building science plastics
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BUILDING SCIENCE
PART (1)
Dr f Dejahang (BSc CEng, BSc (Hons) Construction Mgmt, MSc, MCIOB, PhD)
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Building scienceBuilding science and buildingengineering are fields ofstudy concerned with: the technical performance
of buildingsbuilding materialsbuilding systems
Building scienceThe area is broad enough toinclude:construction technologymaterial scienceurban designArchitectureheat and mass transport
physics
Building sciencedesignconstructionmaintenance of buildings and
StructuresBuilding and Civil Engineering
represent a significant portion of the gross domestic product for countries of the developed world.
Building scienceOperating costs (energy,
maintenance, cleaning and repairs) are also multi-billion pounds expenditure.
Building scientists and engineers seek to improve the manner in which buildings are constructed and maintained to ensure:
Building sciencelong building lifeto improve building performance throughout the expected service life
to allow demolitionReuserecycling
Building scienceBuildings and Climate ChangeThe buildings we live and work in
could be very different in the future if our climate does change as predicted.
Changes in the weather, such as with rainfall, wind and the frequency of storms will affect the way our homes and offices are designed and constructed.
Building scienceAdapting Buildings for Climate Change There is now a clear and overwhelming
opinion that the earth’s climate is being affected by human activities, which is largely due to burning fossil fuels.
Even the most optimistic projections indicate that some climate change is inevitable.
The UK Climate Impacts Programme (UKCIP) anticipates that by 2080
Building science Summer temperatures will rise by 1 to
5ºC. Winter storms and heavier winter
precipitation will be more frequent. Summer precipitation will decrease by up
to 60 per cent. Impacts of climate change on the built environment may include increased risks of flooding, overheating, storm damage and subsidence.
Building science
At the current rate of new andReplacement building by2050, it has been estimatedthat around 70 per cent ofbuilding stock will consist ofexisting buildings.
Building scienceAreas for consideration are asfollows:-Heat gain reductionEffective thermal massVentilation strategyActive coolingEnable future adaptabilityProject Learning
Building scienceFig-1
Natural air ventilation-Natural cooling system
Building scienceHeat gain reduction Cooling requirements for buildings are
largely affected by heat gained from solar radiation.
Reduction of solar heat gain can very effectively decrease the energy consumption of buildings. Some areas for consideration in building design in order to minimise solar heat gain are as follows:
Building science Glazing - extent, orientation and specification of
glazing Use of solar shading Ventilation – use of natural cooling Building footprint – use of narrow building
footprints to allow passive cooling and heating and prevent deep floor plans
Thermal Mass – consideration of building materials, radiant barriers, green roofs etc. to keep heat in building where require and to prevent excessive heat gain through fabric
Building sciencePlastics-Building & Construction residential homes to commercial buildings hospitals to schools architects and designers rely on plastics to help
maximize: energy efficiency durability and performance.In addition to potentially lightening a structure’senvironmental footprint properly installed plastic building products can
help reduce energy and maintenance costs over many years.
Building scienceEnergy Savings A one-year study1 found that the use of plastic
building and construction materials saved 467.2 trillion Btu of energy over alternative construction materials.
That’s enough energy saved over the course of a year to meet the average annual energy needs of 4.6 million U.S. households.
Following are some examples of plastic building products that promote the efficient use of energy and other resources:
Building scienceRoofingRoofing systems made with spray
polyurethane foam (SPF) offer durability, energy savings and moisture control.
This foam can be used to cover an existing roof, helping to reduce the amount of building materials sent to landfills.
Building scienceWalls In walls, the use of structural insulated
panels (SIPs) made with expanded polystyrene (EPS) can help homeowners save hundreds of pounds annually on heating and cooling bills.
Savings vary by material and products. EPS starts out as a plastic pellet and ends
up as nearly 95 percent air, a very effective insulator.
Building science Vinyl is increasingly found in durable, easy-to-clean vinyl
wall coverings It requires only half as much energy to manufacture as
the same amount of paper wall coverings. Windows Plastics also rival traditional materials for windows and
frames. For example, polycarbonate—a material also used in
eyeglasses—is used in windows. These lightweight, shatter-resistant plastic products have
low thermal conductivity, which can help to reduce heating and cooling costs.
Building scienceVinyl window frames save the nearly
2 trillion thermal units of energy per year (USA)
helping reduce the greenhouse gas emissions associated with energy generation—all the while cutting maintenance time, materials and costs.
Building sciencePipingPolyolefin, polyvinyl chloride (PVC),
and acrylonitrile butadiene styrene (ABS) pipes and fittings, offer excellent fusion integrity for continuous pipeline systems
helping to eliminate potential leak points where water could be wasted.
