WEEK 9 Learning Loop I. Joints and Connections II. Movement Joint III. Construction Detailing IV. Composite Materials V. Finish Work
Studio ‘In Detail’ Oval Pavilion (Part 2)
Glossary Appendix
LEARNING LOOP I. JOINTS AND CONNECTIONS (CHING 2.30) Joints and connections functions critically to load (force) transfer and how a whole structural system performs. Structural elements can be joined in 3 ways; • Butt joints o One of the elements joined together can be continuous o Requires a third mediating element • Interlocking or overlapping joints o One of the elements joined together can be continuous o The elements joined together can bypass each other • Structural connection (molded or shaped joints) o The elements are shaped or molded together to form a structural connection
There are 3 kinds of joints; • Pinned joints o Allow rotation o Resist translation in any direction • Rigid or fixed joints o Maintain angle between joined elements o Resist rotation o Resist translation in any direction o Provide force and moment resistance • Roller joints o Allow rotation o Resist translation in direction perpendicular into or away from the faces o Allow expansion and contraction of structural elements Structural elements can also be joined together with connectors. There are 3 types or forms of connectors; • Point, example: bolt • Line or linear, example: weld • Surface, example: glue Linear and surface connectors resist and prevent rotations. Point connectors resist
rotation only if a series of them is distributed on a larger surface area. II. MOVEMENT JOINT (CHING 7.48 – 7.50) Joints must be constructed to allow movements of structural elements (expansion and contraction) to prevent distortion, cracking, and breaks. Characteristics of movement joints: • Provides complete separation of materials • Allows free movement • Maintains tightness Location or placement of movement joints: • Between newly - constructed building and an existing structure • On surfaces with a lot solar exposure • On long and linear building elements, example: fascia, gravel stops, curtain wall framing • At horizontal and vertical continuities
Types of movement joints: • Expansion joints o Continuous o Unobstructed slots o Between 2 parts of a building structure o Sometimes can also acts as control and isolation joints o Elements of an expansion joint: ! A compressible joint ! A weather-stop; usually an elastic joint sealant, a flexible water-stop, or a flexible membrane • Control joints o Continuous grooves or separations in concrete ground slabs and masonry walls o Forms a plane of weakness o Regulate the amount of cracking • Isolation joints o Divide a structure into sections o Protect a nonstructural element from deflection
III. CONSTRUCTION DETAILING Construction detailing is done based on various aspects; • Constructability • Reparability / resistance to damage • Cleanable surface o Example: Use of flooring types • Access for maintenance • Joint movement o Considering the extension and compression potential of structural members o Elongation o Installation of the joints • Health and safety o Example: Stairs o The importance of handrail/ guardrail IV. COMPOSITE MATERIALS In construction processes there are 2 kinds of materials used; either monolithic or composites. • Monolithic: o Consist of 1 kind of material o Example: Metal alloys
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Composite: o Consist of 2 or more materials o Each material used remain distinguishable
Composite materials (usually called composites) consist of two or more physically and chemically different materials that formed a material with completely different characteristics. Characteristics of a composite material: • The materials used as the components differ in terms of their composition and form • The components are bonded together • The components retain its original properties • The product act as a single unit and provide a new synergic properties In the field of construction, there are various types of composite materials; o Particulate o Example: Resins, gravel
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Fibrous o Materials with both discontinuous or continuous fibers Laminar o Example: Sandwich panels Hybrid o A combination of 2 or more composite materials
Fiberglass Made From
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Epoxy Resin Glass Fibers (fabric form or tape form)
Common Forms
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Uses
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Flat-profiled sheet Formed or shaped product Cladding o Transparent o Walls or roof As shaped products o Pools o Water tanks o Baths Lightweight Fire resistant Weatherproof Strong
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Benefits
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There are many composite materials used in the industry. Some of the most common are: • Fiberglass • Fiber Reinforced Cement (FRC) • Fiber Reinforced Polymers • Timber Composites • Aluminium Sheet Composites
Fiber Reinforced (FRC) • • • • • • •
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Cement
Water Cement Cellulose (Glass) Sand Sheet or board products Shaped products Cladding o Exterior and interior (wet) area Floor panels o Under tiles Inexpensive Termite resistant Fire resistant Water damage resistant Rotting resistant
Fiber Polymers
Reinforced Timber Composites
Polymers/ plastics with timber/ glass/ carbon fibers Molded products
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Decking External cladding As structural members o Beams and columns o Rebar Corrosion resistant High strength
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Timber chords •
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Solid timber Engineered timber (solid + sheet)
Aluminium Composites
Sheet
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Aluminium Plastic
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Beams o Floor joists o Roof rafters Trusses
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Honeycomb sheet Lined with external Aluminium sheets Cladding o Exterior and interior area
Minimum material used Maximum efficiency Cost effective Easy to install
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top
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Less Al needed Light and cheap Unbreakable Shock resistant Can achieve and form specific details
V. FINISH WORK (CHING 10) Plaster refers to mixtures in a plastic state and allowed to harden and dry. Coat is how many layers of plaster are applied to the surface of a material. The most common: • Two-coat: o A basecoat (any plaster applied before the finish coat) o A finish coat (as a finish surface or base of decoration) • Three –coat: o A scratch coat (provide better bond to the second or brown coat) o A brown coat (rough finishing, usually as the base or second coat) o A finish coat Example: Gypsum plaster Materials: Gypsum, water, fine sand, lightweight aggregate, and various additives.
