Interior Architecture report

This is an example of an investigative report based on two case studies. As it was a team assignment, different sections were written by different team members.

Click the icons next to each section to show the lecturer's comments. Click again to hide the comment.

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    Show/hide lecturer's comment 1

    Report Title : Polished ConcreteLecturer's comment 1:
    The cover page features a statement of the title of the report, the name of the lecturer, the name of the unit and the student details (deleted here for privacy reasons).

    Show/hide lecturer's comment 2

    Table of contents

    Lecturer's comment 2:
    This section gives a clear outline of the report structure listing headings and subheadings (page numbers appear on the original assignment, but not on this webpage).


    Show/hide lecturer's comment 3Show/hide lecturer's comment 4EXECUTIVE SUMMARYLecturer's comment 3:
    The report has a small number of figures and information is presented in a table form on two occasions. The students didn't compile a list of figures, tables or illustrations. This may have been a good addition for greater clarity and to improve the report's usability. However, when only a few figures, tables and illustrations are used, they can be included in the table of contents, but you should ensure they are clearly indicated.

    Lecturer's comment 4:
    In a report, headings do need to stand out. However, it's not necessary to use a combination of bold print, upper case text and underlining. One of these features would usually be enough. It is wise, though, to clarify with your tutor if you are expected to follow the stylistic features of a particular template.


    Show/hide lecturer's comment 5

  1. INTRODUCTIONLecturer's comment 5:
    The introduction is clearly set out under subheadings indicating the scope, method, limitations, assumptions and background.
  2. Show/hide lecturer's comment 6 1.01 Purpose Lecturer's comment 6:
    The clear numbering of sections and pages helps the reader understand the overall structure. Whichever numbering system you use, make sure it is used consistently throughout.

    1.02 Scope
    1.03 Limitations
    1.04 Method
    1.05 Assumptions
    1.06 Background
  3. FINDINGS
  4. Show/hide lecturer's comment 15 2.01 Material Properties
    2.02 Material Attributes
  5. DISCUSSIONLecturer's comment 7:
    The body of the report is set out in two clear sections: findings and discussion. These sections are divided into subsections which identify and examine key characteristics of the material and issues to be considered. Each subsection begins by defining and describing the subject of the section, giving important technical information and highlighting structural features. These are followed by some examples taken from the studies.
  6. 3.01 Material Limitations
    3.02 Design Considerations
    3.03 New Installation Vs Refit
    3.04 Environmental Issues
    3.05 BCA & Australian Standards
    3.06 Durability
    3.07 Installation
    3.08 Safety
    3.09 Maintenance
    3.10 Acoustics
    3.11 Cost
    3.12 Lead Times
  7. CONCLUSION
  8. RECOMMENDATIONS AND IMPLEMENTATION
  9. Show/hide lecturer's comment 7REFERENCESLecturer's comment 8:
    This report does not contain any appendices. These would usually offer additional information such as tables, questionnaires, data from research or detailed and lengthy material that could not be incorporated in the body of the report.



    Show/hide lecturer's comment 8EXECUTIVE SUMMARYLecturer's comment 9:
    The executive summary is appropriately brief (it usually appears on a separate page at the beginning of a report). It contains a statement of the purpose of the report, provides a background description of polished concrete, identifies the cases used, and gives a general conclusion with recommendations. In addition it could indicate the primary sources used in the report and give the key findings.

    Show/hide lecturer's comment 9 The purpose of this report is to present detailed information on polished concrete, apply the research and analyse for two suitable applications.

    Polished concrete is an option for decorative concrete flooring. The installation and maintenance is simple, which makes it an ideal floor material for many different applications from warehouses to high-end hotels.

    QV's Urban Market and the foyer of Melbourne Museum were chosen to explore how polished concrete is suitable for two applications. QV's Urban Market is a food court, where the traffic circulation is high, and the smooth surface of the polished concrete floor can resist the heavy forklifts or the staining from oil. Melbourne Museum is an educational public space, where durability is an important issue to be considered. Thus, polished concrete flooring is useful as it can remain resilient for years without re-sealing and last longer because of its simple appearance.Lecturer's comment 10:
    It is not necessary to break an executive summary into a series of paragraphs. In fact, executive summaries are more commonly presented within a single paragraph.

    Show/hide lecturer's comment 10 Two alternative recommendations are offered for the applications. Terrazzo would be suitable for the foyer of Melbourne Museum as it has more patterns which make the museum more dynamic. Proxy resin would be appropriate for QV's Urban Market as it has a variety of colour choices and it can still present the casual look to support the QV's 'laneways' idea.Lecturer's comment 11:
    The report features a mix of technical and general vocabulary. Where technical words are used, the student has frequently given a definition or a statement that indicates the meaning of the term. This ensures that all readers are able to understand the content of the report. When writing for an informed professional group, the accurate use of technical vocabulary is important to convey complex details and concepts. It is a good idea to build a glossary of terms that can be a resource when writing assignments.

    1. INTRODUCTION

    Show/hide lecturer's comment 111.01 PURPOSELecturer's comment 12:
    In a report, it's important to distinguish between main headings and subheadings. For an assignment, you may be expected to follow a particular style. Whichever style you do use, make sure you are consistent throughout.

