C O N C R E T E C A N VA S
GROUP 7
Marcos Anton Banon 11037890 Yoanne Chan 15024127 Nikolai Gomes de Almeida 14025325 Jordana Lyden-Swift 08006205 Rudi Perestrelo 10007751 Harveen Sunner 15017540
CONTENTS 1
Introduction
3
Development Process
11 14 15
Materials Aesthetics Services
17 20
Construction and Model Making Component Schedule
32 33 34 36 37 38 40 42 44 45 47 49 50
Drawing Set Exploded Isometric Worms eye Reflected Electrical Plan Reflected Ceiling Plan Short Section Long Section Roofing Detail - Short Section Fire Safety Wall Construction & Cold Bridging Roofing Detail - Long Section Post and beam assembly Rendered Representation
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Design Critique
INTRODUCTION The concrete articulated ceiling designed by group 7 is composed of seventeen reinforced concrete beams and three 73m rolls of concrete canvas. After deliberation our main aims were to use a high tech material to create a low-tech design. Using as little cement as possible and minimizing workforce requirements and environmental impact. We wished to be very honest with the material and transparent with the construction process. These notions of minimized resources, honest execution and integrity to all components run throughout the design and it’s process. 1
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DEVELOPMENT PROCESS
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1. Experimenting with fabric forms 2. C.A.S.T, University of Manitoba 3. Fabric Formwork, Remo Pedreschi and Alan Chandler Initial inspiration from the fluidity and versatility of concrete cast by fabric and structural stability by a thicker central beam to create a rib-like form.
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1. Vodaphone HQ, Porto, Portugal - Barbosa & Guimar達es 2. Andrea Russo - Paper folding sculpture 3. Experimenting with paper folding form The aesthetic flexibility created by concrete, used in the Vodaphone HQ , lead exploration in paper folding forms in architecture. This started the exploration of our approach to the articulated concrete ceiling.
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Testing the experiential qualities of the rib aesthetic, allowing to introduce the exposed qualities of services enhancing the honest nature of the techniques informing the design. Repetition of concrete beams tapered towards the central point for optimum load bearing capacity,
Exploring the link between the structural form, simultaneously being able to communicate a fluid aesthetic was explored through the use of repetition of beams, using the same structural principle with a thick central part. However, with slightly different formwork to create an undulating configuration. This was tested to formulate a design pf undulating ridges that work both structurally and aesthetically
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1. Barrel vault ceiling in Zarzuela Racecourse Grandstand, Madrid, Spain 2. Inverse barrel vault ceiling in the National Assembly, Kuwait
The appeal of creating an honest and unconcealed ceiling celebrating the characteristics of concrete lead us to explore the possibility of the ceiling skin layer that was also structural using the barrel vaults as a structural precedent. Weaknesses in the form concerning drainage lead us to rethink the form to create a shape to allow and to cater for drainage as an integral part of the ceiling design. This allowed us to carry the principle right through to roof detailing.
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Nottingham Contemporary, Caruso St John
Test draping on different configurations of beams to explore how the ‘fabric sheet’ forms a seamless blanket over the structural element of the ceiling.
Concrete Canvas is a flexible, concrete impregnated fabric that hardens when hydrated to form a thin, durable, water proof and fire resistant concrete layer. CC allows concrete construction without the need for plant or mixing equipment. Water just needs to be added to the Concrete Canvas to allow it to set. Concrete Canvas consists of a 3-dimensional fibre matrix containing a specially formulated dry concrete mix. A PVC backing on one surface of the material ensures the material is water proof. The material can be hydrated either by spraying or by being fully immersed in water. Once set, the fibres reinforce the concrete, preventing crack propagation and providing a safe plastic failure mode. This material allows the desired design to be realistically articulated through its use in the blanket layer that forms the shell structure of the ceiling.
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The final design of the concrete articulated ceiling was realised by abandoning the ideas relating to the tapered beams as the thickeneded central element of the beams would compromise the crucual structural junction where the beam meets the post. In addition to this, by mitigating the graduated beam, a large amount of concrete was able to be mitigated from the design, saving cost, and also load of the structure. This allowed for the the beams to be of a slender profile to enhance the delicate draping aesthetic achieved through the the use of high performance concrete.