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Benefits: Durable, lightweight, and fire resistant. A lath is the base panel for plasterworks.
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Gypsum Boards is a sheet material used for covering walls or as lath. It is usually used in large sizes thus more economic.
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Types of gypsum boards: • Regular o Tapered edge o For single-layer construction • Coreboard o Square/ tongue and groove edge o To line elevator shafts, stairways and mechanical shafts • Fail-backed o Square / tapered edge o Serves as a vapor retarder and thermal insulation • Water-resistant o Tapered edge o Used in high-moisture areas o Base for ceramic and tiles • Type-X o Tapered/ rounded edge
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Fire-resistance The core contains glass fibers and other additives Prefinished o Square edge o Vinyl/ printed Backing o Square/ tongue-and-groove edge o Used for increasing rigidity, sound insulation, and fireresistance Sheathing o Square/ tongue-and-groove edge o Used as exterior sheathing
Gypsum boards are commonly used with masonry or concrete based structures and as a stud wall base to provide greater stiffness and prevent buckling/ crackling. Ceramic Tiles are small, modularsurfacing units made of clay or ceramic material. There are 3 main types of ceramic tiles; • Glazed wall tiles o Interior use: surfacing interior walls and light-duty floors
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Exterior use: weatherproof and frost-proof Ceramic mosaic tiles o Porcelain/ natural clay body o Has bright colors o Used for floors and walls Quarry and paver tiles o Unglazed o Impervious to dirt, moisture, and stains o Can be used as floors subjected to heavy loads
Terrazzo Flooring is a mosaic floor/ paving composed of marble or other stone chips, set in a cement/ resin based matrix and ground. When it dries up, it is then polished. The finished product is dense, durable, and has a very smooth surface. Wood Flooring is a combination of durability, wear resistance, as well as comfort and warmth. Timber used for this kind of flooring can be either softwood (southern pine, Douglas fir, and hemlock) or hardwood (oak, maple, birch, pecan, and cherry). Wood flooring systems can be divided into: • Plank flooring • Engineered flooring
Stone Flooring usually consists sandstone, limestone, polished marble/ granite, or split-face slate. Stone tiles or slabs can be arranged in regular or irregular pattern. Stone-flooring application considers; • Color and texture of stone finishes • Abrasion and slip-resistance • Additional dead load on the flooring Carpeting provides floors with both visual and textural softness, resilience, and warmth. Carpet fibers can be made of various materials; • Nylon • Polypropylene (Olefin) • PET polyester • Wool • Cotton • Plastic fibers Pile is the yarn forming the surface of a carpet. The texture of a carpet surface is the result of pile construction, pile height, and how the carpet is cut.
Carpet textures: • Cut pile o By cutting the loops of the yarn producing a range of textures • Loop pile o By weaving, tufting, or knitting the pile of yarns into loops • Combination Acoustic Ceiling Tiles are usually made of soft, sound-absorbing materials (Example: cork, mineral fiber, glass fiber, etc.) These kinds of tile are easily damaged. To improve resistance to damages, the tiles can be factory painted or covered with a ceramic, plastic, steel, or aluminium facing. Wood Paneling are more commonly applied on the interior a building. It usually consists of veneer-faced panels directly applied on furring. Plastic Laminate provide a durable, heat and water resistant surface covering.
STUDIO An elevation is present on the canopy area, although through a person’s eye from the canopy, it is not seen.
Most of the top surface of the canopy is made with a small inclination angle, forming a slant. The main purpose being to control the flow of rainwater to the ground. However an elevation is present with a slight gap from all the edges of the canopy. It is assumed that the canopy area is much thicker than what can be seen from below.
Even with the elevation in the canopy, the top surface still forms the ‘fall’. The main reason for the elevation to be done further inwards is mainly for architectural and aesthetic purposes. That way from below the canopy is seen to be thinner, and more beautifully designed. A large canopy such as the Oval Pavilion would require a thicker ‘beam’ to maintain its balance and form.
The view from below the canopy
GLOSSARY
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Bending: Caused by rotating either end of the material in opposite to its axis. 4
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Sandwich Panel: A panel (usually prefabricated) formed by bonding two thin facings to a thick and usually lightweight core.
Shadow Line Joint: In a panel system, edges and joints create a shadow between the panel and the extrusion. Â 5
Skirting: Timber or PVC that is span across the lower part of a wall to provide extra detailing and aesthetic finish. The skirting are be fixed to the walls with nails, screws, or fixed with adhesives.
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Composite Beam: A beam combining different materials to work as a single unit.
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Cornice: An ornament mold of wood or plaster that encircles a room just below the ceiling.
1 Sandwich Panel. Retrieved from http://www.dictionaryofconstruction.com/definition/sandwic h-panel.html 2 Composite Beam. Retrieved from http://www.dictionaryofconstruction.com/definition/composi te-beam.html 3 Bending. Retrieved from Ibid, 45 4 Shadow Line Joint. Retrieved fromhttp://wallpanelsystems.net/Shadowline_System.html 5 Skirting. Retrieved from Gorse, Dictionary of Construction 6 Cornice. Retrieved from http://www.dictionaryofconstruction.com/definition/cornice. html