Building sciencePlastics in Building and Construction The Building and Construction sector -
currently the second largest user of plastics in Europe
is expected still to grow substantially in the future.
Plastics have over the years become a material of choice for achieving economic and environmental balance between technological challenges and functional design.
Building sciencePlastics in Building and Constructionapplications plastics for decorative laminates plastics for drainage and irrigation pipes plastics for drinking water pipes plastics for electrics and electronics plastics for fittings plastics for floor and wall coverings
Building scienceplastics for insulation materialsplastics for roofingplastics for sewer pipes and
ductsplastics for waterproofingplastics for window and door
profiles
Building sciencePlastics Features and Advantages in Buildingand Construction durability, corrosion resistant cold, heat sound insulation for energy saving noise reduction cost efficiency light weight
Building science maintenance free innovation applications with unlimited choice of
surface, colours and materials for creative design
recyclabilityThermoplastic and Thermosetting A thermoplastic (sometimes written as thermo
plastic) is a type of plastic made from polymer resins that becomes a homogenized liquid when heated and hard when cooled.
Building scienceWhen frozen thermoplastic becomes glass-like and subject to
fracture.These characteristics, which lend
the material its name, are reversible.
That is, it can be reheated, reshaped, and frozen repeatedly.
This quality also makes thermoplastics recyclable.
Building science Thermoplastic Coaters Plastic Coatings - ISO 9001:2000 apply a
variety of thermoplastics www.plasticcoatings.co.uk Sometimes, thermoplastics are confused
with thermosetting plastics. Although they may sound the same, they
actually possess very different properties. thermoplastics can be melted to a liquid
and cooled to a solid,
Building scienceThermosetting plastics chemicallydeteriorate when subjected to heat.
Building scienceThermoplastic molecules
Building science What is the difference between thermo
plastic and thermo-setting plastic?Answer A thermoplastic can be re-melted and reused. A Thermoset cannot. An analogy would be like cake and butter. The cake would be analogous to thermosets. Once it's baked (cured) you cannot re-bake it. Butter would be analogous to thermoplastic. Once it's melted, it can be re-melted and reused.
Building science Heat is used to raise the temperature of
both the Thermoset and thermoplastic until they become a fluid.
They can be injected, poured, transferred into a mould.
The hot thermoplastic is injected into a cold mould, where it then is cooled down into its final shape, then ejected out of the mould.
The Thermoset is injected into a hot mould, where it is cured, then ejected out of the mould.
Building scienceWhat Is Plastic? A plastic is a type of synthetic or man-made
polymer; similar in many ways to natural resins found in trees and other plants.
Webster's Dictionary defines polymers as: any of various complex organic compounds produced by polymerization
capable of being moulded Extruded cast into various shapes and films, or drawn into
filaments and then used as textile fibber.
Building scienceCharacteristics of Plastics Plastics can be very resistant to chemicals Plastics can be both thermal and electrical
insulators Generally, plastics are very light in weight
with varying degrees of strength Plastics can be processed in various ways
to produce thin fibbers' or very intricate parts
Building science Polymers are materials
with a seemingly limitless range of characteristics and colours
Polymers are usually made of petroleum, but not always
Building scienceWhat are the advantages anddisadvantages of plastic? ADVANTAGES Plastic is very useful in the building and
construction electronics (laptops wouldn't work well if they
were made from glass) Packaging transportation industries.
Building scienceVery easy to make - water bottles,
plastic bags, pens, cups etc.the main advantages of plastic
materials are also the reason why plastic is such a problem
It lasts forever and it is very cheap to make.
Building science
Lightstrong and cheap to produceIt does not decompose but it can
instead be recycledThis is done more easily than
producing more plastic.
Building science Unlike aluminium cans, plastic bottles can
be re-used and stored over and over again.
Plastic is usually not breakable and it is see-through
It's light-weight and odourless Plastic comes from a natural resource (oil)
but CAN'T be re-made into bottles (but they can be re-made into other items)
It takes a long time to break down.
Building scienceDISADVANTAGESIt is a compound that is indestructible,
even when it is melted the compound gas that is gives off is very harmful to our health and environment; it weakens the ozone layer.
Most plastic is produced from oilThe world is gradually running out of
oil.
Building scienceScientists are now developing plastics
that are made from vegetable oil and other organic matter.
This means that the plastic is more likely to be degradable, so it will be less of a problem in future.
Another Disadvantage is pollution-Plastic accumulation in the environment is a looming catastrophe.
Building science
It is cheap but it is not easily disposable so it is in a lot of landfills
Plastic bags can kill the marine animals and destroy the soil.