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School of Architecture, Building and Design
Bachelor of Quantity Surveying (Hons)
Building Material
Assignment 1A- Concrete
Date: 29 April 2014
Group Members:
Goh Jeng Jhieh (0315080)
Cassandra Wong XinYue (0313365)
Wong Yun Shi (0315225)
Mak Mun Choon(0314928)
Liu Wei Cheng
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Content
Content Page
Front Page 1
Content 2
Introduction 3
Types of Concrete : 3A Aerated Aerated Autoclaved Concrete 4-6
: 3B Asphalt Concrete 7-11
: 3C Seacrete Concrete 12-14
: 3D Decorative Concrete 15-17
: 3I Roller Compacted Concrete 18-19
References 20-21
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Introduction
3A Autoclaved Aerated Concrete
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Detail view of AAC in 1mm
Definition Of AAC
Autoclaved Aerated Concrete (AAC) is a comparatively new building material in
North America. Other than that, it has been widely used in Europe and also Asia
as a green construction material. The concrete is one-fifth the weight of normal
concrete and it has thermal efficiency that has the ability to reduce a building's
energy consumption by 30-40 percent. Autoclaved Aerated Concrete is easily to
cut any required shape.
Advantages
AAC has been produced more than seventy years. It also offers several
advantages over other cement construction materials. The advantages are;
AAC reduces additional material use
AAC has high thermal efficiency
Minimize waste and pollution
AAC reduce noise pollution and improve indoor air quality
AAC structure are superior to withstand fires, earthquake, and other
natural disasters
AAC structure are price competitive
Larger size lead to fast masonry work
Disadvantages
There are few disadvantages with Autoclaved Aerated Concrete, which are;
Projects far from manufacturing facilities will suffer with higher initial costs.
Contractor experience. They have to adjust to apply thin-set mortar to light
weight blocks, which is a skill that requires more precision.
Load-bearing limitation. ACC less suitable for high-rise buildings.
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Material properties
AAC ranges in density from 25-50 lb with compressive strengths ranges from 290
psi to 1090 psi. It also suitable for loadbearing and non-loadbearing walls.AAC
mansory blocks are available in a variety sizes. The nominal face dimensions are
8” high by 24” long with nominal thickness of 2”, to 16”
U block Modular block
AAC – consider as green &environmental building material
Main ingredient which are quartz sand, cement, lime and water all are
available.
AAC any production waste before the final setting will be reintroduced into
the production cycle.
There is any pollution either water or air
AAC left over the site building can be recycled. Eg.foundation fill back or
crash and use for.
It no contains toxic substances
Process of making AAC
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1. Raw materials which are sand, cement, lime and water.
2. Mixing the raw materials
3. Slurry was poured into mold
4. Procuring stage
5. Cake is separated from mold
6. Mold will be returned for next step
7. Cake is ready to be cut
8. Mold was cleaned
9. Mold is oiled
10.Mold closes
11.Mold returns to mixer
12.Cake is cut in to blocks or panels and waste is recycled
13.Uncured AAC placed into autoclave under steam & pressure
14.Cured AAC removed from autoclave
15.AAC is shrink wrapped and placed on pallets
16.AAC transported for shipping or to storage area
3B-ASPHALT CONCRETE
DEFINITION
Asphalt is well known as a road covering, more technically termed asphalt
concrete, but there are a few different forms in which the substance may appear.
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It is a naturally occurring material present in crude oil and in natural deposits,
notably around certain bodies of water and in oil sands. This substance is found
in either liquid or semi-solid form in nature and is characterized by its high
viscosity and its sticky, black appearance. It consists almost exclusively of
bitumen, a substance composed of polycyclic aromatic hydrocarbons (PAHs).
GENERAL INFORMATIONS
ROLLED ASPHALT - It is made of aggregate or
solid materials such as sand, gravel, or recycled
concrete. This type is used to make roads and
other surfaces, such as parking lots, by being
applied in layers and compacted.
HOT MIXED ASPHALT CONCRETE (HMAC) - It is produced at 320°F (160°C).
