ENVS10003 CONSTRUCTING ENVIRONMENTS A01 LOGBOOK Week 4
Activityďźš Construction Documentation Tour How does the information in your drawing set compare to what you observed at site last week? How does the scale of the building compare to the scale of the drawings? How do the architectural and structural drawings differ? In ground floor plan, size seems to be big enough to cover rooms with different function, but as seen from the real building, it seems to be smaller. The size of chairs in front of oval pavilion also look smaller relative to the building itself, but in the plan drawing it is opposite.
Figureďźš GROUND FLOOR PLAN (Cox Architecture Pty Ltd, 2012, A21-02)
Compare to the below elevation drawing, the size of real canopy in the right hand side above looks much bigger and seem to take much more space, may be because of 1:100 scale. In the drawing, it demonstrates the shape and material (timber frame) in south elevation. There are some slight differences from sense aspect. Figure: SOUTH ELEVATION (Cox Architecture Pty Ltd, 2012, A30-01)
Differences between architectural and structural drawings: Architecture drawings are made in terms of a set of conventions such as section, elevation, plan and detail drawing including scale, dimension and annotations, etc., compared to that, structure drawings is kind of technical drawings that focus more on the structure elements such as trusses and joints. This figure illustrates that the inside structure of the canopy part constructed by grid. The joints are also clear labelled in the drawing. Figure： CANOPY SECTION – SOFFIT JUCTION TIM-06/TIM-06 (Cox Architecture Pty Ltd, 2012, A62-02)
Activity: Scale, Annotation and Working Drawing Conventions Why and how 'scale' is used for documenting building projects? Why to use scale? Scale is usually used in architecture drawings and map drawings to zoom objects into a range with suitable length and width. Through the scale, we can know the dimension easily and that makes work efficient. How to use scale? There are different scales for use depending on the actual size of object and the required size it should be such as 1:5, 1:20, 1:50, 1:100, 1:200, 1:500 etc. Usually scale bars or direct text are used to illustrate scales. There are a number of creative scale bars. Scale bars are beneficial for zooming, because the bar changes sizes with the changes of the whole picture. However, for drawing with text to mention scale, it is more difficult to change size of picture, unless the text is always revised.
Figure： IDoubleFillScaleBar Interface (ESRI Developer Network, n.d.)
Learning Loop Span is the distance measured between two structural supports. Span can be measured between vertical supports or between horizontal supports. Spacing is the repeating distance between a series of like or similar elements. Spacing is often associated with supporting elements (such as beams, columns, can be measured horizontally or vertically. A beam is a horizontal structural element, function is to carry loads along the length of the beam and transfer these loads to the vertical supports. A beam can be supported at both ends of beam, numerous points along the length of beam, points away from the ends of beam, only one end of the beam. A cantilever is created when a structural element is supported at only one end (or the overhanging portions of a member are significant), function is to carry loads along the length of the member and transfer the loads to the support. It can be horizontal, vertical, angled. Floor and framing systems: concrete, timber, steel Concrete system: slabs of various types are used to span between structural supports. These can be one-way or two-way spans. Steel system: steel framing systems take various forms, with some utilizing heavy gauge structural steel members and others using light gauge steel framing Timber system: A combination of bearers (primary beams) and joist (secondary beams), the span of bearers determines the spacing of piers or slumps and the spacing of the bearers equals the span of the joists. A common concrete mix: 1 part cement, 2 parts fine aggregate, 4 parts coarse aggregate, 0.4-0.5 part water. Provenance: hydration – when the cement powder and water are mixed, a chemical reaction takes place and heat is released.If too much water is added, concrete will be weak, if too little water is added, concrete mixture will be too stiff and unworkable. Advantage of concrete: fluid and sharpness before it hardens, can be formed into any shape, formwork is the term used for the temporary support or moulds used to hold the liquid concrete in place until it becomes hard. Formwork can be built IN SITU or in a factory (pre cast). Wall formwork (Ching, 5.0.7) Concrete Process: During the curing process, the formwork needs to be supported as the weight of the wet concrete is very heavy. This achieved by using props and bracings of various types. 7 days-75% compression strength, 28 days- required strength. Formwork is usually removed, stored and reused or it may stay in place.