    The purpose of this report is to research and analyse in depth the specification of polished concrete as a floor material, then to apply the findings to two different applications and finally to recommend two other alternative materials that would be suitable for the applications.

    1.02 SCOPE

    In investigating the polished concrete as a floor material, the report considers the material's properties, its attributes, limitations, design considerations, environmental issues, BCA & Australian Standard issues, durability, installation, safety, maintenance, acoustics, cost and its lead times.

    Show/hide lecturer's comment 121.03 METHODLecturer's comment 13:
    The method could possibly indicate more fully the type of information provided and analysed. What sort of information did the companies offer? Was it technical information based on research? Did the authors find limitations other than time? For example, were they restricted by the type of information available to them?

    Show/hide lecturer's comment 13In order to complete the report, photos have been taken in QV and Melbourne Museum. Many related websites especially the Cement & Concrete Association of Australia's and Boral Companies' have been browsed and analysed. Books borrowed from the library have also been used as references.Lecturer's comment 14:
    Throughout any piece of writing, consistency of style and tone is important. This report maintains an appropriate impersonal, objective tone. Examine the report and note there is no direct or personal reference to the student.

    1.04 LIMITATIONS

    The limitation is mainly in relation to the rigid time, which may mean some information written in the report may not be detailed enough. Besides, relying on limited experience, it is hard to define exactly the floor material of the applications.

    1.05 ASSUMPTIONS

    In investigating the two applications QV and Melbourne Museum, it was assumed that the two polished concrete floors are newly installed, as they are two modern constructed buildings.

    Show/hide lecturer's comment 141.06 BACKGROUND

    QV is a new shopping centre. It is located in the centre of the city. It is the redevelopment of Melbourne's historic Queen Victoria Women's Hospital site. It represents the quintessential Melbourne lifestyle, presenting intimate laneways in the urban centre. So the floor on QV's Urban Market is polished concrete, which gives shoppers a casual and traditional cultural sense.

    Melbourne Museum is a modern and contemporary museum. Its exhibitions are mainly on nature, science and Australian culture. The main idea is to encourage visitors to explore and discover the issues about them. Thus, polished concrete is chosen for the floor of the foyer, just to give audiences a comfortable and high-quality atmosphere to enjoy their journey.

    Lecturer's comment 15:
    The background section provides contextual information that is relevant to the cases.

    2. FINDINGS

    2.01 MATERIAL PROPERTIES – POLISHED CONCRETE

    Show/hide lecturer's comment 16

    'Polished concrete' is a generic term that can be described as a range of decorative concrete flooring options, which leave the concrete surface exposed as the final floor finish. Polished concrete floors provide a reasonable choice for floor treatments, with a wide range of colours and finishes that are comparable with tiles, vinyl and cork. It is an energy efficient, low-maintenance and dust-free flooring.Lecturer's comment 16:
    Apart from in the dot point sections, complete sentences are used throughout. This ensures that the text remains clear and concise even when long sentences are used. Simple, clear sentences that directly state your meaning are preferred in a report.

    Nowadays, a final surface finish can be achieved in many different ways. Modern finishes using liquid polishes, latex coatings, chemical sealers, grinding (to expose the aggregates), colours, stains and special aggregates to achieve 'rock' or 'marble' appearances, are all economical ways of achieving a variety of effects.

    Other than different colours and textures, patterns are also possible. These can be achieved by using different colours and aggregates, with inlaid timber strips, joints or tiles forming borders around individual areas.

    Show/hide lecturer's comment 17RANGE OF FINISHESLecturer's comment 17:
    In the findings and discussion sections of this report, the student uses a mixture of subheadings with and without numbers. In addition, some thoughts are numbered whilst others have dot points. This inconsistency could be avoided by establishing a master list which shows the formatting of different levels of headings.

    STEEL TROWELLED

  • The most basic finish.
  • Normal grey concrete is used, but concrete incorporating off-white cement can also be used to achieve a lighter and more consistent colour.
  • Some trowel marks may be present unless a finish free of trowel marks is specified.

BURNISHED

  • Produced by steel trowelling until the concrete surface takes on a polished or glossy appearance.
  • Power trowelling machine or 'helicopter' is the equipment to use.
  • It is a finish free of trowelling marks.
  • Machine trowelling the entire slab area is required.
  • Achieving this finish on a topping placed after the walls are constructed is therefore not possible.

COLOURED

  • Using a coloured topping slab
  • Applying a dry shake topping or pigment to the surface
  • Chemically staining the concrete surface or applying a surface coating. It may be either bonded or unbonded for topping slab.

COLOURED AND TEXTURED

A surface texture can be applied along with the colour to give the appearance of a range of natural stone finishes.

COLOURED AND PATTERNED

  • Patterns can be created by sawcutting 'pattern' lines into the surface.
  • Brass or zinc strips used for construction joints.
  • Tiled finishes or a variety of colours can be used to create the pattern.
  • Inlaid timber strips, tiles and pavers can also form patterns in the floor.

COLOURED AND ABRASIVE BLASTED

  • Abrasive blasting can be used to texture the surface and form patterns. The surface can be coloured or textured prior to this additional process being used.

