LOGBOOK Brigitte Danks
eLearning and Reading Modules Week 1 Readings: 2.08 – 2.11 Ching
Week 2 Readings: 2.02 – 2.04 Ching
Lectures Week 1
Studio Reports Week 1 Mass Tower Challenge: The challenge for this week’s tutorial was to construct a tower out of medium density fiberboard. The aim was to make the tower as tall as possible, and to view the effects of compression and tension. (Hunt, 2003)The Material
Figure 1: Medium Density Fiberboard (Kronospan, 2014)
Medium density fiberboard (MDF) has the following characteristics: -‐ Dense -‐ Flat -‐ Stiff -‐ Dust produced when producing MDF is very dangerous (contains formaldehyde) (Design Technology, 2014). -‐ Susceptible to fungi growth and termites (Wood Solutions, 2012).
Figure 2 shows the tower constructed by our group. The tower had the following characteristics.
Foundation: It was important to have a flat surface to build the tower on, to ensure a strong foundation. We chose a flat section of the carpet, while other groups used the surface of the underside of a table. Figure 3 shows the shape of the base that was used. This allowed us to build directly upwards in a structurally sound manner.
Figure 3: Shape of base
Figure 4: Running bricklaying
A running bricklaying method (Figure 4) was used to optimize stability and structural strength.
The pieces did not have a 2:1 length to width ratio and therefore did not stack perfectly, particularly during the construction of the roof. This resulted in some pieces being placed perpendicular to the other blocks and protruding out of the structure (Figure 5). Figure 5: Protruding block
Beam: Figure 6 shows the beam we constructed using Figure 2: The completed tower. three blocks and three rubber bands. One Photographer: Brydie Singleton rubber band was placed lengthways combining the three blocks, and two were placed in a diagonal fashion across the width of the blocks. The bulk of the rubber bands created an uneven surface on which to continue the bricklaying. Figure 6: The Beam This made the area above the doorway slightly arched and less stable than the other walls of the tower. Roof: Figure 7 shows the method utilized for constructing the roof of the tower. The structure was incrementally shifted inwards, with two layers stacked at each stage. This was done to increase the stability of the structure by decreasing the rate at which the walls shifted inwards. The construction method used was successful in being Figure 7: Cross-‐section view of pyramid-‐like roof structure structurally sound enough for the tower to remain standing without additional support.
Demonstration of Compression and Tension With our completed towers, we did two activities that demonstrated the effect of compression and tension on the strength of a structure. Firstly, we gradually removed pieces of the tower, as one would in a game of Jenga (Figure 8). We observed that the tower remained standing despite the Figure 1 8: Compression many missing pieces, due to compression, tension and load paths. and tension acting on a block. Each block in the tower is under the influence of both
Figure 8 : Sketch of standing compression and tension (Figure 18). The weight of wall with missing blocks
Figure 9 : The load path for a section of the wall
the load compresses each block inward toward the center of the block, and the tension of the underside of the blocks allows the load paths to travel sideways as well as downwards (Hunt, 2003). Figure 9 shows that the dead load of the structure has a sound load path to the ground. The tower eventually collapsed because the levels could no longer support the downward forces of the compression from above. That is, the load path became too long and indirect. It is generally possible to remove approximately 20% of a tower before the tower collapses. Our tower collapsed after approximately only 10% was removed. This is likely to be due to the fragility of the beam and the area above it.
The second activity demonstrated the effects of compression on the strength of the tower. Applied loads were stacked on top of a tower of sound structure, as shown in Figure 10. Due to the compression, the tower’s strength increased. Small objects were pelted at the tower and had comparably little effect. As certain blocks were knocked out of the tower (as in the first activity), approximately 30% of the blocks were removed. Evidently, the added compression increased the structural strength of the tower and enabled it to withstand more damage.
Figure 1 0: A tower with objects stacked on top
Week 2 The challenge for this week’s studio was to construct the tallest possible tower using only one piece of balsa wood and any adhesive materials desired. Materials Used: -‐ One piece of balsa wood (600mm x 100mm) -‐ Hot glue gun and glue -‐ Masking Tape -‐ Cutting board -‐ Blade -‐ To acquire as many strips as possible while still maintaining a certain degree of rigidity, we cut strips of balsa wood approximately 2mm wide, as shown in Figure 11. Some errors were made resulting in a few shorter strips, were used for the triangles at each level. Figure 12 shows the planned structure for the tower. It consisted of three shorter pieces of equal length of balsa wood, combined to form a triangle, with Figure 11: The equipment three full-‐length (600mm) pieces used to cut the balsa wood standing upright, joining another slightly smaller triangle. Triangles were chosen instead of squares as they had greater material efficiency.
