BubbleDeck Voided Flat Slab Solutions

1 Technical PaperBubbleDeck Span GuideAugust 2006 Revision January 2009 BubbleDeck VoidedFlat slab SolutionsPage 1 of 3 BubbleDeck Maximum Indicative SpansThe appropriate BubbleDeck slab version is bespoke engineered to suit building configuration,span length between supports, applied loadings and vertical alignment of supports. Indicativespans are given as a guide to what can be spans indicated are based on 20mm concrete cover to bottom rebar (1 hour fireresistance); live load 3+1 kN/m2, dead load kN/m2 and lightweight external envelopemaximum 6 kN/m line load. Completed slab mass and Site Concrete Quantity based on 3metre x 9 metre pre-cast elements with 51 kg/m2 total (Multiplebays)CantileverMaximumLengthSpa n(Singlebays)CompletedSlab MassSiteConcreteQuantitymmmmmetresmetres metreskN/m2m3/m2BD230230 1805 2257 2709 31511 36013 *510 41015 *600 50016 * New 2006 BubbleDeck slab configurations: Agr ment certification pending, outside scope of KOMO Design Basic PrincipleAs a general guide for project scoping purposes at feasibility stage the maximum achievablespans for each BubbleDeck slab depth is usually determined by deflection limitations.

2 Thiscriteria is controlled by the ratio of span / effective depth (L/d) stipulated in BS8110 or EC2and modified by applying a factor of approximately , permitted by these Standards to takeaccount of BubbleDeck s dramatically lower dead weight than traditional solid flat Span / Depth ratios (R)L/d 30 for simply supported floors (Single Bay Rows) *1L/d 41 for continuously supported floors (Multiple Spans) *2 Page 2 of 3L/d for basic principle has been verified for up to kPa live + kPa dead uniformlydistributed loadings following full calculation and proven by full finite element analysismodelling to provide a generally reliable *1 Single Bay Rows refers to primary single span in one direction with multiple spans in otherdirection.

3 *2 Multiple Spans refers to multiple bays in both , to determine the span dimension (L) in the case of spanning onto columns withoutbeams ( flat slab construction) take the longest span dimension (in metres) between columncentres, where the slab will span onto walls or beams take the shortest span dimension (inmetres) between the walls or , to determine the effective depth (d) of a BubbleDeck slab use the table below to findeither approximate required total concrete cover (ct); or approximate effective depth (d) fordifferent levels of fire resistance. Effective depth is the overall depth less nominal concretecover to all reinforcement for durability and fire resistance purposes (from bottom meshreinforcement underside to bottom of slab ) and approximately half overall depth of bottommesh reinforcement.

4 Actual effective depth required for any project is determined from acombination of required fire resistance, durability classification, reinforcement quantity andstress levels so this estimation method is only an approximate Total Cover & Effective Depth DataBubbleDeck SlabsTotal Concrete Cover (ct) BubbleDeck SlabsEffective Depth (d)VersionSlabThickness1 HourFR2 HourFR1 HourFR2 HourFRmmmmmmmmmmmmmmBD230230343944196191 186BD280280343944246241236BD340340364146 304299294BD390390444954346341336BD450450 495459401396391BD510520495459461456451BD 600600495459551546541 Table based on nominal concrete cover of 20mm for 1 hour FR, 25mm for hour FRand 30mm for 2 hour FR with mild exposure (internal concrete surfaces) : For externally exposed slabs, such as car parking decks, reduce the effective depthgiven for 1 Hour Fire Resistance by an additional 15mm to allow minimum 35mm nominalconcrete cover below bottom reinforcement to meet durability either:a) BubbleDeck slab depth for given Spans: when the required span dimension is knowndivide span dimension (L) in metres into the span/effective depth ratio (R) for the appropriateslab configuration given above; then add on the required total concrete cover (ct) from thetable to arrive at the minimum BD Voided slab thickness.

5 The required BubbleDeck slab typeis the next size up from the minimum BD Voided slab an example for a 9 metre span between columns with multiple spans and requiring fire resistance, span / effective depth ratio (R) will be 41, so 9 metres/41 = 219mm,Page 3 of 3then adding (ct) of 39 mm (for hour FR in relevant range) indicates a minimum BD voidedslab thickness of 258mm requiring BD280 slab type for this span ) Approximate span for given BubbleDeck slab depth: to determine an indicativepossible maximum span for a given slab depth multiply the relevant Effective Depth (d) bythe span/effective depth ratio (R) for the appropriate slab configuration given an example for BD280 slab version, with hour fire resistance, (d) is 241 mm so 41xdindicates a maximum metre continuously supported (multiple bay) span.