This high temperature serves to decrease viscosity and moisture during the
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manufacturing process, resulting in a very durable material. HMAC is most
commonly used for high-traffic areas.
WARM MIXED ASPHALT CONCRETE (WAM OR WMA) - It reduces the
temperature required for manufacture by adding emulsions, waxes, or zeolites.
This process benefits both the environment and the workers, as it results in less
fossil fuel consumption and reduced emission of fumes.
COLD MIXED ASPHALT CONCRETE - This type of asphalt is emulsified in
soapy water before mixing it with the aggregate, eliminating the need for high
temperatures altogether. However, the resulting material is not nearly as durable
as HMAC or WAM, and it is typically used for low traffic areas or to patch
damaged HMAC.
USAGE OR APPLICATION OF ASPHALT CONCRETE
-Transportation (roads, railway beds, airport runways)
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-Recreation (playgrounds, bicycle paths, running tracks)
-Building construction (floorings)
PHYSICAL & CHEMICAL
PROPERTIES
DURABILITY - Durability is the
measure of how well asphalt concrete retains its original characteristics when
exposed to normal weathering and aging processes.
ADHESION AND COHESION - Adhesion is an ability to stick to the aggregate in
the paving mixture. Cohesion is the ability to hold the aggregates particles after
the pavement is finished.
PURITY - Asphalt is composed of almost entirely bitumen, which is soluble in
carbon disulfide. Refined asphalt is almost pure bitumen and usually more than
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99.5% soluble in carbon disulfide. They are inert if there is impurity present. It
can be said that it is free from water once it leaves the refinery. However, the
presence of water may cause the asphalt to foam when it is heated above 100°C.
TEMPERATURE SUSCEPTIBILITY - It becomes harder (vicious) as the
temperature decreases and vice versa. This characteristic is known as
temperature susceptibility.
AGING AND HARDENING - Asphalt hardens in the paving mixture during
construction and the pavement itself. The process of oxidation where asphalt
combines with oxygen together makes the mixture harder.
ADVANTAGES
WEATHER - Hardening process occurs as the temperature decreases, which
makes the asphalt harder.
COST - It is cheaper to install than driveways made of concrete.
RECYCABLE - Not only can the aggregates be reused but the asphalt cement
binder also retaining the cementing properties and reuse again in new mixture.
DISADVANTAGES
STRENGTH - Asphalt pavement is weaker than concrete pavement.
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HEAT – It becomes softer when it is exposed to hot temperature. The softness
will cause the driveway susceptible to the formation of ruts.
3C Seacrete
Seacrete can be known as Biorock or Seament. It is the end product of electro-
accretion / electro-accumulation alike the electroplating which build up an
electrified metal frame that is encouraged by calcium carbonate. This process
has created man-made distance. The biorock building process is called as
accretion and not to be confused with Biorock sewage treatment. The biorock
building process produces cement like engineering structures and marine
ecosystems. It works by passing small electrical current through electrodes in the
water. The structure grows more or less without limit as long as the current flows.
.
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Physical / Chemical properties
- Mg(OH)2 (Magnesium hydroxide) - (brucite)
Mg(OH)2 + CO2 = MgCO3 + H2O
- CaCO3 (Calcium carbonate) - (limestone)
Ca++ + 2HCO3- = CaCO3 + H2O + CO2
- Compressive strength from 3720 to 5350 lbf/in² (26 to 37MPa)
Appropriate Usage / Application:
- It can produce mix with construction aggregate.
- It can build components in the sea floor or on land.
- Produce (Construction material)
Limestone
Brucite
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- Hydrogen production
- Restoring and protecting coral reefs growth.
- Mariculture
- Sewage treatment
Advantage
- Grows cement-like engineering structures
- Self-growing construction materials
- self-repairing
- Strong construction material
- Constructing new coral reef
Disadvantage
- Consume lots of time
- Need a lot of electricity
Aesthetical value
- It can be decoration materials
- It can be construction materials
- As artistic structures
- Protecting and preserving the marine ecosystems
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Process
The process uses a low-voltage of electrical current through a conductive structure
placed on seabed. In addition to reverse the effects of rusting, the electricity creates
electrolytic processes which result in precipitation of a stony calcified layer on the metal
frame which provides an ideal substrate for the growth of corals. The result is a
composite of brucite and limestone with mechanical strength similar to concrete. Derived
from seawater, this material is similar to the composition of natural coral reefs and
tropical sand beaches.