EXPOSED AGGREGATE

  • Grind the surface of the slab to expose the aggregate.
  • Normal concrete mixes can be used (exposing the dark grey stones).
  • Polished-stone appearance.

EXPOSED AGGREGATE WITH PATTERNS

  • As with coloured and patterned surfaces, different aggregate colours and pigments can be used to create patterns in the surface.

TERRAZZO

  • A form of exposed aggregate concrete.
  • Artistic patterns.
  • Brass or zinc strips to form borders between the colours.
  • Coloured aggregates of marble and plastic can also be used.
  • Glass is sometimes used as aggregate to give a translucent appearance.

CASE STUDY

QV's Urban Market – EXPOSED AGGREGATE FINISHES

Show/hide lecturer's comment 18QV's Urban Market

Fig. 1 QV's Urban MarketLecturer's comment 18:
Note how the illustrations highlight the points being made.

Polished exposed aggregate finishes are achieved by grinding the surface of the slab to remove the cement paste in order to expose the aggregate or stones within the concrete or topping mix. The surface is then polished using progressively finer grinding pads. The degree of exposure of the aggregate and the uniformity of the exposure needs to be specified or a sample approved on site.

Special aggregates for the concrete or topping mix are often selected to achieve the best appearance from this type of finish. Various coloured and polished granite-type finishes can be produced. Aggregate colours, types (round or crushed), sizes, minerals, etc can all be selected and blended to achieve the desired effect. Polished granite floor finishes are used at QV Urban Market.

Fig.2 Exposed aggregate finishes

Fig.2 Exposed aggregate finishes

The equipment used for grinding and polishing the surface is the same as that for terrazzo. The aggregates used in terrazzo work are generally marble chips, glass or plastic, all of which are far easier to grind than the hard, durable aggregates used in decorative concrete mixes. Thus, the cost of grinding pads will increase, as they will wear faster. On the other hand, fewer grades of pads (coarse to fine) are required to produce a polished finish on a concrete slab. The cost of this should be added into the total cost for the surface finish when assessing whether or not to provide special aggregate toppings and ground finishes. Overall, the cost is less but still having the same stunning effects as tiled finishes.

It is easier to grind the slab before walls are built, because there are no edges or corners to worry about. In this case, protection of the surface is required. However, if a topping slab is applied after construction of the walling, specialised small equipment (which can be readily hired), is available to grind along edges and in corners.

Foyer of Melbourne Museum - STEEL TROWELLED SURFACE FINISHES

Steel trowelled surfaces are used as the floor finishes of the Melbourne Museum foyer. It is usually specified when a basic flat, smooth finish is required for the surface.

The usual method to specify flatness, and probably the simplest, is to adopt the Natspec provisions. It covers surface flatness by specifying the deviation from a 3-m straightedge. For polished concrete work, the higher Class A finish which requires a deviation of no more than plus or minus 3 mm from a 3-m straightedge is recommended. The level of the floor also needs to be specified because the entire floor can have a slope and still meet the 3-m straightedge flatness test.

To achieve the normal 'polished' look of the surface, a good quality steel trowelled finish is usually required. This may still include some minor trowelling marks. 'Burnished' finish will often be specified and it is produced by steel trowelling until a very smooth finish and glossy appearance is obtained. The additional trowelling required to produce this finish will ensure that no trowelling marks remain.

Show/hide lecturer's comment 192.02 MATERIAL ATTRIBUTESLecturer's comment 19:
The report uses a table format in two sections. When developing tables of information, carefully consider your objective. What do you intend to demonstrate through the use of a table? In what way can a table improve your communication? Use your research data to develop an appropriate table or if your table is taken from the research of others, make sure you acknowledge the original source correctly.
The table lists pros and cons, however, they are not organised in a comparative structure. The table could possibly have been used to greater advantage to provide clearer comparisons of the various characteristics.

ProsCons
  • High thermal mass: As a heat conductor, a polished concrete floor keeps the room temperature warm on cool nights and offers cool relief on hot sunny days.
  • Low maintenance: With the sleek surface, it will never require stripping, re-coating or re-waxing.
  • Easy to clean: To keep the surface clean and shiny, all you need is scrubbing, dust mopping or damp mopping with a neutral cleaner.
  • Dust free: Because of its smooth, less porous surface, the dust is hard to trap on the surface.
  • Long lasting: With a basic cleaning routine, floors can remain durable and resilient for years without re-sealing.
  • Variety of applications: Polishing is a multi-step process. This versatility allows customers to choose the level of sheen, from satin to high-gloss, to fit their applications. Besides, natural finish also blends in well with most furnishings.
  • High abrasion resistance: With the even and glossy surface, it can resist the marks of heavy forklifts and foot traffic, as well as staining from oil and chemical spills. This is the key reason many warehouses and retail facilities are opting for polished concrete.
  • Cheaper price: Polishing can give concrete a high degree of shine. It is a good alternative for homeowners or businesses that can't afford the more expensive marble or granite floors but want the same brilliant, mirror-like finish.
  • Terrazzo look: By grinding through the top few millimetres of the concrete surface to expose the aggregate, it is possible to produce a terrazzo look.
  • Save refitting cost: Removing all previous treatments and then polishing the floor can be a one-time fix that saves money.
  • Safety: Polished concrete is no more slippery than the average tile on the market. Its slip resistance meets the Australian Standards..
  • Rejuvenation of old floor: Polishing can provide a glossy surface to those old, worn and pitted floors, which gives them a fresh look.
  • Allow custom design: Before new concrete slab installations are made, people can choose the coloured or exposed finish or alternatively custom design.
  • Extremely hard surface: Concrete is composed of stone, sand and cement. They are hard and heavy materials which need comparatively more labour to handle.
  • Not ideal for cooler climates: Because concrete has a high thermal mass, sometimes it is hard to keep the room warm.
  • No choice for the finishes: with an existing concrete slab, it is hard to predict what the finish will be like. People cannot choose the floor surface appearance because after the polishing, what the surface exposes is wholly dependent on the combination of the materials.
  • High embodied energy: As concrete is a heavy material, it costs much for the delivery.