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MATERIAL CHOICES
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CONCRETE CANVAS Concrete canvas was chosen to achieve the effortless fabric form of draping because of its capacity to achieve this form along with its structural stability needed for a ceiling. This was decided after extensive research on fabric formwork and alternative concrete casting techniques. WWW.CONCRETECANVAS.COM Concrete Canvas (CC) is a flexible, concrete impregnated fabric that hardens when hydrated to form a thin, durable, waterproof and fire resistant concrete layer. CC allows concrete construction without the need for plant or mixing equipment. Simply position the canvas and add water. CC consists of a 3-dimensional fibre matrix containing a specifically formulated dry concrete mix. A PVC backing on one surface of the material ensures the material is water proof. The material can be hydrated either by spraying or by being fully immersed in water. Once set, the fibres reinforce the concrete, preventing crack propagation and providing a safe plastic failure mode. CC in avaible in 3 thicknesses: CC5, CC8 and CC13, which are 5, 8 and 13mm thick respectively. CC is used in a variety of civil infrastructure applications, such as ditch lining, slope protection and capping secondary containment bunds. Compared to traditional concrete solutions, CC is faster, easier and more cost effective to install and has the additional benefit of reducing the environmental impact of concreting works by up to 95%. After researching the material, discovering its uses in aid shelters we had an ambition to run with this idea to create a ceiling that could also be constructed on site by minimal labour (2 men). This was achieved by minimising the weight of the components used.
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Fig.1 Concrete canvas component pinned in place for setting
CONCRETE BEAMS Contrasting textures of smooth beams and rough concrete canvas highlighted the aesthetic properties of the materials involved. This was also enhanced by the method of articulating the services. A decision was made to have all services exposed and therefore all wiring was carefully configured as a feature of the ceiling. By using high performance concrete we were able to minimise the cement content and enhance the draping effect of the concrete canvas by having very thin fins instead of bulky concrete beams. Glue laminated timber beams was considered as an alternative to using concrete for the beams because of our aim to use as little concrete/cement as possible. Particularly as the joint detailing of the beams are coincidentally very similar to timber detailing, Using GLULAM beams would substantially reduce the concrete/cement used in the articulated ceiling. However, as our brief was to investigate concrete construction the team wished to further the benefit of the experience of the charette, and endeavoured to push the design remit of standard concrete beams to fully understand the processes and limits of traditional concrete construction as a primary material. In addition, we felt the singularity of the materials used created a desired aesthetic. (being able to showcase very smooth, finished beams in comparison to the rough texture of the concrete canvas,) would hold an honesty in the versatile nature of concrete as a material – an initial aim of the design.
Fig.2 Concrete beams with voids for services
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AESTHETIC CHOICES The majority of our aesthetic choices were made based on the material and construction techniques we wished to investigate. We were enticed by the techniques and properties of the material choice and allowed them to lead the aesthetic decisions. Best showcasing the different capabilities of the material choices. To contrast and compliment the concrete textures we chose brass as the secondary detailing material. The rawness and honesty of the material held true to the ethos we wished to carry through the design.
Fig.3 The variety of treatments concrete canvas could be capable of
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SERVICES CHOICES We endeavored to integrate services, making them a highlighted feature as opposed to finding clever ways to hide them. This was in line with the honesty aim we had from the beginning. Casting services in to the beams would create problems if there is ever a necessity to alter them, however there seems something ‘unplanned’ by simply tacking them to the surface. We chose to showcase instead of hide them by casting voids through the beams to run wires perpendicular to the beams. In line with the minimal workforce required to construct the ceiling, the services are remarkable easy to adapt and appropriate of the placement of the services due to the multiple channels for the wires to run along. We allowed the wires to naturally drape and to reinforce the draping effects between the beams as opposed to running a straight pole conduit through the space which we felt wouldn’t do justice to the form of the ceiling. It also felt a step away from the initial ambitions of honest execution, by hiding the services with in a conduit.
Fig.4 Wires run through the beam voids
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CONSTRUCTION AND MODEL MAKING
Fig.5 Workings out for beam moulds 17
The Model In the making of the model we endeavoured to stay as true to life as possible with both the final representation and the construction process. A substantial amount of time was spent working out how to create the model assessing the benefits of each technique, therefore the model making process went very smoothly and to plan. The model mirrors the actual construction make up of the design, perhaps too much though. In our effort to represent life we applied layers of fabric and felt to mimic insulation and cold applied waterproofing membrane. Unfortunately this hid the pleasant aesthetic of the concrete canvas roof construction from above. However, as this was a ‘ceiling’ oriented project, the interior looked exactly as planned, one just had to get underneath it to appreciate it. As we stayed as true to reality as possible regarding the construction process, we learnt about some of the issues that might be faced. Concrete canvas is not currently used very expansively outside infrastructure projects and mining. It is supplied in 1m wide rolls. The roof would require nine widths to cover the roof. On trying to apply individual rolls we came into problems regulating the curve. However, by combining the individual rolls into one solid sheet we were able to easily apply it. Concrete canvas comes with ties to attach it to itself when necessary. We would possibly recommend creating a solid sheet before application to the roof, however this means additional machinery would be needed to lift it in to place. It would no longer be possible for just two men to apply which is one of it’s great attributes. With proper marking up and care it can be applied roll by roll and joined once in situ. Unfortunately the makers of concrete canvas are quite protective of their product and would not send us a sample. The unavailability of the material of testing was a project weakness.