3D- Decorative Concrete
i) Definition and usage of decorative
concrete
Decorative concrete is created through a
finishing process that is intended to provide an
aesthetic quality. It comes in various colors,
patterns and textures. They are applied to create
decorative effect that enhance and beautify
concrete. It is not just simple a utilitarian medium
for construction, it also acts as an aesthetic
enhancement. Decorative concrete is a versatile
material use in homes for floors, kitchen countertops, patios, driveways and etc.
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It is also a good option for house owners who want high end look for their homes.
Besides that, decorative concrete is also used in commercial and industrial such
as in bridges and highways. Decorative concrete is branch out into different types
of concrete such as, stamped concrete, overlay and acid stained concrete.
ii) Advantages of decorative concrete
There are lots of advantages when using decorative concrete. For examples,
heat resistance, excellent fire protection, good energy insulation, stronger and
more stable than brick and wood, holds up better under severe weather, can be
stacked without mortar or build with mortal for added strength, good durability,
last long and needs less repair, sheer versatility, extremely durable, does not rot
easily, withstand storms, easy to maintain, little maintenance needed, easy and
quick to install. These are all the advantages of it, and that is why more and more
people are considering decorative concrete now.
iii) Disadvantages of decorative concrete
Not only advantages, decorative concrete also has disadvantages behind it. For
examples, the weight of it, it is heavy and very hard to move and it might break if
one step goes wrong. The colors of it might also fade after some time and it
might all be prone to cracking after some time. After all, there are more
advantages of it comparing to the disadvantages of it.
iv) Types of different decorative concrete
Decorative concrete is separated into 3 types, stamped concrete, overlay
concrete and acid stained concrete.
a) Stamped Concrete- Patterns and textures are pressed into newly poured
concrete before it’s fully dry. Combined with stains that add realistic color,
stamped concrete can imitate the look of brick, cobblestones, flagstone,
wood, pebbles or even seashells.
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b) Overlay Concrete- Another option for turning a scuffed-up, plain-Jane
concrete patio floor into a fabulous faux-stone centerpiece for your
outdoor room is the overlay. An overlay involves laying a scratch coat of a
high-polymer modified concrete over your old slab, taping out a flagstone,
cobblestone or other pattern with grout tape, and then pouring another thin
layer over that for texture. When you remove the tape from the almost-dry
floor, it leaves impressions to look like grout lines, and when you add
lifelike color.
c) Acid Stained Concrete- One of the most popular ways to dress up a
concrete floor, acid staining permanently changes the color of concrete
because the pigment soaks deep into its pores. Can be acid stained when
you apply the stain by spraying one to three coats onto the floor, then
neutralizing the acid with ammonia and water, and finally, sealing the floor
to protect the new finish.
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v) How are decorative concrete made?
There are a few steps in giving decorative concrete its color and texture.
1) Choose a color and texture of concrete that complements the natural
surroundings
2) Place and then color the concrete
3) Broadcast color hardener using a wide sweeping arm movement with the
intention of covering as much concrete as possible with each throw.
4) Apply the color release agent
5) Choose a color of release agent to complement the color of the concrete.
6) Texture the concrete
7) Find a team to help you lay the mats
8) Use a high-powered pressure approximately 24 hours after the concrete
has achieved initial set.
9) Seal the concrete with an appropriate decorative concrete sealer
according to manufacturer directions.
3I- Roller Compacted Concrete
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Roller compacted concrete is a special blend of concrete that has essentially the
same ingredients as conventional concrete and it is a concrete compacted by
roller compaction. The concrete mixture in its not hardened state must support by
a roller when being compacted.