3. DISCUSSION

3.01 MATERIAL LIMITATIONS

  • There is an extra expense of applying toppings and difficulty in specifying the seeding process and uniformity of distribution of aggregate in the surface.
  • The use of sealers intended for patterned paved driveways is not recommended on polished concrete floors.
  • The steel trowelled finish required for polished concrete does not allow these sealers to readily soak into the concrete, usually resulting in the sealer remaining as a thick coating on the slab surface. It may also cause problems with the evaporation of the solvent, resulting in the sealer not hardening properly.
  • For particular health reasons, solvent-based sealers cannot be used.

CASE STUDY

QV’s Urban Market and Foyer of Melbourne Museum

Once the concrete slab has been constructed, the final appearance showing on the floor surface cannot be changed. Like for QV’s Urban Market, the floor pattern is from aggregate concrete slab whereas in Melbourne Museum solid colour showing on the floor surface of the foyer is from the structural concrete slab.

3.02 DESIGN CONSIDERATIONS

1. Consider the purpose of the room

It is not a good way to use polished concrete floor in cooler climate as concrete is a high thermal mass. To use polished concrete as a floor finish in cooler climates, insulation of the slab edge is important, as this can prevent warmth escaping through the edges of the slab.

2. Specify the flatness, level and surface texture

The flatness, level and surface texture must to be specified when considering the surface floor finish. Flatness because the polished surface reflects light, thus highlighting any imperfections in the surface; the level to control the slops of the floor, and surface texture as finishes can vary from smooth to those with trowelling marks and other patterns.

3. Consider the uniformly distributed colour

After the steel trowelled finish is done for the polished concrete floor, it may still include some minor trowelling marks. To overcome this, a “burnished” finish will often be added to produce a glossy appearance with no trowelling marks remain on the floor. However, the extent of trowelling may also ‘burn’ the surface as the trowel must be passed over the surface while the concrete is quite ‘dry’. This may result in some areas having a darker colour.

4. Consider the uniformly distributed aggregate

Use a vibrator to compact the concrete or topping mix, or unless ground the surface to a slightly greater depth to obtain an even exposure of the aggregate. Make sure the aggregate density is uniform; otherwise a patchy appearance to the final finish will result, due to some areas having more stone exposed than others.

5. Consider the strength of the concrete

The standard concrete mix used for most residential slabs has a compressive strength of 20 MPa, and is designated as Normal-Class N20 concrete. However, It is recommended to use higher strength concrete for polished work. For ground finished where the hard aggregates become the predominant colour, a minimum N25 concrete is recommended; and for steel trowelled finishes, especially burnished finished, N32 concrete is recommended. The higher strength concrete will give a smoother, better overall surface finish due to the additional cement content.

6. Control the long-term drying shrinkage cracking

When the water in the concrete mix dries out over time, the concrete slab cracks. All concrete will “shrink”, but measures can be taken to limit or control it. For example, keeping the water in the mix to minimum, say 80-mm slump mix is the standard, intended to be a good balance between limiting water and providing workability, and is suitable for most polished concrete work.

7. Consider the slip resistance

With the steel trowelled or sealed treatment, the floor surface can become slippery when wet. So higher glossy polished concrete floor may not good for the wet areas.

CASE STUDY

QV’s Urban Market

QV is the redevelopment of Melbourne's historic Queen Victoria Women's Hospital site. Now QV is a city within a city that represents the quintessential Melbourne lifestyle. To keep the “laneways” traditional culture that everything is to be discovered, QV’s Urban Market uses exposed aggregate polished concrete as its floor, providing a causal and traditional look.

Foyer of Melbourne Museum

Melbourne Museum is a 21st century museum designed by Denton Corker Marshall, exhibits mainly the Melbourne idea, the Aboriginal culture. To promote a modern and contemporary look, a simple and neat floor surface is chosen.

3.03 NEW INSTALLATION VS REFIT

  1. Almost any structurally concrete floor, whether new or old, can be polished. But there are some exceptions. Floor should be in place at least 28 days before polishing begins to ensure adequate curing. Some retail and warehouse facilities that plan to polish their floors after placement may specify the installation of as smooth a floor as possible to minimize the polishing steps required.
  2. Existing floors typically require some surface preparation prior to polishing to remove dirt, grease, coatings, or blemishes.
  3. For existing floor, once the floor has been prepared and possible glues/nails have been removed, grinding can commence immediately.