Figure 1 3: Additional structural support
Some sections required additional support because of inaccuracies in the cutting of the balsa wood. For these segments a strip was placed diagonally across the rectangle (Figure 13), acting as a brace. Figure 14 shows the application of this method.
Figure 1 2: The planned structure
Figure 15 is a sketch of one of the joints. We used a hot glue gun to connect the strips. It was effective as it was a strong adhesive and dried quickly. Figure 1 4: The structure of the base
Figure 15: A joint
Construction continued in this manner (Figure 16) until the tower was completed (Figure 17). The tower reached the roof, at a height of approximately 3.6m. The tower became fairly precarious as its height increased. This was because the length to width ratio of the material was very large, and because of the anisotropic nature of the material. In attempt to stabilize the structure, we taped the sticks together between the triangle levels. A spire was added on top, as it was the most efficient way to add more height.
Figure 1 6: Partway through construction
Properties of Balsa Wood: -‐ Medium to coarse texture -‐ Straight Grain o Easy to cut along the grain -‐ Light (low density) -‐ Soft -‐ Anisotropic (strong in tension, not strong in compression)
Figure 1 9: Balsa Wood (Wood Database, 2014)
Figure 1 7: Completed tower
Structural:( / Cantilever(supported(at(one(end,( suspended(at(other( / Truss% Materials:(( / Steel((hollow,(painted(to(prevent(rusting)(( o Capping(to(prevent(water(damage( / Timber( / Stainless(steel((polished,(reflective)( (Figure(12)(( / Concrete( / Sandstone((Figure(13)( o Large(weight(to(support(load( Services:(lights,(air(conditioning( ((((%
( Structural:( / Frame(system( / Fixed(joints(to(brick(wall((Figure(15)( / Pin(joint(to(accommodate(movement((Figure(16)( / Stringers(and(walkway(beam(form(a(cranked(beam( with(a(very(large(span( Figure%16%
o Allows(for(large(open(spaces( o Supported(by(floor(slab(and(roof(bracing( / Ledge((Figure(28)( o Stop(water(entering( Enclosure:(( / Glazing((glass)( o Doesnâ€™t(fracture( / Mullions(and(transoms((Figure(29)(
Glass:( / Liquid(state:(constant(fluid( state( / Made(from(silica( / Different(types(of(glass( (different(chemical( composition)( o Put(higher(levels(of( metal(in(glass(to(slow( process( % Site%9((Figure(30)(
Structural:( / Pad(footings( o Individual(point(loads( / Stumps( / Strip(footing(for(load/bearing(wall( / Building(paper( o Water(proofing( / Stud(wall( / Cladding(system( Systems:( / Air(conditioning( / Plumbing( / Electrical(pipes( Construction(considerations:( / Include(crawl(space(under(building( o Room(to(fix(piping(problems(etc( %
Drawings SITE PLAN
The drawings differ greatly to observing the site in person for numerous reasons. Firstly the drawings are drawn on a much smaller scale. Secondly the symbols used do not actually resemble the surface or appearance of the material. Structural drawings differ from architectural drawings in that they provide more sections and details illustrating the structural components of the design. For example, structural drawings will include floor plans with footings and structural walls while architectural drawings will not. Architectural drawings are better for finding dimensions from, while structural designs are better at finding measured lengths and descriptions of materials.
Studio 5 Activity The activity was to construct a 1:20 model of the structural system of a section of the new sports pavilion using the construction drawings. Our section was the bottom left section in
Figure 1 : The map indicating the different sections completed in the studio class
Figures 2-‐3 show our model at the end of the studio, which was not completed.
