Log book - Week 4 FLOOR SYSTEMS AND HORIZONTAL ELEMENTS"
Floor & Framing Systems Concrete systems: -The thickness of a slab is calculated by the distance between beams divided 30. As some buildings have a height restriction, this means that each floor of a building must be a small as possible whilst still maintaining the same internal area. One way of shortening the building is to lay the concrete slabs flat instead of standing upright. Although standing the slabs upright gives a lot more compressive strength, it takes up a lot of the crucially needed height. The main things to take into consideration when constructing flooring and framing systems are anticipated floor loads, costs and efficiency. This is necessary for cornet, steel and timber systems. Steel systems: Girders are the main beams, which are usually steel but can be concrete. Water pipes can be carried through the gap between a joist. Important buildings such as hospitals are built with concrete as they are able to withstand fire longer than steel or timber.
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Timber systems: The main parts of timber systems are Bearers(primary) and Joists(secondary) which support the flooring. Eg. supports floorboards or decking. The joists are supported on bearers. The bearers which are supported on concrete columns reduce the length of the joists therefore making them more stable as it increases the number of pathways to the solid ground.
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IMAGE 1: Steel girder.
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Concrete Components: 1 part cement 2 parts fine aggregates(sand) 4 parts coarse aggregates(crushed rock) 0.4-0.5 parts water. When water is added to the cement powder a chemical reaction called hydration takes place. Heat is released from this reaction. If too much water added the concrete will become too weak. In contrast, if too little water added it will become too stiff and unworkable.
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Process As concrete is fluid before it sets it’s able to be moulded into shapes. This moulder is known as formwork. IN SITU - Formwork at the building site" PRE CAST - Formwork in a factory The mould of the concrete can be made out of a variety of materials including timber, metal or plastic.
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Wall formwork: The spreaders keep the formwork apart so that the concrete can be poured in. The inner surface of the panels can leave a pattern on the concrete. Last week when we looked at the oval pavilion being built we saw that a timber formwork had been used to give the concrete wall a wooden effect. IMAGE 2: A diagram of a typical The formwork needs to be supported during the ‘curing wall formwork. process’ as the wet concrete is heavy. It takes about 7 days for the concrete to reach 75% of it’s compressive strength and about 28 days to have full strength. Usually it takes about a day before workers are allowed to walk on the concrete.
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Reinforcement
IMAGE 3: Steel bars awaiting concrete to be poured on top.
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Concrete can also be called ‘artificial stone’ suggesting that the properties of concrete and stone are similar. Reinforced concrete is when metal bars are placed under the concrete as they are strong in tension; whereas concrete is strong in compression. This can be used along footpaths where a suspected tree root may push through the concrete or most commonly in the foundation of a building."
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Considerations Concrete is permeable which means it’s not completely waterproof. In my Reshaping Environments the tutor, David, said that if water is left on concrete for a certain amount of time then the water will begin to drip out of the bottom. At first this was hard to believe but now I know that concrete is permeable it is understandable. A problem with this permeability is that the steel bars can begin to rust if they are too close to the surface. This leads to the steel expanding and breaking away the IMAGE 7: An example of a steel bar that has surrounding concrete. This degrades the structure both expanded and cracked the exterior surface of the aesthetically and structurally. This was evident in the concrete. underground carpark at Melbourne University. We saw that the steel bars were beginning to rust. Another common problem is poor vibration during the pouring process to get rid of the air bubbles in the concrete. If this isn’t done effectively then the bubbles can affect the structural performance of the concrete."
IN SITU Concrete Any concrete that has been poured into formwork and cured(set) on the building site." After the concrete has been poured, workers must act quick to ensure that the concrete is in the desired place before it hardens." -Use floats to get a flat finish of the concrete. Done by hand.
IMAGE 6: A worker smoothing wet concrete with a float.
Uses: Useful within footings and retaining walls. Sometimes concrete can be applied with a pressure hose and sprayed on. This is useful when applying concrete to walls compared to trying to do it by hand. Joints: Construction joints - Divides the concrete slabs into more manageable sections to work with. Control joints - As materials change in shape over time, control joints are used to ensure the concrete doesn't crack."
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Pre-Cast Concrete Pre-cast concrete simply means concrete that has been made in a factory and ben brought to site on a truck. This means that the size of the concrete can’t be too big as it needs to fit on the back of a truck and craned into position. Quality of concrete is much higher. Work on site can be done much faster as there is more space and more active workers. Commonly used in walls and columns. Construction joints: When one material meets another perpendicular Structural joints: the type & performance of the structural connections joining the precast concrete to each other. If joints are visible then you can’t use a patch plate joint on the outside, it needs to be hidden on the inside.