CASE STUDY

QV’s Urban Market and Foyer of Melbourne Museum

Show/hide lecturer's comment 20As QV’s Urban Market and Melbourne Museum are two modern building. Their floors are new installed. Their polishing processes are much similar. After the structural concrete slab has to be constructed, leaves it there at least 28 days to ensure adequate curing, then polishes the floor by the grinding and finally covers the surface floor by sealer.Lecturer's comment 20:
There is an incorrect use of grammar in this paragraph. This detracts from the clarity of the report and makes it more difficult to read. When writing an assignment, it's important to allow sufficient time to revise and proofread before submitting.

3.04 ENVIRONMENTAL ISSUES --- HOW GREEN IS IT?

Fig. 3 Showing how concrete slab radiates and absorbs heat

Fig. 3 Showing how concrete slab radiates and absorbs heat

Recycling

Concrete is composed of 3 main components, coarse aggregate (stone), fine aggregate (sand) and cement. They are all natural materials which can be recycled to reduce the need to use more of the earth’s resources.

High thermal mass1

Concrete floor can help regulate indoor comfort by radiating or absorbing heat. During summer, concrete floor exposes to cooling night breezes so that heat collected during the day can dissipate, which can keep the temperature of the room lower. During winter, concrete floor absorb heat from the sun or other sources, heat can then be stored and re-radiated for many hours afterwards to keep the room warmer.

Environmentally friendly cleaning compounds are used2

Polished concrete floor is easy to clean. It does not rely on any strong chemicals for cleaning; only some soft cleaning compounds can maintain the appearance, which has minimal or no environmental impact.

Fig. 4 Showing how concrete slab radiates and absorbs heat

Fig. 4 Showing how concrete slab radiates and absorbs heat

Healthy3

Using no coverings, polished concrete produces an ecological floor made of pure concrete, which provides a fresh environment, not like timber and carpet which sometimes may trap germs in. It is a great alternative for asthmatics.

No chemicals involved

With the diamond polishing technology, the floor does not rely on any chemicals to achieve a high gloss polished result. The approach is environmental friendly in some sense. However the appearance and quality (hardness) of the concrete has an influence on the finished product.

1Concrete slab floors, Australian Greenhouse Office, Canberra, http://www.greenhouse.gov.au/

2Polished Concrete, Cubic 8, Perth, http://www.cubic8concrete.com.au/superfloor.htm

3Eco- Living Concrete Polishing in Canberra, Toppings, Canberra, http://www.toppings.com.au/Concrete_Polishing.html

Lower lighting cost

When the floor is polished to granite level with a marble-like shine, it can increase the reflectivity by at least 30% and lower the lighting cost, which in a sense saves the electrical energy.

CASE STUDY

QV’s Urban Market

QV’s Urban Market fully uses artificial down lightings to highlight all pathways and to give visitors a market feeling. Even the colour of the floor is grey, and the area looks very bright with the gloss floor surface.

Foyer of Melbourne Museum

The foyer's light-coloured floor surface makes the museum brighter, which reduces the need for lighting, thus saving energy. In addition, the steel trowelled surface finishes are a passive solar design, which engages the issue of sustainability.

3.05 BCA and AUSTRALIAN STANDARDS

The requirements for the level (relative to horizontal) and flatness of the surface are not covered in any Australian Standards, thus Standards such as AS 3600, Concrete Structures, or AS 3610, Formwork for concrete does not require the surface to be constructed or finished to any acceptable industry tolerances.

3.06 DURABILITY

Long lifespan for concrete floor

  • If the concrete is placed and compacted well so there are no voids or porous area, concrete slabs have a long lifespan.
  • Once the concrete floors are treated by polished process, the density and compression strength (hardness) of concrete floors will be higher, which make the floor much more resistant to abrasions and impacts

Long lasting for the surface

  • With basic cleaning, polished concrete can keep its lustre for years
  • Even the shine of floor surface can dull, especially in high-traffic area, it is easy to restore the gleam
  • Because of its simplicity, polished concrete is versatile to all designs and themes

CASE STUDY

Fig.5 Stones have come out

Fig. 5 Stones have come out

QV’s Urban Market

Show/hide lecturer's comment 21After using for around 4 years, the floor surface is still smooth and shine, but some aggregate small stones have come out. It is one of the disadvantages for exposed aggregate finishes.Lecturer's comment 21:
The grammar here is incorrect.

Foyer of Melbourne Museum

Fig. 6 Crack surface

Fig. 6 Crack surface

Show/hide lecturer's comment 22After using for around 6 years, the floor surface still look very “new”, however, some small crack lines have been discovered when looking the surface closely. The overall appearance is acceptable, with regularly maintenance the smooth surface can last longer.Lecturer's comment 22:
The grammar here should be improved.

3.07 INSTALLATION

The first step involves grinding the concrete to expose the aggregate within. The degree of uniformity of exposure needs to be specified. Once a satisfactory level of aggregate exposure is achieved, the concrete is polished using progressively finer grinding pads. Once polished, the final step is to apply a sealer.