Characteristics of Roller compacted concrete
i. Tough, Fast, Economical – Roller compacted concrete has the strength
and performance of common concrete with the economy.
ii. No Rutting, No Pot Holes - The high strength of Roller compacted
concrete pavements clear up common and expensive problems
traditionally related with asphalt pavements.
iii. Economy, Performance, Versatility - The need for a low-cost, high-
volume material for industrial pavements led to its development.
Application Area
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The use of roller compacted concrete for pavements at industrial facilities such
as port and intermodal container terminals is particularly appropriate because of
the ability to construct low cost concrete pavements at large areas.
Bulk material storage
General cargo storage
Container terminals
Road / rail transfer facilities
Ro-Ro terminals
Truck parks
Advantages
i. reduced cost
ii. reduce time for construction
iii. reduced cofferdam requirements
iv. Contain some types of mixtures, structural designs, production methods,
weather, and others.
Disadvantages
i. Roller compacted concrete mixture preparation require very special
equipment, and the amount of time which is consumed in its making is
high.
ii. In the mixture making, process should be done very quickly. Then lay
away on the road immediately otherwise a chance of quick drying is very
high.
iii. The road roller for roller compacted concrete should be selected for
suitable sizes to make it sure that right amount of pressure is being placed
on the roller compacted concrete.
iv.
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References
1. Mhe aac (2014). Autoclaved Aerated Concrete-Green Building Material.
Retrieved from
www.mhe-international.com/aac_autoclaved_aerated_concrete.php
2. Understanding cement(2014).Autoclaved Aerated Concrte(AAC,Aircrete).
Retrieved from www.understanding-cement.com/auntoclaved-aerated-
concrete.html
3. International Masonry Institute (2010).Autoclaved Aerated Concrete
Masonry Units.4,1&4. Retrieved from
www.imiweb.org/design_tools/tech_briefs
4. America’s Cement Manufacturers (2013).Autoclaved Aerated Concrete.
Retrieved from www.cement.org/think-harded-concrete-/
5. Schnitzler,S.(2006). Sustainability and the Built Environment.6, 3-6.
Retrieved from
extension.ucdavis.edu/unit/green_building_and_sustainability/pdf
6. European Asphalt Pavement Association (2014).What is Asphalt.
Retrieved from www.eapa.org/asphalt.php?c=78
7. Madehow (2014). Asphalt Cement. Retrieved from
www.madehow.com/Volume-2/Asphalt-Cement.html.
8. Wisegeek (2014). What are different types of Asphalt. Retrieved from
www.wisegeek.com/what-are-different-types-of-asphalt.html.
9. Virginiadot. Components of Asphalt Concrete. 18,1-18. Retrieved from
www.virginiadot.org/business/resources
10.Mr. David Wu(2013). Kaixian Construction Machinery Official Blog.
Retrieved from http://www.kaixianmachinery.com/blog/roller-compacted-
concrete-rapid-construction/
11.Portland Cement Association (2014). Retrieved from
http://www.cement.org/think-harder-concrete-/paving/roller-compacted-
concrete
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12.Concrete Network (2013). Decorative concrete cost. Retrieved from
www.concretenetwork.com/concrete/decorative/cost.html
13.Valdez.V (2014). Types of decorative concrete blocks. Retrieved from
www.ehow.com
14.Amanda.L.W and Dececco.D(2014). What is decorative concrete.
Retrieved from www.wisegeek.com/what-is-decorative-concrete.htm
15.Cooper.B (2011). The pros and cons of decorative concrete sidewalks.
Retrieved from www.doityourself.com
16.Redbeacon (2014). Pros and cons of concrete flooring. Retrieved from
www.redbeacon.com
17.Wolfhilbertz. Coral reef restoration and shore protection. Retrieved from
http://www.wolfhilbertz.com/accretion.html
18.Garner.A.M. (2010). Seacrete construction solution. Retrieved from
http://welcometogaltsgulch.blogspot.com/2010/09/seacretebiorock-
construction-solution.html
19.Goreau.T.J(2012). Marine electrolysis for building material and
environmental restoration. Retrieved from www.intechopen.com
20.Christopher.S. (2012). Agencies collaborate to protect fish sanctuary.
Retrieved from Jamaica-gleanser.com
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