 4

For design in accordance with Eurocode 4, the following resistances should be used. (N.B. the values below may also be conservatively assumed for sheet thicknesses greater than 0.9mm) Single Studs

Pairs of Studs

BS 5950-3: 1990

Based on BS 5950-3: 1990, the ratio of the stud reduction factor for pairs of studs to single studs is 0.6/0.85 = 0.71. From the tests conducted, the ratio of the characteristic resistance for pairs of studs to single studs is 43.7/72 = 0.61. From tests on full scale beams it has been shown that the factor of 0.85 given in BS 5950-3: 1990 is appropriate for single studs. As a consequence of this, the following equations may be assumed for 19mm diameter studs through-deck welded within TR60, TR80 and R51 sheeting:

Single Studs For single studs, the following reduction factor equation given in clause 5.4.7.2 may be used:

Pairs of Studs

For pairs of studs, the factor of 0.6 given in clause 5.4.7.2 should be reduced to 0.52 (i.e. 0.85 x 0.61 = 0.52) for the following factor equation:

Where is the breadth of the concrete rib and is the depth of the profiled steel sheet (provided that the stud projects at least 35mm above the shoulder of the deck, using the ‘shoulder height’) and h is height of the stud. Longitudinal Shear for SMD TR60, TR80 and R51

Testing has shown that in composite beam applications, the longitudinal shear resistance of floor slabs reinforced with 30 kg/m³ of TAB-Deck™ fibres is, in most cases, sufficient so as not to require provision of additional transverse reinforcement. For example, a 30 kg/m³ of TAB-Deck™ fibres was sufficient to provide a longitudinal shear resistance equivalent to an A393 mesh in a 150mm

solid slab with = 30N/mm². When 30 kg/m³ of TAB-Deck™ fibres are used in combination with conventional reinforcement, it may be possible to gain enhancement compared to cases when bars are embedded within plain concrete. Design Rules

When profiled steel sheeting is oriented with the ribs parallel to the longitudinal axis of the beam (i.e. at primary beam positions) the longitudinal shear resistance may not be sufficient when the concrete is only reinforced with 30 kg/m³ of steel fibres. In such cases, supplementary transverse reinforcement in the form of conventional bars should be provided. Although the tests undertaken so far indicate that an enhancement of approximately 10% can be achieved when fibres are used in combination with conventional reinforcement bars. There is insufficient data at this time to allow improved design equations to be developed. As a consequence of this, when supplementary reinforcement bars are provided, the fibres should be ignored and the design carried out according to the requirements given in Eurocode 2, 6.2.4 or Clause 5.6 of BS5950-3: 1990.

Eurocode 4

For design in accordance with Eurocode 4, the following equation should be used when normal weight concrete slab is reinforced with 30 kg/m³ of steel fibres.

Where is the effective thickness of the concrete flange is the length under

consideration (half the span for a simply supported beam with UDL) is the characteristic compressive cylinder strength of concrete, is the partial factor of safety (= 1.5), υ is the strength reduction factor for concrete cracked in shear

and is the contribution of the profiled steel sheeting, if applicable calculated according Eurocode 4 6.6.6.4 BS5950-3: 1990

For design in accordance with BS5950-3: 1990, the following equation should be used when a normal weight concrete slab is reinforced with 30 kg/m³ of TAB-Deck™ fibres.

Where is the mean cross-sectional area per unit length of the beam of the

concrete shear surface under consideration and is the contribution of the profiled steel sheeting, if applicable, calculated to Clause 5.6.4 of BS5950-3: 1990. The design resistance given in by this equation is equivalent to that provided by

an A393 mesh in a solid slab with = 30 N/mm². Further comparisons of longitudinal shear resistance provided by a 130mm composite slab using 0.9mm TR60 decking reinforced with conventional square mesh and 30 kg/m³ of TAB-Deck™ fibres are given in the following table.

Longitudinal shear resistance comparison table for TR60 deck at 130mm deep composite slab with 0.9mm TR60 decking reinfor ced with conventional square mesh fabric and 30 kg/m³ of ste el fibres Longitudinal shear resistance Vr

Vr † Vr ‡ Vr † Vr ‡ Vr † Vr ‡ Vr † Vr ‡

(N/mm²) (N/mm²) (N/mm²) (N/mm²) (N/mm²) (N/mm²) (N/mm²) (N/mm²)

Square mesh fabric A 142 A 193 A 252 A 393

Cube 30 434.9 133.9 451.3 150.3 470.3 169.3 515.7 214.7

strength 35 449.6 148.6 466 165 485 184 530.4 229.4

fcu 40 464.3 163.3 480.7 179.7 499.7 198.7 545.1 244.1

(N/mm²) 45 479 178 495.4 194.4 514.4 213.4 559.8 258.8

30 kg/m³ of TAB-Deck™ fibres

Cube 30

strength 35

fcu 40 565.6 264.6 565.6 264.6 565.6 264.6 565.6 264.6

(N/mm²) 45

Notes † Secondary beam with continuous decking perpendicular to the longitudinal axis of the beam (with deck contribution vp) ‡ Primary beam with decking parallel to the longitudinal axis of the beam (no deck contribution) ArcelorMittal Sheffield Ltd Structural Metal Decks Ltd Birley Vale Close The Outlook Sheffield Ling Road S12 2DB Tower Park Poole BH12 4PY Phone 0114 239 2601 Ph one 01202 718898 Fax 0114 264 2514 Fax 01202 714980 Email: [email protected] Email: [email protected]

design guidance for tab-deck™ composite slabs...

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