Design for durability of concrete

1. CONCRETE TECHNOLOGY
MKAE 1153

2. Design For Durability

3. Learning Outcome?
At the end of the course students should be able to understand:
• Meaning of green infrastructure, building and its scope
• Consequence of ignoring green idea
• Relation between durability and green construction
• Strategies to achieve green building

7. Answer the following questions::
i. Why are durable structures greener?
ii. How does durable design integrate with other design strategies?
iii. What are the key design principles in creating durable structures?
iv. What are some specific strategies we can employ?
v. What are the economic of creating durable structures?

8. Why build green?
Building green:
●Reduces the ecological footprint of the building
●Creates a safer and healthier indoor environment
●Saves on utility expenses
●May improve property resale value
●May increase affordability.....Malaysia???
●Typically results in a more durable, maintenance-free structure
●Provides security/ passive survivality
●Reduces dependence on fossil fuel

9. The three prime movers (in order)
• Economics–Reducing energy cost/protecting the bottom line
• Health–Maintaining a safe and healthy environment for one’s family &
oneself
• Personal impact –Addressing the greater good minimizing environmental
footprint

10. Definition of Green Building
The effective and responsible
integration of the built
environment into the natural
world to protect natural
resources and ensure healthy
and comfortable indoor
environments

12. What makes it green?
• Low embodied energy (entire lifecycle)
• Minimizes impact on wildlife habitat, green space, waterways, etc
• Minimizes depletion of natural resources
• Poses minimal harm to humans during its manufacture, transport,
installation, end-use or disposal

13. What is embodied energy?
The quantity of energy required to manufacture, and supply to the point of use
including:
• Extraction
• Transportation
• Manufacturing
• Assembly
• Installation
• Disassembly & Removal

16. Cornerstones of Green
Building (Structure itself)

17. How green is it?
• The “no-build” option is always the greenest way
• Smaller is greener
• More efficient material resources use is better
• The more durable (in use) & maintenance free the better

19. General strategies
• Minimize impact on building sites/
area
• Incorporate energy efficient design
details
• Create a high-performance building
envelope
• Use energy-efficient lighting,
equipment & appliances
• Employ water conservation strategies
• Employ natural daylighting techniques
• Create comfortable & healthy indoor
environments

20. Keys to success
• Careful design
• Using a system approach –viewing the structure and all elements
as integrated system
• Early planning (OSHCIM???)
• Using a team approach between owners (clients), design
professionals and code officials, and bringing everybody together
early in the process

21. Economic realities
Up front costs or first-costs of green building are often greater than
conventional building
That doesn’t need to be the case!

22. Justifying increased up-front costs
Making the case for reduced life-cycle cost or Total Cost of
Ownership (TCO):
• Green buildings usually use less energy to operate than their
conventional counterparts
• Green buildings are typically more durable & maintenance-free
due to the application of sound principles of building science
• There are typically additional benefits that help to warrant the
increased cost

23. Managing costs:
Labour vs Materials
Take advantage of marginal cost of
installing higher quality materials
e.g. Adding more durable materials /
systems

24. Consequences Of Ignoring
Durability
• Early failure of systems
• More intensive maintenance routines
• Reduced indoor environmental quality
• Increased cost of ownership
• Reduced resale value
• Aesthetic issues

25. Why is durable design greener?
• Fewer replacement cycles
• Simplified maintenance routines
• Healthier indoor environments

26. Design For Durability
Design for Durability –Key principles
• Respect site & Local climate
• Direct water away from the structures
• Create a weather-resistant shell
• Manage interior moisture
• Choose durable materials
• Simplify maintenance

27. Design for Durability -
Strategies
• Avoid siting structures at bottom of hills, in low-lying or flood-
prone areas, or generally, areas with poor drainage characteristics
• Design for local wind & seismic conditions
• Avoid complicated designs with many intersecting planes
• Reduce envelope penetrations esp in roof
• Use good flashing details
• Use adequate roof overhangs
• Employ double-shell or rain-screen designs

29. • Reduce air movement through envelope
• Provide adequate ventilation
• Direct water away from foundation structure
• Effectively design/ manage site vegetation
• Familiarise occupants with proper maintenance routines
Design for Durability -
Strategies

30. The Prime Suspect Water
Water

31. Ways that water moves into a building
• Gravity
• Capillary (wicking) action & surface tension
• Air movement (wind driven moisture)
• Condensing water vapour
• Hydrostatic pressure

32. Preventing water from entering a
building
• Adequately direct water away from structure(s) in first place
• Appropriately lap building materials: start at bottom!
• Provide capillary breaks like drip channels & air gaps
• Adequately seal gaps & penetrations

34. Thank you