Figure 2 : The floor and wall structural system
Ground Floor -‐ Strip footings -‐ Concrete walls on top -‐ Retaining wall Roofing -‐ Cantilevering off truss
Figure 3 : The roofing structural system
Footings and Structural Walls: = SF1 = SF4 = SB1 = EB2 = CW1 = CW2 = RW1 Figure 4: Footings and Structural Walls
Strip Footings SF1: 400x600 SF4: 1200x300 Ground Beams SB1: 400x400 EB2: 400x500
Retaining Wall RW1: 290x2100 Concrete Walls CW1: 200THK CW2: 200THK (Cantilever retaining wall) Other Load-‐Bearing Walls MW1: 190THK (Core-‐filled blockwork)
Week 6 Presentation of Pavilion Area Models Back Area (3-‐5, A-‐B) Basement o Strip footings o 50mm step down between two floor systems o Structural walls o Concrete retaining wall at back Ground Floor o Structural walls o Rectangular hollow section Figure 1 : The back area is outlined by columns the blue box Roof o Supported by retaining walls at back o Load at front is hung from the truss and goes upward
Interim Submission Presentations Timber Workshop
Week 8 Section Scales
Activity Creating a 1:1 drawing of a detail Detail:
Week$9$ BASEMENT - Car park - Elevated rotating platform o Stockers (where cars drive onto) ! 3 week installation process - Concrete structure o Precast columns o Suspended transfer slabs (in-situ) ! Formwork sheets o Beams placed horizontally ! Less strength ! Because of height restrictions
Walls o Blockwork ! 150-200mm ! Core filled ! Reinforced
! FORMWORK TRANSFER SLAB SERVICES
LOCATION OF DRIP DRAINS
Waterproofing o All external walls waterproofed ! Lined with corrugated drip systems ! Drip drains Services o Suspended sewer o Storm water o Electrical cables o Gas service o Fire service ! Corking
ROOF - Concrete structure o Transfer slab (In situ) ! Different thicknesses o Sit on precast inter-tenancy walls - Areas o Hot water system o Garden area - Concerns o Waterproofing
HOT WATER SYSTEM
! ! ! ! ! !
Particularly important with concrete Concrete poured with crystals (repels water) 2 coatings of waterproofing Screeded Tiled roof on top Water exits the roof through outlet points • Travel through down pipes to basement storm water pipes o Natural lighting in apartments ! Light wells o Fire protection ! Provided by concrete Services LIGHT WELL o Radiant heating system o Duct system for cooling ! Interfering with plumbing and sprinkler o Solar panels o No ventilation (just doors, windows) o No water tanks (plan signed off before new regulations) Safety o Hand rail (during construction) o Balustrades for garden area HAND Construction Issues RAILS o Access to materials (limited space) ! Tower crane (in situ) OUTLET o Dealing with permits POINT ! power lines ! parking o Neighbours ! People don’t like change
TOP LEVEL - Concrete structure o Concrete walls (precast) ! External (structural) • 200mm thick at bottom • 150mm thick at top • Carry two floors ! Internal (non-structural) ! Expansion joints between panels • Grout tubes within panels with backing rod to stiffen for structural stability o Suspended ceilings: 2.1 – 2.4m ! 2.7m roof: double joist for additional support -
Lightweight steel framing o More cost effective because: ! Saves time ! Easier walk-up stage o Less drama with straightening walls ! No noggings Form o Front and rear elevations ! Balconies • Step down (waterproofing) ! Piling structure o Penetrations ! Push and pulls go through Services (attached to roof, floor penetrations) o Plumbing HOT WATER
o Duct work Construction o Work boundaries from gridlines (from drawings) o All concrete but basement and stairwells will be covered
TOWN HOUSE - Two storey town house o 3 bedroom - Windows - Balcony - Duct system o Very expensive o - Need lots of basement spots to be popular on the market - Construction time (excluding planning time) o Normally 1 ½ - 2 years o This project running behind (issues) ! Planning permits ! Excavation ! Council (getting materials off site)
Week 10 Presentation of 1:1 Drawings (following pages) Site Visit:
FEEDBACK: • Change metal decking • Thicken lines appropriately • Add drawing name • Put annotations onto drawing
The Task To construct an object that would span one metre and withstand as great a load as possible.
Plywood -‐ Good tensile properties -‐ Not strong under compression
Pine -‐ Strong under compression and tension
Figure 3: Pine timber cross-‐section
Figure 2: Plywood
Group 1 – My group Materials:
2 pieces of plywood (1200x3.2x90mm) 2 pieces of square pine (1200x35x35mm) 16 screws (1 inch)
Tools: Electric screwdriver
Compression chord (Pine) Web: carries the shear (Plywood)
Figure 4: The design of Group 1
Tension chord (Pine)
Figure 5: Load paths
Similar structural concept to universal beam Compression flange Web: carries the shear Tension flange
Figure 6: Universal Beam
Screws were not inserted in the middle of the beam so that weak points were not created where the load was going to pass through
Performance Failure load: 261kg Maximum Deflection: 23mm Load (kg) Deflection (mm) Notes 191 10 261 20 Plywood cracked 300 23 Structure broke Behaviour: The plywood bent under the compression, because it could not transfer the shear to the tension member -‐ No screws in the middle to connect the timber to the plywood
Figure 7: The performance of the structure under a load.