There are cost benefits for reusing the same formwork for multiple panels.
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Beams & Cantilevers A cantilever is a beam that is only supported at one end and at the other end it has no support. The benefit of this is that it can be used as a shading structure with no supports needed. Cantilevers give an architectural effect that builders and especially architects love. A consideration when constructing a cantilever is that if it is too long or too heavy it will begin to sag down. To allow for this drop, the structure should be built on a slight upwards lean from the point of connection. Engineers are able to approximately work out the distance the cantilever will drop.
IMAGE 5: A cantilever design to provide shelter for a table.
A beam is a long and sturdy piece of timber, metal or concrete that assists in supporting the roof or flooring of a structure.
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Worksheet from tutorial 1. Title Block List the types of information found in the title block on the floor plan page. Scale, title, orientation, architect details(including contact details), project name, consultant details, issue date, client, drawing name, drawing number. Why might this information be important? This information is displayed in a block at the bottom of each page and set out in the same way for each. This is crucial for consultants and anyone else who reads the drawings as they know exactly where to look. 2. Drawing Content - Plans What type of information is shown in this floor plan? -Legend, materials(code found in a hexagonal bubble), room names/numbers, door numbers, area of room(metres squared), surrounding structures and trees, references to other drawings and a grid. Provide an example of the dimensions as they appear on this floor plan? What units are used for the dimensions? Distance between columns= mm. Eg. 5235mm Area=metres squared Distance above sea level=metres Is there a grid? What system is used for identifying grid lines? Yes there is a grid. The grid lines are represented by alternating long and short dashed lines. Dashed lines are used to avoid confusion between walls and other lines. The other purpose of the grid is if you have multiple drawings. The grid will remain the same for each drawing helping you to
identify where on the plan a certain part is.
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What is the purpose of the legend? The purpose of the legend is to easily and quickly read the information by looking at the symbols on the diagram. This is also helpful because you don't have to have all of the information and text on the diagram which would make it look messy and unreadable. The abbreviated legend is also a useful tool as it minimise the amount of text on each page and makes it easier to distinguish between materials and objects.
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Why are some parts of the drawing annotated? Illustrate how the annotations are associated with the relevant part of the drawing. Some of the more important parts of the drawing are annotated as they are too difficult to explain by a drawing. For example: ‘ALL PLANT ROOM WALLS FIRE RATED’. This would be hard to demonstrate without text as there isn't a commonly used symbol for it. An arrow pointing from the annotation to the walls is located in the plant room in this case.
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Illustrate how references to other drawings are shown on the plan. What do these symbols mean? This helps to navigate between different parts of the construction. Some of the construction is at a scale of 1:50 where other parts are at 1:250. If we were to have both scales on the same image the 1:50 would have to be really small and detailed and wouldn't be easily viewable. The 3 in the diagram means section 3 and the A40-01 is the drawing number."
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How are windows and doors identified? Provide an example of each. Is there a rationale to their numbering? What do these numbers mean? Can you find the answer somewhere in the drawings? The doors are numbered as D01, D02, D03… according to the number of doors in each room. The doors aren’t labelled 1, 2, 3… because if the client decides to put another door(number 23 for example) it will most likely be away from number 22 which will make it difficult for the builders to find. The windows are labelled in the same manner.
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Are some areas of the drawing clouded? Why? Some of the text has a clouded bubble surrounding it. This is because the structure has been recently added to or a change has been made to it. It needs to stand out to the builders as they don't want to be building the old plans by mistake. 3. Drawing Content - Elevations (A30-01 & A30-02) What type of information is shown in this elevation? How does it differ from the information shown in the plan? The information shown in the elevation is of the exterior of the building only. The plan showed the interior design such as doors and flooring. The legend contains less information in the elevation. The main points in the legend are the height above datum and the door and window numbers. Whereas the plan included wall types. In the abbreviated legend, the elevation simply has the exterior components and the plan has the interior." Are dimensions shown? If so, how do they differ from the dimensions on the plan? Provide an example of the dimensions as they relate to the elevation. The dimensions between grid numbers 3-7 are identical. This is because it doesn't matter if it’s a plan or an elevation the distance horizontally will remain the same. What types of levels are shown on the elevations? Illustrate how levels are shown in relation to the elevation. The four levels shown are the Function Parapet, Level G and the Existing Pavilion. Is there a grid? If so, how/where is it shown? There is a grid however it only shows the columns not the rows. Also, only columns 3-7 are shown because columns 1 and 2 are on a 7 degree angle to the rest of the structure; therefore this section of the building needs to be on a separate grid. Grid lines A, B, C and D are shown on the east elevation and AA and BB on the west; this is again because the odd shape of the building.
