Midterm 1 Flashcards
Definition: Sustainable Development
The challenge of meeting growing human needs for natural resources, industrial products, energy, food, transportation, shelter, and effective waste management while conserving environmental quality and the natural resource base for future generations.
Sustainable development requires the selection and judicious application of materials that minimize the social, environmental, and economic impact of development.
“Sustainable development is development that meets the needs of the present without compromising the ability of future generations to meet their own needs”.
Definition: Sustainable Construction Materials
Materials that support sustainable development and and are characterized as being environmentally friendly.
Characteristics of Sustainable Construction Materials
- Durable
- Local or regional extraction and production
- Contain recycled materials
- Manufactured with minimal pollution
- Do not themselves pollute
- Reusable
- Rapidly renewable
- Capable of being used in an innovative way to lessen social, environmental, and economic impacts
Most heavily used man-made material?
Concrete
Negative impacts of concrete and steel production?
- Enormity of resources used (not a problem with the material, but with the industry)
- Generation of large amounts of CO2
CO2 emission sources in concrete?
- Material manufacture (cement, reinforcing steel, aggregates, water, admixtures)
- Concrete manufacture
- Repair and rehabilitation throughout service life
- Demolition and recycling
- Transportation emissions related to each stage
Life cycle of materials
Extraction of resources, material production, product manufacturing, use, end of life phase, disposal
Definition: Reduce (and biggest solution to reducing material consumption)
Reduce size of buildings by eliminating unnecessary space. Biggest solution to reducing material consumption is to improve durability of structures to last longer instead of keep rebuilding it.
Definition: Reuse. Give examples
It implies not modifying a material a lot. Salvaging building materials from existing buildings, or even reuse the entire building (renovation) instead of replacing them. Considerations should be made when designing the building to implement materials and construction methods that can be reused in the future.
Examples: Bolted connections instead of welding in steel, mechanical fasteners instead of adhesives, homogeneous materials instead of composites.
Recycle
Least efficient, since much energy is needed to process the original material into a new form. Additionally, the new form is lower quality than the original one for most materials. Steel is 100% recyclable.
How Can the Concrete Industry Become More Sustainable?
- Manufacturing Portland cement more efficiently
- Using waste materials as fuels
- Replacing Portland cement with supplementary cementing materials (SCM’s) and/or fillers
- Using High Performance Concretes (HPCs)
- Making concrete more durable
- Using recycled concrete, or other industrial wastes, as aggregate
- Capturing, storing or utilizing CO2 emissions
- Improving structural design and building codes
- Effective maintenance and repair strategies
Four significant time scales over which we need to examine industry-environment interactions
First – PAST: remedial measures for dealing with inappropriate disposal of industry wastes
Second – PRESENT: compliance with the existing regulations and preventing the obvious mistakes of the past:
– Emphasis on waste minimization
– Avoidance of known toxic materials
– Control of emissions
– Corporate personnel and safety officials often involved- along with manufacturing personnel
Third – FUTURE (10 - 50 years): industry-environment interactions dictated by the industrial products and processes of today (being used in design presently)
Fourth – FAR FUTURE (50+ years): industry-environment interactions dictated by the industrial products and processes being developed for future use (planned changes to current designs)
Abscissa divided into three segments
- Unconstrained industrial revolution during which the level of resource use and the resulting waste increasing very rapidly
- Period of immediate remedial action, during which the most important examples of excess were addressed
- Period of long-term vision during which one can postulate that environmental impacts will be reduced to small or negligible proportions while simultaneously maintaining a high quality of life
Life Cycles of Products & Processes
Stage 1: Resource extraction is performed by suppliers, drawing on virgin material resources and producing materials and components
Stage 2: The manufacturing operation - under the control of the manufacturer
Stage 3: Packaging, shipping, and installation if required - under corporate control
Stage 4: Customer use (consumption) - Not directly controlled by the manufacturer, however, it is influenced by how products are designed and by the degree of continuing manufacturer interaction (a leased product under maintenance control maximizes this interaction)
Stage 5: The product is no longer satisfactory because of obsolescence, component degradation, or changed business or personal decisions - needs to be refurbished or discarded
Engineering materials vs materials science
Engineering Materials are defined as that part of the inanimate matter which is useful to the engineer in the practice of his profession. Can be solid, liquid or gaseous.
Materials Science refers to the knowledge of physical sciences arranged as general truth and principle, in particular physics and chemistry. Materials science is related to solid state physics and solid state chemistry
