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DESIGN DETAIL
4.1 BUILDING STRUCTURE
Pilotis round concrete columns
The proposed building is constructed by conventional reinforced concrete post and beam structure. However, the post joining the roof and roof structure constructed by steel. The round reinforced concrete column was chosen as structure to portray the overall aesthetic value. The round columns are exposed to show the grand view of pilotis which also shown by Le Corbusier's Villa Savoye.
The reinforced concrete columns used are generally 800mm in radius, while the reinforced concrete beams are generally 300mm X 750mm. 110mm ø UPVC rainwater down pipes are concealed in some columns to channel the rain water to rainwater harvesting tank (see section 4.3 for detail in rainwater harvesting system). The steel columns powder coated white are used to join the reinforced concrete columns with roof structure.
The cast-in-situ reinforced concrete two-way floor slab are used together with beams to allow long spans and heavy loads. The r.c. slabs are 150mm thick.
Typical Grid system
Shear Wall Structure system
Grid System is used for easier positioning of beams and columns of the building. Grid lines denote the horizontal beams and the intersection point of the grid line mostly represent the location of columns. Most spaces in the building have regular columns and are hidden in the wall. However, the tower of startup centre employ the shear wall structure.
4.1.1 FOUNDATION
Retaining wall and foundation
Pile foundation is applied as the substructure of Startup. Bottom up construction is used where construction begins from basement. Piles are driven in clusters to a more stable bearing stratum as not to exceed soil's bearing capacity. Each of this pile top by a reinforced concrete pile cap. The cast-in-situ reinforced concrete foundation walls enclosing the basements are retaining walls with waterproofing. Perforated drainage system is installed to relieve the build-up water pressure behind the water. Retaining wall of 400-800mm thick and are categorized as load bearing walls.
4.1.2 WALL SYSTEM
Wall system of brickwork and aluminum box section
Walls generally serve the building as envelope, separate and protect the space with control on daylight, natural ventilation, fire resistance, thermal insulation and sound insulation. The exterior walls consist of 114mm thick brick wall with 19mm thick plaster on both sides with emulsion paint finish and aluminum box section louvers sand blasted white finish.
4.1.3 CEILING SYSTEM
Startup used 3 types of ceiling which are fibrous plaster ceiling, cement sand board ceiling, and aluminum composite panel ceiling. All ceiling below green roof used cement sand board ceiling to endure the potential water leakage. Meanwhile, the soffit ceiling for the metal deck feature roof used white aluminum composite panel for lighter weight. The rest of the ceiling used fibrous plaster ceiling.
4.1.4 ROOF SYSTEM
Roof system used in Startup are 5° pitch metal deck roof, green roof and reinforced concrete flat roof. The 5° pitch metal roofing is supported by steel structural frame to channel the rainwater to mild steel gutter.
Detail of metal deck roofing
Detail of green roof