6 30xd indicatesa maximum metre simply supported (single bay) span, and indicates a metre cantilever is potentially can confirm this estimation method by undertaking preliminary calculations and we wouldbe pleased to give you advice on a specific Tensioned BubbleDeck SlabsWhen mega spans are required (above 15 metres) we can provide a Post Tensioned (PT) BubbleDeck solution incorporated into our BD390 to BD600 slab range. The above span /depth ratios can be increased by a further 15% to 30% with post tensioned slab CalculatorFor more refined preliminary design we can provide a CD Rom containing our BubbleDeckslab calculator contact us for B 5th January 2007 BubbleDeck UKWhite Lodge, Wellington Road,St. Saviour, JERSEY, , JE2 7 TETelephone: +44 (0)1534 725402 Facsimile: +44 (0)1534 739115E-Mail: for various thicknesses, taken from previous results:Continuous spans:(two or more spans in relevant direction) kPa(excl slab weight) (mm)(mm)(m)(m)(m)(m)(m) Lines - Data from FE maximum span calculation results up to BD450, interpolated aboveDashed Lines - Interpolated from lower loadings BubbleDeck UK (2008) Ltd.

7 Revision 15/1/09 Total Imposed Dead + Live Load: BubbleDeck Maximum Span Guide Span - Depth Summary Table For Multiple (Continuous) Span ConditionBubbleDeck UK White Lodge, Wellington Road, St. Saviour, JERSEY, , JE2 7TE Telephone: +44 (0)1534 725402 E-Mail: 1213141516171819202122BD 650mmBD 550mmBD 450mmBD 390mmBD 340mmBD 280mmBD 230mmSingle spans:(one span between columns in relevant direction) kPa(excl slab weight) (mm)(mm)(m)(m)(m)(m)(m) Lines - Data from FE maximum span calculation results up to BD450, interpolated aboveDashed Lines - Interpolated from lower loadings BubbleDeck UK (2008) Ltd.

8 Revision 15/1/09 BubbleDeck UK White Lodge, Wellington Road, St. Saviour, JERSEY, , JE2 7TE Telephone: +44 (0)1534 725402 E-Mail: Maximum Span Guide Span - Depth Summary Table For Single (One Bay) Span ConditionTotal Imposed Dead + Live Load:01002003004005006007003456789101112 1314151617BD 650mmBD 550mmBD 450mmBD 390mmBD 340mmBD 280mmBD 230mmInner bays - simple calculation:hLLydL/ bays - FE calculation:hLLydL/ included.

9 Shrinkage section, non linear Geometry BubbleDeck UK (2008) Ltd. BubbleDeck Maximum Span Guide Simple & FE Calculation Results (Continuous Spans) BubbleDeck UK White Lodge, Wellington Road, St. Saviour, JERSEY, , JE2 7TE Telephone: +44 (0)1534 725402 E-Mail: interior bays - Thickness -v- Span (simple calculation)0510152025010020030040050060 0700 ThicknessSpan, L (m) , L/hLL/dL/hLinear (L)Linear (L/d)Linear (L/h) BubbleDeck interior bays - Thickness -v- Span (FE calculation)0510152025010020030040050060 0700 ThicknessSpan, L (m) , L/hLL/dL/hLinear (L)Linear (L/d)Linear (L/h)Single row continuous bays - simple calculation:hLLydL/ row continuous bays - FE calculationhLLyL/dL/h QP P+I P I=(P+I)-PL/ QPL/ included.

10 Shrinkage section, non linear deflections within or acceptably close to limits(L/250 and L/500).Basic GeometryShaded cases as cases governed by long term load (by inspection of previous above).Single row continuous bays - FE calculationhLLyL/dL/h QP P+I P I=(P+I)-PL/ QPL/ BubbleDeck UK (2008) Ltd. BubbleDeck Maximum Span Guide Simple & FE Calculation Results (Single Row with Continuous Bays) BubbleDeck UK White Lodge, Wellington Road, St. Saviour, JERSEY, , JE2 7TE Telephone: +44 (0)1534 725402 E-Mail: (mm)L (m) (L)Linear (L/d)Linear (L/h)02468101214160100200300400500600700 h (mm)L (m)0510152025303540LL/dL/hLinear (L)Linear (L/d)Linear (L/h)Single bay - simple calculation:hLLydL/ bay - FE calculation:hLLydL/dL/h QP P+I P I=(P+I)-PL/ QPL/ I AgePrecamb.