Type of Breakage The structure broke through the middle. -‐ With the plywood failing to carry the shear, the load was primarily carried by the compression chord -‐ Did not fracture at knot because of its strategic placement -‐ Did not fracture where screws were inserted
Figure 8: The breakage of the structure.
Figure 9: Load path with joined members
The structure would have held a greater load if there was no gap between the two pieces of pine; if they were joined (Figure 9). The screw in the knot (Figures 10, 11) made the point of weakness even weaker. The structure was oriented such that the knot was placed in the area of the beam in compression (Figure 12), so that it would Figure 10: The be less likely to fracture. knot
Figure 11: A screw w as Figure 12: Knots should be inserted into a knot in one of the placed at the top of a beam pieces of pine.
Figure 13: A greater load can be supported w ith greater height as opposed to greater width.
The structure was oriented vertically so the load had the most medium to travel through (Figure 13).
Group 2 Materials: 2 pieces of plywood (1200x3.2x90mm) 2 pieces of pine (1200x42x18mm)
Design: The design did not have a platform on which the load could be placed, so one was added as seen in Figure 14.
Figure 14: The design of Group 2, with load paths indicated.
Performance: Failure load: 200kg Maximum Deflection: 60mm Load (kg) Deflection (mm) 180 10 200 15 200 20
Notes Plywood and pine cracked. Weight dropped to 160. Structure broke
185 60 Behaviour: -‐ Plywood warping under compression to the point of breakage
Type of Breakage: -‐ Split through middle of pine base and plywood
Figure 16: Breakage
Figure 15; Plywood warping
Materials: 1 piece of plywood (1200x3.2x90mm) 3 pieces of square pine (1200x35x35mm)
Figure 17: Group 3’s design, with load paths indicated.
Performance: Failure load: 260kg Maximum Deflection: 40mm Load (kg) Deflection (mm) 11 5 116 10 250 30 260 40 Behaviour: -‐ Structure twisted under load -‐ Brace was inserted to restrain the truss from buckling laterally -‐ Trusses experience similar conditions, and must be braced to counteract the sideways force.
Notes Structure began to twist. Support was added. Structure broke
Figure 18: The structure required bracing to restrain it from twisting
Type of Breakage: -‐ Member that was being braced detached itself under load o Nail slid through plywood
Figure 19: Breakage
1 piece of plywood (1200x3.2x90mm) 3 pieces of pine (1200x42x18mm)
Figure 20: Group 4’s design, with load paths indicated.
Performance: Failure load: 385kg Maximum Deflection: 36mm Load (kg) Deflection (mm) 290 20 332 30 385 36 Behaviour:
Notes Structure broke
Figure 21: Beams bent under the load
-‐ Beams bent under load -‐ Plywood compressed but assists carrying the load through tension.
Breakage: -‐ One beam broke o Broke in middle where nail was inserted into the timber. o Nail inserted into timber created weak point in beam
Figure 22: Breakage occurred where nail was inserted
Glossary Sources used for this glossary are: (Ching, 2011) (Commonwealth of Australia, 2012) (Hunt, 2003) (My-‐green-‐home-‐project.com, 2014) (NSW Department of Education and Communities; Charles Sturt University, 2014) (Vassigh, 2008).
Alloy: a metal made by combining two or more metallic elements, especially to give greater strength or resistance to corrosion. E.g. an alloy of nickel, bronze, and zinc Anchorage: Securing the structure to the ground to resist sliding, uplift or overturning. Axial Load: any load, compressive or tensile, that acts parallel to an axis of the material Base shear: The minimum design value for the total lateral seismic force on a structure assumed to act in any horizontal direction. It equals the total dead load of the structure multiplied by a number of coefficients (reflecting the character and intensity of the ground motions in the seismic zone, the soil profile type, the type of occupancy, the distribution of its mass and stiffness of the structure, and the natural period. Beam: A horizontal element that is supported at each end, such that it can carry a vertical load (Hunt, 2003).