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What types of information on the elevations are expressed using words? Illustrate how this is done." The information expressed with words are the clouded texts and other important features. In total there are only eight annotations on the south elevation and four on the north. The reason that there aren't many annotations is that they have all been mentioned on the plan. The information is represented off the drawing with an arrow pointing to the subject rather than on the drawing where it would get messy."
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Illustrate how the doors and windows are identified on the elevations. The doors(left) and windows (right) are identified as:
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4. Drawing Content - Sections (A40-01) What type of information is shown in this section? How does it differ from the information on the plan and elevation? The information shown in the section is the levels(heights) of the existing pavilion and the new one being built, and also the position of each room. The information in the plan and elevation shows more the materials that are involved rather than the structure. The section isn’t very detailed or annotated, it shows how the building will look from different sides.
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Illustrate how the section drawing differentiates between building elements that are cut through and those that are shown in elevation (beyond). Bold lines are shown where he building has been cut. This is to show builders that there may be something that is extending out past the bold line. Also it differentiates between the structure that has been cut through compared to the structure in the background.
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Provide examples of how different materials are shown on the sections. The materials are shown as their pattern, without any other information. A builder looking at these plans understands that a wall with scattered dots means that the wall is to be made out of concrete. Find where this section is located on the plans. In order to find these sections on the plans, you must identify the number on the section and find the corresponding number on the plan. The arrow outside the circle gives the direction in which the drawing is being viewed from. If the arrow is pointing right then the drawing has been taken from the west side looking east.
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5. Drawing Content - Details (A66-01) What sorts of things are detailed? On drawing number A66-01 the stairs are highly detailed even the tread on the steps is taken into account. As the scale of some of the drawings are 1:5 a lot more detail can be squeezed in compared to the plan for example which was 1:100. Provide examples of how different materials are shown on drawings at this scale. The code FL-13 stands for external timber deck and stairs. FL is the code giving to any flooring material and the number following is to differentiate between materials. If a builder sees the code FL they know that the material will be for flooring. Find the locations of these details on the plans, elevations and sections. Stair 1. "
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The location of STAIR 1 on the plan.
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" " " " The location of STAIR 1 on the elevation.
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The location of STAIR 1 on the sections.
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" " " " " " " " " " " " " " " " A knowledge map of concrete including the characteristics and construction of concrete.
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Glossary Joist: A piece of timber or steel used to support a structure. Generally parallel to each other. Steel decking: The steel that is used in the flooring system, supported by steel beams. Span: The distance measured between the inside of two supports. Girder: Main beams, usually steel. Concrete plank: The planks that are used in a floor system and are supported by beams and loadbearing walls. Spacing: ‘The repeating distance between a series of like or similar elements.’ {1}" Reference list: E-learning: http://www.youtube.com/watch?v=otKffehOWaw&feature=youtu.be http://www.youtube.com/watch?v=c1M19C25MLU&feature=youtu.be http://www.youtube.com/watch?v=c3zW_TBGjfE&feature=youtu.be http://www.youtube.com/watch?v=scYY-MMezI0&feature=youtu.be IMAGE 1: http://www.decor-iron.co.uk/default.asp?page=377 " IMAGE 2: http://collections.infocollections.org/ukedu/uk/d/Jgtz006e/5.2.html IMAGE 3: http://www.pilinglondon.co.uk/foundations.htm IMAGE 4: http://roadware.blogspot.com.au/2010/09/repairing-railings-and-posts-with-10.html IMAGE 5: http://www.uap.com.au/street-furniture/street-furniture/shelter/port-shelter-cantilever/ " IMAGE 6: http://ebeyfarm.blogspot.com.au/2011/12/first-part-of-floor-complete.html IMAGE 7: http://blog.buildllc.com/2012/01/10-things-you-should-know-about-reusing-an-existingfoundation/
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{1}." https://app.lms.unimelb.edu.au/bbcswebdav/courses/ENVS10003_2014_SM1/WEEK %2004/SPAN%20AND%20SPACING.pdf " Ching, F. (2008) Building Construction Illustrated (4th ed.). Hoboken, New Jersey: John Wiley & Sons, Inc. (p. 4.01)