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CONCRË TE
GROUP 7 19
EQUIPMENT AND MATERIALS NEEDED FOR CONSTRUCTION OFF SITE: - Reinforced concrete pre cast beams with services holes 1. 2 end beams, 2. 8 left to right beams, 3. 7 right to left beams precast ON SITE: 1. A lorry to transport 9m beams on to site 2. A crane to lift concrete beams in to place. 3. 3 rolls (9 strips) of 13mm concrete canvas 4. 96 concrete beam ties 5. 630 concrete canvas ties 6. 150 sqm Flexible rigid insulation panels 7. 150 sqm cold formed roof membrane 8. 150 sqm waterproof membrane
Concrete canvas roof -‐ components Item Triangular end beam Left to right beam Right to left beam Concrete beam ties Concrete canvas ties Concrete canvas rolls Flexible rigid insulation Cold formed roof membrane Waterproof membrane Total weight (kg)
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Quantity
3 (73m each) 150sqm 150sqm 150sqm
2 8 7 96 630
Unit weight (kg) Subtotal weight (kg) 387 774 774 6192 774 5418 2 192 0.4 252 1200 4 600
14628
2X
9X
8X
7X 21
1. Concrete beams lifted and installed into place and bolted to the flitch plates in the beams and to each other to create portal frame type joint. Ensure joint to walls are as specified on drawings.
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8X 23
2.
Roll out and cut 9 x 18m strips of concrete canvas perpendicular to the beams, pinning in place to regulate curves using concrete canvas ties to join each strip to the next (alternatively, 9 strips could be tied together before installation, however this would require a larger workforce).
Fig.6 The pinned rolls of ‘concrete canvas’ are wetted 24
10X
CONCRETE CANVAS 25
3. 4.
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Wet the concrete canvas thoroughly and allow to set by leaving 24 hours. Apply waterproofing membrane, flexible rigid insulation and cold form roof membrane to roof. Ensure insulation is inset by 500mm to maintain slender external roof profile.
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5.
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Install LED strip lights on front edge of each beam 100mm from ceiling edge to illuminate and enhance the draped canvas effect.
Fig.7 The services arramgement
15X
15X
LED LIGHTING 29
Fig.8 The feature pendants
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6.
Install pendant lighting in configuration set out in drawings using the precast services holes to hold wiring.
7.
Install smoke detectors in locations specified on drawings, using precast services holes to hold wiring.
9X
39X
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THE DRAWING SET
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Cold applied waterproofing Flexible rigid insulation Damp proof membrane
Concrete canvas
Concrete beams
End beam/wall
Concrete posts
Glazing panels
SIPs panels
Brass end cap
Exploded Isometric 1:200
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Worms Eye Isometric 1:50
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Pendant Lighting
Pendant Lighting Pendant Lighting Strip LEDLighting lighting Pendant Pendant Lighting Strip LED lighting Strip LED lighting Smoke Detector Strip LED lighting Strip LED lighting Smoke Detector Smoke Detector Smoke Detector Light switch Smoke Detector Light switch Light switch Light Motion sensor switch Light switch switch Motion sensor switch
Reflected Ceiling Plan with Symbols 1:50 Pendant Lighting
Pendant Lighting
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Pendant Lighting Pendant Lighting Strip LED lighting Pendant Pendant Lighting Lighting Strip LED lighting Strip LED lighting Smoke Detector Strip Strip LED LED lighting lighting Smoke Detector Smoke Detector Smoke Detector Light switch Smoke Detector Light switch Light switch Light Motion sensor switch Light switch switch Motion sensor switch Motion sensor switch Motion Motion sensor sensor switch switch
Pendant Lighting Strip LED lighting Smoke Detector
Reflected Ceiling Plan with Symbols 1:50 Light switch
Motion sensor switch
Pendant Lighting Pendant Lighting Strip LED lighting Pendant Pendant Lighting Lighting Strip LED lighting Strip LED lighting Smoke Detector Strip Strip LED LED lighting lighting Smoke Detector Smoke Detector Smoke Detector Light switch Smoke Detector Light switch Light switch Light Motion sensor switch Light switch switch Motion sensor switch Motion sensor switch Motion Motion sensor sensor switch switch
Reflected Ceiling Plan 1:50 Reflected Ceiling Plan 1:50
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light
Glazing unit frame
Fixing cap
Damp proof membrane Structural insulated panel Pre-cast post
Short Section
Short 1:25 Section Scale 1:25 38
Glazing unit Window sill External aluminium cladding
Birch plywood
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Cold applied waterproofing Flexible rigid insulation Damp proof membrane Concrete Canvas Canvas pin Rubber movement joint Precast concrete beam
ong Section Long Section cale 1:50 1:50 40
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Cold applied waterproofing Rigid insulation Vapour barrier Concrete canvas Fixing pin