Bending: When bending moment occurs, part of a structure can rotate or bend. Bending stress is a combination of compressive and tension stresses developed at a cross section of a structural member to resist a transverse force. (Maximum value at surface furthest from neutral axis.) (Ching (2.14), 2011)
Bracing: The act of members, usually diagonal, resisting lateral loads and/or movements of a structure (NSW Department of Education and Communities; Charles Sturt University, 2014).
Sheet Bracing: -‐ Plywood -‐ Much stronger
Cross Bracing: -‐ Hoop iron (aluminium)
Braced Frame: a structural system which is designed primarily to resist wind and earthquake forces. Members in a braced frame are designed to work in tension and compression, similar to a truss. Buckling: The sudden lateral or torsional instability of a slender structural member induced by the action of an axial load before the yield stress of the material is reached. Caisson: A cast-‐in-‐place, plain or reinforced concrete pier formed by boring with a large auger or excavating by hand a shaft in the earth to a suitable bearing stratum and filling the shaft with concrete. Also referred to as drilled piles or piers. Cantilever: A projecting beam or other rigid structural member supported at only one fixed end.
Centre of Mass: The point about which an object is balanced (Ching, 2011).
Column: Slender and primarily vertical members; a form of strut that can carry a vertical load, supported by an equal and opposite reaction force.
Ratio of Length:Shortest side of Cross section Behaviour under load Buckle i.e. Type of failure Buckling and Effective Length
Crush (become shorter)
Composite Beam: A steel beam, which has concrete decking above it, and which is connected to the concrete by shear connectors, which cause the steel and the concrete to act together. Compression: An external pushing force that squeezes together the particles of a material, compacting and shortening the material. Concrete Plank: A hollow-‐core or solid, flat beam used for floor or roof decking. Concrete planks are usually precast and prestressed. Consolidation: The reduction in the volume of soil voids containing air or water, due to the load of a structure on the foundation. Control Joint: Constructed to open slightly to accommodate the shrinkage of a concrete masonry wall as it dries after construction.
Cornice: A moulding around the top of the walls of a room just below the ceiling.
Corrosion: The process of a metal being gradually damaged by reacting chemically. Curtain Wall: An exterior wall supported wholly by the steel or concrete structural frame of a building and carrying no loads other than its own weight and wind loads. (Ching (7.24), 2011) Diaphragm: A structural element that resists and collects lateral forces in the horizontal planes of a structure and transfer them to the vertical bearing elements. Deflection: The perpendicular distance a spanning member deviates from a true course under transverse loading, increasing with load and span and decreasing with an increase in the moment of inertia of the section of the modulus of elasticity of the material.
Dead Load: The intrinsic weight of a structure (Ching, 2011). Deep Foundations: One of two types of foundation systems, that extend down through unsuitable soil to a more appropriate bearing stratum. They are employed with the soil underlying a foundation is unstable or of inadequate bearing capacity. Defect: A shortcoming or imperfection, often due to incorrect material selection. Occur when insufficient considerations are given to environmental or exposure conditions. Design Wind Pressure: A minimum design value for the equivalent static pressure on the exterior surface resulting from a critical wind velocity. It is equal to a reference wind pressure measured at a height of 10m, modified by a number of various coefficients (to account for exposure condition, building height, wind gusts, geometry, orientation). Differential settlement: The relative movement of different parts of a structure caused by uneven consolidation of the foundation soil. It can cause a building to shift out of plumb and cracks to occur in its foundation, structure or finishes. Door Furniture: The handles, locks and other fixtures on a door. Down Pipe: a pipe to carry rainwater from a roof to a drain or to ground level.
Drawings: SITE PLAN
Drip: A metal strip or hole that directs water off to prevent it from entering the building.
Dynamic Loads: Loads that are applied suddenly to a structure, often with rapid changes in magnitude and point of application.
Earthquake: a series of longitudinal and transverse vibrations induced in the earth’s crust by the abrupt movements of plates along fault lines. Eave: The part of a roof that overhangs the walls of a building.
Eccentric Load: Any load that is not applied through the primary axis, tending to produce bending. Equilibrium: a state of balance or rest resulting from the equal action of opposing forces (Hunt, 2003).