Polished concrete can be polished both wet and dry. Grinding or polishing wet is the original method used, as it keeps the dust down. While grinding in dry condition is easier and quicker. Grinding dry also saves on labour and equipment that is needed on a job site.

3.08 SAFETY

Safety for the users

  1. If the floor can be kept clean and dry, polished concrete floors are generally no slicker than plain concrete surfaces.
  2. It also tends to be less slippery than waxed linoleum or polished marble.
  3. To provide an extra protection against slip-and-fall accidents, polished floor surface can be treated by some anti-slip conditioners. Those products contain special additives which can improve the surface traction and make wet surfaces safer. However, they must be reapplied periodically.4
  4. Because the joints are minimal, the chances of dangerous joint slippage is lower comparing with Terrazzo.5

4Polished Concrete, Levetec Surface Preparation and Machinery, LLC. WA, http://www.levetec.com/Polishing.htm

5Polished Concrete, Cubic 8, Perth, http://www.cubic8concrete.com.au/superfloor.htm

Safety for the builders

A special dust collection system is used to create a safe work environment for dry grinding. This makes the polishing process faster as well. The dry dust collected is easily discarded as opposed to removing the slurry that is collected from wet grinding.

CASE STUDY

QV’s Urban Market

Using polished concrete without any covering helps to provide a clean and plain surface for visitors. It is a good choice especially for a food court area because some food may contain oil. With a glossy surface, oil is hard to penetrate the floor. Besides, a food court is a busy area especially during lunch hour when people carry their dishes and walk across the floor to interact with each other. It is very dangerous if the floor is slippery. With the slip resistance provided by polished concrete, people can walk safely and comfortably.

Foyer of Melbourne Museum

The museum is an educational public area mainly for young students or teenagers. Safety issues are very important. With the slip resistant floor surface, children will not slip down easily even they run. If they do slip over, children will not experience serious injuries because of the smooth and even surface provided by the steel trowelled surface finish.

3.09 MAINTENANCE

Polished concrete floors are easy to maintain, with only regular cleaning required. The sealer prevents staining and should keep the finish looking good for years. Most sealers will last about five years in a domestic application, with recoating being a simple and economical way to restore the original finish.

Show/hide lecturer's comment 23To avoid a build up in the sealer thickness over time, an alternative to recoating is to lightly wipe over the floor with solvent. This redissolves the sealer, evens out the coating and will restore the lustre to the floor. This also applies to resealing the floor; the solvent in the sealer will dissolve the old sealer and allow a uniform layer to be applied across the floor.Lecturer's comment 23:
Careful use of punctuation improves the clarity and meaning of any text. Capitalisation and a full stop are required to indicate the beginning and end of a complete thought. Commas help to identify a supplementary idea in a sentence and separate items in a list. Examine the use of punctuation in this report and consider how it contributes to the clarity and overall communication of the author's ideas.

Stain or Contaminant TreatmentComments
Timber

Scrub affected area vigorously with chlorine bleach[1], then rinse.

Cover with a bleach-soaked cloth, repeating until stain is removed.

Alternatively, mix oxalic acid[2] crystals with hot water, and scrub vigorously. Allow to remain on the surface until the stain is removed.

Bleaching may vary colour/tone.
Adhesives and caulking compounds

Scrape off excess and wipe with turpentine or denatured alcohol[4].

Apply poulice[3] impregnated with turpentine or denatured alcohol[4].

Once cured, scour remaining residue with commercial grade scouring compound, or hot water and strong soap solutions.

Porous/textured surfaces easily absorb oils/chemical agents. Use poultice of inert material to immediately draw up residual contaminants.
Rust Remove excess rust with stiff brush, cover with poultice impregnated with a solution of 1 part sodium citrate (also known as sodium tricitrate) to 6 parts warm water. Remove when dry. Scrape off residue and scrub with warm soapy water. Rinse with clean water. Cover exposed reinforcement with plastic to minimise effects of weathering during construction phase.
Mortar

Mass deposits may require mechanical removal with cold chisel or shot blasting, then use a pumice or scouring compound in a circular motion.

Minor deposits can be removed using a stiff bristle-brush, followed by rinsing with clean water.

Use barriers, a coating and/or plastic to keep finished concrete clean whilst construction is completed.
Paint Wet paint should be soaked up immediately. Do not wipe area. Scrub with scouring powder and water. Solvents and paint removers should be avoided, as they will thin the paint driving it further into the surface pores. Wait at least 3 days before removing remaining dry paint.

Dry paint: Scrape off and apply poultice of paint remover. Leave for 20-30 minutes.

Scrub surface gently to loosen and remove remaining film.

Clay soil and common beverage stains

Remove loose soil particles by brushing only. Avoid using hard implements which may score the surface. Use absorbent material to blot any moisture.

Dilute and scrub remaining contaminate with soapy water. Repeat process until removed. Stubborn stains may require scrubbing with chlorine bleach[1].

Fresh concrete and open textured finishes are most prone to contamination. Protect concrete surfaces whilst undertaking landscaping.
Rubber marks

Use proprietary rubber-removal compounds as available from hardware stores. Refer to manufacturers recommendations.

Scrub powdery deposits with a stiff bristle brush, then rinse with clean water. Repeat over time until bloom dissipates.