Pre-cast hole (Assembly bolt and nut)
Fixing cap
Movement joint Structural insulated panel
Screw fixing
Supporting bracket Bolt fixing
Damp proof membrane
Pre-cast post
Glazing unit frame
Detail Section 1:5
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Detail Section Scale 1:5
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Fire Safety As mentioned earlier, concrete has a natural ability to resist fire, in fact, the material can sometimes be described as fireproof. Such performance is due to the inert and poor thermal conductivity property when cement and aggregate are chemically combined within the material. Concrete Canvas, inheriting the properties of concrete, can be used as a fire protection layer for the ceiling application. The canvas has been subjected to assessments of fire and health and safety certifications, including approval from the US Mine Safety and Health Administration.
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In case of fire, hazards in the proposed multifunctional hall are likely results of man-made accidents or malfunctioning of electrical in the hall since the concrete canvas ceiling has excellent high temperature performance (eliminating conduction in transmitting fire beyond the hall). Smoke detectors are also installed as to cope with the potential risks.
Concrete canvas
Pre-cast beam
Structural Insulated Panel Supporting bracket
Pre-cast post
Glazing unit (only framed for openable windows) Brass end cap Window sill
Fixing cap
Structural Insulated Panel
Cold Bridging As much as possible we tried to address cold bridging issues as they arose in the design phase. For example, the main post and beam structure is within the glazing line avoiding the compromising junctions that would result. Likewise, insulation is above the roof so that the majority is within the thermal envelope. However, there is a single continuous 13mm cold bridge around the entire structure where the roof thickness meets the external glazing line. To avoid this, wrap around insulation (keeping the entire roof within the thermal envelope) could have been used, but this would have compromised the aesthetic of the extremely thin edge. A secondary option of insulation above and below the cold bridge point (that then continues along inside for 1m) could have mitigated the effect of the cold bridge. Again, this would have compromised the aesthetic qualities of the concrete canvas and was decided against. 45
Fig.9 The draped wires between cast voids 46
Cold applied waterproofing Flexible rigid insulation Damp proof membrane Concrete Canvas
Rubber movement joint Canvas pin
MaxiLux strip lighting
Precast concrete beam
Brass Coated Pendant Light
Detail 1:10
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Fig.10 The beam joints
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Concrete caps
Beam Nuts
Rubber movement joint Bolts
Post
Concrete caps
D1 Post & Beam Assembly
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Rendered representation
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DESIGN CRITIQUE. Whilst the team feel that we were innovative in the use of materials, putting thought in to not only the primary structural elements but also the spaces between, we also feel that the concrete canvas, which was a secondary structure, could have been pushed further. It has good structural capabilities in it’s own right and due to the vaulting technique used in the design, could possibly have been self supporting. We were unable to get enough technical details at the time to be comfortable with that, however, that element of the model itself was self-supporting due to it’s form. The team agrees that one of the strongest parts of the design is the development process that lead to it. Both structurally and conceptually it was developed and streamlined as seen in the process section of this report. As a team we developed common themes around fabric formwork and alternative construction methods, this lead to the discovery and choice of concrete canvas. Once the our material choice had been made, further development of the design took place in order to showcase it in an interesting way. It was important to remember however, that despite it’s amazing flexibility and multiple uses, Concrete canvas was not a panacea. Therefore, to further the benefit of the experience of the charette the team also endeavoured to push the design remit of standard concrete beams. Making them very thin but deep was the first step, this lead to questions on the necessity of high performance concrete. The Team The team worked surprisingly well together. Decisions were made as a whole group and then smaller groups or individuals split off in order to conduct tasks. Everyone was very proactive and at no point was there twiddling of thumbs. There was a good range of strengths regarding model making and computer skills so tasks were split accordingly. However, everyone got their hands dirty at some point, and everyone contributed to the drawing set.
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