(Hunt, 2003) Expansion Joint: A continuous, unobstructed slot constructed to close slightly to accommodate the moisture expansion of brick and stone masonry surfaces. Façade: The shell or envelope of a building, consisting of the roof, exterior walls, windows and doors (Ching, 2011). Fascia: A horizontal member used on the exterior vertical face of a cornice, capping the end of rafters.
Flashing: Thin continuous pieces of sheet metal or other impervious material installed to prevent the passage of water into a structure from an angle or joint through the use of redirection and gravity.
Flutter: The rapid oscillations of a flexible cable or membrane structure caused by the aerodynamic effects of wind.
Footing: The construction whereby the weight of the structure is transferred from the base structure to the foundation (NSW Department of Education and Communities; Charles Sturt University, 2014). Foundations: The substructure of the building constructed wholly or partly below the ground in order to support the superstructure (Ching, 2011). Frame: The skeleton structure of a building. Gang Nail Plate: Used for joining two pieces of timber (sandwiches them together)
Girder: a large iron or steel beam or compound structure used for building bridges and the framework of large buildings.
Gutter: a shallow trough fixed beneath the edge of a roof for carrying off rainwater. Typically vinyl, galvanised steel or aluminium. Also copper, stainless steel, terne metal, wood.
IEQ: Indoor Environmental Quality. Encompasses daylighting, thermal comfort, views and so on.
Insulation: A material used to control the flow or transfer of heat through the exterior assemblies of a building, and thereby prevent excessive heat loss in cold seasons and heat gain in hot weather.
Joist: a length of timber or steel, typically arranged in parallel series to form a structural framework that supports a floor or ceiling.
Joist Flooring System
Lifecycle: The lifecycle of a material is: acquisition; processing and manufacturing; transportation and distribution; construction, use and maintenance; and disposal, recycling and reuse. Lintel: a horizontal support of timber, stone, concrete, or steel across the top of a door or window. (Commonwealth of Australia, 2012) Load Path: The direction in which each load situated on a structure will pass through connected members to the ground.
Masonry: Stonework, clay and concrete.
Moment: The tendency to make an object or a point rotate (Vassigh, 2008). Mo = F x d Moment of Inertia: A geometric property that indicates how the cross-‐sectional area of a structural member is distributed. It is equal to the sum of the products of each element of an area and the square of its distance from a coplanar axis of rotation. Moment Resisting Frame: A structural system that is constructed with rigidity connected joints that provide a continuous interface between the horizontal and vertical elements. Thus the frame is made rigid enough to act as a monolithic unit under the impact of lateral loads. Natural Period: The time required for one complete oscillation. Nogging: A horizontal member placed between studs to strengthen the framework and prevent buckling.
Pad Footing: A footing that consists of a pad under a stump.
(Ching, 2011) Parapet: An extension of the wall on an edge that acts as a protective barrier
Pier: Stump made from block work (masonry) i.e. bricks, concrete blocks. Takes more load than stump.
Pile Foundation: A system of end-‐bearing or friction piles, pile caps, and tie beams for transferring building loads down to a suitable bearing system.
Point Load: A load that rests on one place along an element.
Portal Frame: a rigid structural frame consisting essentially of two uprights connected at the top by a third member.
Purlin: a horizontal beam along the length of a roof, resting on rafters.
Rafter: a beam forming part of the internal framework of a roof, spanning from the top plate to the ridge beam.
Reaction Force: A force that resists any applied force in an equal and opposite manner (Ching, 2011).
Retaining Wall: Any wall subjected to lateral pressure other than wind pressure and built to retain material (NSW Department of Education and Communities; Charles Sturt University, 2014).
Sheet Roofing -‐ Water flows easily -‐ Doesn’t need big pitch -‐ Materials: o Fibre glass o Galvanised steel Tiled Roofing
New and old roofing systems OLD HOUSES NEW HOUSES - Rafters span - Truss roofing large distances - External load bearing walls (5-6m) only (taking far greater load) - Internal and o Important to consider external load connections between bearing walls truss and wall Sacrificial Formwork: The tension component of a concrete slab that remains permanently
Sandwich Panel: A composite material consisting of a phenolic resin core sandwiched between two external skins of aluminium sheets. Sealant: A material used to seal something so that it is airtight or waterproof. Seams: Standing Batten Lock
Seasoned Timber: Timber dried to a moisture content that is stable.