Solid deposits may require removal by abrasive blasting or a solution of 1 part acid[2] to 10 parts water.

Spot test inconspicuous area for adverse structural and/or decorative effect.

Condition may reoccur over a period of several months.

Acids may affect integrity and appearance of concrete surface.

Oil, fat and grease

Contain spill with sawdust, cat litter, sand, or dirt. Residue should be soaked up with absorbent blotting material or poultice.

Remove mass, then cover with fresh poultice of 1 part lime to 2 parts turpentine.

Cover with plastic sheeting and leave for 24 hrs. Remove contaminated mass and repeat process if necessary. Scrub with warm water and laundry detergent, then rinse with clean water.

Soak up spills as opposed to spreading across & into surface.
Organic growth

Brush affected area when in a dry state.

Sterilise area with a strong fungicide such as household bleach[1], formaldehyde or a fungicide cleaner. If growth reappears, repeat the process.

Specify adequate falls and drainage to all flatwork.
Smoke stains

Remove by scouring with powdered pumice or grit scrubbing powder.

Bleach stain using either a cleaning powder or household bleach[1] solution.

Fire-related staining may actually carbonise concrete, changing the colour.
Chewing gum

Freeze using ice cubes and scrape off excess.

Apply a poultice saturated with methylated spirits to the remaining residue then leave until dry.

When the gum has turned brittle, scour the surface with a stiff bristle or wire brush. Finish by washing with hot soapy water and rinsing.

Due to artificial colourings, some gum may significantly stain the concrete surface.
Red wine

Immediately soak up excess liquid using an absorbent material. Do not wipe.

Flush &scrub with soapy water, rinsing regularly. Ingrained wine stains can be loosened by diluted cleaning alcohols, then scrub with soapy water &rinse.

Stubborn residue may require a poultice containing household bleach[1].

The tannins in certain wines will impregnate the concrete surface. Early intervention will minimise extent of stain.

Show/hide lecturer's comment 24

Lecturer's comment 24:
If the table was compiled by the authors from a range of sources, then general referencing in the reference list may be adequate. However, if the table was taken from a particular resource and used exactly as it was published, reference details of the original should follow the table.

  1. Bleaching may lighten colour, vary or tone down vibrancy. Consider treating extended area for uniformity.
  2. Acids may affect concrete integrity and/or appearance. Spot test different acids and strengths.
  3. A poultice is a mass of dry (or heated) material used to draw or soak up liquids, eg. cat litter.
  4. Denatured alcohol is cleaning alcohol rendered unfit for human consumption, eg. methylated spirits.

3.10 ACOUSTICS

A concrete floor or slab is one of the great acoustics insulations. It can reduce music or conversation noise being transferred from one level of a home to another, or between rooms on the same level.

CASE STUDY

QV's Urban Market

As shopping areas or food courts are always crowded with people, chatting, negotiating and laughing are very common activities within the space. To provide a comfortable area where visitors can enjoy their eating or shopping experience, a polished concrete floor is a good acoustics insulation to avoid or to block the noise being transferred from one area to another area.

Foyer of Melbourne Museum

Show/hide lecturer's comment 25 Acoustics control is very important for Melbourne Museum because within the museum different themes of exhibitions are promoted in different galleries. Sometimes they may have audio or video elements to draw visitors' attention. With the exposed aggregate concrete as the foyer floor, it can reduce the noise being transferred from one gallery to another gallery.Lecturer's comment 25:
Spelling also contributes to the clarity of a written text and the ease of reading. In addition, it is important when writing a professional document to maintain the presentation standards required by the profession. Accurate spelling is generally expected by all professional groups. Study this report and note the way the authors have generally used clear, concise and accurate language. Always allow extra time in your planning for carefully editing your text.

3.11 COST

The price varies according to the condition of the slab, the size of the area, the level of grinding required, the aggregate exposure desired and the final finishing sealer. Polished concrete is a cost effective alternative comparable to timber, tiles, carpet, vinyl, pavers, stencil create etc.

  • Residential price is about $60 sq/ m from Polished Concrete Specialists, Western Australia. A two-stage system polishing where the construction slab becomes the final floor.

3.12 LEAD TIMES

Time for curing the concrete slab

Curing is needed for a concrete slab. The longer the curing period, the greater will be the strength gain. Normally a minimum curing period for interior concrete is 3 days, for exterior concrete is 7 days.

Time for curing the polished concrete work

For a polished concrete floor, 14 days is a preferable curing period, to minimise the potential for cracking. If the surface of the slab is to be ground to expose the aggregate, a minimum of 7 days curing is recommended to ensure that the surface has sufficient strength, and is hard enough to achieve a good quality finish from the grinding or polishing process. A minimum of 7 days is also recommended for toppings.

Time for polishing the floor

Polishing the floor is an easy task. When the concrete slab is ready, all you need is the finer grinding pads to polish the floor. Once polished, the final step is to apply a sealer. It may just need a day to finish but it depends on the size of the area.

Show/hide lecturer's comment 264. CONCLUSION

Polished concrete floors are an ideal low cost solution well suited to residential, commercial, educational and industrial applications. In general, it provides a healthier and dust-free environment and low maintenance for the user.

