[WEEK 4 – STUDIO]
1
Floor systems
Reinforced Concrete
Folded steel sheeting
On the left, steel reinforces the concrete making it more durable and less brittle and open to fracturing or cracking On the right folded steel sheeting typically used as form work (pour slab on top) Sources (left to right): http://www.concretebasics.org/articlesinfo/reinfhandbookfig52layers.JPG http://img.archiexpo.com/images_ae/photo-‐m2/concrete-‐floor-‐slab-‐profiled-‐steel-‐sheet-‐66905-‐ 7139747.jpg
Concrete Flooring -‐ One way: Thickness = span/30 -‐ Two way: x&y span -‐ Concrete able to cope with fire better than timber or steel Timber Flooring: -‐ Joist and Bearer -‐ Span usually 450-‐600mm Formply: Laminated Plywood, usually used for formwork. Made by cross hatching sheets at 90 degree angles to create a sturdier material. Source http://www.plyco.com.au/images/formply1.jpg
Concrete -‐ Mix = 1 part cement + 2 parts fine aggregate + 4 parts coarse aggregate +0.4-‐0.5 parts water -‐ Too much water, = weak -‐ Too little water = stiff and unworkable
2 [WEEK 4 – STUDIO] -‐ Formwork: molds concrete is poured into (insitu and offsite) -‐ Reaches 75% compressive strength in 7 days -‐ Sacrificial framework: leaving the framework on the concrete wall. -‐ Poor conductor of heat and electricity -‐ Concrete is not impervious and if the steel bars are to close to the surface they will oxidize and rust causing the structure to be unstable. Source: http://i.ytimg.com/vi/zO6ZNB_ITUw/0.jpg
In Situ Concrete -‐ Needs form work (a mould) -‐ Air bubbles removed by vibration -‐ Limited time to complete or it will dry and become unworkable -‐ Shotcrete: used to spray concrete into place with a hose Sketch of control/construction joints -‐ Construction joint: divides slab into smaller sections -‐ Control Joints: minimizes shrinking and expanding etc. The Pantheon -‐ The weight of the dome creates a downward force (F= MxA) this is evenly distributed through either side of the dome like in an arch, a common building technique used in the Roman empire (1-‐2AD). -‐ In 3D the same properties apply but in all directions not just one. -‐ ‘Drum’ 6.1m thick -‐ Diameter of dome 43m -‐ Roman concrete uses large bits of rock with mortar. More ‘laying’ of wall than ‘pouring’ (modern concrete) -‐ Uses Brick-‐faced concrete Source: http://engineeringrome.wikispaces.com/file/view/F8%20T est.jpg/451482338/F8%20Test.jpg
[WEEK 4 – STUDIO]
3
Primary and Secondary Members
RHS: rectangular hollow system SHS: square hollow system CHS: circular hollow system Span = Distance between two points of support Spacing = Distance between two similar members -‐ L.V.L can span up to 6m, where as steel can go a lot further -‐ Primary Steel Members à Hot Rolled Section -‐ Secondary Steel Members à Cold Formed Section
The corrugated steel although the same thickness as the sheet of steel (0.5mm, 0.6mm galvanized and coated) has depth in the oscillation making it a stronger material. Technical Drawing R.L Level: Metres above sea level. Used as reference point. Grid Line: Used to show center of a column, so even if the column changes shape it will always have the same center. R.L Level and Grid line example. Photos and scans of the pavilion
4 [WEEK 4 – STUDIO] -‐ Lift shaft or stairwell can be used as a main structural component instead of columns. -‐ Windows, most often built in Aluminum.