Seismic Base Isolator: A connection placed between the foundation and the substructure that allow the substructure to move independently ��of the foundation during earthquakes. Settlement: The gradual subsiding of a structure as the soil beneath its foundation consolidates under loading. Results in consolidation. Settlement loads: Imposed on a structure by subsidence of a portion of the supporting soil and the resulting differential settlement of its foundation.
Shadow Line Joint: Narrow joints that leave a slight shadow between panels. Shallow Foundations: One of the two types of foundation systems, employed when stable soil of adequate bearing capacity occurs relatively near to the ground surface. Shear Force: An internal, unaligned force caused by an external force, pushing one part of a body in one direction, and another part in the opposite direction.
Shear Wall: A structural element made of rigid materials (reinforced concrete, steel framing with bracing) that resist lateral loads in the vertical plane. They collect the lateral loads from the horizontal resisting elements and transfer them to the foundation. Skirting: A wooden board running along the base of an interior wall to protect the plasterboard.
Slab on ground: A foundation slab that is laid directly on the ground Soffit: The underside of a structural component, such as an arch, balcony, beam, staircase, cornice or eaves. Soft Storey: A multi-‐storey building in which one or more floors have windows, wide doors, large unobstructed commercial spaces or other openings. Space Frame: A long-‐spanning three-‐dimensional plate structure based on the rigidity of the triangle and composed of linear elements subject only to axial tension or compression.
Spacing: The centre-‐to-‐centre distance between two parallel structural members.
(Commonwealth of Australia, 2012) Span: The distance between two structural supports, measured along a member.
Stability: The state of being firmly fixed and secure. Static Loads: Loads that are assumed to be applied slowly to a structure until it reaches its peak value without fluctuating rapidly in magnitude or position. Steel Hot Rolled Cold Formed o Poured into its final form o Bent into shape o Far greater tensile strength o Thinner, not as good quality o Used for secondary support (e.g. Purlins) Steel Decking: Light-‐gauge, corrugated steel sheets used in constructing roofs or floors.
Steel Members Universal Circular Beam (UB) Hollow [Strongest] Section (CHS)
Parallel Flange Channel (PFC)
Square Hollow Section (SHS)
Equal Angle (EA)
Unequal Angle (UEA)
Stud: an upright member in the wall of a building, forming part of the structural framework and/or to which laths and plasterboard are nailed. Metal: Timber: -‐ span far greater lengths Stress: Load (force) per unit area that tends to deform the body on which it acts. E.g. Deflection, bending Strip Footing: The continuous spread footings of foundation walls (Ching, 2011). Structural Joint: A connection between two elements (Ching, 2011). Stucco: A coarse plaster composed of Portland or masonry cement, sand and hydrated lime, mixed with water and applied in a plastic state to form a hard covering for walls. (Ching 7.36, 2011) Substructure: The underlying structure forming the foundation of a building (Ching, 2011). Superstructure: The vertical extension of a building above the foundation (Ching, 2011). Tilt-‐Up Conctruction: A method of casting reinforced concrete wall panels on site in a horizontal position, then tilting them up into their final position. Timber: Classified as either hardwood or softwood (depending on density).
Tension: A pulling force that stretches and/or elongates the element or material. Top chord: The top beams in a truss, generally in compression.
Torsion: Twisting. It is usually the result of varying perimeter strength in a building. (Common in structures with an open storefront of vehicular access on one or two sides and concrete firewalls on the other sides.) It can be eliminated by ensuring that the building has a uniform stiffness throughout its perimeter.
Trusses: A structural framework, consisting of top chords, bottom chords and web members.
Underpinning: The process of rebuilding or strengthening the foundation of an existing building, or extending it when a new excavation in adjoining property is deeper than the existing foundation. Vapour Barrier: Any material (typically a plastic or foil sheet) that resists the diffusion of moisture used for damp proofing. Water Strategies -‐ Use gravity NO OPENINGS KEEP WATER AWAY FROM OPENINGS NEUTRALISE WATER FROM OPENINGS E.g. Drip, cavities -‐ most common -‐ e.g. brick veneer
Vapour Retarder: A material of low permeance installed in a construction to prevent moisture from entering and reaching a point where it can condense into a liquid.
(My-‐green-‐home-‐project.com, 2014) Window Sash: The part of the window frame that holds the glass and moves with the window.
Yield Stress: the stress level at which a material ceases to maintain its form and structure.
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