Polished concrete floors come in many forms and can be used to provide great thermal comfort and lifestyle advantages. Passive solar design and long term durability can easily be achieved. Heating cables could be installed within the slab, to provide warmth to the entire floor finish of the application.

A wide range of finishes such as steel trowelled, burnished, exposed aggregate and terrazzo, can be used for applications, depending on their requirement. Whenever the finish starts looking a little dull, recoating can easily restore the floor to its original appearance. Lecturer's comment 26:
The conclusion provides a good summary of all the main points made in the body of the report. It generally covers the positive attributes of polished concrete as a floor surface. There is no mention of any significant negative or unresolved issues which would give the report a more balanced view. It can only be assumed that these issues do not exist.
There is no direct reference to whether or not the material selected suited each of the specific applications researched, as was asked for in the assignment brief. This conclusion only focused on generalised information about polished concrete.

Show/hide lecturer's comment 275. RECOMMENDATIONS AND IMPLEMENTATION

Lecturer's comment 27:
Generally, recommendations refer to a suggested course of action and are frequently presented in clear statements in order of importance. This assignment asked for some alternative solutions for the selected application, reasons for the choice and whether or not the alternatives would be more suitable than the material researched. The students have responded in part to the task, although they have not compared their chosen material with their alternative choices.

For QV's Urban Market

The alternative material that would be appropriate for the flooring of QV's Urban Market could be epoxy resin. The reasons are:

  1. Excellent adhesion to a variety of substrates and reinforcements
  2. Low shrinkage on cure
  3. No cure volatiles
  4. Good chemical resistance and solvent resistance
  5. Thermal stability
  6. Good moisture resistance
  7. Good dimensional stability and fatigue resistance
  8. Versatility, many modes of cure, many resin types, wide range of modifications possible

Most of the properties at the site are food premises, therefore flooring material with good chemical resistance like epoxy resin could go well as flooring at the site. Stains from vinegar, oil and grease could be avoided and lower the cost of maintenance. Besides, it could also prevent slippery flooring and provide a safe place for the user.

For Foyer of Melbourne Museum

Another material which could be used as flooring of the Melbourne Museum is terrazzo. The reasons are:

  1. Natural quartz is very hard
  2. Available in a large variety of colours, styles and designs
  3. Not porous, doesn't have to be sealed
  4. Easy maintenance
  5. High colour consistencies

Show/hide lecturer's comment 28 To avoid a dull effect, terrazzo could be installed as the flooring of the museum. Terrazzo has a wide range of colours and patterns which could be used to give a freshness and a creative design, instead of polishing the uninteresting existing floor slab. This could gain the user a great interior experience while visiting the museum. Moreover, it is easy to maintain which could lower the maintenance cost for the museum. Lecturer's comment 28:
Well-written paragraphs exhibit a clear structure and often begin with a statement or topic sentence that indicates the content of the paragraph. This is usually followed by details and examples, ending with a general statement which summarises the main point of the paragraph and links to the next main point.



Show/hide lecturer's comment 29REFERENCES

Lecturer's comment 29:
The reference list here is predominantly a collection of electronic resources with a small number of published books. It is organised in alphabetical order, however, the electronic sources frequently begin with the title of the document rather than the author or organisation responsible for the site. For advice on referencing consult the Citing and referencing library guide and this online tutorial Demystifying citing and referencing.

Atomic Concrete Polishing, Atomic Concreting, viewed 10 Auguest, 2006, Australia, http://www.atomicconcretepolishing.com.au/

Briefing note: Polished Concrete Floors, 2001, Cement &Concrete Association of Australia, viewed 10 August 2006, http://www.concrete.net.au/viewpdf.php?pdffile=pdf/ccaa_polished_05.pdf

Concrete Categories, Boral Companies, viewed by 12 August,2006, http://www.boral.com.au/

Concrete slab floors, Australian Greenhouse Office, Canberra, view 12 August,2006, http://www.greenhouse.gov.au/

Eco- Living Concrete Polishing in Canberra, Toppings, Canberra, viewed at 12 August, 2006, http://www.toppings.com.au/Concrete_Polishing.html

Flooring: buying guide, Home Site, viewed 11 August, 2006, Australia, http://www.homesite.com.au/indoors/living-areas/flooring-concrete/buying-guides/flooring-buying-guide

Gray J. I., Lee S. M., &Lee M., 1989, Reference Book for Composites Technology, CRC Press.

Grinding and polishing concrete floors, Infolink, viewed 10 August, 2006, Australia, http://www.infolink.com.au/articles/C1/0C042FC1.aspx

Koones. S, 2004, House-About It: Home Improvement / Construction, Gibbs Smith, Salt Lake City

Polished Concrete, Cubic 8, Perth, viewed 10 August 2006, http://www.cubic8concrete.com.au/superfloor.htm

Polished Concrete, Levetec Surface Preparation and Machinery, LLC. WA, viewed 12 August, 2006, http://www.levetec.com/Polishing.htm

Standing the test of time, Polished Concrete Specialists, Perth, viewed 10 Auguest, 2006, http://www.polishedconcrete.com.au/images/press/PICfloors01.jpg

Watts, A., 2001, Modern Construction Handbook, Springer Wien, New York