Concrete finishes: sand-blasted; exposed aggregate; raked finish; bush hammered; board-marked; board & batten Concrete- reinforcement: artificial stone, properties of concrete and stone are similar. Concrete is strong in compression but is weak in tension. To improve the structure performance, steel (strong in tension) reinforcement in the form of mesh or bars is added. Concrete properties in hardened state Concrete considerations: Concrete in permeable (not completely waterproof). If steel bars are too close to the surface, they will not be protected from moisture and oxidation- cause aesthetic and structural degradation; Poor vibration of concrete during the pouring process. (Concrete is vibrated to get rid of air bubbles.)
In situ concrete: is any concrete that has been poured into formwork and curved on the building site. Once the concrete has been poured, there is limited time before the concrete starts to harden and become unworkable. Labour intensive process. Usesgenerally used for structural processes (either self-supporting or as primary structure), widely used in footings, retaining walls are bespoke structural elements. Joints: potential weak joints in terms of water and moisture control. Construction joints – used to divide the construction into smaller and more manageable sections of work Control joints- required to absorb the expansions and contraction that thermal variations cause and the long term tendency of concrete to shrink over time.
Pre- Cast Concrete: is any concrete element that has been fabricated in a controlled environment and then transported to site for installation. Ensure a much standardized outcome, better quality control, allow work on site to progress faster, more efficient and cheaper, save labour costs. Uses: associated with the structure of a building, bridge or civil works, forming part of the primary structure of self-supporting panel type elements, rarely used in footings, commonly used in retaining walls, walls and columns. Joints: generally depend on the desired aesthetic outcome. Construction joints- the panel/ element nature of pre-cast concrete mean that joints naturally occur when one pre- cast element meets another. Structure joints- the type and performance of the structural connections joining the pre-cast elements to each other and to other parts of the building. Comparison: Pre- cast concrete elements can be limited in size due to transport. On site changes are very difficult to incorporate.
Glossary Appendix Joist: ‘is one of the horizontal supporting members that run between foundations, walls, or beams to support a ceiling or floor. They may be made of wood, engineered wood, steel, or concrete (Oxford English Dictionary, 2009).’ Girder: ‘In building construction, a large main supporting beam, commonly of steel or reinforced concrete, that carries a heavy transverse (crosswise) load. In a floor system, beams and joists transfer their loads to the girders, which in turn frame into the columns (Merriam-webster, 2014) .’ Steel decking: ‘Steel deck is a type of coldformed corrugated metal most commonly used to support the insulating membrane of a roof. It is created by stamping and pressing traditional sheet steel into the desired shape, which, upon installation, provides extra support between the roof’s joists and beams. Many different manufacturers sell their own trademarked brand of steel deck, although the most important qualities that builders tend to look for remain fairly consistent across all brands (Heidelberger, n.d.).’
Concrete Plank: ‘A hollow-core or solid, flat beam used for floor or roof decking. Concrete planks are usually precast and prestressed (Dictionary of construction.com, 2014).’ Bearer: ‘A horizontal member of a scaffold on which the platform rests and which may be supported by ledgers (Dictionary of construction.com, 2014).’ Spacing: Spacing is the repeating distance between a series of like or similar elements. Spacing is often associated with supporting elements (such as beams, columns, can be measured horizontally or vertically.
REFERENCE Cox Architecture Pty Ltd (2012). Oval Pavilion Construction Drawings. Dictionary of construction.com (2014). Concrete plank Definition. Retrieved 28 August, 2014 from http://www.dictionaryofconstruction.com/definition/concrete-plank.html Dictionary of construction.com (2014). Bearer Definition. Retrieved 28 August, 2014 from http://www.dictionaryofconstruction.com/definition/bearer.html ESRI Developer Network (n.d.). IDoubleFillScaleBar Interface. Retrieved 27 August, 2014 from http://edndoc.esri.com/arcobjects/9.2/ComponentHelp/esriCarto/IDoubleFillS caleBar.htm Heidelberger, M. (n.d.). Steel Deck Definition. Retrieved 28 August, 2014 from http://www.ehow.com/info_12194092_steel-deck-definition.html Merriam-webster (2014) girder, retrieved 28 August, 2014 from http://www.merriam-webster.com/dictionary/girder Oxford English Dictionary Second Edition on CD-ROM (v. 4.0) (2009) Oxford University Press