Formwork and finishes - final.ppt

1 5/27/20161 Formwork and finishes for cast in situ concreteElaine ToogoodBA(HONS) Grad Dip Arch RIBAS enior Architect, The Concrete CentreThe Concrete Centre:Taking concrete forward Free resource for specifiers Concrete Quarterly Publications: general and technical Practice workshops Seminars and conferences Training courses Webinars Concrete Elegance Concrete Society publicationsFurther reading5/27/20163 The National Structural Concrete Specification for Building Construction NSCS v 4 Definitive, simple and straightforward Prepared by the industry clients, designers, contractors and specialists Aims to benefit all, with information collected together in one place Download free pdf: cast insitu concrete requires greater care in specification and execution than most concreteEast Ham Customer Service CentreRick Mather Architects/ Engineers HRW5/27/20164 Achieving visual cast in situ concrete - a summary Correct and consistent mix Suitable facing, Formwork and accessories Appropriate release agent Careful workmanship/process for all elements Adequate protection Test panel(s) Team work and communication A little bit of luck!

2 Specifying visual cast insituconcrete It is a team effort. Structural Engineers specification will require input from the architect. Concrete contractor input required for final details. Consult suppliers pre tender Understandthe creation processes Be realistic about what is achievable Describeclearly the result you want to achieve (use benchmarks)5/27/20165 Bespoke Formwork and selected facingUnderstand the processLocal MaterialsReady-mixed in batching plantSpecific mix delivered to siteVisual cast insitu concrete- as struck finishEvelyn Grace AcademyZaha HadidSouth Bank, Dennis LasdunPersistence Works, SheffieldFielden Clegg Bradley Studios5/27/20166 Efficient Formwork systemsMany options of form facing materials5/27/20167 Understand form face qualities Range of repeated use Cost Quality Potential shapes/forms finish of concrete produced Size Fixing method Edge conditions Relationship with release agentImage courtesy of PeriGalileo Satellite Control Centre,Oberpfaffenhofen.

3 Germany5/27/20168 Ability to be shapedBent plySteel sheets 2D curved shapes by casting against bent Formwork Braced to support weight of concretePlastic lined cardboardThe Aquatics Centre,London Olympics 2012 Zaha Hadid Architects5/27/20169 The Aquatics Centre,London Olympics 2012 Zaha Hadid Architects 5 axis router to cut multi dimensional surfaces in polystyrene Subsequent processes included: Lining for rigidity, milled further & resin sealer Glass fibre forms created from curved mould, and stiffened for supportColumn form workPrefabricated steelPrefabricated cardboardBespoke ply faced5/27/201610 Impermeable form liners Impermeable materials: tend to give a smooth shiny finish Typically can be re-used many 100 s of times ( cores/high rise) Blow holes are likely Tend not to add colour to the concrete**steel can create dark mottling,especially if over compacted* High levels of GGBS create a temporaryblue colourPolyurethane facingGRPS heet steel or plate Smooth, large format sheets Typically imperial ply sheet sizes (2440 x1220) but metric and oversized boards also available Shiny, matte or slight timber grain finish depending on ply facingPlywood facing5/27/201611 Ply facings for visual concretePhenolic Film Faced Panels and High Density Overlay (HDO)- Smooth Shiny finish to the concrete.

4 (hard wearing multiple re-use).High quality medium density overlay (MDO) Resin impregnated paper faced Panels. Matt non- shiny surface finish to the concrete less re-useHigh Quality Birch faced (or other) ply Matt finish , light timber grain expressed. Often little re- use possible5/27/201612 Chose finishSeona Reid BuildingStephen Holl/JM architectsDundee HouseReiach and Hall Architects / Buro HappoldGrain of timber and repairs to plywood facing cast into concreteCoin Street neighbourhood CentreHaworth Tompkins Architects5/27/201613 Collaboration Teamwork is the key only with all of the team engaged will the client get the right result Grout tight joints Type and profile of edges Means of sealing Avoid exposing site cut boards5/27/201614 Dark staining loss of water between Formwork panelsExpressed board jointsUniversity Square.

5 StratfordMake5/27/201615 Agree surface tolerances Establish board fixings (usually from behind so hidden and avoids damaging board facing) Requirements often refined during process of trial panelsWestminster underground stationHopkins Associates Tighter tolerances Working platformLibrary , Dun LaoghaireCarr Cotter & Naessens / HorganlynchDouble boarding5/27/201616 Board marked concreteCaponata restaurant, CamdenBurd Haward ArchitectsSaw cut timber facing1 Centaur StdRMM /AKTK ensington Church St5thStudio / Price & MyersScaffolding boards pressure washed and wire brushed to expose grainTimber as Formwork liner5/27/201617 Oriel mostyn galleryLlandudno : EWA Architects Sandblasted SW timber cut throughs are hand burnishedOriel mostyn galleryLlandudno.

6 EWA Architects 100mm boards lining plywood Formwork Limited reuse of boards possible Could be re-sandblasted to remove concrete out of grain with a harder wood Oak5/27/201618 Lincoln museumPanter Hudspith Planed redwood boards of differing thicknesses Self compacted concretePear Tree HouseEdgley designRe-using formwork5/27/201619 Canadian grown douglas fir Sand blasted timber face to expose grain Self compacted concrete with fly ash Dark colouring enhanced by sealantIStrcutE offices, LondonHugh Brougton Architects/ Expedition engineering, IStrcutE offices, London, rear wallHugh Brougton Architects/ Expedition engineering, Smooth faced boards Self compacted concrete with fly ash Dark colouring enhanced by sealant5/27/201620 Parque flooring Dark colour from fly ash in concrete and probably unsealed timberThe Hearth HouseThe AOC / Engineers HRWF abric faced form linerImages courtesy of Max Frank - Zemdrain, 5/27/201621 Right quantity appliedToo much agent appliedAppropriate Release Agent Not essential to be specific at tender Specify to suit concrete mix and facing material but also to test on site before use Correctly applied to manufacturers guidance - other wise will be visible on the concreteDescribe details5/27/201622 Set tie bolt positions (design intent only)The ForumADP / AKS WardIndicative layoutEg.

7 Subject to structural req Aligned with each other Equal number per board minimum number required tie bolt positions (design intent only)RW Church, Korea Nameless more are required for aesthetic expression5/27/201623 Describe/agree where day joints are to be avoided Consider expressing joint for large areasConsider location Of day work jointsAngel building, LondonAHMM/ AKTH orizontal boardsJohn Henry Brookes Building, OxfordDesign EngineDay joint at mid board position5/27/201624 Appropriate tie bolts, covers and spacers Specify types appropriate for visual concrete. with minimal appearance on face of concrete Similar colours where possibleProprietary form liner productsManchester School of ArtFCB Studio Polyurethane or plastic mats bonded to inside of Formwork Designed for single or multiple use Bespoke or ready made designs5/27/201625 Camden Square Adventure Playground.

8 PeckhamEger Architects and Margret HigginsonPlastic dimpled drainage board used as a mouldSet out Formwork Design intent drawing by architects Contractors proposals agreed before constructionDwg by Burwell Deakins Architects5/27/201626 Design and describe elements in 3 DUnderstand and describe the forms to improve buildability and optimise formworkEast Ham Customer Service CentreRick Mather Architects/ Engineers HRWP recast Formwork for Experian Data CentreSheppard RobsonTHANK : 07932 666370@elainetoogoodSculptural retaining wall, RedruthWalter Jacks Studio